lhill58

My 2007 5.4 Lariat 83,000 running MC 5w20 when warmed up to normal temps at idle oil pressure goes down to 23 sometimes but mainly stays at 25-26 measured with a mechanical oil pressure gauge. I have a VCT solenoid that was replaced on driver side 6 months ago with 3l3z-6m280-ea was quiet until here lately when I finally replaced the passenger side because of clanking noise after warm up in the 1000 to 1200 rpm range with 8L3Z-6M280-A which is a updated part according to dealer it is quiet as a mouse but the driver side is now clanking again. When I unplug the VCT the noise stops.
Wonder if my oil pressure is to low causing vct to make noise. Think I will take the oil pan off to check for any obstructions since i do get low oil pressure light sometimes on startup and have had the chain to rattle couple times in the last few months. dreading it since its 4wd have to drop the axle.

s_vares

whats your hot idle rpm? if its low, your oil pressure will be low.

lhill58

Hot idle rpm is around 580.

s_vares

maybe try some 5w30 in er next change. You may have blown out tensioner seals. They cause low oil pressure. how has the engine been maintained so far during its life?

CozyEvergreen

Throwing any codes? I've been battling something similar but it seems to have cleared it self for the time being. I was get a low rpm rough idle and p0012 as a code. Changes oil back to motor craft 5-20 and it comes and goes( the code) since changing oil and VCT solenoids the rough idle had all but disappeared but the code persists. I still have a horrible dry start unless I park the truck pointing down hill. Too much that can go wrong in the VCT system to diagnose without pulling it apart.

kevhead75

23 is fine. The VCT system will operate at 20 and below. If you were showing 15 I would be concerned.

Mod (Ret.)

^ Times two.

s_vares

I do agree with these guys, 23 is not too bad.
Im wondering if its a bum phaser as you said it goes away when you unplug VCT

kevhead75

Not to thread jack the OP but if you are getting dry starts I would suspect the chain tensioners. The seals on the back of them kinda suck(or blow haha)As you said you would have to pull the front of the motor off to check them. It seems harder these days to find a good mechanic that can do diagnostic work. A good diagnostic person should be able to monitor different pcm functions such as cam timing, position, etc and make an educated guess.

lhill58

I bought the truck last year in Feb. with 73,000 and no service records. I checked oil and fluids before I bought it which looked ok but it did have a generic oil filter on it when I first got it assuming the used car lot took it to a quick oil change place while they had it. I didn't know about the 5.4 oiling issues with non MC oil filters until I joined the forum later but as soon as I got it home that day I changed the oil and filter to motor craft. I didnt notice anything wrong with the truck while test driving just seemed like a slug but figured plugs were the problem and sitting on the lot. The Inside and outside was well taking care of and when I replaced the VCT I had to remove the valve covers there was no sludge and chains seemed tight on phasers. I don't get any codes just random running rough like a mild cam enough to notice the belt buckles shake but goes away after warm up. the plugs and coils have been replaced.
I read on a forum somewhere that the Ford hotline said 26 was the minimum hot idle . Thanks for the replies guys