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BillA · Joined: 27 Dec 2002 Posts: 170 Location: Syracuse, NY

Ok I've seen many posts but can't find anything on exhuast fumes inside the car, both my 78 and 79 are pulling in fumes from somewhere! I've changed hatch seals, door seals, resealed the tail lights and even gone as far as swapping out the exhaust systems. One has a header and the other is stock! It is more pronounced when I lower the window! This is very frustrating!!

Smoothie · Posted: Sun Apr 08, 2007 10:16 am Post subject:

I get exhaust fumes if I only open the left window or if I open the left more than the right. -And no fumes if I roll the right side about 3/4 or full down and open the left side 1/4. See if this same weirdness happens with your car. Also - measure the distance from the end of the tailpipe to the rear of the metal part of the rear bumper (not including the rubber snubber). That distance on mine is 3.75". What's it on yours? - I'm wondering how much it has to do with the fume problem.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

924RACR · Posted: Sun Apr 08, 2007 10:14 pm Post subject:

You guys haven't replaced the rubber gearshift boot, have you?
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
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924guy · Posted: Mon Apr 09, 2007 12:26 am Post subject:

check the foam under the boot in the shifter well. if it is cracked, decayed, or otherwise damaged itll draw fumes into the car like a straw.. foam piece is NLA , however a can of expanding foam from the hardware store will do quite nicely. just spray and then carve it out where appropriate so theres no hangups on the shifter and related parts.

also, have you checked the sealing on your fuel filling tube and rear marker lights? id imagine those could also be sources for exhaust fumes entering the car if poorly seals..
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Eric
78 924
82 931 SE "smokey"
99' VehiCross
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BillA · Joined: 27 Dec 2002 Posts: 170 Location: Syracuse, NY

Thanks guys I had not thought about the shift boot and foam or the fuel tube! I'll check them!

Of all the things I've lost, I miss my mind the most!
Mark Twain

Nobbi · Joined: 24 Aug 2006 Posts: 1398 Location: Germany

Hey ,

i am dealing with that problem a long time.As smoothie says, it s the same thing with my car.Just checked it today.Very hot weather here in germany, so i lowered the windows on both sides a bit.-No problems with exaust fumes...
The "Boot" Issue is interesting, i took out the complete inner material and just have that Outer-Rubber -Cover installed.But i thing thats not the cause, i am pretty sure its coming from the backside somewhere.
But i do test it and let you know.

Nobbi

Smoothie · Posted: Sun Apr 15, 2007 4:31 am Post subject:

Nobbi - Could you measure the distance from the end of your tailpipe to the end of your bumper? I'm still wondering what affect that might have in letting exhaust fumes get under the car then in through the shift boot and/or windows.
My current problem is different from yours - I get no fumes with windows closed. I do get fumes with just the left window open and no fumes with just the right window open.
If your rear hatch struts are strong (still charged with gas (I drilled mine to let the gas pressure out*)), try disconnecting them so the hatch seals tighter. If the fumes disappear after doing this, then you know the fumes were coming in around the hatch seal.
*-I did this years ago to cure a fume leak through the hatch.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

BillA · Joined: 27 Dec 2002 Posts: 170 Location: Syracuse, NY

Hey guys,
I've done the tail pipe measurement thing and had it extended without any luck! I tried a 931, 944, and 944s2 exhaust systems and met with the same result, fumes in the cockpit! I'm still testing, this is one of the most frustrating problems I've ever come across! I am going to let the pressure out of the rear seal! I'll let you know what happens!

Of all the things I've lost, I miss my mind the most!
Mark Twain

Smoothie · Posted: Sun Apr 15, 2007 5:40 am Post subject:

Whoa! No need to let pressure out - just disconnect both struts at one end each.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

timstar924 · Joined: 04 Jul 2004 Posts: 284

lol. I had this problem with my 924 and now with the 944 also ( I think but not as bad).

I also reasealed the tail lights, remove it and use new caulk. duct tape all any holes in the spare tire area that have missing grommets.

but the most likely area I think is the rear hatch, a new seal may not fix it (like me), I think after so many years and the design of the rear hatch and people constantly slamming them they probably warp a bit and probably leak somewhere.

the thing is the rear hatch has to be completely airtight, even a tiny crazy space between he seal and hatch is enough for gas to get sucked in.

probably use pressurized water to spray the hatch all around and if water gets in then so does gas.

