Run away engine 😢

Jxhcob

Active member
Joined
Apr 17, 2022
Location
California
TDI
2002 Jetta Wagon TDI
So you all may have seen that I recently purchased my first tdi…. Less than a week ago. ya well I drove it for the first time today as I finally got it insured apart from the 1/2 drive home when I bought it. While driving I noticed the revs climbing when I wasn’t on the throttle. Perplexed and not thinking about a runaway engine I hit the clutch and the engine revved way passed redline before I could do anything. Stupidly I instinctively turned the ignition off (first diesel used to gassers being able to just cut the ignition) instead of stalling the car out. I had also instinctively pulled it out of gear or at least I think I did I don’t actually remember doing that. Within about 5 seconds of sheer panic the engine shut off and I was coasting to the side of the road. My questions are should I just scrap the car / part it out (I’ve never actually done this) so it would be a first. Or should I bite the bullet and try to put a new engine in it. This would be a big challenge for me as I’m 17 and have a very tight budget to work on with my minimum wage job and have never swapped and engine. Or should I try my luck selling the car as is. (Pm offers if interested). The car is mint besides the now I assume blown engine. I will be doing a compression test tomorrow to confirm however the car would not start after sitting for a while and I didn’t want to press my luck. Anyway it seems like god was not on my side today any advise or help would be greatly appreciated.
 

Mpaw

Well-known member
Joined
Aug 21, 2018
Location
Germany
TDI
Caddy 2005 1,9 105 ps; Polo 2015 90PS Bluemotion
First, best not to panic.
It's possible it's fixable - but probably not cheap. How much do you want to learn / do? Is the engine actually seized?

First search for more info on internet....
 
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Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
If this is a 2002 Jetta wagon 5 spd rust free California car then even with a dead engine someone will want it. I would if I wasn’t on the other end of the country.

If you want to learn then finding another engine and replacing your current motor, assuming it needs it, is not a bad job I’ve done it a couple of times. It’s a learning experience for sure.

 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
Do a compression test, there's a chance it's still fine, but drain any residual oil out of the intercooler first, that's probably what caused the run away.
At least you keyed off, your ASV may have saved the engine.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
So calm down its probably fine.
If it never ran dry of oil then it's actually probably fine.
Go out to the car. Take the intake charge pipe off the engine so it cant get boost.
It will not runaway now.
Drain the oil from the intercooler via taking off the bottom pipe. Now be prepared for a lot of oil to be shot out of the pipe so do tjis over some gravel. Ot wont be a lot of oil bit it will look like it as it's being blown around.
Now check the oil on the dipstick to ensure there is enough in there. Start it up. If it starts and idles it's fine.
Uou can get a replacment turbo fairly cheap. Go with one of our vendors.

If it will not start make sure the asv is working properly and tru again. If it cant start then go with compression testing and a leakdown test.

As long as the engine did not run out of oil then it's probably still good. It did not last very long so it's probably fine.
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Before you ever crank the engine, remove the glow plugs. Crank the engine over to remove the oil. Will geyser with force any accumulated oil out of the cylinder...will shoot 10-15ft in the air so be careful. Otherwise, the other posts are correct - remove the hose going into the engine so as to avoid ingestion of any more oil. Add oil to crankcase if low.

It will be super smoky for a while as it clears out any oil. what you're looking for is a nice smooth idle. If it is 'lumpy' you've burned a piston or bent a rod and you'll need to repair.

HTH.
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
Personally I'd recommend barring it over by hand, would hate to have a rod decide that was the time to bend, by forcing fluid through a tiny hole.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Ignore mongler.

Two things possibly happened when it ran away:

1) it over revved and valves could have contacted pistons.
2) it drank too much oil and could have hydrolocked a cylinder or two (usually #2 and/or #3
or...

Your engine escaped any serious damage.


All of the above are possible.

If it were my engine, I would bar the engine over as above, with the GPs removed to ensure there is no more oil in the clylinders.

I would also remove the valve cover and inspect the tops of the lifters for any fine cracks indicative of the valves hitting pistons. If you see these fine spider-web like cracks, do not try to start the engine. If valves hit, then valve stems can be cracked, and will eventually allow the valve to drop into the cylinder causing much carnage.

If both the above check out, I would reassemble everything, drain the oil out of the intercooler, and only then would I try to crank the engine.

