best way to flush engine?

What's the best way to flush an engine? Is any brand better than another? I heard that trns fluid might be best, as it won't ruin seals. Motor is a 1990 4.9L Ford with 100k+ miles. Has low oil pressure after warming up.

I take it that you've change the filter and oil. Does the pressure drop and then pick back up if you accelerate? If so you need bearings. if it increases you probably need a new pump. How low is the pressure anyway?

ervinj

your pressure will always drop at idle, and could also could be bad pump or cloged pickup. I would get some 10w-30 and replace one of the quarts of oil with marvels mystery oil, it will clean your motor out in no time. Change your oil every 500 miles doing the marvels thing about 3 times and it will be cleaned out in no time.

I take it that you've change the filter and oil. Does the pressure drop and then pick back up if you accelerate? If so you need bearings. if it increases you probably need a new pump. How low is the pressure anyway?

ervinj


Hi ervinj

Yes, I changed the oil and filter recently. Oil turned black after a few days. Yes, the pressure picks back up if I accelerate to about 2000 rpms for a while, then it stays low no mater what I do. I drive at about 1500 rpms. The pressure needle reads beyond low after that. I still have a dry start problem, with knocking for about 10 seconds until the pressure increases, then it's ok for about 5 minutes, then the low pressure thing begins.

thanks

bills150

your pressure will always drop at idle, and could also could be bad pump or cloged pickup. I would get some 10w-30 and replace one of the quarts of oil with marvels mystery oil, it will clean your motor out in no time. Change your oil every 500 miles doing the marvels thing about 3 times and it will be cleaned out in no time.


Hi 97chevyman

My pressure drops while I am driving at 1500 rpms, needle reads past low. What do you mean by clogged pickup? I live in a dusty rural area, could it be clogged with powdery sand? Will cleaning it out help stop a dry start? It seems to be worse in cold weather, with some squeaking coming from the driver's side of the motor and knocking until the oil pressure initially increases. Pressure drops after warm-up, takes about 5 minutes. I'll try the marvel and 10w30 thing. Motor is a 4.9L 6 cyl EFI.

thanks

bills150