Strong diesel fumes in the cabin

I've just turned 300K miles (100K on the geared balance shaft) and have just noticed a very strong diesel exhaust smell in the cabin whenever the car is not moving. It starts immediately after I start the car and when I get out of the car I can also smell it coming from the engine compartment. There's no diesel leaking from what I can tell. No warning lights have come on. I don't have access to a diagnostic tool.
I'm getting ready to have the timing belt done and I'd like to give the mechanic some ideas on what to look for. Any thoughts?

tandem pump leak?

thundershorts said:

tandem pump leak?

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If that is the problem, it appears some people have had luck repairing their existing pump. With my kind of mileage, should I bother to try and repair it myself or should I just replace it?
I do plan on keeping the car for at least another 100K miles (about 3yrs).

replace if its leaking. its not in an easy spot to mess around with attempting to repair

sschnath said:

I've just turned 300K miles (100K on the geared balance shaft) and have just noticed a very strong diesel exhaust smell in the cabin whenever the car is not moving. It starts immediately after I start the car and when I get out of the car I can also smell it coming from the engine compartment. There's no diesel leaking from what I can tell. No warning lights have come on. I don't have access to a diagnostic tool.
I'm getting ready to have the timing belt done and I'd like to give the mechanic some ideas on what to look for. Any thoughts?

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If you're smelling exhaust, why are you looking for a fuel leak? Since you can also smell it in the engine compartment, you should check the EGR System, turbo, downpipe and cat for exhaust leaks. Just my $.02

1854sailor said:

If you're smelling exhaust, why are you looking for a fuel leak? Since you can also smell it in the engine compartment, you should check the EGR System, turbo, downpipe and cat for exhaust leaks. Just my $.02

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I thought a fuel leak might be possible if it was a small leak and smoldering on a hot part of the engine.

But it turns out that there's a hole in a pipe on the very top part of the engine. Very easy access. It's a hard, silver pipe but it has a little flex section built into it. The leak is right in the middle of the flex section. There's a small area of soot (my first clue) around the hole. I can feel warm air pulsing out of it and it's coming out with enough force that you can hear it too, so I assume it's related to exhaust or emissions.

It looks like I can replace it myself but I'm trying to identify the pipe online and not having much luck. I may have to stop into the dealer and have them order it for me.

That would most likely be your EGR pipe.

sschnath said:

It looks like I can replace it myself but I'm trying to identify the pipe online and not having much luck. I may have to stop into the dealer and have them order it for me.

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That would be the EGR Cooler Pipe. Give idparts or World Impex a call. Don't forget new gaskets. Good luck!

sschnath said:

I've just turned 300K miles (100K on the geared balance shaft)...............

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Nice! 300K miles....I feel like a pup with only 139K on ours...

EGR cooler pipe it is. No visual references to it anywhere on the web except for a used part on Ebay that I finally found but that confirmed it. Thanks for your assistance!

I'm not sure I'm going to have time to do the work myself this week, so I called the dealer to get their estimate on time to replace the EGR cooler pipe. They're claiming approx 90 mins. Unless there's more to this than it appears, it looks to be a 30 min job to me (unless unexpected problems arise).

I want to make sure I'm not oversimplifying this. Is this just a matter of unbolting the old pipe at each end and inserting the new pipe and gaskets? Can the old bolts be reused? Is there anything else I should be thinking about?

A bottle of coolant and a cold engine for two.

It is held on by 3 5mm or 6mm allen head bolts. the one over the turbo is a pain and IIRC need a ball end alen to get it loose.

The bottom coolant hose clamp is a pain to get to also. I would recommend draining the radiator first so coolant doesn't go everywhere when you take the hoses loose or maybe I should say a LOT of coolant. Youwill still lose some from the lower hose.

Also, the 2 or 3 10mm nuts where it is bolted to the manifold are a pain to get to. I suggest removing the air box for easier access.

vwztips said:

A bottle of coolant and a cold engine for two.

It is held on by 3 5mm or 6mm allen head bolts. the one over the turbo is a pain and IIRC need a ball end alen to get it loose.

The bottom coolant hose clamp is a pain to get to also. I would recommend draining the radiator first so coolant doesn't go everywhere when you take the hoses loose or maybe I should say a LOT of coolant. Youwill still lose some from the lower hose.

Also, the 2 or 3 10mm nuts where it is bolted to the manifold are a pain to get to. I suggest removing the air box for easier access.

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tips,

His leak is in the upper EGR Cooler Pipe, not the cooler itself. It is on the gas side of the heat exchanger, so there's no need for coolant. Four socket head bolts - two on each flange.

Tried to upload this the other day but just couldn't get it to upload - operator error!

10:038 131 521 CB
11: 069 131 547 D
13: 038 131 547 A

I think the service dept thinks they are changing the lower part too. They've done good work previously and I trust them although like Ronald Reagan, I like to verify too.
I had called the parts dept and ordered the part prior to arranging for the service appointment and the service department never actually got a chance to see what they'll be working on. I'm guessing they haven't seen many of this particular problem.
So I'll give them the benefit of the doubt that once they actually get the parts in hand, this will go much faster than 90 mins.

