NEED ADVICE 2000 Jetta TDI troubleshooting

[rjsummer]

My 2000 Jetta TDI has been running fine up till 2 weeks ago. With 335,000 KM on it, I was passing a car on the highway. I dropped down into 4th and floored it. After releasing my foot at the speed limit in 5th gear, the car kept accelerating as if on cruise. Cruise was off, and I fought the car with the brake, no help, pulled over, stupidly hit the clutch, it rev'ed up for a second as I turned the key off. It stopped.
Then it was hard to start. Finally started, and ran rough, then fine. Since then, it starts with the glow plugs at -20 degrees C but after about 5 seconds gets really rough and doesnt run evenly or on all cylinders. Lots of smoke out the tail pipe. After about 10 minutes of driving, (it gets progressively better as it warms up) it is fine and runs like normal.

Took it to the dealer. Glow plugs ... ok
Injection pump... ok
Timing ... ok
Fuel filter... they said it wasnt staying full, draining out of the filter overnight type thing. Replace the filter they said, so I did. No change. Took it back. They said my new filter was defective. They wanted to replace the filter. I said ok. They claim their VW fuel filter was staying full. But... no change.
Then they said it was the injectors maybe, they took them out and had them pop tested. Spray pattern was off a bit, so they said rebuild or replace. I replaced them with new ones. No difference. On the test drive they said the car took off on the tech. They said the turbo was toast, leaking oil caused the runaway events as it was sucked in the intake. They said on the last runaway the seals blew and so they put a new turbo on it. Still runs exactly the same as in the opening paragraph. 2,500 dollars later they say it must be a mechanical fault in the engine. They want to tear it down to check the pistons and rings and so on.

At this point they've had the car a week, and I'm bled dry of money. I told them to forget it.

Anyone have any ideas?
They claim a normal compression test is within spec but a cold test (which they admitted youre not suppose to do cause it can skew the readings) said there was an 8.8 bar difference between cylinder 4 and the rest , only when cold.
If the engine when cold is tighter fitting, why would it have worse compression cold?
Could lifters that are beat cause this and take a while to pump up to pressure? There is some ticking amongst the diesel sound.

No codes ever came up. When warm the engine did and now has normal power and gas mileage.

Any helpful advise would be appreciated.
-Jeff

 

[puter]

certainly sounds to me like runaway.

check your intercooler for oil to see if it is the turbo. I'm astounded they didn't look at that first given the symptoms.

Some things you need to know: runaway can destroy your engine. If your engine goes into runaway you may not be able to kill it with the key. The first thing you need to do if you are in the car is keep the car in gear, pull over, and hit the breaks. Keeping it in gear and braking will cause the engine to die...hard on clutch and transmition but much better than hydrolocking when it exceeds rev limiter.

If you are not in your car then you need to manually block the airflow to the engine by closing the anti shudder valve. That is the valve that is hooked up to your egr.

FYI, if the car is not in gear (or the clutch is in) you have about 10 seconds to stop the runaway before your engine is toast. You should not be driving the car unless absolutely necessary.

Also, get your car away from the dealer. They do not know what they are doing and they will keep taking your money and throwing parts at the problem. Any trusted mechanic or guru would have known immediately what to look for based on your description. The 101 section has a trusted mechanics list...use it.

 

[ninedee_golf_tdi]

Since you said 335km's you are in Canada ?

 

[rjsummer]

Thanks for all the advice on the runaway scenario. I think I knew most of that. The clutch in at the end of my stop was just habit I think, coupled with the fact that when something as unexpected as a runaway happens, your mind is kinda racing trying to figure out what's going on.
Anyway, any idea what could cause really rough running and missing after a perfect glow plug start, gradually smoothing out when driven and almost perfect running when hot?
This morning was about 50 degrees F and the glow plugs didn't come on cause it was too warm outside. Engine started rough from the get go so obviously the really cold starts are smooth at first because the glow plug is heating the chamber but as soon as the glow plug cooks the roughness starts.
Could a quiet or otherwise good appearing pump cause this if there is a fault in the pump? Everything started with the runaway and brief 3 second rev. Gould the runaway incident have damaged the pump when it reved up?

 

[Doug Huffman]

Did you get the car away from the stealership now that you're bled dry? Their interest is not in fixing the car but in having a full rice-bowl.

Get the car to a guru and pay again to have him fix it.

 

[PDJetta]

High mileage on the engine (lots of blow-by past the rings) or a failed turbocharger may have caused the runaway condition. You need to address why it happened. My first guess would be the turbocharger. See if the intake manifold is full of oil. If so, its a bad turbo.

Given your description of what happened, I would highly suspect that the run-away has bent one (or more) of your connecting rods, due to excess oil going into the engine and hydrolocking it. Part of the detective work shoud be giving it a compression test. Low on one or more cylinders should confirm this.

Since you state it now runs rough when cold and white smokes (unburnt fuel), that is usually a sign of low compression (the fuel is lit off by compression ignition), and this is most likely because a rod bent and hence its piston will not move up as far in its cylinder, thus lowering compression in that cylinder.

You may be in for a new turbocharger and replacing a connecting rod (head and oil pan must come off).

You may also want to just go ahead and rebuild the engine, or get another one.

Or get rid of the car, depending on your preference.

--Nate

 

[hevster1]

certainly sounds to me like runaway.

check your intercooler for oil to see if it is the turbo. I'm astounded they didn't look at that first given the symptoms.

Some things you need to know: runaway can destroy your engine. If your engine goes into runaway you may not be able to kill it with the key. The first thing you need to do if you are in the car is keep the car in gear, pull over, and hit the breaks. Keeping it in gear and braking will cause the engine to die...hard on clutch and transmition but much better than hydrolocking when it exceeds rev limiter.

If you are not in your car then you need to manually block the airflow to the engine by closing the anti shudder valve. That is the valve that is hooked up to your egr.

FYI, if the car is not in gear (or the clutch is in) you have about 10 seconds to stop the runaway before your engine is toast. You should not be driving the car unless absolutely necessary.

Also, get your car away from the dealer. They do not know what they are doing and they will keep taking your money and throwing parts at the problem. Any trusted mechanic or guru would have known immediately what to look for based on your description. The 101 section has a trusted mechanics list...use it.

Engines do not hydrolock when they over rev. They hydrolock when lots of liquid gets into the cylinders.

 

[puter]

I was under the impression that if you caught a runaway in time you could prevent engine damage.

 

[rjsummer]

From the replies, I don't think I've been really clear about my problem so to simplify things, I've started a new thread titled ... NEED Advice Here are the symptoms... have a look there and see if anything triggers any ideas. Thanks.

 

[puter]

In the future, it would be better just to post that back to this thread rather than starting a new one.