BRM Cam Failure again?

BRM Cam Failure again?update Broken exhaust valve now

So a little about my situation. 06 Jetta TDI BRM 237000 miles

Bought the car in 2012 with 162000 on it and was told that the EGR had been replaced and that the cam and lifters looked ok but to keep an eye on it and that the TB was just changed and had receipts to show it. Got the car home and notices the burping sound coming from the intake. tell tale sign of a bad cam. So I opened up the engine cover and sure enough needed a new cam. No big deal I enjoy working on things. Called around and nobody had a Colt Cam available so I went against my better judgment and purchased an Oem one from KERMA TDI with all new lifters and everything that is supposed to be replaced. Installed it and ran great.

Fast forward to today and going home yesterday from work and the car just all of the sudden felt like it dropped a cylinder. It could barely keep speed and you could def tell it was having a hard time running. I limp it home another mile and park in the driveway pop the hood and listen to see what is going on. I have had the hissing EGR for about 5000 miles but have just been pushing it to the side for a while now and hoping that is not the issue. Anyways pull the engine cover and number 1 lobe is pretty worn down. Cant see if there is a hole in the cap but the chamfered edge is def gone on the lobe. Plug VCDS in and it states P0303 Cylinder 1 Misfire. The car now has 236000 on it. I have been running Rotella t6 the whole time.

So my question is it possible to burn through an OEM cam in 70,000 miles and if so is it possible to make the vehicle run so badly that it really has a hard time moving under its own power? Or should I be looking into a possible injector failure although uncommon on these engines?

Also a notable mention is I had a water pump lock up on me and partially shred the timing belt approx. 10000 miles ago. It never jumped timing but is at least worth mentioning.

That genuine VW cam was bought about 5 years ago. That's not terrible service life from a part but of course we want better. And can do better. The downside of the colts being so popular is that they are often hard to keep in stock. And when you need a cam, you need a cam. You need to do what you need to do to get back on the road.

It's probably worth reiterating, the problem with the OEM cam remains the initial steep ramp rate. It's been compared to a solid lifer cam using hydraulic followers. This encourages the cams to wear out along with the followers. This problem persists in any replacement cams that use the OEM lobe shape. Even if the OEM-style cams are made of "billet", the underlying problem remains as long as the OEM shape remains.

Aftermarket cams from "billet" blanks offer benefits beyond the materials. While the improved materials do help, that is not the main purpose of using a "billet" cam. Starting fresh allows the use of designs that can't be realized from regrinding existing cams. Billet allows substantially more latitude for fixing the flawed factory design to achieve better functional durability.

Billet cams that do not modify the OEM profile to solve this problem are not gaining any benefit from the use of "billet" other than maybe a marketing advantage. If you are going to buy a billet cam with a factory profile, you are probably better off with a genuine VW cam, or an inexpensive aftermarket cam if saving money in the sort term is the top priority. Just remember that any cam with the factory profile carries the same risk of failing just like the factory cam, regardless of the material.

That said, factory cams are generally fine for a few years, as demonstrated by the OP above. Cam failures weren't a "thing" of any frequency until about 5 years after the cars were out, so you can probably expect similar service life from any aftermarket parts that use the factory design.

regarding the injectors: keep in mind that we are talking about a car that's more than 10 years old. While injector failures were rare "back in the day" they are starting to wear out. It's just a fact of life with anything mechanical, stuff eventually wears out. Quick and dirty check the of injectors health by observing the IQ at no load warm idle. Generally speaking if it's in the range of 6-7 or more they are showing wear. Of course the cam should be healthy for this test to be valid!

Pull the cam cover to be sure - no sense speculating on the condition of the cam unless you look at the lobes and the lifters.

So I pulled the cam last night and #1 intake and exhaust lobes have quite a bit of wear but not nearly as bad as the first time I changed the cam. When I changed it 70k ago I had a hole in the #4 lifter and it never ran this bad. The lines do have a pretty distinct flat spot on them. I ordered a new cam so I will put that in anyways but looking for what to look t next. I read some posts about the wiring harness for the injectors but mine seemed just as loose as all of the other ones. Any extra advice is appreciated.

I would think that if the harness connector came loose on one of your injectors, it would set an additional code showing high resistance across the injector coil - did you only have the misfire code?

If so, that would point toward the problem being mechanical - either a failure in the injector, bad compression etc.

Yes the cylinder 1 misfire was the only code displayed. And I am just grasping for straws here about the harness. I just read quite a few posts about injector harnesses coming loose or chafing. I just don't understand how it could go bad so quickly. I mean it was like someone turned on aswitch and it ran poorly. And didn't improve after shutting off and restarting.

Are you able to do a compression test to rule that out?

A poor-man's compression test can be done by disconnecting the injector harness at the side of the head and cranking the engine for a few revolutions. the engine will not start, but if the compression is even, the starting compression pulses should also be even, as the engine cranks, each compression stroke should be audible - Juh-juh-juh-juh-juh-juh-juh etc.

If every fourth pulse sounds different (usually high pitched) then you may have a compression issue on that cylinder.