Also, if the engine has a hard time starting or runs like crap, its possible that a hydrolock bent some connecting rods. If that's the case, the engine is coming apart further to repair the damage.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Why bother. If the engine is fubar its fubar. OP is not going to be able to fix it with bent valves or bent rods. Yea turning it by hand is a good idea lol and pulling the blow plugs could be a disaster if one snaps.
Listen to.me... don't... I dont care.
Bottom line is either ita fubar or it's fine. Aside from some hand tuning there is not much OP is going to be able to handle and even a turbo swap can be clanging for a 17yo.
 

Jxhcob

Active member
Joined
Apr 17, 2022
Location
California
TDI
2002 Jetta Wagon TDI
First, best not to panic.
It's possible it's fixable - but probably not cheap. How much do you want to learn / do? Is the engine actually seized?

First search for more info on internet....
I’m willing to learn as much as possible I’ve been restoring a classic Chevy since I was 13-14 and that’s where most of my knowledge has come from. I checked the dipstick and there was still plenty of oil. I have school and work today so I’ll try and do a compression test between the two And post my results. Thank you of for ur advice.
 

Jxhcob

Active member
Joined
Apr 17, 2022
Location
California
TDI
2002 Jetta Wagon TDI
So calm down its probably fine.
If it never ran dry of oil then it's actually probably fine.
Go out to the car. Take the intake charge pipe off the engine so it cant get boost.
It will not runaway now.
Drain the oil from the intercooler via taking off the bottom pipe. Now be prepared for a lot of oil to be shot out of the pipe so do tjis over some gravel. Ot wont be a lot of oil bit it will look like it as it's being blown around.
Now check the oil on the dipstick to ensure there is enough in there. Start it up. If it starts and idles it's fine.
Uou can get a replacment turbo fairly cheap. Go with one of our vendors.

If it will not start make sure the asv is working properly and tru again. If it cant start then go with compression testing and a leakdown test.

As long as the engine did not run out of oil then it's probably still good. It did not last very long so it's probably fine.
I probably won’t be able to get into that till later in the week when I have time but when I checked the dipstick the oil was still full so I don’t think it starved the engine however it did shut down on its own and would start. But I’ll till cross my fingers and pray.
 

Jxhcob

Active member
Joined
Apr 17, 2022
Location
California
TDI
2002 Jetta Wagon TDI
Ignore mongler.

Two things possibly happened when it ran away:

1) it over revved and valves could have contacted pistons.
2) it drank too much oil and could have hydrolocked a cylinder or two (usually #2 and/or #3
or...

Your engine escaped any serious damage.


All of the above are possible.

If it were my engine, I would bar the engine over as above, with the GPs removed to ensure there is no more oil in the clylinders.

I would also remove the valve cover and inspect the tops of the lifters for any fine cracks indicative of the valves hitting pistons. If you see these fine spider-web like cracks, do not try to start the engine. If valves hit, then valve stems can be cracked, and will eventually allow the valve to drop into the cylinder causing much carnage.

If both the above check out, I would reassemble everything, drain the oil out of the intercooler, and only then would I try to crank the engine.

Also, if the engine has a hard time starting or runs like crap, its possible that a hydrolock bent some connecting rods. If that's the case, the engine is coming apart further to repair the damage.
Thank you the I definitely will pull the head and Check the cylinders to check for the damage. Should I be concerned with the piston that bent the valve if that’s what happened?
 

Jxhcob

Active member
Joined
Apr 17, 2022
Location
California
TDI
2002 Jetta Wagon TDI
Why bother. If the engine is fubar its fubar. OP is not going to be able to fix it with bent valves or bent rods. Yea turning it by hand is a good idea lol and pulling the blow plugs could be a disaster if one snaps.
Listen to.me... don't... I dont care.
Bottom line is either ita fubar or it's fine. Aside from some hand tuning there is not much OP is going to be able to handle and even a turbo swap can be clanging for a 17yo.
Im confidant that I could do a turbo swap lol I planned to do one before the engine did this I’ve rebuilt heads on my Chevy be fine before. Also so long as the lower end of a diesel and gasser are the same I might be able to rebuild it effectively.
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
Just to state it again, do a compression test. Doing so will tell you a lot about the internals without opening up the engine.
A bent rod will have compression significantly lower than a straight rod. If all holes are pushing 400+ Psi, I wouldn't crack it open.
 

