Using my eyeball.

 

Do you use a bit of vaseline to get a good seal when you put your eye right up in that dirty little tail pipe?

 

How have you found exhaust leaks in your engine bay? Smoke machine? Soapy water and, or foggy mirror method? Is blowing air with shop vac into the tail pipe a viable option? I've seen tons of videos of gas vehicles using the shop vac method, but none with diesels. All the diesel videos seem to be about boost leaks in the turbo, but I don't think that's my issue.

I've seen videos where they say using a smoke machine is the fastest and most reliable. I don't think they distinguished as to whether it works best for gasser or diesels.
I wonder if a sniffer machine would work good for this as well.

 

I've seen videos where they say using a smoke machine is the fastest and most reliable. I don't think they distinguished as to whether it works best for gasser or diesels.
I wonder if a sniffer machine would work good for this as well.

I've seen some of those videos as well and it looked like the way to go, so I got a smoke machine, but it didn't work. Plugged it into the air intake hose that connects to the turbo, but air intake hose gets pressurized as if air isn't getting passed the turbo, because when I pull the smoke hose out it pushed air/smoke back out at me with some pressure, so seems like a valve of some sort is closed off, but I don't know enough about TDi to know if that what it could be, or not.

 

Start the car up when it is cold outside.

 

Thanks for the suggestion. That was one of the first things I tried when it was in the teens down here. Next thing I tried was a trick I saw a diesel mechanic do. Put vehicle in drive, put parking break on, hold break pedal down firmly, and floor it, but I still didn't see anything.

 

I’ve had small exhaust leaks on my TDI that I could smell, but could not visually see any smoke on startup or carbon at the leak site… the dealer found and fixed them under warranty with a smoke machine by blocking off the tailpipe.

 

Thanks for the reply. Wish I had some warranty left, but even if I did I've had such horrible experiences with the two dealerships here that I never want to go back. One time I accidentally left my dash cam in the car when they were doing warranty work and it recorded one of their techs accidentally breaking one of my windshield wiper arms, so that it stopped operating. They still tried to get out of fixing it even with video evidence. Took a couple months, VWOA, and me finding the part for them for it to finally be fixed, so all trust is lost with that place.

 

Realistically, every "leak" will be different, and it doesn't matter what @casioqv 's solution for locating it was, or what mine was, or anyone else's was...... the OP will never find his problem by searching a forum..... (he can only get clues or suggestions of what to do - so one is use a VW dealer and warranty, another is use a greasy up eyeball)
He needs to do actual diagnostics & inspections on his own ride...

 

Considering my warranty is up and both VW dealerships in town have been a nightmare to work with I won't be doing that. I did take the TReg to an independent VW shop, but they didn't find a leak and basically told me "diesels are supposed to smell like that", and from other comments they made it sounds like they don't like working on diesels and specifically Touaregs. Anyways, I left the issue alone for a while, but fumes got worse. Seemed like it should be an easy thing to hunt down, but these engines as you well know have a lot crammed under the hood and it's hard to get an eyeball on a lot of stuff. As for trying to diagnose on my own...I've tried many things and all involved my eyeballs. I've been under the car and on top of the engine and I've been reading on multiple forums and searching you tube as well. That's where I've seen the shop vac trick, but not on a diesel, so it concerns me that blowing ash back up into the engine might not be a good idea. I've spent hours hunting this thing down, so that's why I'm coming to a forum. Even if I hadn't tried anything yet what does it matter? This is why forums exist right? For people with a variety of skill levels and experiences to help each other out?

 

Nope, I only use common sense.....
If you can smell it in the cabin, it's significant enough to see it with the naked eye when looking under the hood\vehicle under those startup conditions.

Nope, I only use common sense.....
If you can smell it in the cabin, it's significant enough to see it with the naked eye when looking under the hood\vehicle under those startup conditions.
[/QUOTE

Start the car up when it is cold outside.

Start the car up when it is cold outside.

 

Maybe you're blind

 

Here's an example:
I smell something.....
I look around the engine bay, can't find or see anything.....
I crawl under it....




Disclaimer: Zero eyeball lube was used in this diagnostic session.

 

Here's an example:
I smell something.....
I look around the engine bay, can't find or see anything.....
I crawl under it....




Disclaimer: Zero eyeball lube was used in this diagnostic session.
[/QUOTE

Maybe you're blind

Here's an example:
I smell something.....
I look around the engine bay, can't find or see anything.....
I crawl under it....




Disclaimer: Zero eyeball lube was used in this diagnostic session.

WAIT! TOUAREGS HAVE AN UNDERSIDE?

 

Only ones that have an exhaust leak....

 

Testing for exhaust leaks on the intake side.... I think I'm starting to understand the issue here 😩

 

WAIT! TOUAREGS HAVE AN UNDERSIDE?

I'm not sure what port you are talking about, but what you are describing sounds like something on the compressor (intake) side of the turbo. Probably pulling an EGT sensor would be the easiest way to put smoke into the exhaust system- there are no hoses attached to the exhaust side of the turbo, it would be too hot and they would melt.

I'm not sure what port you are talking about, but what you are describing sounds like something on the compressor (intake) side of the turbo. Probably pulling an EGT sensor would be the easiest way to put smoke into the exhaust system- there are no hoses attached to the exhaust side of the turbo, it would be too hot and they would melt.

Thanks for the input. I'm definitely not experienced with turbos, or turbo diesels and couldn't find any videos on how to test for exhaust leaks in the engine bay, or at least not with a smoke machine. Figured I was doing something wrong.

 

As above, you had it on the intake side. Take a sensor out of the exhaust, plug the tailpipe, and stick the smoke machine in the sensor hole. Failing that, it will probably work if you just jam it in the tailpipe and block off around it to seal it up.

 

I’m gonna pull a sensor and plug the exhaust pipes once I have some time and then update the post. Thanks for the response.

 

Wow ... so much trolling ...
I've been to to have a friend with a glove cover the tail pipe or pipes. The back pressure tends to make leaks whistle or hiss. Fair warning, I have not tried this on a turbo and I have stalled gasoline 7.4L engines.

 

I appreciate you noticing how some folks just can’t help, but be condescending and juvenile. Thanks for the input.

 

I tried a smoke machine to find a leak where I smelled diesel in the cabin.
I first tried plugging one exhaust and pumping in the other and had no joy.
I I think that there was too much distance from the tailpipe to the engine for that to work.
I was going to plug both exhausts and then use the EGT port abt the hot side of the turbo and pressurize the exhaust (and EGR system, but then I removed the heat shield and used my camera to take a picture of the upstream corrugated pipe for the EGR and identified the soot and could see a crack in the base of the bellows.
I think that the smoke would work where it is not blocked by various mufflers, CATs, DPFs and other impediments.
If the smoke has to go far then I think that it will settle out and condense on the cooler metal before you can see the result. Plus there has to be flow and pressure to do some good.

 

Thanks for the input. I found the soot in the same area you found your’s. I didn’t see a crack in any of those pipes using soapy water, or with my telescopic mirror and lights. I’ve been busy so haven’t tried the smoke machine again, but when I do I’m gonna take the advice someon else on here gave me and pull one of the exhaust sensors that I can get to under the hood and blow smoke from there. I’ll def. update when I do that.