Blown injectors or burned up valves?

Hey guys, my car broke again. I have started troubleshooting but don't know what to do next.

I drive a 2002 Jetta TDI with 380,000 miles on it. I do most of the maintenance and repairs myself. We will find out if that is a good thing or not

Short version: I think the engine was starved of fuel and broke stuff. Please help!

(Skip to the bottom for the questions if you don't want to read the story)

Long Story:

I filled up while on a trip. 34 miles later I started getting black smoke and loosing power. I pulled off at the first exit and checked all fluids. Everything checked out. I pulled out my VAG-COM and computer and checked my timing (within spec) and also not showing any codes.

I limped it 5 miles to the next town and it kept getting worse. Now I realize I really should have just stayed on the side of the road but at the time I didn't realize how bad it was going to get. By the time I got to the shop I was doing 20 MPH with the pedal on the floor, it was running super rough and a fair amount of white smoke. The smoke appeared to be white diesel smoke and not oil smoke. I got to a shop but he was too busy to help so I did some troubleshooting myself. Checked all vacuum lines, actuators, and solenoids. All appeared fine. Only one engine code for under boost. It didn't come back when I cleared it.

At this point the engine was running very rough and misfiring. I called it a day and got a rental car for the 400 miles back home. A couple weeks later I managed to tow it back home again.
I suspected the gas I had purchased so I called the station (well know large chain). They responded promptly and investigate. They had not other complaints and their sensors said that here was nothing wrong with the fuel.
So I started troubleshooting.

First thing was the fuel, so I hooked up some clear lines to the injector pump and primed and ran the engine on some fresh diesel from a place down the road. the engine immediately ran differently. Much more stable but still loud and rough. At this point I was able to hear a clacking sound that I am not sure what it is. Also go an engine code for misfire on cylinder 2. Deduction: fuel or fuel supply was part of the issue.

The next thing I did was tear open the fuel filter. It was quite new as I recently replaced it. There was a fair amount of waxy residue in the filter, not a massive amount but enough to probably clog it. So fuel supply may have been severely inhibited. At the time I was running a summer additive, not a winterizer additive (I live in Texas).

Next thing I tried was running some LM Diesel Purge to see if that would help any. It smoothed the engine out some, but not much. Still loud, running rough, lots of smoke, low power, clacking/ticking/banging sound coming from the engine block. Using a long screwdriver I listened at the injectors and it sounds like there is a physical problem inside the block.

Here is where I hope your wisdom and experience can help point me in the right direction. Also, if there is a thread that I missed, I apologize and please just point me at it and I will go there.

- Can running an engine lean raise EGTs high enough to burn up the valves or pistons?
- How can I test if the valves are shot?
- What else can I test?

I am afraid I may have totaled it this time.

Any advice is appreciated!

Thanks,
Clevenger

Assuming you checked the Anti-Sudder Valve, I'd take off the valve cover to inspect the Cam and Followers. If one of the Intake cam lobes and follower have worn out to the point that the valve is not opening, this may explain the rough running, smoke, etc. key word "may."

Lean fuel would result in slow engine. Fuel and air is what the diesel lives on. Cut back the fuel and the engine slows down. Cut back the air and normal fueling, engine will smoke white and be low on power.

Any time you let up on the accelerator, the fuel is shut-off, regardless of engine speed... down to idle (903 RPMs).

I did check the ASV. It was wide open while running.

I recently had the valve cover off when I was changing my timing belt. That was about 1000 miles ago. I did not see any unusual wear on the lobes, it looked like they had worn through the surface finish toward the edges, but they were smooth to the touch and I didn't see anything that stood out. I can look again though.

Before starting to troubleshoot, I started the car and while it did run, there was no throttle response at all. I could mash the padal to the floor and the RPM would remain constant. That feature went away when I was feeding it fuel directly.

Clevenger - I don't believe you have a a fuel problem. It is impossible to run a diesel "lean" - they run over 100:1 AFR at idle and light load conditions so you can scratch that off your list of possible issues.

AndyBees has a good suggestion to pull a valve cover and inspect the cam/lifters. If those check out good - pull a lower intercooler pipe and see if you get a lot of oil out of it. Might have a blown oil seal on the turbo. Engine oil smokes white out the exhaust.