Boostlee

Well-known member
Joined
Jun 24, 2019
Location
Canada
TDI
05 Jetta wagon
Listen, if that is really a super clean 02 wagon, keep it and fix it! That's a GEM of a find!
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Thank you the I definitely will pull the head and Check the cylinders to check for the damage. Should I be concerned with the piston that bent the valve if that’s what happened?
Pistons in these engines protrude just above the deck/block. Check piston protrusion with a dial indicator and a magnetic base to ensure all are even. If you have a bent rod, then that piston will be lower than the rest and the rod will need to be replaced
 

4th4

Active member
Joined
Mar 24, 2022
Location
PNW Washington
TDI
2005.1 Jetta Wagon BEW
Why does this happen exactly?

Is it because oil accumulates in the intercooler and gets vacuumed into the combustion chamber?
How does one prevent this? This sounds terrifying.
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
It could happen from oil accumulation in the intercooler, or a failed turbo seal.

Oil naturally accumulates in the intercooler, due to the way the crankcase breather is setup. You can either regularly (like once a year) drain your intercooler, or do what some call the Italian tune up. Romp on it hard for a few minutes to get enough air flow going to clear anything out and work the engine hard.

If it were the turbo seal, there's no real way to show if it's failing. It is pretty uncommon though.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Food for thought. I quite literally exploded myturbo in my bhw a couple years back. The car drank 2L of oil in about 2km. Never ran away even though the turbo essentially became a 5th injector wide open. Ive only ever been in one other two runaway... An ALH which had a recent intake cleaning. The increased airflow sucked up accumulated oil and the engine surged.
In my case, I left it in gear (5th) and turned off the ignition (close ASV) and kept on the brakes. Luckily in my case it never came close to red line and there were no I'll effects.
 

Jxhcob

Active member
Joined
Apr 17, 2022
Location
California
TDI
2002 Jetta Wagon TDI
Thank you to everyone for the help I think I might keep it regardless of the engine condition as I still have another car I can drive and if I can’t find a new engine I will rebuild this one over my summer break. At least I can cross rebuild an engine off my bucket list. So get ready for a lot more questions later down the line and thank you for being so welcoming to someone so new to the community.
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Two things possibly happened when it ran away:

1) it over revved and valves could have contacted pistons.
2) it drank too much oil and could have hydrolocked a cylinder or two (usually #2 and/or #3
or...

Your engine escaped any serious damage.


All of the above are possible.

If it were my engine, I would bar the engine over as above, with the GPs removed to ensure there is no more oil in the clylinders.

I would also remove the valve cover and inspect the tops of the lifters for any fine cracks indicative of the valves hitting pistons. If you see these fine spider-web like cracks, do not try to start the engine. If valves hit, then valve stems can be cracked, and will eventually allow the valve to drop into the cylinder causing much carnage.

If both the above check out, I would reassemble everything, drain the oil out of the intercooler, and only then would I try to crank the engine.

Also, if the engine has a hard time starting or runs like crap, its possible that a hydrolock bent some connecting rods. If that's the case, the engine is coming apart further to repair the damage.
I've never heard of valve/piston contact during a runaway. Can you share an example? (always ready to learn :) )

Bent rod or burned piston, absolutely.

 

dhangejr

Veteran Member
Joined
Mar 1, 2017
Location
PNW is my home
TDI
mk4 Jetta
IF it’s A PD check the cam shaft too.
My first TDI had a runaway, I learnt a good lesson about rolling on to the throttle...

Luckily, like you I was able to stop mine from consuming consuming all the oil.

After I found the turbo shaft had shaped causing the runaway, I cleared the engine of oil as described above.

I did spin it over by hand several times listening for any binding. I think I disconnected the pipe from the intake manifold to the inter cooler so the turbo was outta the game ? Don’t recall regardless
I started it up for a little bit and it seemed good so I slapped a wrecking yard turbo on snd drove it for about a year maybe more before I regrettably sold it.

I was honest with the seller about it and gave a great deal. As far as I know he drove that car all over the country. I know for sure he drive it 400 miles home.

