JettaD build thread
 

Bought this car at 230k miles. It intend to at least double that :D

It has some obvious issues, cylinders 1, 3, and 4 have bad glow plugs, EGR is stuck open and the turbo needs to be cleaned. a/c needs to be recharged.

Plan to also clean the injectors, replace the fuel filter, change oil and filter plus trans fluid/filter. Brakes are a bit soft, will be looking into replacing the master cylinder, rotors, and pads. Will also do a coolant flush and replace the thermostat.

After repairs and maintenance are done a baseline economy will be established and I'll mod from there :D

Hi,
With respect to the a/c; get yourself a freon detector from Harbor Freight when one is on sale or get a 20% off coupon from any auto mag. This will tell you where the freon is leaking. Could be an a/c compressor seal, a porous hose (most likely), or a loose connection, or one of the two radiators.
Good luck.

Sounds like a good plan. The TDIs can do some impressive mileage.

Thanks for the a/c tip! I'll probably get around to it in March or April next year. It's not super hot where I am.

Got the oil changed last night. Manual says to use either 5w-40 or 5w-30; sticker from the last change says they used 15w-40. I used 0w-40 any thoughts or ideas on me using 0w-30 next time?

Also done last night: replaced cabin air filter, washed intake air filter (k&n), cleaned MAF sensor, ran half a bottle of seafoam through the motor at a 50/50 mix with diesel, installed LED tail lights, dropped half a can of seafoam in the oil crankcase, replaced the fuel filter.

Also plan on putting a full can of seafoam in the tank at my next fill up. Gonna replace the brake rotors and pads, replace the glow plugs, and change the transmission fluid and filter.

Any idea what I should be using for trans fluid? I'm having a hard time finding answers on Google.

Any other thoughts or comments? Maybe some rear wheel skirts done in sheet metal? Would need to be removable to rotate/replace tires.......,...

Here's pictures! JettaD no mods https://imgur.com/gallery/burXu

With respect to oil viscosity: A while back, someone on this site referenced an "expert opinion" piece by an oil expert (engineer?). In that write up, the expert said that 0-30 would be preferable to higher viscosity oils because it flowed easier. He said that because the oil flowed easier, the oil pump would be able to push more oil thruout the engine. Further, because the oil flowed easier, oil pressure would be higher in the bearing surface areas such as the rod bearings and main bearings. The 0-30 would also be better at start up.

Well, I normally run 10-40 Mobil 1 Full Synthetic in my vehicles and change the oil at 4000 to 5000 mile intervals. It was time to for an oil change in my 3500 Silverado, 6.0 gasser. So I tried out his advice. 6 quarts of Mobil One 0-30 and a new oil filter into the truck. Normally, this engine is very quiet and smooth, no rattles or lifter noise. Now with new oil, lots of lifter noise and other engine rattles (Mains? rods?).

I ran this 0-30 oil for about 1100 miles, thinking that maybe the noises would quiet down. They did not quiet down, so out with the 0-30 and back in with the 10-40. All the noises went away.

So I would say, what does the engine tell you? Is it using oil? Does it rattle more with lower viscosity oil? And there was a reason that 15-40 was used. Although that reason could have been that the oil change place was just out of the of the 30 weight oil.

The car is not my daily driver yet, it won't be until I get the brakes figured out. Rotors are warped (minor) and they don't stop very quickly. I had to almost double my normal stopping distance when driving it home. Gonna try a brake fluid flush to work out any possible air bubbles and if that fails I'll go for the rotors and master cylinder.

When it's my daily driver I'll be able to get a better sense for what it's telling me with this new oil.

I'm gonna search for this "expert" opinion and see what he says. Do you have the link by chance?

P.S. this is mobil1 full synthetic oil I'm using.

Hi CappAttack,

No, I do not remember his name or even when it happened except to say that I think that it was in the last 18 months.

I just did a search on "oil viscosity" and did not find the reference.