Third thing to try is pull the injectors (in pairs - leave 2 in the engine). Start with a visual inspection of the tips (are they still there - do they look the same?). Reconnect the injectors to the tubes, but rolled back so they're pointing in the air outside of the engine. Crank/start the engine - do they spray well? Repeat for the other 2 injectors.

Did it run ok on the IV setup for the purge or was it still rough? I ask because there’s a ball valve in the tank pickup that sometimes causes fueling issues, you can drill it out.

That is a really good point about the throttle cutting off fuel. I know EGT is a complex subject. Is there a way that the air/fuel ratio can damage the engine?

Another piece of information that may be important. One of the things I had to do to limp to the shop was disconnect the turbo return. I had pulled the flexible tube off while on the side of the road to check the ASV and EGR valves and I noticed that it ran better when it the turbo was disconnected. So I left it disconnected for the final mile. Later during testing when I would reconnect the turbo, it would begin misfiring and running even worse. The Turbo appeared to be running fine though.

I didn't see the above two posts before my latest response. Sorry.

Fix_Until_Broke - I checked the inter-cooler and I only had a couple of drops of oil come out of it. The turbo spools normally and sounds right. I can pull injectors on monday and test them out. Is this kind of failure normal for injectors?

KyleMillione - It ran pretty rough even on pure Diesel Purge. When increasing RPM it shook really bad around 2200 rpm and sounded like there was a mechanical clacking sound in the engine.

Thank you guys and AndyBees for your quick responses!!

It might be safer to start with a compression test. A mechanical clacking is never good.

Did you check the timing belt/tensioner?

Be very careful testing the injectors as described above. The diesel is exiting the nozzles with enough pressure to penetrate your skin and be injected into your blood. It can kill you.



Which flexible tube did you have off? The one on the EGR valve or the one going to the hard plastic tube that goes to the turbo?

Nasty mechanical noises are never good. I'd check the mechanical timing and everything under the timing belt cover first. If you have a problem there you may as well stop screwing around as you've got plenty of work in front of you.

A serious misfire could POTENTIALLY be one injector that's not working at all, but how that happened and what collateral damage it did is where things get tricky. R&R on the injectors isn't hard but does require new copper sealing washers and a cleanout of the bores or they may not seal properly. If there's a tip missing or similar it should be instantly obvious on inspection and that's entirely possible. However, if there's a tip missing the tip went SOMEWHERE, and the "somewhere" often does cylinder, valve or turbo damage on the way out. As noted just above be very, very careful about having injectors fire out of the engine -- the pressures involved are VERY high and if you manage to have the spray penetrate your skin (yes, it's easy to have it happen) it can cost you a finger or, in an extreme circumstance, your life.

Where in Texas are you located?

I dont want to appear too critical here but you have a high mileage car and by your own admission you might not be the best mechanic out there. You say you changed your timing belt 1000 miles ago........ your symptoms to me sound like skipped timing. Have your timing checked by an experienced guru.

Like the ideas to check compression, evaluate valve train. Also possible the IP is busted.

A bad injector tip will let it overfuel and cause very poor running with stumbling. The clacking noise might be due to the misfire. All this could be related to a leaking valve.

Getting a compression test and/or leakdown test is needed. You need to also investigate for physical damage in the valve train as been recommended.

miningman said:

I dont want to appear too critical here but you have a high mileage car and by your own admission you might not be the best mechanic out there. You say you changed your timing belt 1000 miles ago........ your symptoms to me sound like skipped timing. Have your timing checked by an experienced guru.

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Could the cam sprocket have slipped on the cam?

I'd second to check the timing and make sure the cam and crank are still in time...that'd take 30 minutes and gets you some hard facts and a starting point...and you should have the cam lock tool if you did your own timing belt

Sent from my Pixel XL using Tapatalk

You can get a bore scope for almost nothing from Amazon or Walmart. That would give you a picture of the condition of the tops of the pistons and if anything broke off in there. Probably not a good idea to crank it too much before figuring out more. Pull the timing belt cover and look for something that may have fallen off.


How was the car running between the timing belt job and this failure?

Thank you for all the suggestions!

Concerning the injector testing: If I test them out of the engine like that I will be very careful! I have a healthy respect for 2000+ psi fluids.

