Exhaust smell in car

[vwsb1974]

I have an 89 MKII with a 1.6N/A and a 2.25 exhaust put on it. If I crack the windows I get a bad exhaust smell in the car, no smell with the windows up there are no leaks in the system and the car has no rust holes. I can’t figure out where the smell is coming from just wondering if anyone has had this problem.

[wolf_walker]

If the pipe does not exit where the stock one did, that may well be the problem.

[CRSMP5]

what a horriffic memory this brings...

why.. cracking window creats a cabin vacum....

smell/where hole in floor, or by rear quarterpanel.. behind rear bumper area are "vents" that your getting the exhaust thru..

i always extend me tail pipes beyond the bumper to prevent that issue..

91 jetta big bumper... broken/rusted tail pipe = right in trunk...

[bajacalal]

I've battled this to varying degrees the whole time I've had this car...

Is it a Golf or Jetta?

Here's what helped on my Golf...

1. If you put the front window down, you have to put the rear window down too, because otherwise it creates a draft which draws air forward. If it's a 2 door... IDK. Turn the blower motor on, it helps.
2. Make sure your trunk/hatch seal is in good condition and that the trunk/hatch lid is properly adjusted so that it seats on the rubber.
3. Ditto for the doors.
4. The fender area to either side of the trunk is hollow and has a drain hole on the bottom. I filled the entire cavity with closed cell expanding foam.
5. The hatch also has drain holes on it, that lie outside of the rubber and can allow outside air to be sucked in. Seal them off (you may want to leave one, on the opposite side from the exhaust, to let any water drain).
6. Any missing emblems will also let a significant amount of outside air in, under the right conditions.
7. Make sure the exhaust tip goes past the bumper.

[annieneff]

Good write up baja.
Do all those things! And make sure you do them sooner rather than later, like right now. This is one of those "you might die if you don't" things.
Click and Clack (registered trademark) were always appropriately dramatic about exhaust leaks. They admonished their callers to fix them, and fix Em now.
Rent a smoke machine if you have to, but find the leak. Don't die, and Good luck--

Andrew

[745 turbogreasel]

If you vent exhaust into the low pressure are which trails  as much as 50 feet behind the car it will swirl and linger.  Diagonal or side exit  will use exhaust velocity to shoot it clear of the pocket of disturbed air around the car.  Also the troopers test noise emissions from directly behind.

[vwsb1974]

thanks for all the help the car is a Jetta. The exhaust is the same as stock just larger the stock dose not extend past the bumper so why do stock cars not have this problem? I will post some picts when I get a chance

[wolf_walker]

It sounds like stock one's do have this problem from the other posts.  Wonder if it's a late A2 thing?
Never had a problem on early cars. 
I'd move the tip out further just to experiment, maybe a slight turndown.

I can tell you if you exit the exh to the rear on a Caddy pickup it will cover the bumper, tailgate and taillamp (inside and out) with
soot, but if you exit it out the side behind the rear wheel like VW told us to it's not a problem.
Sometimes the factory dun gud.

[CRSMP5]

behind rear bumper area are "vents" that your getting the exhaust thru..

[smutts]

Check the boot/ trunk lid seal.

[vwsb1974]

I did look at the trunk lid seal and I found where their was soot build up on the trunk lid. I am going to replace the trunk lid seal.

[wolf_walker]

I did look at the trunk lid seal and I found where their was soot build up on the trunk lid. I am going to replace the trunk lid seal.

Symptom, not problem.
Your tip is exiting right into all sorts of turbulence, air goes up from right there and hugs the body.
That's why you see rear valances and defusers and stuff on the rear of cars.

[bajacalal]

It sounds like stock one's do have this problem from the other posts.  Wonder if it's a late A2 thing?
Never had a problem on early cars.  
I'd move the tip out further just to experiment, maybe a slight turndown.

My '85 always seemed to have some issue with this, with the factory exhaust,  and the custom exhaust made it no better nor worse, really... but in retrospect I should have done a turn down, right now it's like the mk2 GTI tip that points towards the left side, away from the vehicle, but that doesn't really seem to do much to keep the exhaust out. I could have also made the exhaust stick out farther but then it would be something to trip over. A turndown would probably be the best solution.

Did the mk1 cars not have this problem?

I don't think there's that much exhaust getting in the car either, but the smell of diesel exhaust is potent and it only takes a little bit to be noticeable.

* After looking at the photos supplied, the exhaust outlet is definitely located too far underneath the car. It needs to be brought out 3-6"

[wolf_walker]

At least you smell diesel exh, long before it'll kill you.  If it was a gasser you'd just have a weird headache, or worse, and might never know it.

I haven't spent enough time since I was young in early Jetta's but I've never noticed any problem with Rabbit's or Caddy's,
other than the sooted up tailgate on the Caddy if you don't exit it out the side like the factory did or get it
well out of the rear under the bumper and turn it down.  Even with the opening back glass.
It's reasonable to think some cars might be more prone to it than others.
It's a must-fix in my book, I don't like sooted up cars and I really don't like
people riding with me and commenting on my "smelly diesel".  My junk don't smell
like a diesel anywhere unless your nose is a foot from the filler, the engine, or the pipe when it's
running. 

If ya'll ever notice that weird S on the end of 80's Volvo exhausts, it's to put the tip somewhere
that will take the gasses away I'm pretty sure.  A fairly slight change can make a big difference. 
That bendable exhaust tubing is a good way to experiment.

[vwsb1974]

So I extended the tail pipe with some of the flex tubing and replace the trunk weather stripping and the smell has gotten better it’s still their but just a bit. Thanks for all the help. I don't think I have a leak at the manifold if you put your hand on the tail pipe it builds pressure and I don't hear any leaks.