Does the manual specify synthetic oil and long change interval? 5w-40 is (I think) only available in full synthetic because of the wide viscosity spread, and that particular weight, along with 15w-40, is a diesel truck oil which, not being API certified, usually contain higher levels of anti-wear additives zinc and phosphorus. Because it's an older car, designed for an older oil which would have contained more of those additives than current API SN (maximum phosphorus limit has been steadily reduced, from 1400ppm in SL to 800ppm in SN), I would default to a truck oil in 5w-40 myself. ETA: since 5w-40 is readily available here; I've never seen 5w-30 on the shelf locally.

Hiya! Update on my dear Jetta (she still needs a name), got the rotors turned and bled/replaced the brake fluid. Brake pedal went from being super spongy and soft to super stiff and still not stopping the vehicle. I suspect the power brake booster as it has a cracked vacuum line. Going to order a replacement this coming payday.

Also, I found some 0w-30 full synthetic oil that meets the VW 505.00 spec for my car! It made me happy. What do y'all think? Castrol 06244 EDGE 0W-30 SPT Full Synthetic Motor Oil - 1 Quart Bottle, (Pack of 6) https://www.amazon.com/dp/B007G7PUMS/ref=cm_sw_r_other_apa_e8zayb05TDBN9
I'm gonna wait and see how it plays with the 0w40 it has now and decide from there but I'm hopeful for a thinner oil :D
Metro: the manual says either conventional or synthetic is okay, but I personally prefer full synthetic oils.

Transmission fluid is burnt and sparkly from all the metal fragments flaoting in it. It reacts like a ferrofluid when I pass a magnet over it. I have added a bottle of Lucas oil stop slip and will wait to see when it starts having problems before I start looking to get my tranny rebuilt. I got my info on transmission fluids from this dude: https://youtu.be/o690DovjDAc

Glow plugs got replaced and that cleared up three of my trouble codes (one for each of the three bad plugs)

Do you already have some mods planned to do after you get the car fixed? BTW would you eventually consider some experiences with alternate fuels?

Planned mods: smaller driver side mirror, passenger side mirror delete, full belly pan, partial grill block, basjoos the front end, LRR tires (after current ones wear out), rear wheel skirts(maybe), Malone eco tune or stage 1 tune.

I have not considered alternative fuels. If I did go through route I'd want the car to retain its ability to run on normal diesel or at least have a way to switch it back somewhat easily.

Having the ability to run on some alternative fuels doesn't mean that you would become unable to use regular Diesel fuel.

Are you replacing the vacuum line or the booster? Hard to tell from your wording...

I'd assume it isn't getting vacuum, but I'd check/replace vacuum lines and check for vacuum at the booster and at the vacuum pump before replacing the booster itself, if you were going to.

I am replacing the vacuum line and the check valve. Hopefully that fixes it...I don't wanna spend $300 on a new power booster.

Rooster: how would one go about getting set up to run alternative fuels? And good sources for me to look at?

Parents surprised me by taking it into the shop for me. Mechanics there are gonna look at the brakes, Ballance the tires, and make sure everything is aligned. Yay! :D

Just before that happened, I got my passenger side mirror delete done. Covered the hole with some coroplast held it all on with silicone and spray painted it black. Passenger mirror delete https://imgur.com/gallery/UliZb

Mechanic said he's Gonna replace the thermostat, thermostat gasket, coolant, CV joints on the front left and front right, EGR valve, vacuum line for the brake power booster, and the vacuum pump. he will also Ballance the tires and align the front end.

I hope to have a much better vehicle by the end of all this! It should be out of the shop Monday evening.

Finally got it back! Throttle response and braking are much improved thanks to a new EGR valve and new vacuum pump. The new cv axels/joints helped a ton with how much it was vibrating. Mechanic also told me that the injector pump is leaking. He noted that it not original to the vehicle so it's possible someone forgot/didn't seat a gasket properly when installing it.

I have been strongly encouraged by family to re install my passenger side mirror for safety reasons. Does anyone have some ideas for low profile mirrors that I could diy?

I've cleaned my air filter (k&n), it needed a good bath and some fresh oil. Gonna get started on my belly pan after some baseline numbers get in!

Any thoughts on either a bigger or smaller intercooler? For hotter or colder air intake....am I crazy to consider this?

