Help needed with Eco-mods for VW AAZ Diesel engine!

[oil pan 4]

Also I ran many gallons of vegetable oil through my diesel from 2006 and 2011. When I tore it down for a rebuild every thing looked normal.
I didn't use more than 30% waste vegetable oil in the summer and ran tanks of regular pure diesel from time to time.

[sallen]

Sorry for getting on this thread a little late - I have one of these cars and can tell you the following:

Ultimate ecomod for the car > buy TDI engine, fit TDI engine, enjoy OBDII diagnostics and tunability and instant 10-15% mpg increase.

Ultimate ecomod for the car with the AAZ engine would be a 5th gear swap (google is your friend, you have an "020" gearbox) as those Golfs seem to be fitted with "petrol car / town driving" gearboxes. My AAZ screams its head off at 70mph, it's just not geared for motorways compared to TDI engined cars.

This brings me to what I've done over the past few years, most of these mods were (a) rubbish and (b) poorly built by me, and fell off...

(1) Undertray - 4% improvement, don't copy my build tho, that plastic sheeting stuff takes up water by capillary action and sags / gets heavy.
http://ecomodder.com/forum/showthrea...1-a-12816.html

(2) LRR tyres - tiny mpg difference and lots (LOOOOTS) more road noise + huge loss of grip... FA grip in fact, even when compared to the "ditchfinder" el-cheapo tyres I took off.
http://ecomodder.com/forum/showthrea...ars-14023.html
http://ecomodder.com/forum/showthrea...res-14134.html

(3) Grill block and tyre spats - zero difference and the spats got destroyed by the tyre and high kurbs. Don't worry about running hot, these cars have HUUUUGE radiators and the AAZ engine produces very little heat.
http://ecomodder.com/forum/showthrea...olf-10970.html

(4) Misc other aero stuff - sweet FA of a difference
http://ecomodder.com/forum/showthrea...rbo-12757.html
http://ecomodder.com/forum/showthrea...uild-9391.html
http://ecomodder.com/forum/showthrea...1-a-12763.html

(5) Biodiesel is safe, I've done thousands of miles on it - those Bosch pumps would push out gravel if you could feed it to them. LOWERED my MPG though (lower calorific content) but it's cheaper to buy so the per-mile cost of bio is +1p (11p per mile dino, 12p per mile bio)
http://ecomodder.com/forum/showthrea...ing-10810.html

(6) EGR delete made FA difference to power or economy, maybe I have a cleaner intake manifold now though???

My final observation is if you want your AAZ to continue working, google "crank pulley wobble". There are two preventative fixes that you can do next time you have the engine out.

Oh, and final, final observation... If you are thinking of lowering it for FE / aesthetics check you don't have the rear brake bias valve that works by rear axle position (more rear brakes with a loaded-up car turn!!!

I don't mean for the above comments to paint a negative picture, the 'old tractor has been very reliable for me. It's just not a very efficient package - Big CC low power engine in a bad-handling, heavy hatchback.

I'm also happy for feedback on unsuccessful mods if I've been an idiot somewhere!!

Steve

[320touring]

Originally Posted by sallen

Sorry for getting on this thread a little late - I have one of these cars and can tell you the following:

Ultimate ecomod for the car > buy TDI engine, fit TDI engine, enjoy OBDII diagnostics and tunability and instant 10-15% mpg increase.

Alas, I got the car for peanuts, and dont need another "project"= it offers 10-12mpg more than the "petrol equivalent" on my 328i, so already I've seen a benefit to having it. Plus, the lump is strong and runs well!

Ultimate ecomod for the car with the AAZ engine would be a 5th gear swap (google is your friend, you have an "020" gearbox) as those Golfs seem to be fitted with "petrol car / town driving" gearboxes. My AAZ screams its head off at 70mph, it's just not geared for motorways compared to TDI engined cars.

is this a fairly simple swap? Take its just swapping out 5th for a longer ratio?

This brings me to what I've done over the past few years, most of these mods were (a) rubbish and (b) poorly built by me, and fell off...

