what damage occurs from a runaway engine?

I was considering buying a 96 Passat TDI that had a run away condition. The owner told me what happened and said when the engine stopped running there was no reading on the dipstick. He says it will start and run but doesn't want to let it run very long for me to see. My question is;what damage possibly occurred since the motor ran at a high rpm until it stopped? I think there would be engine damage even though it may still run.Any thoughts would be appreciated.

I'm no expert ,but you will need an engine rebuild. Any engine that runs dry will have some major damage. How much will be determined after testing and break down to take a look. Price will be everything in considering the challenges.

It really depends. If it still will start and run, that's a good thing. I'd fill it up with oil, and see how it is behaving.

But the question remains as to why it ran away in the first place.

I've had some that were just from excessive blowby and/or driving too easy for too long, I've had some from a bad turbo, I even had one blow an engine to pieces when the injection pump stuck internally, (literally threw chunks of rod/piston out 3 sides of the block), and I had no idea what the cause was until the used engine I installed (with the existing pump) blew up after about 12 seconds (bent 3 rods, scored all 4 pistons).

When my '91 started running away from excessive blowby (broken ring) it never really did any damage, just a few brief smokey spurts on the highway. And when a 52hp diesel runs away, it really isn't the pants-browning event like in a 90hp TDI. It just momentarily felt like a healthy TDI.

If there's any way to run a compression test you'll be much wiser.

Generally it's not the RPMs that are the issue during a runaway... it's the slugs of liquid oil the turbo bearing pukes into the intake manifold... if in fact it was a failing turbo that caused the runaway.

Unfortunately if the dipstick was empty when he stopped the engine that points in the direction of turbo failure and the potential for bent rods.

The owner ran a post on tdiclub that the car was sold.I was afraid to take a chance on it considering major engine damage. Run away engine that didn't quit running until it ran out of oil. Even though the engine would start and run afterwards.

Hi all,

Today I had a 'pants-browning', as described above, runaway on my 03 ALH.

I towed it back to my place; I had disconnected the air pipe from the turbo to the intercooler, and it puked some oil, and more after I got home. About twelve hours later, I checked the dipstick and it comes out dry.

At the time, I pulled the fuel lines, and it died about a minute afterwards. I thought I had successfully averted total runaway and seizure, but after seeing the dipstick, I fear the worst.

So what are my first next steps? I'm seeing here I should do a compression test. What should I be looking for in that test, just that everything's normal?

Obviously my turbo is toast, and the intercooler needs to be totally cleaned.

But it sounds like I need to pull the head... Right? :-/

Thanks in advance...

a 1981 diesel rabbit was given to me after this sort of thing happened and no problem drove it 20k before selling it but my 2003 jetta was another story it completely destroyed the motor guts hanging out of the oil pan

Right on, thanks. Should I investigate the engine top-down, through the cams, or bottom - up, through the oil pan? There's no catastrophic damage in the sense that nothing went through the block...

Mapachurro said:

...I'm seeing here I should do a compression test. What should I be looking for in that test, just that everything's normal?

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You want to make sure everything is in the normal range, but probably even more important, you want to make sure that all 4 cylinders have similar compression readings. Cylinders considerably lower than the others could indicate one (or more) bent rods. This has to be handled from below not from the top.

Have Fun!

Don

JSWTDI09 said:

This has to be handled from below not from the top.

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^in the case of your post. you ll start at the top and take care of this from the botom.

you are probably going to have oil in oil pan, just not enough to show up on dipstick-1:.
what caused run away, did engine take oil in the intake until in was low, or you didnt check oil level and now it came to that, and perhaps with low oil pressure it sucked oil past the rings into intake?
the first cause may seem you failed to check oil level in the first place. /or you didnt notice oil loss at any rate until you got into your runaway condition.
-your turbos gonna be toast. you can disconnect intake pipe to turbo and spin (a little) by hand and see how bad it is. if its ok and spins freely(it wont) dont turn it much, you dont have oil in there.

The cause is a cheap Chinese CHRA and probably my non-expert installation of same. So I'm already planning on getting a used BEW VNT-17 for the upgrade... if the engine survived, that is.

I've been putting off cleaning out the intercooler properly for about six months now, so this seems to be a case of initiating the runaway with the intercooler oil, and continuing through the turbo.

