Tazzy

New to Mustangs, I have an 04 Mustang GT that I just purchased with the 4.6L with 76k miles on it. Question is, Is it normal for the engine to rattle for a couple seconds when first starting it after setting a couple hours? Sounds like crank bearing rattle to me. Was thinking that maybe the oil filter was emptying during sitting causing the problem. Is there a brand of filter that can hold the oil for extended periods? Any input would be appreciated.

Obsequious1

Sometimes when I start my car I hear a rattle too but I think its my exhaust. It sounds like its coming from the flywheel area. Mine is a 5 speed manual btw. It comes and goes as it pleases. I use Fram filters. I think all oil filter " mounted vertical " hold oil always.

cliffyk

After sitting for "a couple hours", and if it does it every time you start is a bit excessive. What weight oil are you running, what weight oil did the PO run and how often did they change it?

What is the climate where you live?

'Twas me here in Florida I'd put 10W-30 dino or synthetic in that puppy and see how it does for a couple thousand miles. If it still rattles consistently after a couple hours of rest (if it is) then I'd go to 20W-50 MaxLife...

I have 78k on mine (10W-30 synthetic) and it has a bit of a rattle 2 or 3 times a week in the morning. Part of this is that new EFI cars start too damned fast and the oil pressure does not have any time to build while cranking. Running that ****-thin 5W-20 crap does not help this out in the long term.

I have seriously considered installing a fuel pump kill switch so that I can crank it for a couple seconds before a cold start.

mustangman281

You should only use motor craft filters on a modular engine because the are designed to not let oil drain back.

But I don't think that is your problem. More then likely you have what is called piston slap. It is very common in ford modular engines. It is caused by the piston rings being undersized. It causes the piston to rock making the noise you hear until the chamber temp rise and the rings expand. Talk to the 4v guys they get it most. It doesn't hurt anything its just embarrassing.

Its the price you pay for buying the cheapest sports car on the market.

cliffyk

Every modern oil filter I have ever dissected (and I've done more then these) has an anti-drainback valve--they could not claim to meet OEM specs without it, and it's a hard thing to fake...

Tazzy

I'm using Mobil 1 5W-20 as recommended for the car, and my oil filter sits horizontally not vertical. The rattle seems to coincide with the oil pressure gauge, when I watch the gauge while starting, the engine rattles until the guage reaches the normal running position which takes a couple seconds on a cold start. I'm going to find a filter with the anti drain back and give it a try. It doesn't rattle every time, only after sitting for 4-6 hours which leads me to think the oil filter is draining.

DaRkHoRsE2003

It may be your valves rattling because my car does it sometimes. The deal on the oil is just keep running 5w20 because its the best for the engine. Anything thicker would cause less oil flow robbing you of power and engine life. Run full synthetic if you want the best performance (Mobil 1). I bought my car with 27000 miles now i have 93000 and ive ran Mobil 1 synthetic the whole time for 7500 miles between changes. The oil in my engine to this day is still clean (mild brown) after i put 7500 on it after a oil change. For the engine knocking you can try Lucas Fuel System Cleaner and Lubricant which cleans injectors and lubricates your whole fuel system and upper cylinders.