interior and exterior smells - where to start

[Bukowski]

'87 944 na

wondering what the most common sources of smelliness in the 944 are.

there are lots of different smells inside my 944, I am trying to parse them out. the 944 is ostensibly in good shape. minor oil leaking from engine especially the rear cam seal. carpets could use a scrubbing for sure, the seats are worn out but OK and washed w/ leather cleaner occasionally. interior piece of door - the "Fibrit" - is likely somewhat yucky. I could go on

but:

sometimes the smell is gas, but maybe it is oil sometimes. when I had the cluster out, the rubbery material that forms the underpart of the dash was stinky. rubber under the rear carpet is OK but crumbly.

so if I clean the carpets, the aroma will cover up the other odors. so any guidance through this would help.

[Gawernator]

If it's a fuel smell at RPM's over 3k or hard acceleration, it's probably the O2 sensor. Is your hatch seal original?

[Bukowski]

O2 sensor is old, not sure if past due, need to test with voltmeter.

Ah, the seal IS original. I patched the little gap in the middle though. Might explain odor inside then, good call.

gas odor can appear after steady driving outside. Hard to pinpoint. I changed the fuel damper, regulator and that one small line under the rail on the engine. Lines near tank appear unbroken but corroded.

UPDATE: lemmee see.... my O2 is a Bosch 13011 (944-606-135-02), MAYBE 3-wire. a little over 5 years old, over 50,000 miles. [pulls up Clark's garage...]

"Generally, heated O2 sensors last about 60,000 miles and non-heated (single wire) sensors last about 30,000 miles. Porsche recommends replacing the O2 sensor every 60,000 miles but, does not differentiate between heated and non-heated sensors."

... well OK then, might need to do that sooner than later.

.... also about this area of the car : what about the exhaust test tube? I have (had) a metal tube extending from the exhaust before the O2 but after the headers. It was claimed to be for testing emissions. it broke off eventually, and I never sealed the hole - any good ways to seal the hole? I tried thermoseal, and it didn't work probably b/c the rust/corrosion was so bad.

[Gawernator]

This hatch seal is a bargain over the Genuine Porsche and is good quality, it fixed my general car smells. Porsche 944, 944S, 944S2, 951 Parts

I had a strong fuel smell over 3,000 RPM and thought I had an exhaust leak or something. Replaced the O2 sensor with a Bosch Universal heated sensor and my MPG is better and all weird smells are gone now.

[GreenWater]

Thanks Gawernator,

The rear hatch seal can make a big difference and can keep a lot of smells out of the car.

I would get that exhaust test tube sealed or a new one welded on. Depending on what state you live in and what emission testing needs to be done. If it's not needed then I would make sure to seal it up. Welding it closed will probably be the only way. The exhaust gets VERY hot and will melt most thing used to seal a hole. An exhaust leak will do damage to the cat., make the car smell inside, and is just not good. You might want to check your inner shift boot as well. It's the rubber boot under your shifter cover. If you are missing it, or it has holes in it, then it needs to be replaced. This will cause fumes from the engine to go directly into the car, via the ash tray area. Smells can also get in through the AC, through the seal under the hood that seals the engine compartment from the AC blower fan.

If my memory is right, I believe there is a plastic cover under the gas tank that covers the fuel pump. Take that off to see if there is fuel leaking. I have had the banjo fitting come loose that connects the fuel lines to the fuel pump. I found fuel actually leaking on the ground when that happened.

Good Luck

[Bukowski]

thanks for these interesting points to consider.

Originally Posted by GreenWater

... Smells can also get in through the AC, through the seal under the hood that seals the engine compartment from the AC blower fan.

when you say AC blower fan, this is just the blower motor? my AC isn't operating so can't test it.

[GreenWater]

I was referring to the blower motor. It controls the AC, Heater, and just plain air blowing into the car. So it doesn't matter if your AC works or not, all the air comes from the blower, under the hood.

[89-944NA]

That exhaust test pipe is no longer used for emissions tests, that was used to test exhaust emissions before the tail pipe sniffer was developed. Take the fitting off the exhaust pipe and use a ball bearing (one large enough to plug the hole, but NOT fall into the pipe) to seal the fitting, or get a solid threaded cap (steel, brass, etc) to plug it.

Another possible cause for the gas smell in the cabin area is the fuel filler and reservior, there are a number of rubber hoses and connections that do deteriorate over time. These are located in the right front of the cargo area (just behind the rear seat). It's a bit of a pain to get at, you need to fold the rear seat down, remove the right side cargo lining (carpet on the right side), and the metal cover to get access them. Make sure you reseal the metal cover if you remove it