I have a '94 Mustang V6 and all of a sudden I start it up one day and there is this loud clicking which sounds like it is coming from the center of the engine. After 3 minutes of idling, the clicking got softer and then stopped. I drove it and it ran fine. Next day, same thing. I changed the oil and filter, and it was fine for about a week. Now, every day when I start the engine after the car sits a few hours, the loud clicking starts. If I drive the car, after 5 minutes or so, the clicking gets softer and then stops. I check the oil level it is not low on oil. Someone told me it might be the lifters not getting oil.
It could be low oil pressure or worn main bearings, but it more likley you are experiencing "piston slap." This is a noise generated by the pistons rocking in the bores. As the piston reach the top or bottom of a stroke, the rod angle shifts from one side to another, changing the side trust on the piston from one side to the other. This casues the piston to rock in the bore. If there is excessive clearance, there is a lot of movement and the piston builds up enough speed to hit hard enough to generate an audible click. As the engine warms up, the piston expands faster than the bores and the clearance is reduced, so the noise goes away. Changing oil brands / viscosity might reduce or eliminate the noise. If not, you would need to rebuild the engine to compeltely eliminate the noise. Since your car is older, it is likely that the piston slap (if it is piston slap) is related to wear. In recent years piston slap has been a common complaint even for new engines (Ford, GM, Toyota, Nissan have all had problems). If the noise goes away relatively quickly, I would not worry about the noise. Fixing it might cost more that the cost of the vehicle. As long as the engine is running OK and not using oil, just keep driving. However, it is not a bad idea to have someone check the oil pressure with a mechanical gauge. This would verify that your problem is not related to low oil pressure.
Well I understand the 4.6s are (were) known for that problem that Ed =
mentioned, but it kind of sounds like a bad lifter to me.
--=20 "I get the impression that Jamie is a papusa or two short of a combination plate." - Kent Wills
"So you think AUK is some kind of really tight knit CABAL? ROTFLMAO! Its a bunch of lazy tossers with too much time on their hands and few friends. WELCOME TO USENET. Drive thru please..." - =A7=F1=FChw=A4=A3f
Ok, well after reading all replies, after I verify that the oil pressure is OK, it sounds like there is not much I can do. I just need to live with it or maybe try synthetic oil or a heavier weight oil? I am using Castrol 5w/30 now.
If you live in the south you can use 10w/30 it is a little lighter, flows better. bet it is a lifter/valve and it may just go away in time. let car idle for a min before going anywhere, time gets oil flowed to all upper places, and computer is dialed in on conditions.
10w30 and 5w30 will have the same hot viscosity. Cold viscosity 5w30 =
is thinner.
--=20 "I get the impression that Jamie is a papusa or two short of a combination plate." - Kent Wills
"So you think AUK is some kind of really tight knit CABAL? ROTFLMAO! Its a bunch of lazy tossers with too much time on their hands and few friends. WELCOME TO USENET. Drive thru please..." - =A7=F1=FChw=A4=A3f
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