I've noticed that after having WOT there is a faint fuel smell in the car.

My fuel cap may or may not be faulty, not sure if this would affect it?

Anyone know of what could be causing this smell inside the car?

This brings back dreaded memories of my HQ holden which reaked of fuel inside the car. In short I repalced the fuel filter, then the fuel lines, then carby. On that car, thats pretty much the entire fuel system and even the fuel filler cap. The issue was the fuel tank neck was slightly bent so the fuel as I took off splashed back up the neck of the tank, and out of the cap, and ran back down and vented into the cabin via the boot. It took months to work it out and a new fuel tank and I was sorted. THis is not the solution for your issue lol, but its a process of elimination. I notice on my wifes TJ that sometimes it smells of fuel outside the car, there are fuel vent points on the car and usually in hot weather or when the car is full it occurs. Try seeing if your car smells with say just a qtr of a tank of fuel. If not, then it could be something else. Either way, start small by checking the fuel cap, its probably the cheapest thing to replace first. Next, check your engine bay for any visible fuel leaks, stains etc. Perhaps check the fuel filter, but other than that, thats where I'd go to a mechanic next if the smell continues on, cause those are some simple easy checks anyone can do first.


I remember my HQ made me feel so sick due to the smell, I had to have all windows down as it was crazy. In the end I only ever filled the tank up half way as it wasn't as bad when it was half full. I swear I lost many brain cells over that.

It did it last night with the fuel level very low (under 1/4).

The smell is very faint though which makes it difficult to pinpoint. At first I wasn't even sure if there was a smell or maybe just my imagination, though considering I sense the smell time and time again after WOT runs I think it's not my imagination.

I will change the fuel cap, but is there a way a faulty fuel cap could cause fuel smell inside the car while at speed?

I remember my HQ made me feel so sick

Is that what causes it? fuel fumes? I get that impression from a lot of holden owners, especially when a ford is in the general vicinity? Poor sods...
Did you get over your 'sickness' bro or are you still hanging phully sik burnouts at the local kay ef cee?

As for OP i'd be breaking out the nose, sniff the fuel cap. I had same issue and one whiff at the fuel cap confirmed the problem. Everything else smelled just fine except inside the cabin

Is that what causes it? fuel fumes? I get that impression from a lot of holden owners, especially when a ford is in the general vicinity? Poor sods...
Did you get over your 'sickness' bro or are you still hanging phully sik burnouts at the local kay ef cee?

As for OP i'd be breaking out the nose, sniff the fuel cap. I had same issue and one whiff at the fuel cap confirmed the problem. Everything else smelled just fine except inside the cabin

Dropping a few stereo types there mate, what are ya trying to say?

Dropping a few stereo types there mate, what are ya trying to say?

He is paying you out for being an ex-HQ owner. But most of us, including me, owned a Holden of some sort in the past, before we saw the light. lol

As for fuel smell, in case it hasn't been mentioned before, check the three ratcheting teeth on the fuel cap - if one breaks, you can't get the cap tight enough.

Also look under the car where the filler joins the tank, a couple of different size joints rubber to metal, look for fuel stains.

A hq is actually a nice car when taken care of or restored, when referring to burnouts, you're more in about the vn vp bogans aren't you?

I've heard that if the charcoal canister in the engine bay is faulty it can give off a fuel smell.

Any way to test the canister?

Any way to test the canister?

I'm checking YouTube for you to get some ideas... these examples may not be Mitsubishi but I assume the operating principle is the same.


https://www.youtube.com/watch?v=HkttFZBn1uw


https://www.youtube.com/watch?v=oEu5IwYmI20

Thanks :)

I have a similar problem of having a faint fuel smell. I don't think it has anything to do with WOT - Wide Open Throttle. I have the feeling it is the charcoal canister or similar. When I take the fuel cap off there seems to be a lot of pressure in the tank. I am not sure it was always this way.
I looked at the utube videos of the guy in America, with his theory that the valve get corrosion in it and it can be freed up with WD40. I disconnected the charcoal canister and just jointed the hoses together and it didn't seem to go away, but the fuel smell is really strongest at the canister when it is connected. There is a vacuum operated valve that I think opens at certain operating conditions to burn the fumes though the engine. I was wondering if anyone had any trouble with that.
Want to get it fixed soon or the wife will want a new car. (I have one)

The canister is full of carbon granules. The canister is open to atmosphere at the opposite end to where the inlet hoses connect. The open port to atmosphere has to be open and not clogged with dirt etc..
The canister functions by ADSORPTION of the vapour ON TO THE SURFACE of the granules. The granules dont have an unlimited ability to adsorb the vapour, so if it happens on a hot day then the the granules cant adsorb any more vapour and so the vapour spills out of the canister.
When the motor starts there is a valve which opens to the motor to allow the vapour to be sucked back in to the motor.
The granules can become contaminated over time and then it is necessary to either replace the canister or rejuvenate the carbon granules. To do this, dismantle the canister and remove the carbon, and heat the granules in an oven at a high temperature; 200 degrees C is not too hot but hot enough.
hope this helps.

Thanks for the input.

I have noticed that it doesn't smell if the car is full or near full.

"I have noticed that it doesn't smell if the car is full or near full. "
The fuel tank gets pressurised under normal operation of the car. If the tank is full or near full, there isn't much volume of fumes to leak out before the tank pressure dissipates. The fumes would leak out quickly and then the problem apparently goes away until you start up the car next time. You would find that the problem is even worse with a near empty tank. The issue is to find out where the leak is, and I suspect that it is your fuel cap. You could get the car with a near empty tank and then start sniffing around the fuel tank cap and the charcoal canister. The empty tank will hold up the pressure longer than a full tank for this test. Obviously don't use a naked flame to sniff.

Another cause would be a simple fuel leak somewhere, but I would hope that you have already ruled that one out.

I've checked and not noticed a fuel leak.

Checked for smell in the engine bay and there was none.

Does smell around the fuel cap, and after removing the fuel cap there is no depressurization.

The only reason I was/am skeptical of the fuel cap is how does the smell enter the car at speed?

"The only reason I was/am skeptical of the fuel cap is how does the smell enter the car at speed? "
At speed, do you have the windows up or down? If you have the air control on recycling, you can get all sorts of fumes (including exhaust gas leaks) into the cabin. The petrol fumes could easily come from the fuel cap, and then pass to the low pressure area at the rear of the car. From there, it can be sucked inside the cabin. I always run with the car air on fresh air, especially on a dusty road, to minimise dust entering the car. If dust can get in, so can petrol fumes. Similarly, if the windows are down, you cannot pressurise the car and petrol fumes can come in from anywhere.

Fixed mine! I was unable to get a new charcoal canister from Repco or Mitsubishi. Went for a trip to the friendly wreckers and could only find a similar aged Magna to mine. Took that one, but charcoal granules were falling out of it in the shed. I had a theory that they are basically the same on all cars, so the latest car I could find at the wreckers was a 2008 Suzuki Swift, so I grabbed that one too and paid $20 for both. (Plus the $2 entry fee) I did have to buy some longer vacuum hose to make it fit and it is held to the Magna bracket with zip ties, but there is no more smell. I wonder if this is a common problem with Magnas or cars in general about 10 to 13 years old? In my 10 years on the motor industry 1993 to 2002 I never had to replace a canister or have one replaced for any customer. Maybe I was lucky.