(1) Undertray - 4% improvement, don't copy my build tho, that plastic sheeting stuff takes up water by capillary action and sags / gets heavy.
http://ecomodder.com/forum/showthrea...1-a-12816.html

(2) LRR tyres - tiny mpg difference and lots (LOOOOTS) more road noise + huge loss of grip... FA grip in fact, even when compared to the "ditchfinder" el-cheapo tyres I took off.
http://ecomodder.com/forum/showthrea...ars-14023.html
http://ecomodder.com/forum/showthrea...res-14134.html

(3) Grill block and tyre spats - zero difference and the spats got destroyed by the tyre and high kurbs. Don't worry about running hot, these cars have HUUUUGE radiators and the AAZ engine produces very little heat.
http://ecomodder.com/forum/showthrea...olf-10970.html

(4) Misc other aero stuff - sweet FA of a difference
http://ecomodder.com/forum/showthrea...rbo-12757.html
http://ecomodder.com/forum/showthrea...uild-9391.html
http://ecomodder.com/forum/showthrea...1-a-12763.html

(5) Biodiesel is safe, I've done thousands of miles on it - those Bosch pumps would push out gravel if you could feed it to them. LOWERED my MPG though (lower calorific content) but it's cheaper to buy so the per-mile cost of bio is +1p (11p per mile dino, 12p per mile bio)
http://ecomodder.com/forum/showthrea...ing-10810.html

(6) EGR delete made FA difference to power or economy, maybe I have a cleaner intake manifold now though???

My final observation is if you want your AAZ to continue working, google "crank pulley wobble". There are two preventative fixes that you can do next time you have the engine out.

Oh, and final, final observation... If you are thinking of lowering it for FE / aesthetics check you don't have the rear brake bias valve that works by rear axle position (more rear brakes with a loaded-up car turn!!!

I don't mean for the above comments to paint a negative picture, the 'old tractor has been very reliable for me. It's just not a very efficient package - Big CC low power engine in a bad-handling, heavy hatchback.

I'm also happy for feedback on unsuccessful mods if I've been an idiot somewhere!!

Steve

Thanks for the advice and experience- very useful, giving me plenty to consider!

cheers!

[sallen]

On the 5th swap... all the info you need is on:
020 GEAR RATIOS
http://www.brokevw.com/5thswap.html
and

5th gear swap on VW manual transmission

I ruled out this mod because the 5th cog itself was around £300... perhaps you can find a cheaper option?

[sallen]

... one other thing... I'm changing my timing belt (fun times) this week.

There is anecdotal evidence that on VW diesel engines you can retard the timing slightly for better FE (stock is 0.8mm, performance tuners say 1.0 to 1.05mm).

Hopefully I'll get a chance to try this out & can report back.

[320touring]

Originally Posted by sallen

... one other thing... I'm changing my timing belt (fun times) this week.

There is anecdotal evidence that on VW diesel engines you can retard the timing slightly for better FE (stock is 0.8mm, performance tuners say 1.0 to 1.05mm).

Hopefully I'll get a chance to try this out & can report back.

I have heard similar- Maybe worth looking into when I come to do the belt on mine

[JasonBourne]

It is true that some of the old vehicles especially diesel vehicles show some problems with fuel efficiency. Regular maintenance and oil change can improve the performance and the efficiency of your diesel car. It is better for you to show your car to a good mechanic to fix all the problems.

[werfu]

You'll want to head to vwdiesel.net forum, in the IDI section for more info about old, mechanically injected diesel. Most mod people do don't only increase power, but usually increase efficiency. I've read tremendously about the AAZ lately (I bought one last fall) so I can sum it up for you :

First, biodiesel IS damageable to only one part of the AAZ engine, the injection pump. Low sulfur fuel damage the seals of the pump. However, replacement seal kit are now resistant to this, so you can get your pump resealed. Quite costly tough, you'll surely wait 'till the pump start dripping, but don't wait to long or you'll run into trouble.

Second, a TD engine will always be less efficient than a TDI. Direct injection is more efficient. But you can increase it's efficiency quite easily, unlike the TDI which require a computer. First you'll want to tune your max fuel and and give a couple of turn to turbo actuator arm bolt in order to reduce the time it takes to the turbo to engage. There's complete guide for basic tuning that can be done with little modification.

Third, you can add/change stuff to increase fuel efficiency. Switching the 5 gear to reduce the ratio is well documented and will lend you some nice economy on highway driving. Adding an intercooler is another, low cost solution that works fine. Cold-air intake are an easy job. A lot of people will say that cone shaped air filter will increase airflow, but you're better off keeping the stock air box with a high efficiency filter and replacing the tubing with better flowing one.

I could keep on for a long time, but I'll let you read, you'll learn more about diesel this way. Diesel engines are unstoppable machines that simply needs to be well maintained. Don't cheap out on oil and filters , do your maintenance on regular schedules and keep it clean.