I have a 1990 Aerostar that has leaked gas 3 or 4 times and I have no idea why. I am not sure where it is coming from exactly but it seems to be towards the back of the engine, kind of near the torque converter. This leak happened 2 days ago when i was warming the van up and it was cool outside. The time before that, it was after driving for a while. The day before yesterday I drove it probably 50 miles with no problems and it was about 85-90 degrees outside. I drove it today and there was no leak and today is a cooler day.
This is not a common problem. Have you tried pulling the 'doghouse' door (the engine cover inside the cabin) and looking at the rear area of the engine for any signs of leakage there? With gasoline and a warm engine, it will evaporate fairly quickly unless puddled in one of the upper engine crevices. Is there a strong gas smell associated with the leak or when you remove the rear cover? If not, it may be a leak of a different variety.
A couple of likely components in the engine compartment:
The fuel vapor cannister has a rather hard plastic rubber line that runs across the front of the engine to the intake manifold. It's possible that line could have cracked, causing vapor leaks, but only when the EEC is trying to purge the cannister. So you could smell it at random times.
The other thing would be the fuel lines themselves. The high pressure line goes into the fuel rail on the driver's side of the intake manifold near the back. It has a threaded tube nut fitting with seals. The return line comes from the fuel pressure regulator at the front passenger side of the fuel rail. It uses a push-in fitting with an O-ring secured by a plate. If the leak is in the pressure side, you will be smelling gas all the time. If it's on the return side, you will most likely smell it while the engine is under low-load, like idling.
I had a badly seated gasket in the cap on the fuel tank, and I smelled gas most often when the tank was near full.
leaking gasoline in the engine compartment is a critical safety issue. please have a mechanic look at it immediately.
another possible to add to the guys above is the FPR Fuel Pressure Regulator, diaphram leaking gas or fuel return hose broken down and leaking gas. leaking diaphram will dump gas into crankcase and into engine compartment if its vacuum line is cracked. i've also seem them leak directly onto engine depending on design and construction.
also, could be a high pressure spray from the flex in/out lines on the fuel filter located on the frame rail, shooting forward. have seen these damaged by road debris logging road brush. the rubber flex breaks down with age.
Thanks guys for the replies. I am going to go look at it here in a few minutes to see if I can find any new clues. The only thing that confuses me is that I do not smell gas most of the time and I think if gas is leaking (even if I can't see it) I would smell it. Is it even possible that it is only leaking some of the time? If something is cracked or broken, its cracked and broken 100% of the time. By the way, the amount of gas that I lost the other day was significant, like a liter at least. It was just dripping from the van.
But I will tell ya, I love that van. I have never owned a van before and I was moving from Oregon to California so I thought it would be a good idea to buy the van. It was cheap and it did the job but I would like to keep it around a little longer.
Ok, enough of that. I will go see what I can find.
**************Here is the update**************************************
I just let it run for a few minutes and I pulled off the doghouse door. I could smell just a little bit of gas in the cabin but when I was looking around under the hood I really noticed the smell when I was near the input for the oil. I pulled the oil cap off to smell it and it did not smell like gas. So it seems the leak is near that area. When I went back into the cabin, I smelled around that side to see if the smell was as strong and it was not. But, I could not see any dripping. Ideas????
Did you actually see gas dripping before? And losing a liter, those are really dangerous conditions. Better keep a fire extinguisher handy.
Which engine is this?
The front is where the fuel pressure regulator is, and where the fuel return line is connected. The regulator at the front right corner of the fuel rail, which is sandwiched between the upper and lower intake manifolds. Find the fitting that the return line is connected to and see if there are signs of leakage around there. You may have to remove the intake air hose and throttle cable shield to see it.
If the diaphragm in th regulator is broken, the engine will run extremely rich, and not very well. It could send a lot of fuel down the exhaust and cause the catalytic converter to burn up, or catch the carpet on fire.
Good luck, and I hope this condition doesn't burn down your van.
Oh yeah, I did see the gas dripping before. This is not a vehicle that I need to drive so I can either fix it or get rid of it. I was hoping that they would pass the car trade in bill thing that they have been talking about but I did not see that it is official yet.
Anyway, maybe I will start taking things apart tomorrow and see if I get lucky.
Thus far, this does not sound like a gas leak because even a tiny amount of gas makes a very noticeable odor - even standing outside, next to the van. I hesitate to ask the next question, as you seem to have above average automotive skills but here goes: Since you recently acquired the van and may not be aware of all it's nuances, could it be possible that what you are seeing is condensation from the air conditioner? This would present as a leak of clear fluid on the passenger side of the van near the transmission area. Depending on humidity/temperature it may be evident some days and not others. Just a thought.
Thanks aerocolorado, I accept your observation of above average auto skills. I really know very little and figure it out as I go. I have recently become very knowledgeable about the transmission on my van.
Anyway, I know it is gas. There was no question about it, plus my A/C needs to be charged so it is not even being used.
So I just got back from a drive. I took it on a 5 to 10min drive where i got up to 60mph. I did that because I was not smelling any gas at all...from anywhere. I took the throttle cable guard off to see behind it and of course I could not see any liquid.
The other thing is that I do have a decent amount of liquid coming from my exhaust and so that made me think it could be the FPR because of what xlt4wd90 said about the fuel going down the exhaust. I smelled the liquid today and it had no gas odor.
So, is it possible that something is failing intermittently???? All I can think to do is to run it everyday and see if I can smell gas. If it dumps gas again I will try to get a video of it. Anyone have any other ideas?
My van was leaking between the plate that the fuel pump and level sensor was mounted on and the gas tank opening. The gasket that was supposed to seal that interface was not properly installed at the factory, so it must have been leaking since day one, all the way through the 4 years that the first owner had it. It was worst right after a fill-up. I had to lower the tank to open up the plate and re-seat the gasket.
I hope Nicole's 1990 Aerostar is still running, and did not go up in a blaze from the leaking fuel.
In my case, I saw traces of leakage on the side of the gas tank, and the gas smell occurred the most often and strongest right after a fill up. So that's where I looked.
If that's not where you're finding your leak, I would suggest looking along the fuel lines. Does you engine use fuel injection? There would be two sets of lines, the pressurized source line, and the return line that bypasses excess fuel back into the tank. A potential leak is in the pressure regulator. There is a vacuum line that attaches to its top side; you can pull it to see if there is fuel in there. That indicates the regulator is leaking, and needs to be replaced. The other thing that can cause gas smell is the fuel vapor recovery canister; its line has been known to break. But most of these problems can cause the engine to run badly.
Thank you. For the quick reply!!!!
Yes it is fuel injected..
I will check what you suggested ..
yes it does run bad..like has a vacuum leak..
I love the van..hate the fact that there is no room to see anything under the hood..
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