bigjayzway Posted July 14, 2005 Report Share Posted July 14, 2005 I have pulled all my hair out trying to find a gas leak. I have noticed a strong odour of gas fumes. We looked everywhere, but there is no leak. I went to take off the gas cap, and it flew out of my hand! I have never seen this much pressure in a gas tank. Is this normal? Does anyone have any suggestions? Big Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
jhall Posted July 14, 2005 Report Share Posted July 14, 2005 Some pressure is OK. I believe the owner's manual and possibly the gas cap label will indicate that the pressure should be allowed to vent before removing the cap. If it's really high, you might want to start looking at the evaporative system for a plugged or kinked line. Sounds really strange though. Link to comment Share on other sites More sharing options...
adallak Posted July 14, 2005 Report Share Posted July 14, 2005 I agree with Jhall. You cannot see a leak perhaps, because there is not anything wrong with the fuel lines etc. Just for some reason (dirt, plugs?) you got your system overpressurized and even tiny defect in fittings or something will let the gas vapores or even gas out. The same defect would never do that under regular pressure. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
jhall Posted July 14, 2005 Report Share Posted July 14, 2005 Big Jay, I did some checking and have some additional info that may help. This info was pulled from the Helms manual for a '97 Deville: There is an evaporative solenoid valve that receives 12 volt from the ignition circuit. When the solenoid is energized it allows the canister to purge. This might be the reason the tank pressure is building up - assuming the valve does not open, but I'm not too sure since a failure of the valve should cause a venting problem for the tank and would eventually cause a vacumm inside the tank itself. I'm not sure of the exact location of the solenoid on your car, but on a 4.6L it should be mounted on the rear valve cover on the driver's side of the car. Perhaps one of the other forum members can confirm the locations of the EAP Solenoid and the Purge Vacuum Switch. Ideally, you need a scan tool to check the valve operation, but there are some manual tests that you can perform. Turn the engine "off" and attach a hose to the vapor line that comes from the charcoal canister and try to blow through it. If air passes through the solenoid, replace the solenoid. A second test requires the use of the scan tool to put the PCM into EVAP solenoid override. Again, if you don't have the scan tool, you can try to feel if the solenoid is vibrating when the car is started - or use a voltmeter that can check the voltage to the solenoid and then use an ohmmeter to check the coil continuity. The Vacuum Purge Switch activates the evaporative purge solenoid and allows the charcoal canister to be cleared (fumes pulled into the engine intake) when a sufficient vacuum is present from the manifold. Good luck!! Link to comment Share on other sites More sharing options...
bigjayzway Posted July 15, 2005 Author Report Share Posted July 15, 2005 This is on my 94 Deville with the 4.9. My mechanic, canadian95sts, and myself have exhausted all options, and still cannot find the problem. I will have to try to find the solenoid, if there is one in the 4.9... this one is really starting to get to me! Life is too short to grow up! Link to comment Share on other sites More sharing options...
Bob D Posted July 15, 2005 Report Share Posted July 15, 2005 You can run diagnostics on your car with the on board OBDI system. Just push and hold the off and warmer buttons on the climate controls system. It will blink, and begin to read out codes, if they're are any. This may help lead to to the source. It sure sounds like a plugged purge line, or the charcol canister. You can read the codes by going to the FAQ section on the home page here, or post them, and somebody will help. '93 STS.. opened, dropped, wide...fast. Link to comment Share on other sites More sharing options...
bigjayzway Posted July 15, 2005 Author Report Share Posted July 15, 2005 There is nothing in the codes. You read the codes how??? I should hope I know how by now...LOL Life is too short to grow up! Link to comment Share on other sites More sharing options...
chevyorange Posted July 15, 2005 Report Share Posted July 15, 2005 Is it in the cabin or just outside the car? If inside, check for cracks in your air box on the firewall. Just thinkin'. Link to comment Share on other sites More sharing options...
bigjayzway Posted July 16, 2005 Author Report Share Posted July 16, 2005 No it isn't coming in the cabin, unless I roll the windows down. my mechanic and myself have searched our brain out, and come up with nothing so far! Life is too short to grow up! Link to comment Share on other sites More sharing options...
maydog Posted July 16, 2005 Report Share Posted July 16, 2005 Have you checked the fuel pressure regulator, fuel rail and the quick disconnects to the fuel line. The 96 aurora had a fuel leak we could smell when we would put the car into reverse. I could never find it until I started wiggling the lines with the engine running - one of the disconnects would squirt gas with some lateral pressure on the line. Link to comment Share on other sites More sharing options...
bigjayzway Posted July 17, 2005 Author Report Share Posted July 17, 2005 Yup...tried that too. We tore a lot of stuff off today, and seems like it won't give is an odor when we are working on it. I find if I get her really hot, then it becomes strong, but then it is too hot to get in her to look. Life is too short to grow up! Link to comment Share on other sites More sharing options...