Also have some odd bits to fix: rear driver side window won't roll up, headliner has all but fallen off...I'm gonna glue it back on, a/c need to be recharged, and and I wanna check the trans cooler. I've read about others finding it either Clogged or cracked.

When you charge up your AC, just get some pressure into it and spritz a little soapy water around on the hoses, esp. at the hose connections. if you find a connection bubbling, it could be you just have a dried-out or cracked O-ring. New O-rings are super cheap.

My Forester bled out its refrigerant, new O-ring and 10 minutes, $15, done.

Fifteen bucks because I didn't know exactly which size and the assortment was pretty comprehensive and now I have a bunch of spare O-rings.

Some thoughts...
 

Hey ALH TDI Friend!
First, ditch the K&N. A quick googleing will give you all sorts of horror stories. Short answer is it ruins the MAF.

Most of the work the mechanic is doing is normally thrown on top of changing the timing belt and cleaning the intake with a new2you higher miliage car. When you get it open you might find you also need a new cam seal(easy) and/or crank seal(more difficult).

Most people who buy these cars used change the timing belt so they know the true zero and that it was done right with good parts.

Not saying your mechanic isn't good, but be very careful. If you are mechanically inclined it is to your advantage to get the few special tools and do your own work.

VAG-COM is required. Read all you can about timing for full requested range. If you want it bumped, use the variation and mechanically time again and test to get full requested range.

A scanguage or other will help train you. It also helps with codes and monitoring things. It had been stated here and on other sites, make sure your thermostat is working properly. You can't even time one of these engines without it at full operating temp. A stuck open stat will never get there and your 50+mpg will be 35 easy as that.

I have done vac lines in OEM braid and in silicone. Get silicone. Easier, better and looks trick. With known good lines it makes troubleshooting easy.

Search for the door lock microswitch repair threads. Man are the overly complicated door mechanisms fiddly. Better to yank some from a wrecker and have them ready for when they malfunction.

Someone might have mistreated your gearbox. The manuals aren't known to make metal. Change the fluid and hope for the best.

Most effort with any worthy older car is removing the idiot tracks left all over it by the previous owner. The alh is worthy!

If you havent seen, you can lose a lot of the exhaust system. Check online.

I would do the ventectomy(easy) and cut out the snow screen and get the cold weather paper element. Google is your friend!

On big road trips with the family, I have to stop for every reason but getting fuel...

Good luck!

IThanks for the amazing and detailed responses! I was actually considering a mufflerectomy and ventectomy. Also plan to get a skid plate for under the engine bay Evolution Import: Atlas Skid Plate Kit With Oil Drain Hole & Cover For MK4 Volkswagen New Beetle, Golf & Jetta (TDI)
It will add about 26 pounds to vehicle weight.

Previous owner told me that the water pump and timing belt were services about 1k miles before I got it. Ultragague currently reads that I'm getting 20mpg D:

Along with my leaky injector pump I am currently getting a p0704 code P0704 Clutch Switch Input Circuit Malfunction
Which doesn't make a ton of sense to me since my car is an automatic. It is shifting smoothly, you can feel a very slight shudder when it shifts 3-4. I am driving for economy 90% of the time. Don't rev it or go unreasonably fast without good reason (being late doesn't count). I will probably just glue down the door handle/switch panel on the driver side, it has broken loose from the door panel. Headliner needs to be glued up so I can have my rear window back. Rear driver side window seems to just be hopping off track whenever I try to roll it up. It keeps going if you give it a push.

What exactly is VAG-COM? I am unsure, beyond some searches telling me that it's software to monitor all of the sensors in my vehicle.

Any suggestions for what to replace my k&n with? Stock OEM?

I am not familiar with the ultragauge, but I assume it needs to be calibrated to be accurate. Check that first. and do some full tank averages for a real mpg.

The mpg numbers for your car indicate you have some real issues. I am sure you are aware.

First, Ross Tech is the source for the real deal vcds and vag-com. I can't post a link because I am a noob. Sorry. Google will get you to the ross tech store and the KII USB vag com you need.

I would start with all the basics. Alignment. Go through the brakes and wheel bearings. Check tires. Change air and fuel filters.

