Reply With QuoteDoes this sound go away after it's running or is it continuous???, if you didn't have adequate oiling at start up you would hear the lifters clatter. If the mains are shot you won't here a grinding sound!. Is the starter hanging up???????
My girlfriend has a 3.8 V6 in her mustang, which is the first problem, the second problem is, when she starts it up, there is a loud grinding sound coming from under the car. Its a 5 spd and it does it with the clutch in and out, eliminating the throw out bearing and main shaft bearing on the trans... I think. What I think is happening is the the main bearings are not getting oil off start-up and are grinding up real bad. Her father seems to think its the air conditioning, however when I pop the hood and start the car, you can't hear anything from the front of the car, only under it.
So my question is, does anything think I am right on with my prognosis, and to show my g/f's dad he doesnt know what the f is going on, is it terribly bad for a car to be turned on and off with the A/C on (his theory why its making that sound) ? I have a friend who leaves his A/C on from the day he buys the car to the day he sells it and has never had a problem like this. Thanks guys !
Does this sound go away after it's running or is it continuous???, if you didn't have adequate oiling at start up you would hear the lifters clatter. If the mains are shot you won't here a grinding sound!. Is the starter hanging up???????
Remove the serpentine belt and start it if the noise is still present you just eliminated the a/c.
doesn't sound like a main bearing noise if it goes away.
Check the exhaust system.they are notorious at cold start for making noise.
next smack the cat converter with a rubber mallet see if the converter is coming apart on the inside.
But what do i know i only work on Fords everyday.
One other thing you may want to check.
check the motor mounts if they are weak or worn out the exhaust may be grounding out against the frame.
I checked with my buddy, he's a service manager at Earnhardt Ford here in AZ, and he says that in older cars having the A/C on while starting the car would over load the buses, whatever they are, since both the starter and A/C units would be drawing a lot of amperage at the same time, both working against one another. He said this hasn't been the case for some time since there is an interrupt for the A/C when starting your car. He also says that he doubts that it's a main bearing since it stops. He says if the bearings were grinding it wouldn't stop and would keep up since you would most likely be doing severe damage in the begining. He said to check the inspection cover on the trans housing, sometimes they come loos and one of the mounting ears grinds on the flywheel and makes a really bad noise until it moves.
He said that you can call him if you want....480-838-4442 his name is scott.
DAMN you guys are helpful ! The sound does go away, and th oil pressure jumps up real fast on start up, so I guess I can elimnate my theory. I like the exhaust theory, what in there makes noise that would go away after about 10 seconds off start-up though ?
The car has 115k miles on it, so it's no spring chicken, but the noise just started happening in the last month or so. She says she can also hear it after a long drive on the freeway (La Canada to Northridge) when she gets off, it makes that same grinding sound.
But I'm telling you, it comes from under the car, right in the back of the motor, so tranny and exhaust are right there. It happens almost every time you start the car up if it sits for more than an hour maybe when its hot, and every time you start it consecutivley when its cold. Thanks again guys, you rock, I really want this fixed so she will stop bugging me to drive my car !!!
My girlfriend has a 3.8 V6 in her mustang, which is the first problem, the second problem is, when she starts it up, there is a loud grinding sound coming from under the car. Its a 5 spd and it does it with the clutch in and out, eliminating the throw out bearing and main shaft bearing on the trans... I think. What I think is happening is the the main bearings are not getting oil off start-up and are grinding up real bad. Her father seems to think its the air conditioning, however when I pop the hood and start the car, you can't hear anything from the front of the car, only under it.
So my question is, does anything think I am right on with my prognosis, and to show my g/f's dad he doesnt know what the f is going on, is it terribly bad for a car to be turned on and off with the A/C on (his theory why its making that sound) ? I have a friend who leaves his A/C on from the day he buys the car to the day he sells it and has never had a problem like this. Thanks guys !
Pilot shaft bearing !!!
In those they run a real sealed bearing and it can go bad.
It does not hurt it to leave the A/C on it is just harder on the battery.
un plug the A/C and start it.
It may just be the ideler pully. Mine is going bad and makes a real nasty sound.
Also the throw out bearing can be bad even if old school test shows it not to be cause.
Engine main bearings no !!!!
Jim
Since this thing is a stick, bump start it cold. If it still makes the noise you can eliminate the starter staying engaged..............MP
The sound is not coming from the front of the motor, so I think I can eliminate the accesory drive. I will bump start it though to elimnate the starter.
How can I find out if its the exhaust though ? Hammer the cat while its started, see if it stops ?
Pilot shaft bearing !!!
Agreed. I had a car that did that one time (but not a Ford), and it was as you described.
If we starting a pool...I'll put $10 on the pilot shaft bearing.
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