Click Here for a YouTube video of what the engine sounds like right now.

jokila – I am in Greenville TX. Northeast from Dallas by 45 minutes.

miningman – Don’t worry about being critical. Just because I tried to do a semi-advanced repair myself, doesn’t automatically mean I get a trophy and everything works out in the end. If I screwed it up, then I screwed it up. It sucks, but it happens sometimes. I appreciate the advice

flashmayo – I have a borescope ready for when the cylinders are open. I will upload pictures as soon as I get to that point. The engine was running perfectly after the timing job. I was getting 38 MPG on the highway (which is exactly what I have been getting for the past 4 years). It was actually running slightly smoother than before the belt job. I set the timing to be in the top third between the center line and the top line per normal procedure. It smoked a little less. There were no symptoms that anything was wrong until I started seeing first black smoke, then white smoke while going down the highway.

Based on the comments, it looks like things have shifted towards something being wrong with timing or injectors. I have ordered a diesel compression tester and will proceed with troubleshooting as follows:
-Remove timing belt cover and check tensioner, pulleys, hardware, etc.
-Remove valve cover and check TDC on CAM, IP, and flywheel to see if they still match.
-Compression test when the tester arrives.

And then based on the results possibly proceed with injector test or leakdown test.

Thank you guys so much for your help. Sounds like a good place to start. I will keep you updated with progress. If it is timing, maybe I can learn something and save other people from making the same mistakes!

That doesn't sound too scary- definitely not right but not the sounds if imminent death from my speakers. Use a hard handled screwdriver as a stethoscope and see if you can pinpoint the noise. You could also crack injection lines loose at the injectors one at a time and see if the noise goes away when one cylinder is not firing.



I noticed the backside of your injection pump is very wet, was that just from hooking up the test jug of fuel?

Alright. We have made real progress now!! And I have lots of gory pictures

blow_your_money - The sound was not imminent death. It was death has already occurred sound The pump was wet with diesel spilled during the process of priming and running the pump on fresh diesel from a jar. I actually had to push the car out and clean up the floor because of how strong the garage was smelling.

We pulled the timing belt cover and inspected the tensioner. The tensioner marks lined up as they should. The belt is healthy and taut.

Next we pulled the valve cover and vacuum pump off, and were met with mechanical carnage.





It appears that one of the cylinder #2 lifters exploded. There are pieces of lifter and disintegrated spring everywhere.

At this point I accept that the engine is most likely a total loss. Now I want to understand what happened so that I can avoid it next time and maybe help prevent other people from making the same mistakes. Or maybe it was an unrelated problem. I would like to know what you guys think happened.

Even though the engine is done, I decided to rotate the engine to TDC and check timing anyway to satisfy my curiosity. I rotated the cam until the cam was TDC and then used a mirror to line up the alignment hole on the IP. The IP and Crankshaft were in time with each other, but the cam was no longer in time. (I am sorry the pictures of the cam shaft end are upside down. Not sure why that is the case)





At this point I noticed that there was some serious wear on the coupling between the camshaft and the vacuum pump.





I have had the vacuum pump off before, and I know that wear was not present when re-assembling after the timing belt job. The engine has about one hour of run time since it broke down. I wonder if this damage happened before or after the blown lifter.

I tried to get my bore scope into an injector hole, but the diameter of the hole was a little to small, so all I got were blurry pictures of grime and nothing useful.

So now my questions are:

- What do you guys think the order of failure was? And what caused it?
- Is it possible that a lifter failed and knocked the timing off while shredding the head? There is a lot of damage and one huge gouge just under one of the cam lobes.

Don't worry about being critical of my work. If I screwed up, I need to know it!

Thanks for all the help and advice!! Let me know what other pictures you want and what else I could check.

Thanks,
Clevenger

Not sure if you've seen this thread or not but you might find it useful.

http://forums.tdiclub.com/showthread.php?t=493019

With any luck only the head is damaged and that may well be repairable.
You'll know more after removing the head and checking the piston protrusion.

....
"The IP and Crankshaft were in time with each other, but the cam was no longer in time."

maxmoo said:

Could the cam sprocket have slipped on the cam?

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Have no idea if this is it but I read that on your 3rd timing belt replacement, replace the camshaft sprocket. That the taper doesn't grip the cam and may slip. Forget where I read it and can't find it right now.

burn_your_money said:

Not sure if you've seen this thread or not but you might find it useful.

http://forums.tdiclub.com/showthread.php?t=493019

Click to expand...

That's my thread. But, my cam did not lose time, where it appears Clevenger's did, so I didn't have possible valve/piston contact.