Photo and examine everything for leaks. Degrease and clean everything and drive around a bit and find out where you are leaking.

Moving on to older tdi stuff, yes, replace the k&n with the factory cold weather filter. Then cut out your snow screen. Easy to do when you have it up in the air doing your brakes.

Check online for how to reseal the pump while on the engine. TDIClub or vortex or both have the writeups. I have not done the job but I read that it is possible.

How well do you know/trust the person who said the timing belt was changed 1000 miles ago?

Specific to the alh, you need to run the variable turbo vanes through their range of motion. With the engine warm and out on the highway onramp, gun it from put put speed all the way to really speeding. You want to get full rpm range under load. Italian tuneup! If your turbo sticks because of this and spits a code, know it had to be fixed anyway and was probably going to do that to you on a road trip somewhere and some time not of your choosing. The alh was made to be revved occasionaly, and must be. I do it a couple times a week. If you never do it you will have problems.

You might want to do this at night for 2 reasons. First, if you and the PO have been babying the car it is going to blow smoke. If running sort of correctly, it will clear up with only one or two blasts. Second and more scary, your intercooler might be filled with oil which will lead to a temporary runaway as it inhales the oil. On the highway, easy and drive through it. In your driveway in park... well, you dont want that.

Read what I typed, google my words and understand what you are doing. You could get a band clamp tool and take your intercooler off to drain it, or install a drain screw, but what is the fun in that?

Blasting through the revs also gives you the chance to log with vcds and check on the real health of things.

But for that car to get 20mpg it has to be dripping fuel and more.

So, I am a betting man and my money is on a clogged snow screen, clogged intake manifold, fuel leaks, poor alignment, dragging brakes and pressure side intake leaks thrown in for a bonus. Auto trans? Yeah...

And if you are modding for efficiency, just remember these cars just need to be running correctly. It is almost impossible to get the mods to pay for themselves unless they are cheap(cloroplast/tape/delete aeromods) or changes when parts need replacing(injectors or trans swap).

I got the ultragague calibrated. You were right to have me look for that. It now reads 41mpg hwy. About 35 around town. I have replaced the fuel filter, changed the oil/filter, gotten an alignment (had to replace cv joints/axels before they could do it) and had tires balanced. Also replaced egr valve, thermostat, and coolant.

As to my trust of the PO when he says the timing belt was serviced. He probably took it to a shop and they told him it had to be done. Guy seemed to know nothing at all about cars. I only ever met him once when I bought the vehicle from him.

Ventectomy is done, got the snow screen removed, and I got a paper filter to replace the k&n.

She threw a new trouble code on the way home from work today: P0740 Torque Converter Clutch Malfunction OBDII Engine Light Trouble Code | Engine-Codes.com
I checked the transmission fluid once I got home, it was low. Added about half a bottle (12 oz) of Lucas oil stop slip to top it off. Hopefully the code will clear up in the next few drive cycles and I won't have to do anything major...if I wind up having to add more that the second half of this second bottle of the stop slip I'm thinking of just using new vw atf. Any thoughts or ideas on that scenario? On a similar note: I am opening a savings account that will get about $75/month toward what I feel like is an inevitable transmission replacement about 2 years from now.

I plan on making an upper grill block and belly pan out of coroplast after this first tank runs out and I can get a baseline number for FE. I found a local shop that will sell me 4'x8' sheets for $24. The belly pan will run from the rear edge of the skid plate (once I get it) all the way to the rear bumper. I'm thinking of using sheet metal and pop rivets to work near the tail pipe.

Also got the head liner glued up! It doesn't look super bad now, just a little bad.

P.s. the p0704 code cleared before this one popped up.

Didn't you get any reciepts ?

If not have a look around the timing cover, often a kind mechanic will write the milage and date of the change.

I would be a little suspicious of no reciept especially if it was recently done.

I unfortunately have been conned a few times so I don't trust people.

MJamson has the same fears I do... People selling used cars lie. The timing belt, rollers and tensioner are impossible to age accuratly. When they fail... Well, you don't want that.

