Engine/pump/something stays on for a few....

[peter.sellers]

seconds after I turn the engine off. Anybody know if this is some oil pump that cools the turbo? I was thinking of getting a turbo timer but if there is some sort of built-in-timer, I might put buying a timer off for a while.....

Sorry if this topic has been beaten to death and answered somewhere else.....

Thanks

 

[Bu11dogg2]

cooling fan

 

[dan1101]

My cooling fan stayed on for the first time ever on Sunday. It wasn't even that hot outside.

 

[Bravnik]

The fuel pump also stays on for a few as well. There are actually quite a few circuits live for about 30secs after you turn the car off.

 

[dan1101]

There's something towards the back passenger side of my car that I heard once. Could have been the fuel pump but IIRC it was something else.

 

[oaklandopen]

i belive the owners manual may say something about it as well

 

[LBV]

You'll hear your throttle body making a noise too right behind the rad.

 

[nullmod]

There's something towards the back passenger side of my car that I heard once. Could have been the fuel pump but IIRC it was something else.

I heard a strange whirring noise back there as well; I never did figure it out. Once, it happened a while (hour plus) after shutting the car off. Came on for about a minute and then shut off...

 

[dan1101]

I heard a strange whirring noise back there as well; I never did figure it out. Once, it happened a while (hour plus) after shutting the car off. Came on for about a minute and then shut off...

Somebody here or the "other" message board told me what it was. Smog pump? Can't remember.

 

[Speed3B]

Smog pumps are a pain to fix. You should get the car looked at!

 

[justanothermp5]

my moms cx7 does this too, its weird
u turn off the car and then get out and if u listen by the front u can hear that something under the hood is still running,then it turns off after like 10 secs

 

[Hank3]

Yeah - it's a high-pitched electronic noise. I thought it was the headlight leveler, but it isn't. The radiator fan does stay one once in a blue moon. Not when I drive it hard - usually at times I don't expect it to.

 

[matsuda]

1) The high pitched noise immediately after shut off (for 20~30 sec.) is the throttle body.

2) A noise from the rear that happens hours after shutting the car off is a pump used for testing the evaporative emissions system for leaks.

 

[Hank3]

1) The high pitched noise immediately after shut off (for 20~30 sec.) is the throttle body.

Hmmm...mine doesn't seem to stay on that long. Maybe 10 secs. tops. And pardon the ignorance, but is it just its shut down process or something?

 

[Bravnik]

1) The high pitched noise immediately after shut off (for 20~30 sec.) is the throttle body.

Yep this is fact. Mine even squeaks a bit when shutting down. Worries me sometimes to be honest but thus far no issue.

 

[MikeHTally]

I suspect something is making the engine oil circulate for a few seconds after shut-down. Mine is accompanied by a few clicks, like solenoids are switching.

 

[matsuda]

Hmmm...mine doesn't seem to stay on that long. Maybe 10 secs. tops. And pardon the ignorance, but is it just its shut down process or something?

You are right, it is closer to 10 sec.

The ECU is doing a test/calibration procedure for the throttle body motor and sensor (used for position feedback).

 

[matsuda]

I suspect something is making the engine oil circulate for a few seconds after shut-down. Mine is accompanied by a few clicks, like solenoids are switching.

You may be hearing some relays.

There is no oil circulation (the oil pump is engine driven).

Regarding turbo cooling, the following was lifted from the Honeywell web site:

Water-cooling of turbocharger bearing housings has been widely used to enhance bearing durability. It is designed to remove heat from the center housing after the engine is shut down. This is accomplished because a thermal siphon is set up in the center housing. As heat from the turbine housing and exhaust manifold soaks into the center housing, the water is vaporized and rises, drawing in cooler water. This continues until there is insufficient heat to cause the process to continue.

Many would argue (including turbo manufacturers) that a turbo timer is unnecessary for a water cooled turbo. If someone wants additional piece of mind, they should simply use synthetic oil and forget the turbo timer.

 

[mo4130]

its the midgets that run your turbo

 

[matsuda]

its the midgets that run your turbo

No, it's hamsters.