Rolls Posted January 17, 2013 Share Posted January 17, 2013 When I turn my car off in 37c+ weather the fuel pump makes this weird as hell vibrating whine, totally different noise to when it is priming or running though. I've even got a mate to be sitting with a multi meter ready and the pump is getting 0v but it still makes this weird as hell whining/buzzing/ringing noise for maybe 15 seconds after the car is switched off. Only happens if the car has been sitting in the sun and I've been driving around town getting everything stinking bloody hot, could it be fuel boiling or something odd? Anyone experienced things like this before? The pump was replaced before I got the car but I believe it is a nismo drop in for an R32, it is however still using the stock wiring loom and getting ~11v. Ideas? Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/ Share on other sites More sharing options...
scotty nm35 Posted January 17, 2013 Share Posted January 17, 2013 The fuel in the rail evaporating, causing the one way valve in the pump to release pressure? Do you have a gauge on it? Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6710610 Share on other sites More sharing options...
GTSBoy Posted January 17, 2013 Share Posted January 17, 2013 Yuh, it's the check valve leaking down. Normal. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6710647 Share on other sites More sharing options...
abr33 Posted January 17, 2013 Share Posted January 17, 2013 37 is cold! Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6710832 Share on other sites More sharing options...
GTSBoy Posted January 17, 2013 Share Posted January 17, 2013 Well, it's 42 here today. It's certainly not cold outside. Stepped out an hour ago and suffered a dehydrated eyeball in the first 2 seconds. I kept the other eye closed, just in case. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6710845 Share on other sites More sharing options...
discopotato03 Posted January 17, 2013 Share Posted January 17, 2013 Just out of interest could you could try releasing any pressure in your tank by cracking the filler cap before you shut down . Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6711059 Share on other sites More sharing options...
Rolls Posted January 17, 2013 Author Share Posted January 17, 2013 I can try that, is the fuel evaporating a bad thing? Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6711377 Share on other sites More sharing options...
ARTZ Posted January 17, 2013 Share Posted January 17, 2013 Damn pressure from.opening my half full tank today almost blew me away... Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6711558 Share on other sites More sharing options...
scotty nm35 Posted January 17, 2013 Share Posted January 17, 2013 So hook your damn carbon canister back up Artz. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6711588 Share on other sites More sharing options...
discopotato03 Posted January 17, 2013 Share Posted January 17, 2013 Pressure in the fuel tank doesn't help . A . Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6711603 Share on other sites More sharing options...
abr33 Posted January 17, 2013 Share Posted January 17, 2013 So hook your damn carbon canister back up Artz. Mine holds heaps of pressure and I have carbon canister still? Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6711636 Share on other sites More sharing options...
scotty nm35 Posted January 18, 2013 Share Posted January 18, 2013 It's not working then. The carbon canister is only a part of the evacuation circuit that sucks all the fumes from the tank and into the manifold. There should always be vacuum in the tank, (which is sometimes mistaken for pressure) or the system isn't working as designed. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712067 Share on other sites More sharing options...
discopotato03 Posted January 18, 2013 Share Posted January 18, 2013 My old Zoob RX Turbo used to pressurise its fuel tank in hot weather and if it was real hot (hight 30s/40 like today) I didn't tighten the cap . Its hardly going to fall out and I'd nip it up if I stopped anywhere . I think you can get weird things happening because the pump is trying to return fuel to the tank which is at higher than normal pressure . I think some of these problems occur because the fuel pump is circulating a lot more fuel than is necessary for the power being used and its possible that at low speeds the steel fuel lines may be absorbing some radiant heat from baking hot roads . I think manufacturers have sometimes integrated a heat exchanger into the air con system because of fuel temp problems in hot hot weather , may have been an early V12 Jag can't remember . A . Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712092 Share on other sites More sharing options...
JustinP Posted January 18, 2013 Share Posted January 18, 2013 When I turn my car off in 37c+ weather the fuel pump makes this weird as hell vibrating whine, totally different noise to when it is priming or running though. I've even got a mate to be sitting with a multi meter ready and the pump is getting 0v but it still makes this weird as hell whining/buzzing/ringing noise for maybe 15 seconds after the car is switched off. Only happens if the car has been sitting in the sun and I've been driving around town getting everything stinking bloody hot, could it be fuel boiling or something odd? Anyone experienced things like this before? The pump was replaced before I got the car but I believe it is a nismo drop in for an R32, it is however still using the stock wiring loom and getting ~11v. Ideas? I know the exact noise you mean, my motorbike has always made the same noise when its hot, from new. Sometimes even 24 hours + after driving it. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712209 Share on other sites More sharing options...
abr33 Posted January 18, 2013 Share Posted January 18, 2013 It's not working then. The carbon canister is only a part of the evacuation circuit that sucks all the fumes from the tank and into the manifold. There should always be vacuum in the tank, (which is sometimes mistaken for pressure) or the system isn't working as designed. Now that you mention it, that might be the case. Will investigate. On a similar topic why does my car stall after first start particularly when cold? Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712432 Share on other sites More sharing options...
GTSBoy Posted January 18, 2013 Share Posted January 18, 2013 Idle air valve sticky. Takes a moment to open up far enough to stabilise idle. Moment is too long. Clean up the valve so it moves faster and maybe it will react fast enough to catch the idle. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712481 Share on other sites More sharing options...
abr33 Posted January 18, 2013 Share Posted January 18, 2013 Idle air valve sticky. Takes a moment to open up far enough to stabilise idle. Moment is too long. Clean up the valve so it moves faster and maybe it will react fast enough to catch the idle. Ok, Thanks Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712487 Share on other sites More sharing options...
jiffo Posted January 18, 2013 Share Posted January 18, 2013 Some strange replies here so I'll add mine. While the car is running, fuel is circulating in the rail at pressure controlled by the fuel reg. Turn the engine off and the rail stays at pressure, maintained by the fuel reg at one end and the fuel pump at the other. All good. Now heat soak the fuel rail and that petrol will quickly expand, it has nowhere to go but to open the fuel reg and discharge to the tank. The noise you're hearing is the pressurised fuel slowly bleeding through the reg back to the tank until rail pressure has stabilised. Nobody else experienced vapour lock back in the old carby days? Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712607 Share on other sites More sharing options...
ARTZ Posted January 18, 2013 Share Posted January 18, 2013 But no Carbon cannister is worth +1000 street creds. but seriously my carbon canister has carbon falling out of it when i turn it upside down...is that normal? I'm quit happy to reinstall it if I know it works..I love having more junk in the engine bay to make life hard when I am working there.. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6712672 Share on other sites More sharing options...
Rolls Posted January 19, 2013 Author Share Posted January 19, 2013 Thanks for the explanation jiffo, makes sense now. Link to comment https://www.sau.com.au/forums/topic/417958-fuel-pump-making-weird-noise-when-car-turned-off-in-hot-weather/#findComment-6713440 Share on other sites More sharing options...
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