Doh! You are correct. So 4 - 6mm allens and 5 minutes later in the parking lot and you will be done

vwztips said:

Doh! You are correct. So 4 - 6mm allens and 5 minutes later in the parking lot and you will be done

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So it turned out to be a parking lot job after all. I started experiencing loss of power on acceleration on the way to work this morning. Upon further inspection the pipe was just about completely severed.

Luckily the dealership is in the middle of my 90+ mile commute and the part had just arrived. They weren't able to work me into today's schedule but there was a home improvement store across the street where I bought some allens, some PB Blaster (and some stuff to clean up with too!) and was able to complete the job in about 1/2 hr.

This included some extra time with one of the 4 bolts that just didn't want to make the job go too easy and another trip into the store to get something to scrape the paper gasket off with. It's interesting that one gasket is metal and one is paper.

It's nice being able to roll the windows up again as it's been pretty chilly here the last few days. Thanks again to everyone for the assistance.

Déjà vu all over again

It's been 14 months and 36K miles since I replaced the EGR cooler pipe that started this thread and the smell is back again.

Because I got 300K out of the first pipe I figured odds were low that it would be the same problem but there it was, soot in the middle of the pipe, right in the same place as the previous crack. It's only a matter of time before it fails--again.

I know how this movie ends so I'll be ordering another pipe tomorrow. I assume it's out of warranty. Should I even bother complaining to VW about it? Am I wrong for expecting better longevity from this part? Is there something else that might be causing this problem?

Since it's cracking in the flex area, could it be excessive vibration? I've not yet changed the motor mounts (that's planned for the next timing belt change @ 400K) and the car isn't running as smooth as it was when it was new but it's certainly not terrible either. Any ideas out there?

The BEW's are very sensitive to the sequence of tightening various fasteners in the EGR system. In other words, if not done properly some stress is induced into the part (pipe) when it's fastened and then over time the pipe fatigues/breaks.

I don't know whether something similar could be going on with your BHW, or why it ever broke in the first place. Have you checked all the fasteners for the EGR system to make sure nothing is loose or misaligned that would cause the upper pipe to "bind"? Hopefully someone will chime in with more insight. Good luck.

That's good to know. Replacing the pipe itself was pretty straightforward and there wasn't any issue with alignment of the pipe itself. But if something else is out of tolerance down the line, it might be flexing the pipe beyond it's expected range. I guess I'll have to have the dealer take a look at it. I don't want to be replacing the pipe ever year.

My comments about the BEW may not have any application at all to the BHW, but based on my experience it may be worth a look around to see if there's a recommended installation procedure for the BHW. And frankly, again in my experience, the (my) dealer was not the answer in the case of the BEW installation procedure.

It just seems odd that your upper pipe would break again in such a short time -- it's not something we see posted here very much. While it bolted up just fine, it may possibly have bolted up in a position that put it under some stress -- or not. Just thought I'd throw it out there for consideration. Again, good luck.

I understand the concern about the dealer but I'm lucky that I have two to choose from that I trust. One of them is going to look at it on Tuesday and I'll report back.

I've also just started getting a grinding noise that seems to go away when I step on the accelerator and gets very loud when I take my foot off the accelerator. Perhaps it's related to the cooler pipe problem.

But I can also feel an occasional thump in the center of the car when I take my foot off the accelerator. I'm hoping it's not the torque converter and that something is just loose but given the number of TC problems posted here and my mileage I'm not feeling good about my odds.

I know my AC is not working again (that's becoming an annual problem) so I may be at a tipping point where I'm spending as much on repairs annually as a car payment. And with interest rates on new cars generally being so low, the trips I take and the inconvenience factor, it may not make sense to hold onto it any longer. If I could do my own work then the equation might be different but I don't have the time or skill.

We'll see what happens Tuesday.

sschnath said:

I understand the concern about the dealer but I'm lucky that I have two to choose from that I trust. One of them is going to look at it on Tuesday and I'll report back.
I've also just started getting a grinding noise that seems to go away when I step on the accelerator and gets very loud when I take my foot off the accelerator. Perhaps it's related to the cooler pipe problem.
But I can also feel an occasional thump in the center of the car when I take my foot off the accelerator. I'm hoping it's not the torque converter and that something is just loose but given the number of TC problems posted here and my mileage I'm not feeling good about my odds.
I know my AC is not working again (that's becoming an annual problem) so I may be at a tipping point where I'm spending as much on repairs annually as a car payment. And with interest rates on new cars generally being so low, the trips I take and the inconvenience factor, it may not make sense to hold onto it any longer. If I could do my own work then the equation might be different but I don't have the time or skill.
We'll see what happens Tuesday.

