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So as the title says, a friends dad is getting rid of his Jetta with 116k 5 speed, on its second VNT15. I have never owned a VW, but a decent mechanic, have rebuilt DSM Eclipses in the past, still own a 90 AWD.

Here is the symptoms.
He says the Jetta started to burn lots of oil, 1q in 500miles. That was weeks ago and he has continued to drive it. Currently when I test drove it, it had NO power, it struggled to get to 45mph, I dont hear any turbo whine either. Wasnt smoking when I drove it. It starts up quick, idles fine, sounds ok.

He has a veggie oil conversion in the car and has a 2nd tank full of veggie oil. He thinks that using veggie oil that was not properly heated may have broken the motor.

I think its a seized turbo, stuck plate, clogged intake...

I was reading a thread about low power and it wouldnt allow me to continue to read and research until I posted something. So this is my first post :) I live in Chicago btw.

thank you
Yohei
 

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There is a ton of stuff that can go wrong with a veg-oil conversion.

buildup on valves, buildup on intake manifold, buildup on turbo, buildup inside injection pump

The more regular suspects: bad turbo, seized VNT actuator, cracked vac lines. My guesses at the oil consumption: the piston rings may be stuck by the byproducts of the veg oil conversion. What is the engine compression?

PS, my family bought of of the first DSM in the state. It was a red Eclipse GT, quickly traded for a GSX. I put 200,000 miles on it, still going strong, great car.
 

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Hi, thanks for a quick reply!
He told me he has read something about rings going bad with the use of veggie oil.. and I was trying to think its an easier solution :)

Yeah, DSM 1st gens are the best :) gas guzzler tho...

I haven't touched the car yet as he is still driving it to work on daily basis. Since it starts up fine and didnt smoke at idle, I was hoping that the motor it self is still ok. I dont even have a compression tester for a TDI. I have one but i think they only go to 200psi or something. Very new to TDI... been doing alot of reading here but SO different than gas engines, alot to digest and learn....

Once I take possession, my plan was to take the intake/egr off and inspect, remove turbo and clean the VNT mechanism, and then drive it... I guess if the rings are bad, or valves are bad it would not be a very wise investment...
 

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He wants 3000$, since a good runner are still 6-7k for low milage, I thought it was worth that much. Had no idea that veggie oil ran cars were something to be weary of :(
 

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On the bright side, TDI are very easy for power modding. There are plenty of suspension options as well.

Since the user is the one responsible for grease car fueling, how well it turns out is highly dependant on them. Some work fine, others screw up. If you put bad fuel into the car, expect the car to get messed up. If you do your homework and take care of the car and put high quality fuel into it, expect the car to work well.

Some oil in the intake is normal because of piston blowby but if the rings are stuck, power may be low and blowby could be high = more oil in the intake. A bad turbo is also possible, if too much oil is in the intake = runaway: http://www.myturbodiesel.com/1000q/stop-runaway-diesel-engine-how-to.htm

It sounds like it has gummed up piston rings. If it were my car, I'd plan on fixing those and cleaning the intake. Also removing the grease car system, sell it or junk it. Another possibility is a gummed up injection pump. The fuel injectors could also be bad.

$3000 sounds fair, overall miles are very low. The timing belt should have been done a while ago as well, if not done plan on budgeting for that too. But if you're serious about it I would give it a thorough check and decide if you want to tackle this project. As the title states" Buying a 2001 Jetta TDI with problems..." dot dot dot
 

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Discussion Starter #8
CCBB, thanks, your right as in it will be a project. He told me timing belt was done right before 100k, and turbo was bad before and had that replaced, i didnt ask how long ago.

gummed up rings, would involve pulling the motor out right? Ive done full rebuild on the 4G63 DSM, have a hoist in my garage, but I bet prices on these are high and it would quickly add up parts alone.

and I assume if I had to pull the head off anyways, i might as well put all new timing/pumps stuff too..

when i drove it the rear passenger suspension sounded like it had a bad mount or something, banging noise occasionally. koni or bilsteins? ill search :)

his veggie oil is actually new, and uncooked with. in the holding tank it looks like yellow clear oil. he has a huge huge tank in the garage.

after reading alot, it sure sounds like he may have used NON heated veggie oil and that is causing problems, his commute is very short and thus there are not many miles on the car, he bought it from a dealer with 17k on it.

i guess at the minimum from what i have been reading,
new fuel filter, new VNT15 or 17 if the seal/bearing are shot, block off EGR, CCV catch can, clean intake, make an exhaust (turbo back), get injectors cleaned, maybe new fuel pump, maybe new MAF... lots of parts needs attention from the look of it.
i will buy a compression gauge first see if there is any good rings left. but from how easy it was to start up and idle, i am HOPING the rings are good... that will be a deciding factor.





On the bright side, TDI are very easy for power modding. There are plenty of suspension options as well.

Since the user is the one responsible for grease car fueling, how well it turns out is highly dependant on them. Some work fine, others screw up. If you put bad fuel into the car, expect the car to get messed up. If you do your homework and take care of the car and put high quality fuel into it, expect the car to work well.

Some oil in the intake is normal because of piston blowby but if the rings are stuck, power may be low and blowby could be high = more oil in the intake. A bad turbo is also possible, if too much oil is in the intake = runaway: http://www.myturbodiesel.com/1000q/stop-runaway-diesel-engine-how-to.htm

It sounds like it has gummed up piston rings. If it were my car, I'd plan on fixing those and cleaning the intake. Also removing the grease car system, sell it or junk it. Another possibility is a gummed up injection pump. The fuel injectors could also be bad.

$3000 sounds fair, overall miles are very low. The timing belt should have been done a while ago as well, if not done plan on budgeting for that too. But if you're serious about it I would give it a thorough check and decide if you want to tackle this project. As the title states" Buying a 2001 Jetta TDI with problems..." dot dot dot
 

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