Ranger Posted July 19, 2005 Report Share Posted July 19, 2005 Check all the lines to and from the EVAP valve and the charcoal canister. If those are OK then I would suspect a malfuntioning solenoid. Link to comment Share on other sites More sharing options...
bigjayzway Posted July 19, 2005 Author Report Share Posted July 19, 2005 I don't think we checked the canister yet! I will give it a shot!!! Thanks a lot. Big Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
sonjaab Posted July 20, 2005 Report Share Posted July 20, 2005 BIG JAY................Since you live in the land of salt, snow and rust. Heres a thought................... You could have a rotted fuel line in the frame rail............ Small pinhole leaks are hard to find. Usually the frame rail will always be dry and no stains are visible. But lots of gas smell! Easy to check..............Wrap a rag around a air blower nozzle. Insert into fuel filler and apply pressure CAREFULLY !!!!!!!!!! Check frame rail, gas line, and hoses for leaks...................... Gas evaporates quick so 1 guy putting the air to the tank and 1 guy looking works best !!!!!!!!!!!!!!! Been there and done that with my old winter rat cars here in salt, snow and rust land NY.......................geo 93 DeVille-13 Chevy Impala 72 GTO - 77 Triumph Bonneville 84 Z-28 Syracuse NY Link to comment Share on other sites More sharing options...
bigjayzway Posted July 20, 2005 Author Report Share Posted July 20, 2005 Easy to check..............Wrap a rag around a air blower nozzle.Insert into fuel filler and apply pressure CAREFULLY !!!!!!!!!! Check frame rail, gas line, and hoses for leaks...................... Gas evaporates quick so 1 guy putting the air to the tank and 1 guy looking works best !!!!!!!!!!!!!!! Now there is something I have not even thaught of trying? Big Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
adallak Posted August 24, 2006 Report Share Posted August 24, 2006 Easy to check..............Wrap a rag around a air blower nozzle. Insert into fuel filler and apply pressure CAREFULLY !!!!!!!!!! Check frame rail, gas line, and hoses for leaks...................... Gas evaporates quick so 1 guy putting the air to the tank and 1 guy looking works best !!!!!!!!!!!!!!! Now there is something I have not even thaught of trying? Big Jay Have you found the leak?? The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
bigjayzway Posted August 26, 2006 Author Report Share Posted August 26, 2006 I am sorry I forgot to post. I figured out a way to get rid of the fumes on this car!!!! I SOLD it! Big Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
BodybyFisher Posted August 26, 2006 Report Share Posted August 26, 2006 I like your innovative ways to solve problems, buy cheaper radiator without oil cooler and eliminate the oil cooler... gas leak, can't find it, sell it.... Can't fault your results.... Problem solved! Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
bigjayzway Posted August 27, 2006 Author Report Share Posted August 27, 2006 I like your innovative ways to solve problems, buy cheaper radiator without oil cooler and eliminate the oil cooler... gas leak, can't find it, sell it.... Can't fault your results.... Problem solved! Yeah Mike you know me. I will play so long, then pass the headache on....LOL Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
BodybyFisher Posted August 27, 2006 Report Share Posted August 27, 2006 Hope all is fine Jay, Mike Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
jfreezn Posted August 27, 2006 Report Share Posted August 27, 2006 Yup...tried that too. We tore a lot of stuff off today, and seems like it won't give is an odor when we are working on it. I find if I get her really hot, then it becomes strong, but then it is too hot to get in her to look. I vote strongly for the evap control solenoid, on the 4.9 it appears to be mounted just to the driver's side of center on the fireewall. Especially if you have been running a lot of ethanol fuel, such as E-85. Remove it and see if you can blow through it with the coil energised. On my 95 Mustang, the solenoid valve rubber melted and clogged the valve. Then the purge cannister overflows through an open vent line, and vents into the fender well or someplace you can't see but you surely can smell. Regards, Jim in Phoenix Jim in Phoenix Link to comment Share on other sites More sharing options...
KHE Posted August 28, 2006 Report Share Posted August 28, 2006 I like your innovative ways to solve problems, buy cheaper radiator without oil cooler and eliminate the oil cooler... gas leak, can't find it, sell it.... Can't fault your results.... Problem solved! Jay, Are you car shopping? What are you driving now? Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
bigjayzway Posted August 29, 2006 Author Report Share Posted August 29, 2006 I like your innovative ways to solve problems, buy cheaper radiator without oil cooler and eliminate the oil cooler... gas leak, can't find it, sell it.... Can't fault your results.... Problem solved! Jay, Are you car shopping? What are you driving now? I am driving the 98 STS, and a 1988 Chevy conversion van. They are both great. Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
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