Clevenger,
My car ran with an obvious misfire when the lifter failure occurred, but I was able to drive about 10 miles home at highway speeds. Whereas my damage was limited to the top end, you may have additional bottom end damage. After you remove the head, you'll want to check piston protusion to see if you have any bent rods.

You have a few options if you don't have a bent rods... Brand new head. Salvage head, just throw it in. Salvage head, have a valve job done on it before putting it in. Have your own head repaired and valve job done. If you have bent some rods, though, you've got more to work to do.

For anyone listening, I recommend putting in a new cam and set of lifters as a part of a 300,000 mile maintenance. This lifter gave way at 380,000 miles, mine went at 350,000. It's only about $200, and at 300,000 miles presumably you're doing a timing belt already, so you've got the valve cover and cam sprocket off anyway.
Brett

03TDICommuter said:

Have no idea if this is it but I read that on your 3rd timing belt replacement, replace the camshaft sprocket. That the taper doesn't grip the cam and may slip. Forget where I read it and can't find it right now.

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Found it on IDparts website

Other Things To Consider
As the ALH engines increase in miles we have seen a few cases of camshaft sprockets that have developed fatigue cracks on the inside where it mates to the camshaft. If the sprocket is fatigued it may not be able to hold the friction fit to the taper of the camshaft and may slip, causing valve-piston contact. If you are at or above 300k miles we strongly recommend purchasing a new camshaft sprocket as well.

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The tail damage on that cam strongly suggests the vacuum pump seized, resulting in the slippage on the cam and subsequent destruction of the lifter due to piston/valve contact.

That's not "wear"; the vacuum pump tang jumped under (heavy) load, and the only way I can see that happening is if the pump seized, which would effectively attempt to lock the camshaft from rotating.

The cam and lifter in question are destroyed and piston/valve contact obviously occurred. The head has to come off; there's a decent chance one or more rods are bent but you won't know until you remove the head and check protrusion. If the pistons and rods prove up ok then I'd send the head out and replace the vacuum pump and cam sprocket (which likely had its taper bore damaged by the forced slippage under load.) If not then I'd source a replacement engine; while you CAN fix bent rods and/or damaged pistons (assuming the bores are ok) the cost is likely high enough, especially at this mileage, that a running used replacement engine is cheaper considering that you would need a timing belt kit in any event as well (and it's much easier to do the timing belt with the engine out of the car!)

Genesis said:

The tail damage on that cam strongly suggests the vacuum pump seized, resulting in the slippage on the cam and subsequent destruction of the lifter due to piston/valve contact.

That's not "wear"; the vacuum pump tang jumped under (heavy) load, and the only way I can see that happening is if the pump seized, which would effectively attempt to lock the camshaft from rotating.

Click to expand...

That's a good point. I'd like to see the vacuum pump opened up.
Brett

To be sure, I'd dissect the vacuum pump to see if it did in fact lock-up.

I tend to agree with Genesis diagnosis. However, that valve looks like it may be an Exhaust Valve, assuming that is #2 cylinder as indicted by the OP. Thus, if the Cam is in fact out of time enough to hit one Exhaust Valve the other three should have damage too. As I hold my LapTop upside down to view the end of the Cam, it looks to be out of time by about 2 teeth and no more than 3. I don't think there will be valve to piston contact being off by 2 teeth but certainly at 3 teeth.

A lifter giving up could explain the Cam being out of time (slipping in the Cog taper). But, that does not explain the Vacuum Pump gouging on the other end.

So, again, I tend to go with Genesis' assessment.

Well, he says he's out of time; he TDC'd the engine and the slot on the cam is NOT horizontal. So it's fairly obvious the cam timing did indeed slip at the nose, and since the crank and IP are in-time the belt did not strip (he also didn't find stripped teeth.)

The remaining question is WHY did the cam slip on the sprocket? The possibilities are:

1. A valve or lifter locked up hard enough to prevent rotation of the cam.

2. The sprocket slipped due to being incorrectly torqued or it, or the nose, was damaged or not assembled clean, and as a result did not have the required holding force on the taper.

3. Something jammed the cam from rotating on the other end. That "something" would be the vacuum pump.

There is evidence of #3. #2 is very hard to prove after the fact. #1 leaves evidence everywhere and pieces of lifter could do it in the right circumstances, but there's no way for said pieces to get into the vacuum pump area beyond the last cam journal and result in that sort of damage. It takes a LOT of force to deform a notched shaft drive like that.