ok im working on a 08 f-150 with the 5.4L 3v. hot idle get 20psi. replaced all timing components due to a collapsed l side tensioner and thought maybe it was leaking down pressure. retested and same results. removed oil pan and inspected rod/crank bearing and everything looks good. thrust it in spec also.

found good amount of scoring on cam journals on both heads. now my question is would this cause a great amount of pressure drop?
cold start i see 75psi and see the press drop as warms. idle is 20psi when hot in park. if rpm is increases to 2k i see 70psi hot


thanks brandon

 

Twenty psi @ hot idle is ok. You are getting 75 psi cold and that is normal as well. Be carefull thinking you have scored cam bearing surfaces. It is normal for those surfaces to give a scored appearance when in fact the machining of those bores will/can leave some deeper grooves which are normal and therefore not a concern. Now, if you are seeing metal movement/melting and burning of those bearing surfaces then there is a problem. I don't think from the discription you are giving that you have a problem with this engine. p/s if you want to send a few pics of the cam cap bearing surfaces (worst case) I can tell you if its normal machining marks or damage but I'll bet its normal.

 

thanks for your reply! the head that had the collapsed tensioner had the new one collapsed as well when i torn down again. i could hear the timing chain slapping before and after the rapairs. also the cam journals in the same head have grooves and burn like marks in it. gonna try a oil pump and new heads. also all the lifters on the problem head were bled down as well giving me signs of low pressure in the head. i was told i need a min of 25psi in gear hot idle per tech at ford

 

20 psi with 5W20 oil?

According to the AERA, 60 psi @ 2000 rpm is "normal" hot oil pressure @ 2000 rpm.

For further perspective, I have a low miles '05 5.4L (only 30K on it) with an aftermarket oil pressure gauge. With fresh 5W20 full synthetic oil, my truck ran 25 psi at 200F oil temp at idle in gear and about 63 @ 2000 rpm at the same oil temp. With 10W30, it runs 30 psi at idle and 65 psi @ 2000 at the same oil temps. My cold temps were about 70 at idle cold and now are 75.It's a nice, tight, quiet engine, too.

You may have other issues but 20 psi sounds good enough to me given that my really fresh engine had 25 psi.

 

With the added information it appears that you are having a pressure issue at least in the cyl head. However twenty psi at idle hot is fine. I see them lower than that with no problems. I think even with a new pump your pressure will be close to the same. Sounds like you have a blockage or restriction somewhere. You said you replaced the timing components, were the original parts like guides worn or damaged? You removed the oil pan, did you notice any debris stuck in the oil pickup tube screen? Once those heads get oil starvation or poor lubrication the cam bearings can score and burn and it sounds now like yours are damaged. The lack of oil pressure will also cause the lash adjusters to lose their pump as you say they have. This all could have started from a lack of lubrication caused from a blockage or low oil fill level and now you have head damage. I just don't think your oil pump is the problem and the oil pressure you are currently see is sufficiant. I would look for a blockage in the system possibly from debris blocking the pickup screen or from metal or sludge etc. blocking oil supply holes in the head

 

there was a bit of sludge in the bottom of the pan and the pick up had a couple tiny pieces of what looked like old guides, i did the pump just for insurance (was only 75$) but the heads had no sludge build up that you usually see from lack of maintence. but the guides looked ok. im thinkin there was a blockage in the head as well,seeing the other head was fine.

 

ok so finished it just now and ran it up to running temp, now i got 45psi hot idle and not making the chain slapping noise. so i will test drive it tomorrow and double check it. but seems that i have got this one! thanks for your replys guys!

 

Great! That's gotta be a load off your mind, eh?

FYI, your "hot" oil may only be 150-180F, so expect to see some lower pressures themore you drive it... and don't be worried. As oil temp increases, OP will decrease. My idle OP @ 150-180F is around 45 psi, which is why I comment. Even in this hot weather, it takes a good 15 steady miles of driving to get the oil temp up to around 200F. I strive to record "normal" pressures at or near the 212F grade viscosity rating temperature. It's hard to get the EOT up to 212F... it is for me anyway. I generally end up seeing 195-200F most of the time in warm/hot weather. In cooler weather it runs 180-190F and takes a lot longer to get there. Cooler oil runs thicker. At 180F, a typical grade 20 oil is running as thick as a grade 30 oil. Until you get close to that 212F mark, the oil is thicker than it's rated grade, The "grade" (20, 30, 40, etc.) is actually a viscosity range. Depending on the oil, you may not reach grade until 190+F oil temp.

 

You're right JimAllen. We used to see sump temps of 260 deg and sometimes higher running peak power WOT. When the engine would come down to idle after a run like that the oil pressure would drop down to 10 psi. We had shutoffs set at 9 psi. So thats why I am confident that even with your 20 psi at hot idle you should not have issues with the chain tensioner and lash adjusters collapsing. We ran at 10-20 psi at hot idle all the time with no pressure related issues. Glad you got it fixed.

 

thanks guys! you were defenitly help!

 

blown95svt, I am experiencing the same issue. What did you ultimately do that fixed the problem with the low oil pressure?

 

Sounds like timing components and an oil pump.

 

How did you make out with the pump and timing kit