Jetta diesel - too loud or normal?
 

I found a 1992 Jetta turbo diesel for sale, it has 336,000 kms on it. 5 speed, body and interior are in nice shape, and has the factory 13 inch alloys on it. It hazes a little blue out of the tailpipe at idle, but doesn't smoke badly at all when going down the road. The thing is the engine is loud. Like you can hear it idling from half a block away loud. My only VW diesel experience has been driving my friend's TDI Beetle, so I don't know if these old VW diesels are supposed to be that loud or if this one is getting tired. Any advice?

Also, are these older VW diesels good candidates for experimenting with veggie oil etc?

If you haven't bought it yet, take it to a reputable VW dealership and get a pre purchase inspection done on it. With the miles that are on it, my first thought is that the injectors are worn out or are on the way there.

Get a sample of the oil and send it out for analysis. That's going to tell more about what is going on than anything.

These engines are excellent for SVO/WVO.

Thanks for the info. The car is actually for sale for less than the cost of those inspections I think, so I am willing to take a chance on it to try out some veggie oil action. My office is in a complex with a bunch of restaurants, and there is a cooking oil disposal bin beside us, so it's hard to not want to try driving for almost free!

Be sure to do the timing belt, asap. These engines are interference style, and the carnage is nothing nice. After that, check the valve clearances, change out all the fluids and filters and run a good diesel treatment. I like the Service Power cleaner with boost ( silver bottle ).

Before you start running the waste oils, you should do the injectors and make sure that the pump settings are right. Make sure everything is proper and you won't have to look at it again for a long, long time.

Thanks again, I will call the guy tomorrow and make an insultingly low offer, he has no interest in the thing so hopefully it will work.

Just a thought. That IDI turbodiesel is very desireable. If you get it, start stocking parts to get her right. Keep it forever. The motor and trans are $$$$$$$ on the market right now.

Worth a thought, most of the noise on older diesels is from the pump so that could be having issues especially at that mileage and if it has stood for a while.

Be sure you talk to people and see for yourself what they are actually doing to get the waste veggie oil thing to work. Its a lot more than just filtering. There have been quite a few nice diesels ruined by people that thought it was just as easy as filtering the oil. Getting rid of extra moisture in the oil and making sure the PH is right is very important.

The blue haze would worry me a little as it sounds like its time for a rebuild or the turbo's rear oil seal is about to go. Rebuilding/replacing the injectors can reduce the diesel clack noise quite a bit if they are indeed the cause.

My friend's boss owns an alternative fuels conversion shop, and he makes his own veggie oil fuel at home. If I get the Jetta I will try to get invited over to see for myself what the process entails. He runs a 2008 Chevy Duramax on the fuel he makes, so I like to think he knows what he is doing!

Those IDI engines are loud. I drove a 6.2 GM diesel for 17 years. It’s a wonder I’m not deaf as a post. The racket is normal. The blue smoke says “wear.” It has an oil leak somewhere.

VW diesels are so hot on the market that if you can get one it is worth it even if you have to drop $1500 in repairs. You are looking at a 45 MPG vehicle with no mods.

Diesels offer a whole world of alternative fuels. Old Benzes (similar engines to yours) run straight waste vegetable oil (WVO for short), but it’s a bit of a ceremony. You have two fuel systems – dino diesel and WVO. You start on dino diesel and run til the WVO is warm enough to pump. When you get to your destination, you switch back to dino diesel to get the injection system full of the low viscosity dino diesel so it will start the next time. You can also refine WVO into biodiesel (B100). Good stuff but like WVO gels at a fairly warm temperature.

Diesels will run nicely on used lube oil. Big thing these days is what is called W85. You take waste lube oil and filter it down to 3 microns and mix in 15% (by volume) RUG to make it flow. They tell me it works well with unit injectors (like the pompa dusa injectors on mid 00s VWs.) I’ve added 10% waste lube oil to my dino-diesel but haven’t tried waste oil and RUG. They tell me WVO is getting hard to come by but every oil change shop in the country is up to their ears in waste lube oil.

Unless it is an unmitigated rust bucket, buy the car and fix the engine if necessary. Much cheaper than an old Insight with a played-out battery.