Timing belt event

[drucifer]

About a month ago I had a timing belt event. The car lost power on the highway. I pulled over and got it towed to a mechanic I've worked with in the past but this is his first tdi a bew wagon. Things that were found
Cam sensor not communicating to ecu
Lower timing cover full of
oil
Cam and crank seal leaking
Egr and intake full of gelatinous oil.
1.5 to 2 quarts low on oil
14 teeth missing on belt
14 teeth separated

Here's what was done
Cam sensor replaced
Oil cleaned out of timing cover
Belt replaced
Cam and crank seal replaced.
No oil in the intercooler
Torsion is at zero
Compression 550 -600
Current miles 350k

Previous work about 30k ago
TB job
Frank 06 Cam
Vnt17
RC 1+ and immobilizer delete and egr turned down

Currently the car runs great so there is no reason to question that the torsion is actually 0.

My questions are
How did the oil get in the intake?
Is the egr tune contributing to the oily build up?
A couple months ago an egr cooler tube was cracked causing intermittent limp mode. The cooler was replaced and fixed the limp mode.

Thoughts?

 

[Mozambiquer]

Wait, so he didn't pull the head and fix the bent valves? Don't run it if so!

 

[drucifer]

Car runs well. Great power. Pulling off the head and checking does not seem economically feasible. I'm not interested in getting another head. If compression was bad after putting on a new belt I would have moved on to another car.

 

[Mozambiquer]

Car runs well. Great power. Pulling off the head and checking does not seem economically feasible. I'm not interested in getting another head. If compression was bad after putting on a new belt I would have moved on to another car.

Ok, well be prepared for a new engine when the valve breaks and smashes into your piston. If it doesn't seem economically feasible to pull the head and replace the smashed valves and lifters. If you don't, the lifters and cam will fail, and the damaged valve(s) will fall into the cylinder and kill the engine. I cannot count how many times I've seen that happen. Right now it's cheaper to fix than if you let it go.

 

[pedroYUL]

x2

 

[AndyBees]

This is a long story made very short. Similar circumstances with an ALH engine in a NB that belonged to a good friend of mine. The belt snapped driving along at 45 mph. He only installed a new belt. Just over 1100 miles later the engine quit. Two lifters were destroyed. A new Rebuilt head from Frank fixed it.

Here is a similar story about a used 03 Jetta my brother bought in 2009 from a place on the trusted mechanics list ......... about 2700 miles after he purchased it, a lifter gave way! They later admitted to him that they bought the car at auction and it was actually pushed thru. They obviously put a new Timing Belt on it and put it up for sale. I have a load of photos in my gallery of what I found.

Anyway, I agree 100% with what the other guys are saying!

However, you never said if the 14 teeth were all stripped off in one section or not. I assume that's the case. If so, there is zero doubt that at least one Exhaust Valve made contact really hard with it's piston. No, it is likely not bent as the compression numbers tell that story. But, the valve(s) is damaged and likely to break. And, you can bet the farm that the Lifter has spider-web cracks on top of it. Also, at 350k miles, it is highly likely the other Lifters are worn as well as the Cam. This past summer I replaced the Cam in an 06 Jetta with the BRM engine. Every lifter was worn really bad with about the same miles as yours. The BEW Cam is the same as the BRM relatively to fitment and that's what the guy had me install.

 

[Windex]

At the vey least pull the valve cover and inspect the tops of the lifters for very fine spider cracks. If there are any cracks there (with 14 teeth gone, this is assured) then valves hit pistons, and the above mentioned pending carnage is about to happen.

Re&Re head now... Or entire long block later. Your choice.

 

[drucifer]

Windex,
No cracking spider or otherwise.

 

[2004LB7]

I had my timing belt jump one tooth off and the valves hit. no other visible damage anywhere else that could be seen. only when I pulled the head was I able to see the marks on the piston. if I'm not mistaken, seven of the sixteen valves needed replacement

 

[AndyBees]

I suppose sometimes we just go with what's going to happen next if the OP does this or doesn't do that. (I highly doubt the pistons are damaged.)

Maybe we should ask why did the TB strip off 14 teeth. This is a BEW engine ...... big wide belt! Down below, I'll post a photo of a TB event I had on my ALH in May, 2017.

I assume you feel quite confident that the TB was in fact new, a complete TB job, including everything that touches the Timing Belt. If so, why would a new TB with only 30k miles on it strip off teeth? Was it the oil from the Cam and Crankshaft seals? Probably since oil and diesel fuel are two chemicals that will eventually destroy a TB. But, how long does it take oil to damage a TB? Surely it didn't take only 30k miles. If so, that means the oil leak was there from the beginning. However, you would have noticed a leak on the driveway and definitely on the dip stick.

I'm confused that no oil was in the Inter Cooler.... I've never seen an Inter Cooler on an MK4 TDI that didn't have oil in it. Do BEW engines have run-a-ways? I've never heard of one. (thinking Turbo Pressure blew out the oil).