Quick fun is to check your coolant color. If it is not fancy and correct, I would suspect that nothing had been done correctly. Cheap coolant, incorrect oil, mark and pray timing belt swaps...

As for the codes, TDIclub is the place for that knowledge.

So... even though wrecking yards have gotten expensive, you can still find good ones and some have alh tdis or vws of the correct years. Find some you like and start with small stuff. I would get some door lock modules. I would pay $20 to 40 for one I pulled that looked great. Less if they don't know. If they have 10 or more of the cars up on rim stacks parting out, odds are they are cheap. High volume big yards don't have time to price small assemblies. Get a price before you pull.

These little parts let you see if the yard is reasonable and if they deal. If not, find another.

Most wrecking yards don't know how expensive vw/porsche/audi relays are. Get some sets of them while you are hunting.

You can do it and do it reasonably, you just can't if you are waiting for things to break and paying a mechanic.

idparts, dieselgeek and boraparts all get my gold star award. Every few months autozone will put rotella t6 on sale by the gallon. LRR and battery from costco.

Get ahead of the maintenence and get it on a schedule.

Mpg I got for half a tank fill up is 40.3 mpg. I fabricated a missing piece of my air intake so that it routes to the upper grill properly. Also blocked the remainder of the upper grill, it did heat up a bit faster, about 1.5-2 miles instead of 3 miles to reach 190* F. I also fabricated some ductwork to help funnel air into my smic and cut a vent in the wheel well.

I got a new set of headlight lenses yesterday as the ones it came with were extremely foggy. The driver side lenses adjusted properly, the passenger one......it casts a spot about 8ft in front of my bumper. The adjustment screws are broke...I spent all night last night swearing at it and hoping to somehow reseat the adjusting point as others have said they can do online to no avail...alas, I may have to return them to Amazon.

I will look into a timing belt kit. I have my eye in the high mileage kit from kermaTDI.

Also interested in a skid plate, belly pan to connect said skid plate with the rear bumper, and (once everything works properly) some bi-xenon hid projectors.

I'm going to look at re calibrating the speedo, according to my phone GPS it's about 4mph slow. Maybe replace the gear oil while I'm down there?

I've read that vw prefers and encourages people to use castrol oils and Mann filters. Is this true? Does anyone know why?

I'm scared of the transmission cooler and the trouble code for the torque converter clutch. My trans fluid appears so old and laden with metal particles that I fear it will reveal a clutch problem if I change it. Also fear that the trans cooler has a plugged coolant circuit as that's a problem I've read about lots of people finding.

No, I don't have any receipts or written maintenance before of any kind previous to my purchase of the car.

I will post pictures, when I get home, of all my various fabrications. Any requests for other pictures?

depending on how bad the fogging is they can be polished. Cheap bulbs help fogging in the long run, so it is IMO better to spend the extra on the good low UV Bulbs

You would be wise to do so, unless you are 100% certain take is as it hasn't been done :(


Most speedos are bult to a tolerance and for a difference of 4 mph any re-calibration isn't worthwhile.

Possibly it is down to money, as manufacturers are building a vehicle they will often get discounts to recommend certain brands.

Oil: just Run Rotella T6, it is amazing for the money.

Brakes, I'd bet that you have a stuck brake caliper/ piston. The MKIV cars have electronic brake distribution and will stop straight even with 1 brake completely dead.

Put a vaccum gauge on the nipple that feeds the control vaccum system, super common failure is the small vaccum line system and those are super easy and cheap to fix.

I wound up going with the castrol edge 0w30 full synthetic just before you posted about the shell rotella. But I've heard good things about it all over the interwebs and will definitely give it a try on my next oil change in 10k miles.

I replaced all the vacuum lines and the fuel lines that were under the hood, also replaced my oil pan gasket (it was leaking, about 1 drop every 30 seconds with the engine off).

Next is the diff fluid and that darn leaky injector pump.

My skid plate should be here tomorrow! I'm super excited cause it is not only gonna protect my low hanging oil/trans pan and compressor but it is also the start of my belly pan. I will get some 4'x8' sheets of coroplast to finish it out on my next check.