I don't know what a cheap solution is, getting a new hatch costs like 3000.

you can buy a new hatch off of a car that doesn't have this problem and the hatch is not separating.

cheap solution? I'm going to duct tape the hatch to the seal from the inside, the Red Green way, fix everything with duct tape. plus it's not really permanent, you can remove duct tape.

you might not be able to get duct tape on some parts though like where the rear wiper is and where the pins are so if it leaks here than it wouldn't fix the problem.

also I'v heard you may need new hatch pins as old ones wear out and the hatch won't close properly or tight enough and the pins may need adjustment to get it to close as tight as possible.

timstar924 · Joined: 04 Jul 2004 Posts: 284

that's why I got rid of my 924.

If I can't fix my 944 exhaust problem I'll get rid of it too.

It's most likely the hatch or the taillights.

even if you seal in the tail lights they might have cracks in them, so if water gets into the tail lights it will also get into the car.

my tailights are water tight now so it's my hatch that's not sealing fully.

I know one guy on Rennlist had this problem and he bought a new hatch (3000 dollars) and that fixed it lol, but most people don't have 3000 for a hatch. I might try and look for a used good hatch, mine is separating badly at the top so maybe it's also warped where it seals.

timstar92404 · Joined: 22 Sep 2004 Posts: 2075 Location: richmond BC

this is pretty rare, a new hatch on ebay 200 starting bid. It says it was used on prototypes and never installed, it kind of looks different than a regular 924/ 944 hatch .

http://cgi.ebay.ca/PORSCHE-944-Rear-hatch-and-glass_W0QQitemZ130100776316QQihZ003QQcategoryZ33656QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
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78 924 sold.
85.5 944

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

timstar,

The truly CLUELESS like you who do not listen to advice should NEVER advise to those seeking assistance.

If you had paid attention to the advice given to you, your problems with your 924 could have been solved.

If you had paid attention to the advice given before you bought the poor example of a 944 that you now own, you would not have bought it in the first place. And if you had listened, you would have solved the problem with the 944 that you now own a long time ago.

Now here is an observation for you... The hatch in the ebay link you provided is NOT A PORSCHE FACTORY PIECE. Look at the shape of the hatch frame, and the black paint band on the glass. DO THEY EVEN LOOK CLOSE TO THE PORSCHE FACTORY PARTS?

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Really want to eliminate exhaust leaks that allow exhaust gasses into your car?

Start by replacing the rear hatch rubber seal, door seals, sunroof seals (if you have one). CRANKING DOWN THE REAR HATCH LOCKING PINS WILL NOT SEAL THE REAR HATCH IF THE SEAL IS SHOT. THE ONLY THING THAT WILL HAPPEN IS THAT YOU WILL DAMAGE THE GLUE BOND BETWEEN THE GLASS AND THE HATCH FRAME.

Then go under the hood and replace your exhaust maifold if it is cracked, the exhaust manifold to downpipe gasket, the gaskets between the exhaust system parts, and replace every single rusted out exhaust part. Check the muffler and resonator seams as they rust out.

Then, replace the seals on the gear shift lever, and seal all of the opening on the firewall for the heater hoses, ac hoses, brake pedal pushrod, etc. with silicone sealer.

Now go over every inch of the bottom of the car, and the lower half of the body within the wheel wells looking for rust holes, and repair them as you find them.

timstar92404 · Joined: 22 Sep 2004 Posts: 2075 Location: richmond BC

lol ok Gohim I won't give any advice.

If it's so easy to fix the exhaust leak then how come there are so many people with this problem, and I'm not the only one that hasn't been able to fix it easily. Alot of people have given up trying to fix the problem.

I did get a new hatch seal on my 924 adjusted the pins to make it tighter etc. sealed the tailights non of it worked.

when I got a new hatch seal installed and the pins adjusted I could still see light going through so it's not always the seal the actual hatch could be warped.

I didn't say the hatch on ebay was an original porsche, I did mention it looked odd.
_________________
78 924 sold.
85.5 944