Lony story short , find out why it ran way most likely excessive oil in the intercooler or turbo seals. You can probably just start it to test Then fix it and send it…you can buy the special tools and II need for compression , great plan as lots of people will tell you that in time it will drop a valve. No experience there but I’m positive it’s true , throw the dice
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
I probably won’t be able to get into that till later in the week when I have time but when I checked the dipstick the oil was still full so I don’t think it starved the engine however it did shut down on its own and would start. But I’ll till cross my fingers and pray.
It's possible that there was just some oil buildup in the ic and with a heavy foot the motor injested it. Still everything needs to be checked. Pull the charge pipe off the ic, clean it and pull the charge pipe off the intake. Have something stiff ready to cover over the intake. Roll the engine over by hand. These have electric injectors right? Unplug the injector harness and crank it over. It may start and die with the oil that's in it. Check for oil on charge side of turbo. Does it sound even while cranking?
Plug the injectors back in and start it. Let it run a bit and ceck charge side of turbo again. Everything seem okay?
Let it warm up and give a few revs.
This is the procedure I did with mine. My turbo didn't want to drain when it was -30 and it pushed oil out the seals till it warmed up. When this happened enough times and When the oil hot enough it got sucked in and acted like a runaway. Everything was fine. Was just accumulated oil. Everything was just fine.
 
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Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
IMO if the engine was shut off manually like OP had and only ran away for a few seconds..... the chance of a hydrolock / oil filled piston or any other damages are minimal.
If it had to be stalled or it shut down on its own... yea carnage imminent.
best of luck..... it really sucks that this is your first experience with a TDI and you got what may fee like a lemon but its probably just coincidence and otherwise is not to be considered a bad omen.
you may want to check the "trusted TDI mechanics" on TDI 101. see if there is one close by. might be worth taking to them and getting a check over while your at it. If cared for you will take this car to a very high mileage for very little $ and time. so a upfront investment might be in your best interest.
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
IMO if the engine was shut off manually like OP had and only ran away for a few seconds..... the chance of a hydrolock / oil filled piston or any other damages are minimal.
If it had to be stalled or it shut down on its own... yea carnage imminent.
best of luck..... it really sucks that this is your first experience with a TDI and you got what may fee like a lemon but its probably just coincidence and otherwise is not to be considered a bad omen.
you may want to check the "trusted TDI mechanics" on TDI 101. see if there is one close by. might be worth taking to them and getting a check over while your at it. If cared for you will take this car to a very high mileage for very little $ and time. so a upfront investment might be in your best interest.
I've noticed wayyyyy to many have the sky is falling mentality. Look close at the situation people. Sheesh
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Some TDI'ers say to remove the glow plugs and then turn the engine over to clear out any possible oil. What is more important than that is to remove the power lead from the IP solenoid, that way when you turn the engine over to clear the cylinders, raw fuel is not getting blown out too.
The last time I had a partial runaway, I removed the injectors to clean out the cylinders and there was a fair amount of oil that came out.
I pulled the injectors because I was upgrading them, or size-wise downgrading them.
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
I've had one mildly run away - pulled injectors and cranked with starter. New turbo, cleaned intercooler and it was good. But.... It was stalled out immediately. They don't shut off on their own. I actually started the car with no turbo to make sure it ran before replacing it.

That car had had prior run-away damage. Previous owner overheated it, let it runaway, refilled the oil and did it a second time.

 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
I've had one mildly run away - pulled injectors and cranked with starter. New turbo, cleaned intercooler and it was good. But.... It was stalled out immediately. They don't shut off on their own. I actually started the car with no turbo to make sure it ran before replacing it.

That car had had prior run-away damage. Previous owner overheated it, let it runaway, refilled the oil and did it a second time.

That'll buff right out!
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
My guess is it was a vehicle that was driven conservatively until a 17 year old new owner romped on it. How about it Jx??? Any history on the car you can share?

There're a lot of suggestions have been offered here, some somewhat cornfusing or possibly missing some important steps. This is what I would do with a splanation of why I'd do each. Again, nothing that wasn't touched on above but now all in one place

If you want to do a compression test you must disable the fuel supply or the cylinder you're testing can fire. Pull the wire off the solenoid above the fuel pipes on the pump.

Remove all the glowplugs and crank the engine for a while to blow out the oil or you get false readings. Use the towel. Draining the intercooler first would be a good idea or disconnect the hose at the ASV. Anti shudder valve. It should stay open on its own for the test but you can use some means to keep it open if you want.

Do the testing. I do 1-2-3-4-1 to make sure 1 repeats and demonstrates the battery held up.

As was stated, if you had serious inhalation of oil 2 and 3 could be expected to be lower since it's a straight shot for the oil to enter those cylinders.
 
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