eddieviv

OK...I posted this before and I got a lot of great feedback...Thank-you. I've now adjusted the rear hatch to a point where I can't tighten the screws anymore. I've replaced the "seal" on the firewall - new, y'know the one that sits up against the hood, I've plugged the holes in the two cubbies in the back and the one in the spare wheel well, I've corrected the rich running engine to some degree but I'm having "symptoms" according to some of the readers that it's STILL running too rich. Replaced all the seals, sunroof, doors, hatch and I've still got a smelly car. (Exhaust coming in the cab, especially when the windows are down). I smell nothing when I have the windows rolled up with only the fan going - NO air. Sooo. I'm in Canada with 80 degree weather with the windows rolled up with no air...I'm dyin' here either way from either the heat or the fumes. I really hate this car!

Giantman

This has probably already been suggested but have you checked all the exhaust connections e.g. from headers, wastegate, cat etc. for proper tightness and that the flanges/gaskets are not leaking? Also have you made sure there are no holes or cracks in the exhaust? These are sometimes tiny and hard to find.

eddieviv

My assumption is that the Porsche dealer I took it to would of checked all of this without me suggesting it. They maintain that there are no leaks in the system. Now I did put some aftermarket headers on two years ago but they never seemed to be a problem. It's weird that even after turning off the ignition and getting out of the car I can still smell the fumes hangin' about the vehicle. Ok, call me crazy.

kos_007

It looks to me like you have an oil leak which is dripping on one of the exhaust pipies and makes the smoke nad "that old car smel" inside the cabin.My approach would be to clean the engine and the exhaust system and see what happens next.Common place is the back of the cam tower gasket leak with oil dripping on the cross-over pipe (easy to fix), but it also could also be the rear main seal.Another overlooked source of smoke or exhauste leak into the cabin is the shifter boot.Under the leather cover there is a rubber cone cover which air-seals the the opening in the central canal where the shifter is mounted.Many times it is cracked and deteriorated.Sorry to hear about your challenge.Please keep us updated!

RRRandy

I'm having a similar problem. I am focusing on fixing the exhaust leak fixed. I think I found it on the bottom of cylinger2 where the header meets the head. However, I am amazed that such a small leak can cause such a smell in the interior.

kos, Thanks for the info on the shifter boot. I had mine off the other day and it is definitely rotted. Didn't think of that as an entry point for the fumes.

Randy

bill4brickwork

iv'got the same problem noticed ifyou run the engine i can smell fumes under bonnet seems to be coming off of headers 86 turbo that stinks

hosrom_951

There you go, leaking exhaust.....

Headers, header flange(s) at cylinder head, x-over pipe, headers to x-over pipe crush ring(s), test pipe and wastegate flange(s).

Did you re-use any of the crush ring(s) at one time? they are single use, most likely the headers, they do take a beating from heat and age (not to metion some cheap stainless steel used by the factory).

Jakerx

smelly car, smelly car, why are you a smelly car?

eddieviv

Thanks again!!

"There you go, leaking exhaust.....

Headers, header flange(s) at cylinder head, x-over pipe, headers to x-over pipe crush ring(s), test pipe and wastegate flange(s).

Did you re-use any of the crush ring(s) at one time? they are single use, most likely the headers, they do take a beating from heat and age (not to metion some cheap stainless steel used by the factory)."


OK...this stuff I'm hearing about the hatch having a crappy seal and the windows open creating a vacuum which is then pullin exhaust from the "back" of the car is a whole bunch of "hooey"? Because I'm running out of options here. To replace the whole hatch assembly to new would be way too cost prohibitive and I wouldn't even know who to start with here in Canada to know who could restore the one I have back to new without having to spend what some people are saying could be $2,000. CDN $

I'm going to back to the Porsche Dealer here in Toronto (with your exact note in hand) because they're tellin' me it's not an exhaust issue but rather a rear hatch problem not sealing and I need a whole new assembly OR they will restore the old (with no guarantee that the exhaust problem will be fixed).

Bill

Check your fuel system.