If not, then the injector is suspect.

bad cam can cause a misfire code too

I will be doing a compression test tomorrow to narrow that down. And I understand that a bad cam may throw a misfire code but when I replaced the cam 70k ago it didn't run anything like it is now and it had just started to wear a hole in the cap surface.

Ok so put a new cam and lifters and still the same thing. Pulled the glow plugs and did a compression test and there is no compression on cylinder 1. So now what to do. Is it possible to check to see if a valve stem is bent without taking off the head? Can I use a little cam through the glow plug hole?

justintime_3 said:

So a little about my situation. 06 Jetta TDI BRM 237000 miles


Also a notable mention is I had a water pump lock up on me and partially shred the timing belt approx. 10000 miles ago. It never jumped timing but is at least worth mentioning.

Click to expand...

I'm wondering if this event caused any unnoticeable damage at that time that now has surfaced? Just a thought.

Yeah that is what I am curious of also. The thing is it never jumped timing though. Basically the water pump bearing blew out after running it empty. It starts to angle sideways and the water pump just ate some of the belt. I shut it off as soon as I heard it happening. When I got it home and started the timing belt everything was still aligned correctly. That's why it doesn't make sense.

You will not be able to insert a little cam through GP hole as it's too small.
Injector hole is exactly 7 mm, so you will need a 5.5 mm cam for that.

However, I doubt that the cam will reveal anything...

We already know... No compression. So we have the possibility of valves, a badly leaking head (Maybe cracked, but I suspect not.), or bad head gasket. If either, then you'll be dumping coolant into the oil sump or out the exhaust.

Then piston and rings. Very unlikely as these little engines are pretty robust.

My bet? Given the sound made you have a lifter/ valve problem. I think likely that your piston made unholy contact with a valve and either bent it, or pushed it right into the lifter. Either way it's time to pull the head.

nord said:

We already know... No compression. So we have the possibility of valves, a badly leaking head (Maybe cracked, but I suspect not.), or bad head gasket. If either, then you'll be dumping coolant into the oil sump or out the exhaust.

Then piston and rings. Very unlikely as these little engines are pretty robust.

My bet? Given the sound made you have a lifter/ valve problem. I think likely that your piston made unholy contact with a valve and either bent it, or pushed it right into the lifter. Either way it's time to pull the head.

Click to expand...

Ok thank you. I will say that I looked in the coolant tank and it looked like some oil haze floating on top but didn't really think much of it. It hasn't lost any coolant and the oil still looks pretty good. Not frothy or anything and the bumper has always turned black from exhaust since I purchased it. And you say that the valve may have pushed into the lifter. I just completed the cam and lifters and none of the lifters were holed or broken. Would there be noticeable damage to a lifter if it had contacted the piston?

Piston cannot touch the lifter, except with help of a valve. There may be a slight mark on the piston top if a valve interfered with its upward travel. Usually nothing more. IF this happened DO NOT even consider anything but replacement of the valve and a thorough head inspection.

Actually all this is beside the point. You can guess or you can know. You'll end up pulling the head and praying for as little damage as possible. Do not just strap the head back on because something is very wrong even though not terribly noticeable.

Once he head is off you'll further need to check for a bent rod. Again not usually an issue. Measure the other three at their max upward position and this should match.

Been there. Done that. My younger son "saved" lots of work and took his timing belt job to one of our local foreign car repair shops. A couple of days later a call that all was silent in front of the driver and the car was at the side of the road.

So to our shop and dear old dad, along with older brother breathed life back into the old girl. Head was trashed and we had it rebuilt. Other than that I think we must have done a pretty good job as he drove on for another 100k miles without a problem.

Quit guessing!

Ok so just an update to keep others informed possibly. So I got the head pulled off and sure enough I am missing a chunk out of the #1 exhaust valve but it is burnt black kind of like it has been that way for a while but who knows. My asv has major build up and so does #1 intake and exhaust. #4 also has some moisture in it but not nearly as bad as #1. I have had a failed EGR cooler for some time now and am wondering if that contributed to the valve breaking. Maybe pushing fluid into the intake? Who knows?

Anyways I am going to go ahead and replace the one valve and remove all of the valves clean them up real good and lap all of the valves and replace the valve seals. I know I should send it to Franko6 but I am hoping that I can fix this a little bit cheaper mainly because I have already purchased the new cam and lifters and Frank has said that the cam I got is really not worth using and would have to charge me for a new cam and lifters. I completely understand where he is coming from though. I am just having a hard time putting 2 grand into a car that may not last much longer.

I will also be deleting the failed egr while I am in this far. I checked turbo play and there is none so that's a plus. Also just something else to mention is that there has always been since I bought the car five years ago major soot buildup on the back of the car. The back of the car is always black. That is kind of the reasoning behind maybe replacing the valve seals. I know I should replace the valve guides also but its a last ditch effort to save some money. Any advice good or bad is welcome. Thanks to everyone on this forum.

Go buy a Honda. Seriously.

narongc73 said:

Go buy a Honda. Seriously.

Click to expand...

Great help. Thanks.