I got the wrong headlight casings in the mail two times, first one I posted about above had fog lights and my car isn't wired for them, messed up my blinker, and the second set was just plain wrong. Gonna check local shops for a set before I go online again.

Transmission cooler looks okay, but my mind is on getting an aftermarket one since the coolant averages about 190*F and the trans is supposed to be closer to 140*F....also noticed that my coolant circuit has an oil cooler on it, nice, but I'm gonna leave it alone for now. Don't want to over cool anything.

I really want to do the timing belt myself but I'm scared of having to retime it and don't really trust anyone else enough to do it. The kit I'm looking at has new rollers, new serp belt, and new water pump as well as everything needed for the timing belt. Indicates 100k miles change intervals with their kit.

Just did the 5 brake light mod after replacing all rear light, except blinkers, with LEDs. Also strongly considering a mufflerectomy.

Oil
 

It's a long read but worth it if you want to know more about oil and viscosities.
Just google "bob is the oil guy motor oil 101"

Capp, TDIclub forum will have every answer you need for this car short of the ecomods. Sign up and use the advance search function to find your answers. If you ask newbie questions without searching you will get flamed because literally every question has been answered. Your auto trans is a known problem for this car read up on it on the forum. Read about cleaning injectors with straight diesel purge. Timing belt change procedure is spelled out step by step. Make sure oil is made for diesel engine. My 02 Golf TDI with original(not rebuilt)engine and manual trans has 477000 miles gets 46 mpg driving slightly hard. I change the Mobil 1 5W40 turbo truck oil every 15000 miles. Rob

(More) practical mod suggestions
 

CappAttack, hope you're having fun fixing and repairing the car back up to snuff.

1) Intercooler mod - add a drain.

Some of the mention of the intercooler made me think of something I saw some time ago, that I did do to my second TDI to avoid oil buildup.

https://www.youtube.com/watch?v=yeKpRMF7ecw

ThomasEXOVCDS Pointed this out in his wealth of VW repair videos, that just drilling a small hole into the bottom of the intercooler and using a screw to seal it.

In my case, I used one of the many many T20 exterior screws I've acquired while on runs to the wrecking yards to replace parts on my car. As in, the T20 screws that are used to hold in the inner fender liners on the car.

I can't say I've had hordes of oil drain from the intercooler in this car, I did it more for peace of mind -- something I can check and drain, when doing a major maintenance, like an oil change, tire rotation, or timing belt change.

2) Skidplate

DO-EET! I lost three (3) oilpans on my first TDI; one to a slow leak scraping, two to catasphrophic impacts. The oilpans are fragile, and since yours is a bit higher mileage, the suspension might not be at full height, which leaves your oilpan hanging lower than stock.

If you're intent on getting another 200k miles out of the car, the skidplate will cost you as much as two oilpans and oil changes, and might save you an engine.


And not a mod, but another suggestion - in addition to TDIclub, www.myturbodiesel.com is worth signing up for a forum account there, if only for their timing belt change writeup. They also have a decent buyer's guide for the A4 platform (Golf/Jetta/Beetle) that might give you more ideas for things to check for maintenance wise.

Started a thread for my car over at TDI club, y'all can follow it of you'd like to: My mk4 Jetta tdi - TDIClub Forums

I'll be posting there from now until it comes time for modding, and I'll keep my fuel log over here.

This will be a post containing several points and answers that I have read on the first pages. This is from my experience of owning an 02 Golf manual TDI with 340K mi and still getting 50mpg.

Trans fluid that is used should be (from memory but see links below)G50 the new version is G52 do a search for using G52 in an 02J (the manual trans model).
Auto trans ATF fluid removal, drain, and replacement on VW TDI engines | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum
Manual manual transmission gear oil DIY service and fluid replacement-mk4 VW-Audi | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum


Oil I only use Mobil 1 European 0w-40 the cheapest I find it is at walmart and it will have 1 qt extra so every 5th oil change the oil is free. The other oil I have used was Mobil 1 Turbo Diesel Truck 5w-40 and Shell Rotella T6 5w-40. List of TDI oils Engine oil list for TDI diesel | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum
A side note I do 10-15k oil changes my last one was more like 17.5 and I was a little low on oil but I drive 85% highway.