The top of the fuel tank has an access port into the rear hatch area to allow service of the fuel gauge sender. If the fuel gauge sender gasket leaks, fuel will pond and fuel vapor will enter the cab.

The fuel filler neck and the fuel vapor lines also are routed inside the vehicle. If there is a bad hose or connection, fuel vapor will be vented into the cabin.

I have long wondered what Porsche was thinking when they routed all these items inside the cabin.

alex_cristocea

I had the same problem this winter when I brought a Chrisms tree and I had to came back home with the rear hatch open.There was a serious amount of exhaust gas inside the car.Also check the rubber bot sealing the shift leveler.

jacklet

oil smell could be seal at rear of cam tower

Magown

eddieviv, I can tell by most of the replies to this thread, that post of these people fortunately do not have a clue what you’re talking about. Unfortunately, I know first hand and have been chasing it for a few years now.

Lets compare notes and see if I can describe exactly what you are experiencing.

If any of the 4 conditions are met and you drive the car, when you reach your destination you and your clothes reek of exhaust fumes, not fuel vapors and not oil smoke. The 4 conditions are:
1. windows open
2. sunroof open
3. recirculation switched on
4. a/c snow flake switched on

Other than those 4 conditions you could drive it 300 miles and get out smelling like a rose, except now you’re covered in sweat because you’re blood is boiling from sitting in a green house.

There is only one thing that all 4 conditions have in common:

1. windows down, the air rushing by the windows creates a vacuum effect in the rest of the cabin.
2. sunroof open, same as 1 but not as strong.

3. when the recirculation flaps close, the fan draws it’s air from the cabin and a vacuum is created

4. every 85.5+ 944 I’ve ever seen has closed it’s recirculation flaps as soon as the a/c snow flake is pressed, (why the crazy Porsche HVAC engineers programmed it that way, I’d love to know), so it’s the same as 3.

I to am at my wits end and have done just about everything on your list. One of my cars ran very rich for a while and left behind a little clue. The nasty black soot would collect on the back of the car and was mostly concentrated under the hatch lip and the license plate area. It had the same funky smell. That leaves me with a few possible leak spots:

Hatch seal – This is the first thing everyone suggests. When you had it replaced was it cut? It takes a lot of effort but it can be done w/o cutting, 95% of 944’s I see have a big gap right there and not to may people complain about this smell, so my poor mans guess is that the exhaust is probably being sucked up around the lip and not inside the cabin through these gaps. So if it’s cut, it may not matter.

Key hole seal – these things are usually in pretty bad shape on a lot of 944’s I see, but the same aero dynamics might apply as the hatch seal.

Rear tail lights – I believe they were sealed from the factory with some kind of black goo, which has probably deteriorated in 15 to 20 years. On my list of things to do is to pull them and reseal with butyl tape. The majority of the black soot on my car would collect in the license plate area, I don’t have a clue about aerodynamics but my best educated guess says, if any spot on these cars experiences “draft” it’s right here and I can picture the exhaust gases rolling around back here briefly before they blow away, just long enough to get sucked into the mystery leak. (I’m putting my money on this one)

License plate lights – (far shot in the dark)

Hatch glass separation – (even farther shot in the dark)

Since you and I have never discussed it, I will describe exactly what you are experiencing and you tell me if I'm right.

Rob Ruff

Why not try sealing the perimeter of the rear hatch with tape to see if the problem goes away. If you are worried about image you could test drive it after dark )
My car has a similar problem but it is most noticeable when I am stopped so I doubt it is the hatch.

Magown

These thread revived my interest in finding a solution for this problem. I just pulled the pass side tail light out of my $hit box 86 951, while this may be a highly bastardized car it looked as if pass side had never been removed, as all the washers were still in place. Putting all of those washers back on looks like it will be a real chore, so I doubt joe blow in the past would have gone to the trouble. Especially the moronic PO, I got it from. Just as I suspected the entire top part of the light had virtually no seal left, the sides bottom were still glued very tight. Tomorrow I may try to obtain some butyl tape and reseal it. The drivers side tail light on this car looks like it's been removed, washers are missing and it looks like it's been resealed with windshield glue aka urethane, I removed the nuts but couldn't push it out to save my life.