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We just picked up a new set of wheels for the wife and got 1.49% financing through our credit union (PenFed). It's a good time to buy a new vehicle with the rates as low as ever, especially if you plan on keeping the car for a long time (as we are).

Tom_B said:

My comments about the BEW may not have any application at all to the BHW, but based on my experience it may be worth a look around to see if there's a recommended installation procedure for the BHW. And frankly, again in my experience, the (my) dealer was not the answer in the case of the BEW installation procedure.
It just seems odd that your upper pipe would break again in such a short time -- it's not something we see posted here very much. While it bolted up just fine, it may possibly have bolted up in a position that put it under some stress -- or not. Just thought I'd throw it out there for consideration. Again, good luck.

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Good call Tom_B...EGR cooler was loose. The engine is doing some serious vibrating and some of the bolts had been damaged from the vibration so they replaced the mid and the rear bolts. I hadn't opened the hood with the engine running in a while and I was surprised by how much vibration was going on in there. I guess I got accustomed to it.

I was told they couldn't do the front bolts without removing the turbo. So a new EGR cooler pipe is on order and I'll be replacing it myself (again) when it comes in. That will take care of the immediate problem.

Also found that the grinding noise that started this weekend was related to the AC not working and not the TC/tranny (thankfully). However, the AC compressor clutch has sheered off. So that means a new AC compressor is needed. Although I live in Maine, I do want working AC for defrost and the stop and go traffic I deal with to/from my job in Massachusetts. I can deal with it for the short term but long term it needs to be addressed. But with the clutch out of the system at least the noise is gone.

We're not sure what's causing the excessive engine vibration. They did mention that they had seen a similar vibration recently that, after much troubleshooting, was ultimately fixed by a transmission fluid and filter change. They couldn't say with certainty that it would fix my problem but threw it out there as an option. They did not think motor mounts would fully address the amount of vibration we were seeing.

I had a similar tranny service done @ 200K miles (same time as the balance shaft) but I'm not sure I'm willing to do it again @ 336K. I don't want to induce problems in the transmission that will set me back another $4K. The car still has a little resale value left but if the TC/tranny goes then so does any remaining value.

I also know from various postings here that an axle going bad might cause vibration. We didn't talk about that. Is there an inexpensive way to check the axles?

Would a compression test be useful in predicting remaining life expectancy on the block itself? Any other thoughts out there?

Pull the valve cover and look at your cam.

1854sailor said:

Pull the valve cover and look at you cam.

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I should have thought of that given all the discussion here. Probably should check for codes too while we're at it.

I'm not in a position to buy a new TDI right now and the only thing I'm finding used in this area that I have any potential interest in is an Audi A3 TDI (anyone have any experience with the A3 TDI from a reliability perspective?). I've considered the Jetta Sportswagen but I'm not sure that's for me.

I'm going to test drive the A3 just to see if it really is a potential replacement. But if I have to go used, I may be trading the devil I know for one I don't and potentially even bigger problems. So if I'm rolling the dice either way, maybe I'll just stick with what I know assuming the cam looks ok.

The amount of work left to do is probably equal to 5 car payments or less anyway so if I can get through the summer without any additional repairs then I'm ahead of the game.

I've never had an issue pulling the plug on a car before but this one's not making it easy, even with my mileage.

Cam inspection results

Cam was checked this morning. Camshaft, roller rockers and lash adjusters have scoring and wear. I was told that it's just normal aging -- no issues related to use of the wrong oil.

The mechanic indicated that if it were his engine, he'd change it sooner rather than later but that's what I would expect him to say! We did discuss potential failure modes as well though so I understand the potential pitfalls. The service writer thinks I may still get pretty close to 400K as is. The engine is still working well at the moment and there were no codes set so the correct answer is probably somewhere between the two.

So I'm not in immediate danger of a failure but I was told that once the engine starts behaving badly (and we don't know when that will be) that I should get it addressed immediately as the deterioration will rapidly accelerate once it starts.

After all that, my immediate plan is to do nothing for now other than look for a used AC compressor. If I'm able to get to the 400K mark without doing anything else, the amount of money that will need to be invested at that time may be better spent on a down payment but that decision will wait for now.

The mechanic is right about the cam. Its foolish to continue running it in that condition. Also you might be pleasantly surprised to see how much better it runs. If you don't change trans fluid , you run a very good chance of transmission failure, although, with the miles on yours, its probably not going to make too much difference.

thundershorts said:

The mechanic is right about the cam. Its foolish to continue running it in that condition. Also you might be pleasantly surprised to see how much better it runs. If you don't change trans fluid , you run a very good chance of transmission failure, although, with the miles on yours, its probably not going to make too much difference.

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Regarding the transmission flush, I did it once @ 200K. I'm concerned that doing it again now may do more harm than good. I know these transmissions are supposed to have a pretty good life expectancy but realistically, what kind of life should I expect from it? It's given me very good service up to now but the flush isn't cheap so will I get a decent return on the investment? Or should I just put the flush money towards a replacement a little later?