Brakes if you are not losing fluid I would assume the master cylinder is fine. Change the rotors pads and check the lines at the calipers if they are worn replace them. Also make sure to clean up the slide pins on the caliper and grease them. Then flush the fluid with DOT4. You will also need to flush the clutch. Brake fluid and clutch bleeding and flush - mk3 and mk4 VW and Audi | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum

As for the AC Check the fuses on top of the battery and see if the engine fans turn on when everything is set to high. Then check the line pressure if you have pressure even if might be the ring that engages the clutch that is out. That can be tested by jumping it at the connector under the car. That is the step I'm on with fixing mine but I needed to fix my parking brakes first so I could lift the front.

First page addressed.

Is the car an automatic or manual?

Now for the rest of the pages and my comments.

Grill block you can easily go for a full block in cooler weather. I have my upper blocked behind the grill and the large lower blocked year round. When it is cold out I add pipe insulation into the lowest opening to completely block the grill other than the opening for the intercooler.

When you flush your coolant I would recommend changing the t-stat to a higher temp one I think 190 or 195f is the highest you can get without pressing your own. Also look into Sieara coolant it is nontoxic I have been using it for my last two timing belt changes and have had no issues. (Just read that you had it flushed already)

Intake/Intercooler you want as cool or air is you can into the engine and the engine warm for economy/power on a diesel. With that said clean the intercooler but I would not replace it unless there is an issue with it.

K&N addressed on page 3 done.

Skid plate is a great idea it has saved many people. Just for me I hit a semi tire that was blown in the middle of the road about 3 weeks ago I can see the marks on the pan and the tire busted the welds on the down pipe.
MK4 Jetta skid plate Golf New Beetle GTI R32


Transmission issues p0704 I believe that is torque converter clutch code on the auto. Starting point Picked up a 2002 Jetta GLS w/01M - rpm question - TDIClub Forums
Same for the p0740 How Serious is P0740? - TDIClub Forums


What is VAG-COM (VCDS) - Ross-Tech: VCDS
Don't want to pay for one check these two locator listings someone might be in your area.
VCDS VAG-COM Locator - TDIClub Forums
VAG-COM Diagnostic Service Locator

Update: I replaced the diff fluid, used Walmart brand 75-90 gear oil. No change in how it runs since the swap. Installed a diy ccv filter, made it out of an agricultural strainer and a steel will scrubbing pad to catch condensation. After about 1k miles I've gotten about 1 cup of water mixed with a bit of oil, I check it every couple of weeks and empty as needed. no change in performance or mpg noted after this was installed.

Recently I have been chasing a leak that is letting rainwater into the front passenger side footwell. Never a visible puddle, but it's enough to soak the carpet anytime we get a moderate to heavy rain storm. I have removed the glove box, and the headliner and narrowed it down to a combo of the sunroof drains and the pollen filter door. The water runs from the base of the A pillar down around the blower motor and falls to the floor just behind where the glove box normally sits (it's in the trunk right now).

Ordered a deep belt tensioner arm and pully to go with the enhanced+ timing belt kit I am getting from blauparts.

Timing belt kit: http://www.blauparts.com/proddetail....od=GH21120-1-C
Serp belt tensioner: http://www.blauparts.com/proddetail.asp?prod=GJ12613-C

I have also ordered a filter, gasket, and fluid for the transmission. Gonna drop the pan and change fluid/filter when that gets here. I opted to go with OEM VW g52 fluid. Still scared by what I might find but I have, somehow, found confidence in changing the diff fluid and not having it explode.

Also replaced the seals on my injector pump, it doesn't leak anymore! Still have flashing glow plug light but I've read that can be caused by having led brake/tail lights, which I do have.

And finally, I ordered an OBDeleven device, base model. Its a well rated, and seemingly well received alternative to vcds(vag-com). Instead of running on a laptop it is a Bluetooth obd-II dongle that pairs with their Android app.
Android 4.1 or later, no iOS app available. OBDeleven: Audi, Volkswagen, Seat & Skoda diagnostic system

Regards,
Andrew