jzc28

an '89 C4 - on warm days while driving I notice a gas smell in the cabin. Replaced the original gas cap - helped but did not solve the problem. The odor is most noticeable under the front hood - no surprise. Anybody else dealt with this problem?

wellcraft290

well your tank is in the front under the carpet. I have heard not to fill it all the way to allow the fuel to expand in teh heat.

jimq

the fill tube can cause it. There is a replacement part for it.

Rocket Rob

My cab had this problem. The fix was to replace the gas tank filler neck. Its really easy. Wachuko wrote a DIY procedure for it. Note: I had to go purchase a large set of snap ring pliers to do mine. Otherwise, it was a 20 minute job. It made an immediate difference. What was also odd was you couldn't see any noticeable cracks or defects in the original part but the new one is clearly an updated design.

Procedure = https://rennlist.com/forums/964-1989...placement.html

jim_l

+1
replaced mind this year, gas smell is gone

tommyz

Hm. Getting rid of the gas smell? I had never considered getting rid of it. I will have to think this over.

-nick

A new fill tube didn't solve it for me. I'm still hunting.

meek

I also used Wachuko's instructions ( thanks matey! ) last wekend; gas smell now gone when chucking it about the twisty bits. It was an obvious leak, as checking around the filler neck after spirited runs showed a small pool of fuel. Now need to get round to replacing the plastic bowl, as the washer bottle neck is cracked and leaking; wheel off and liners out.

JDD

I too have replaced the filler neck and checked all hoses/clamps but the smell persists...

pete000

I tell my wife that's the classic old Porsche smell they all have it...

I notice it only occasionally on my car if its been couped up in the garage all closed up for a while...

BlueHeeler

You mean the anti smoking deterrent? I am keeping it as is.

92silver964

FWIW - I had the same problem, aggravated during hard turns. I did the gas cap changeout too, but no improvement. The thing that fixed it totally was to change the filler neck tube. I thought I have seen where that is a somewhat typical problem with the 964. I love the Porsche oil smell, but not gasoline.

user 783003

Mine got better after I re-connected the tube going to the carbon canister. I noticed it was disconnected when I pulled out the heater blower while doing the valves.

Wachuko

I went ahead and updated my thread... another source is:

Vent valve at the top of the small fuel tank on the drivers side could be craked. Part No. 964 201 175 01

Shack2112

I also had this problem. When I had it in the shop recently the mechanic noticed that the fuel fill drain line was plugged. After this was fixed there has been no problem.

1990 964 C4 aka "Baby"