truck back to acting up, Engine knock at idel

[jonstreet]

Just noticed this , but when I first bought the truck drove after a tune up and oil change, the oil pressure dropped and started knocking, pulled over and parked on the highway got it towed to the nearest Auto store and did a flush haven't had a problem till now. I oil pressure would always move up and down with the gas pedal, under a load and stuff, was told this is a good thing means its working?, So tonite coming home I noticed that the oil pressure IS not Move at ALL! bad? was going to replace the oil pump with a newer style high flow, but thought I'd ask the CREW what you guys thought? THX JON

 

[SAATR]

Lots of possibilities for low/no oil pressure, and the pump is only one potential cause. You mentioned that a flush helped out the first time. If that's true then you had/have a fairly significant sludge problem, and probably need to just drop and clean the oil pan and pickup tube to restore oil pressure. You may also want to check under the valve covers and in the lifter valley as sludge will accumulate there as well. A good mechanical cleaning followed by several flush and short oil change cycles should help a lot.

 

[ShadowRejects]

Dropping the oil pan is no easy task. But it honestly sounds like an oil pump issue. Knocking is never good.

 

[jonstreet]

Yes its a scary scenario, the truck does have the gummed up valve covers even when just looking threw the oil cap, It did smoke after oil changes put the truck sat for awhile before I came along, I do call it a knock but its only at idle mainly on first cold to cool start ups I think i'll plana deep clean for tomm. and hope for the best.

 

[jonstreet]

the knock is more like a ping, and its hard to tell where its coming from, with exhaust and the oil pressure acting out could just be me thinking of the worst but I can't have this truck fail. thx guys!

 

[jonstreet]

ahh ha! the exhaust manifold has a crack in it, this maybe the pinging I'm hearing, I Hope!

 

[jonstreet]

Lots of possibilities for low/no oil pressure, and the pump is only one potential cause. You mentioned that a flush helped out the first time. If that's true then you had/have a fairly significant sludge problem, and probably need to just drop and clean the oil pan and pickup tube to restore oil pressure. You may also want to check under the valve covers and in the lifter valley as sludge will accumulate there as well. A good mechanical cleaning followed by several flush and short oil change cycles should help a lot.

the flush I'msure helped but I sat on the side of the hwy for about an hr and when I started it back up I had oil pressure and limped to the next exit and got a tow to an auto parts store and did the flush to make sure whatever caused it to gum up was out. but i'll do everything you guys said as a precaution I got a trip planned, thx Again!

 

[highspeed]

Some start up "knocking" could be piston slap also. I have 60+ psi of oil pressure at cold start, and i get piston slap on cold starts

 

[jonstreet]

yeah but wouldn't it continue mines just at idle likei think i said the oil pressure would move the the throttle now it like it wants to stay about 60psi a buddy pulled at yota on a dollie the other day and said I seem to have good compression and all, he thinks it might be a Cam bearing? anythin on this idea guys thx again Jon

 

[highspeed]

Compression shouldn't have anything to do with oil pressure. If a cam bearing was going out, you would have fairly low oil pressure and some metal shavings in your oil. Both would be signs of a ticking time bomb.