From time to time there appears a fuel odor inside the cabin of the car. This is somehow correlated to the driving on the curvy roads/breaking and(or) rapid acceleration. For example on the 400 miles trip on highways the odor came in just a few times. On the other hand, while driving in city, the car gets the odor pretty often.

The car ('87 240 wagon) had fuel tank and exhaust replaced just before I bought it. Any ideas what to check/what may be the cause?

 

I'd check the fuel tank ventilation system. supposed to be connected to a carbon canister thats up near the radiator, and in turn connected to a vacuum line into the intake manifold.

I'd also check the fuel filler pipe plumbing.

I'd sort this out ASAP before your car catches on fire and goes down in a blaze of glory.

 

Little drain/ vent tube in trunk from filler tube that drains out the bottom of the pass. side wheel well. Take off the plastic cover to expose filler tube and see if the drain tube is detached.

 

Could you be more specific about this tube?

I was sealing some rust in the passenger side rear wheel well. And there was this black plastic tube which had one end going into the bottom of the well. The upper end of the tube was detached, and I couldn't figure out where it was supposed to be attached. What are it's functions?

 

the tube Fochs is talking about is the one for the drain just the outside/below the fuel filler cap that catches any fuel that spills when you remove the gas nozzle.

the vapor hose I was talking about attaches to the fuel filler pipe below the gas cap, if you remove the plastic cover in the trunk that hides the fuel filler pipe, you should see it.

there's also the cover plate on the top of the gas tank where the in-tank fuel booster pump, and the gas level sender unit are, if thats not properly sealed, gas could slosh out there, and end up under the carpet in the trunk, under the 3rd row seat in a 240 wagon...

 

I had the same exact problem on my car ('91 244). Check the base plate of that fuel sending unit (the metal plate on which the pipes go into the tank and in-tank pump). In my case, every time I primed the fuel pump, gas would seep out from that plate due to the corrosion. A new one is about $180 or if you want to skimp on costs, try JB weld and let it set for 48 hours (I let mine set for 48 hrs instead of the recommended 24 hrs at about 45-50F). Mine hasnt leaked for the past 8 months. But like Pierce said sort this before things get really HOT

 

The point is that the fuel tank has been recently replaced. Doesn't this imply that there shouldn't be any problems with the fuel sending unit?.. Anyway, as far as I understand it is easy to check -- I just need to open the bottom compartment in the trunk and get at the very bottom of it. Will check out things tomorrow morning.

Would you suggest bringing the car to the shop ASAP if I don't want the things to get hot? The odor comes may be once per 25 min ride, but I understand that the leak may be serious, but most of the smell may not reach the cabin.

 

who did this fuel tank replacement? was it done by a shop? if so, bring it back to them ASAP, and explain what you're smelling, that its right after a sharp turn or whatever.

 

It was done by the previous owner -- I believe by his friend who is mechanic. He claimed that the original volvo gas tank was installed. Probably I can try to contact him for more details on what was done..

 

my guess is, as I said before, one of the vent lines is loose/disconnected, or the fuel filler pipe is improperly secured, or the tank access plate is not sealed properly. just because something is new, doesn't mean its perfect.

 

Since the tank was out recently, my bet would be the clamp that holds the filler tube onto the tank. It is in a tight spot and a pain to install. If not installed properly it is a source for leaks.

Second guess would be leaks on the top of the sending unit as 240-FAN suggested. My '90 had leaks there as well and I would smell gas when going around curves with a full tank. However, if they dropped the tank, I would hope they addressed any problems with the sending unit. But it is easy to check there.

 

Ok, I've checked all of the above.

Tank ventilation system seems to be ok, if I've correctly found it. Am I right that the hose should enter into the black box which is after the air filter?

Next, I've looked at the top of the fuel sending unit (see the pic below). It seems to be fine, and there is no sign of smell whatsoever.

Finally, I've take a quick look at the filler pipe plumbing. There was some weak odor there. I will try to reproduce the conditions when the fuel smell coming to the car cabine, and then pull out from the road, open the trunk and see if the smell is coming from there.

 

those are /NOT/ fuel injection safe hose clamps you have on there... the correct clamps for FI hoses look like

 

Thanks Pierce. Are these generic clamps -- can I buy those in a usual parts store?

Also, what would be the way to proceed if I confirm that there is a leak at the filler pipe plumbing?

 

they are standard fuel injection clamps. I have to say, the fuel hose looks really ratty in your pictures, too.

um, if there's a leak somewhere in the filler pipe plumbing, you fix it that plumbing is a combination of pipes and rubber tube fitting/joints.

 

After refilling the tank, I realized that the problem of odor is very strongly correlated with the fuel level. With the full tank I got strong smell in the car pretty soon after I've started to drive. When I checked the fuel filler pipe connection, the area has very strong fuel odor there. On the other hand, I could not locate any leaks/traces of gasoline. I am curious if the odor can so quickly get from that compartment in the trunk (I have a wagon) into the cabin, or if the filler pipe plumbing is not the ultimate cause of the odor?

Anyway, the filler pipe plumbing has to be fixed. Would you recommend to do the "cosmetic" fix and try to put some putty/other insulation on that area? Or do I need to reinstall the filler pipe again? In this case it seems easier and safer to bring the car to the shop.

 

I would re-check the top of the fuel gauge sending unit when you have a full tank and can smell gas. It looks dry in the picture but could you smell gas when you took the picture.

Also, the picture you took of the fuel filler line, was that where the filler goes through the body of the car or is it where it enters the tank? Where it enters the tank, there is supposed to be a clamp that holds it in. That clamp is hard to get off without breaking (especially if you live in the rust belt). My hunch is that when they had the tank out, the broke the clamp or didn't install it properly. You have to crawl under the car to have a look at it.

 

any place you suspect gas might be leaking out, temporarily wrap in paper towel, then test drive, and the leakage should leave obvious stains.

 

Thanks for suggestions -- I will check the clamp.

But so far the mystery has partially resolved. After topping the full tank and circling small circles counterclockwise on a parking lot@20mph, I got about a CUP of gas coming out through the fuel cup.. Thus, in the normal conditions the gasoline/smell was getting into the trunk compartment, since I decided not to fix the black tube before I figure out the leak cause.

After inspection I saw that the filler pipe is bent (not that obvious in the pic) where the cup screws on. However, seems that there is also something wrong with the one-way valve. Is it supposed to have holes?

Finally, is there a way to fix this stuff without replacing the entire filler pipe? If no, what is the best way to get the parts?

 

i suspect the best way to get a replacement filler pipe is a pick-n-pull junkyard, or a craigslist car being parted out.

yeow, parts diagram indicates the WHOLE filler pipe, from where the cap threads on down to the clamp fitting into the tank is all one piece. its a discontinued part from the dealer, but the same pipe fits ALL 240 sedans and wagons from 1984 forward.

my son had a 1991 940SE who's filler pipe was deformed where the gas nozzle rubs against it when filling... I managed to tap it back into roundness with a rubber mallet and short piece of hardwood dowel, then used emery cloth to smooth it out til it sealed reasonably well. I also put a new thicker/softer gasket in the filler cap, this helped (make sure you use a gasoline safe rubber! many rubbers will swell and deform in the presence of gas fumes).

In California, the filler cap seal HAS to be air tight or it won't pass smog tests.