So, why would the Cam and Crankshaft seals be leaking? Were they not changed out when the TB job was done 30k miles earlier. At 320k miles, they were definitely no longer spring chickens. Was it a mistake to not replace them?

I'm not sure what oil in the Intake means. Was the Intake just oily on the inside? If so, that's normal. Oil mist from the PCV system alone will coat everything from it's entry point to the Intake Valves. Also, all Turbos ooze some oil past the expansion seals. So, that's why I am a bit surprised there was no oil in the Inter Cooler (assuming a stock cooler sitting in the normal upright position).

I'm not sure what an EGR Tune is or how it suppose to perform. With the ALH engine, it is possible to do a mod that reduces the amount of time the EGR is in cycle (allowing exhaust gas into the Intake).. I suspect that's the same with the BEW engine EGR. Soot from the exhaust and oil will make a gooey mess in the EGR and can eventually build-up in the Intake.

Back to the Timing Belt stripped teeth. I want to think something catastrophic happened. Why? Old belt? Oil damaged old belt? Was it just an old belt left in place? Seems the seals were not changed or someone sure done a botched job changing them. Belts with 150 miles on them look dam good but are nothing but a time-bomb.

Below is a pic of the trashed TB on the ALH engine in my Vanagon. The water pump locked up tight (zero movement). I was lucky to have caught the incident when I did. The TB had at least 50k miles on it. The WP was likely original at about 180k miles. Anyway, the TB did not (DID NOT) jump time ........... (Side note: I actually started the engine to move the Van farther off the road while I waited for the tow)

 

[drucifer]

Thanks Andy for getting to the oil situation. I believe the oil was the culprit of the teeth taking their leave. There was only enough oil in the intercooler to get some on the self tapper threads I installed at the low point. I think there is something to it about the reduced egr gasses circulating and the ccv or pcv causing the gooey oil.

Could oil ruin the cam sensor causing the loss of power?.

There were no oil leaks on the ground but back of engine was always wet. Seemed like a lot for a new vc gasket. Engine side of the skid plate fairly messy. Dip stick was low after a month or so.

Ptfe seal used on cam. Old style on there now.

TB kit and cam kit provided by Frank06

 

[jmodge]

FWIW, I once found Donna's ALH belt saturated with oil at 40,000 miles, There was a stretch she hit 3 deer and found at least one giant pothole, So I don't know how long it had been wet because it seems I was always chasing trauma leaks in that car constantly. But the belt and timing cavity was very wet.
Anyway, I replaced the front crank seal, cleaned the belt with soap and water and put it back in. So now I started watching the belt. It ended up wet again, but the lower cavity was dry this time. The seal behind the IP pulley was leaking. Replaced the pump, cleaned the belt again, and went a grand total of 107,000 miles with that timing set.
So, maybe, but count me as skeptical also that belt failed @ 30k because of oil. It didn't bother me to clean that belt and put 107k on it, but I think If your belt failure happened to me, I would definitely want to pull the head and look for valve contact on the pistons. Or have another engine or car ready. I pretty much live a charmed life, but even I draw the line occasionally.

 

[AndyBees]

My first VW Diesel was a 1980 Rabbit with the little 1.5 engine. Obviously back in those days there was no Internet and I had not heard of a Bentley Manual. I purchased it from a guy one month after he bought it from the dealer. It had 1950 miles on it. (the dealer paper mats were still on the floor)

Anyway, I changed the first TB at 110k miles. Then, when the 2nd belt was approaching about 90k miles I was doing some maintenance and had the cover off the TB. I spilled diesel fuel on it while changing the fuel filter. I had assumed the 2nd belt would go beyond 100k too. Well, one day I was zooming along about 70 mph and was approaching a major three way intersection with a traffic light. About 200 yards away I could see the light was red. I kicked the transmission in neutral and let up on the accelerator at the same time ........ snap went the belt. It was a bit down hill, so, i was lucky to coast thru the light and make an immediate right turn into a service station lot. If I remember correctly, that little 1.5 engine spins at or above 4000 RPMs at 70 mph with the short geared 4-speed.

Did the diesel fuel cause the catastrophic failure? Did the sudden reduction of the accelerator with no load on the engine cause it? Or, was in a combo of those two probables as well as beyond the rated life of the belt? I don't know, but from that point on, 80k for all TBs until I purchased my first TDI ....... 100k-105k and pop off the cover to inspect for contamination as well as critter invasion every time I change the fuel filter.

I have a 1984 Jetta with the 1.6 engine. I was driving it when I purchased my first TDI. Anyway, just to make sure everything stayed lubed up, I started the engine about once every three months. Well, one day last spring, while it was idling the TB snapped ! ........hmmm .. maybe a critter got in there chewing.