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fuel seeping from my valve cover

1260 Views 10 Replies 3 Participants Last post by  *ka24e*
A long story short..went away in the winter for three months while the car sat. When I came back I knew I would have a dead battery, but when I started it the engine shook and gas started to drip out of my valve caver..yes,the valve cover. I gave it a complete tune up prior to leaving and she ran like a champ. Since this problem I have replaced the oil and filter from contamination,the fuel filter,the spark plugs,the injectors,and the fuel pressure regulator, and I still have the problem. I have no idea whats going only guess now would be a worn or cracked cylinder. Now we had a bad winter with snow and freezing temperatures but I don't think that's what caused it. I never drove the car a lot(milage wise) and never drove it hard. She has 260,000 miles on it and the previous original owner really babied her. The car sat for three months untouched. I'm at a loss and I'm starting to get desperate and losing my hair from pulling it out. Can someone help me?...sincerely,Desperate
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Is it fuel diluted oil, or straight up gas? You sure its coming from the valve cover, lol? And finally, would this be a SOHC or DOHC?
It's a sohc,it is is gas,and's coming from the valve can see it spurting out from the seam in the back right hand side facing the motor. It's also filling the car up with a strong gas smell. I will try and take pics and post them but I dont want to keep the car running under these circumstances. Every mechanic I called said they never heard of it so I'm stumped. The oil dipstick even smells like gas.
I cannot think of any way gas would be spurting from the valve cover...... This is going overboard, but maybe if a valve seal was completely destroyed/removed etc, gas could be shooting up into the head, causing the oil level (in the head, not the crankcase) to rise up past the valve cover gasket, and gas could be leaking out. But, gas would only be spurting or spraying out if the crankcase pressure rose dramatically enough to literally push oil/gas out of a weak spot in the valve cover gasket.
I forgot to ask but how does it run?

Here's a list of things to try:
1. Start the car without the oil cap on. (hold a rag slightly over it to prevent oil from splashing, but be careful of the fan)
If you have excessive crankcase pressure, this will eliminate that. See if gas still sprays out with the cap off.

2. Take the valve cover off and inspect the valve seals. There kinda hard to see, so get a bright ass light and make sure none of them are destroyed.

3. Check each cylinders spark plug. If any one of the plugs are completely fuel fouled, ohm the injector and see if it isn't stuck open causing a massive fuel dump.
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Yeah it is a strange thing. As far as the car running.. she was rough when I first started her back in April..the motor shook a lot. After I replaced everything as stated in my first post she wouldn't start at all which was strange cause she started before..the motor would try and turn but not start. I pulled the first two plugs right under where the leak is and they were soaked. The last two were completely dry which led me to believe it might have been my injectors cause I'm assuming if it was my pressure regulator all of them would be soaked. So I replaced the injectors,the regulator and the plugs and she finally turned over without the engine rock but the gas seep still and the strong gas smell inside the car.
Any leaks at the fuel rail? Maybe its shooting gas over to the valve cover and it looks like its pouring out of the cover itself.
no leaks at the can see it spurting right out of the seam of the valve cover just in the back right corner. I will try and do what you said and see if that helps, but like I said, I'm stumped. I wanted to try and fix it myself because I cant think of anything major that is wrong with it. It sat for three months. I know my mechanic can hook the code reader up to it and see exactly what it is, but the cost of towing,parts,and labor is something I can not afford right now. I'm just mentally exhausted from it lol and I want my car back.For a while something was telling me that it's something small I can do myself but now I'm starting to have doubts because I thought I narrowed down the process of elimination but I still have the problem after spending money on the parts that I thought was causing it.
Your mechanic can hook up the code reader........? To what, lol?. You can check codes yourself with a Phillips screwdriver, and a small flat blade screwdriver. The 89-90's did not have OBD2 hook-ups. To check codes you had to read a series of blinks/flashes from two LEDs on the ECU itself.
Here's a tutorial on how to do it:

WikiAnswers - What are the codes for the ECU on a 1990 240sx

The ECU itself is behind the passenger side kick panel. Unbolt the ECU and spin it 180 degrees to access the screw and see the two LED (one red, one green) lights.
thanks bad. I appreciate all your help.One more thing,could it be the O2 sensor?
Causing the fuel leak? Very doubtful. The o2 just picks up air fuel ratio and reports back to the ECU. Besides that, the ECU only accepts the o2's signal in closed loop (cruising, idle) and it ignores it at WOT.
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