Cold start noise
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Freshman User
Joined: May 2006
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Cold start noise
I did a few different searches and didnt see anything. Its been doing it for many years now, but I wondered if other V10s were doing it too. When I havent driven my truck for a week or so and start it, the initial cold crank results in a half second loud noise. The noise is actually hard to explain. I hate to say it, but it almost sounds like a frozen motor part breaking free.
I imagine that the oil has pretty well settled out of the engine and into the pan and perhaps for a split second the poor motor has to spin with very little lubrication till it circulates or is spread a bit.
Perhaps I should move on to synthetic or something.
Any thoughts?
I imagine that the oil has pretty well settled out of the engine and into the pan and perhaps for a split second the poor motor has to spin with very little lubrication till it circulates or is spread a bit.
Perhaps I should move on to synthetic or something.
Any thoughts?
Logistics Pro
Joined: Jan 2002
Posts: 3,733
Likes: 38
The noise you hear has been discussed a lot but mostly under cold start puff of smoke threads
If you are using 5W20 MotorCraft it is a semi synth blend
I doubt the quick romp to higher rpm and the associated noise that I get (maybe 3-4 times a year) will cause any serious damage or wear. Mine only does it after sitting more then three days during cool/cold weather. It does not do it no matter how long sitting in warm weather. I live in an area where the low temp can still be above 70 over night.
What I think is happening is two stage...during the long inactivity the fuel pressure is bleeding down... I think some may seep past injector seal into one or more cylinders
I know the vacuum is bleeding down (blend door slamming shut)
So the vacuum and fuel have to build up for some length of time to be back to normal. On Cold start the PCM detects the Air and coolant temps are cold and sets a richer then normal start condition
That is where we get the sudden high rpm initial start, some times with a puff of blue smoke and always startling...
I think the sound is mostly exhaust related and not bad mechanical motor clanging and banging...
It happens so fast I can not really tell..could be valve train clatter... but what I hear is deeper growl so I am not too concerned
If you are using 5W20 MotorCraft it is a semi synth blend
I doubt the quick romp to higher rpm and the associated noise that I get (maybe 3-4 times a year) will cause any serious damage or wear. Mine only does it after sitting more then three days during cool/cold weather. It does not do it no matter how long sitting in warm weather. I live in an area where the low temp can still be above 70 over night.
What I think is happening is two stage...during the long inactivity the fuel pressure is bleeding down... I think some may seep past injector seal into one or more cylinders
I know the vacuum is bleeding down (blend door slamming shut)
So the vacuum and fuel have to build up for some length of time to be back to normal. On Cold start the PCM detects the Air and coolant temps are cold and sets a richer then normal start condition
That is where we get the sudden high rpm initial start, some times with a puff of blue smoke and always startling...
I think the sound is mostly exhaust related and not bad mechanical motor clanging and banging...
It happens so fast I can not really tell..could be valve train clatter... but what I hear is deeper growl so I am not too concerned
Elder User
Joined: Mar 2005
Posts: 735
Likes: 1
From: SW Iowa
I attribute it to the Power steering pump winding up and pressurizing the hydralic system. I get it on cold start up and lasts only a couple of seconds. My crown vic 4.6 will chirp the serpentine belt for just a second on a real cold start up. Again, ps pump.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,562
Likes: 424
From: Long Island USA
This is a known "weirdness" with the V10.
I get something once in a while like a "HrrrrrumMMMPH!"
I theorized that it's the IAC being wide open, sorta like holding the gas pedal half-way down with a carburetor.
The V10's instant-on torque makes a huge sucking sound
I get something once in a while like a "HrrrrrumMMMPH!"
I theorized that it's the IAC being wide open, sorta like holding the gas pedal half-way down with a carburetor.
The V10's instant-on torque makes a huge sucking sound
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