The last thing I did with the car before this was an oil change with about 4 liters of nice new castroil... So at least I know I was burning clean oil :-D

Thanks for the advice everybody. I'll update when I make meaningful progress.

when was the last time you checked your oil level? once a week is the bare minimum.
sounds like you need to pull apart the top, the bottom among other things, just about everything.?.
perhaps a complete new or working long block would be both easier and cheaper. that is after checking how far gone yours currently is.?.

Mapachurro said:

The last thing I did with the car before this was an oil change with about 4 liters of nice new castroil... So at least I know I was burning clean oil

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isnt 4.5 quarts of oil bare minimum for these cars, perhaps 5Qts, or as much as 5.5Qts? (-depending). 4 liters sounds waaay short on amount of added oil.

On 1Z/AHU a crankcase fill takes 4.75 quarts.

Steve

Hey everyone,

So I did my compression test, and it came out kosher, so I put a BEW turbo on my 03 ALH post-runaway...

And it started and was glorious. And then it stopped...

Help! Video here:

https://youtu.be/BeSm2KQz_Fs

Engine is seized. This is from starving the oil system. A compression test is only going to tell you that your rings are not leaking. What was the PSI, should be WAY HIGH. like 400-500 PSI unlike a gas, unless i have that data wrong, someone here can correct me but last i knew it was 400-500psi.
What i do know is that if you starve a engine that is reving up like that during a runaway, you are going to rob the main bearings of oil. in a nut shell you should have pulled the oil pan and the connecting rod caps and measured and inspected the bearings same with the mains. Then pulled the cam and inspect the lifters and pull the oil filter and inspect the filter for metal. Use an old can opener to open the filter and inspect. im 99.9% sure you have an engine that is sized and that was trash to start with and the turbo was a waste of money. I hope i am wrong. You need to pull the oil pan before you do ANYTHING ELSE. PERIOD.

Right on, thank you for the prompt and detailed response. What weirds me out is the battery light that switches on when I try to start it, and the only code it's throwing is P0113. So I just wonder if there's an electrical problem of some kind -- though, of course, a seized engine would explain it too...

Oh and the compression was like 470-510.

p0113 is intake air temp. Dont think this is the issue lol. Pull the pan, valve cover and try and rotate it by hand at the crank bolt if you can. You can pull the glowplugs to relive the compression to help. You can try to put a few drops of motor oil down the glow plug holes to help lub it up to try and get it to turn. If you can get it to turn no problem than the starter might have bound up or something. I would not crank it any other way other than by hand until you have it sorted. Maybe a valve dropped into the engine, maybe its just seized. My hunch is that its seized due to oil caking up on the rings and not letting any lubrication happen. it does not sound like you ran it dead out of oil but at high rpm's if your lacking oil flow to the squirters than your going to have a bad time um'k. You might be lucky and you might have a healthy system other than a few things. If your having issues hand turning the crank then take off and label the orientation and position of each rod cap and try and push up the rod and piston by hand. If thats a no go then your pulling the head off. You should by this point see whats wrong. If it is seized the best case here is the crank is ok and you need to install new rod bearings, piston rings and do a dingle berry hone (brush hone) *light. Clean up the ring galleries and put it all back together. I would at that point use a plastigauge and a bore gauge and micrometer calipers to see what shape the bore and crank are in. Worst case, its completely buggered. there is a member here *jeff who sells used engines for cheep. Defiantly open up the oil filter and check for debris. if you find any, the oil pump is shot and probably more. Keep us posted.

TLDR version. take it apart and you should find whats stuck and buggered

Mapachurro said:

Right on, thank you for the prompt and detailed response. What weirds me out is the battery light that switches on when I try to start it, and the only code it's throwing is P0113. So I just wonder if there's an electrical problem of some kind -- though, of course, a seized engine would explain it too...

Oh and the compression was like 470-510.

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See if you can turn the engine over by hand from the crank bolt. If you can, it's not seized. Then look at Whitedog's no start thread and go from there.

http://forums.tdiclub.com/showthread.php?t=199398

Mapachurro said:

What weirds me out is the battery light that switches on when I try to start it,

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The battery light will come on whenever the key is ON *and* the alternator is not turning fast enough to charge the battery.

For instance, while the engine is being turned over during a start.

Or if it's jammed and not turning over at all.