Peterbilt Cat C15 oil pressure problem

Throw some Lucas in it.

 

Did anyone figure this one out? I am having the same problem with an sdp c15. Shows 55 psi at idle when cold. It drops to 22 psi when oil gets to about 210 degrees but will maintain 55 to 60 psi driving. Had replaced oil pressure sensor, oil pump replaced, main bearings look ok for an 800k mile truck. Pic attached. The shop is considering pulling out the oil cooler. Runing out of options here. Any ideas will be appreciated.

 

Pretty sure it's normal. I have about 60 psi running down the road, 20 psi idling, and 70-80psi at cold startup.
I haven't had a lick of issue with both C-15 I have and have same pressures. All my oil samples come back good on bearing wear.

 

I have a 05 acert. Oil pressure varies, on start up between 60/70, once warmed up 30. Going down road over 60 mph 65ish, when Jakes come on oil pressure goes up a bit. With fresh oil psi might be 5 pound higher than with oil ready to be changed. Also more blow by the older oil gets. Had a oil sample all good. 1.2 million miles.

 

I get it. But I have owned two acerts and I can tell you oil presure below 30 psi isn't normal. My idle on both were around 40 psi. If we are talking about non acerts then I get it. I assure you this didn't occur overnight. It gradually decreased from 40 psi to 22 psi and I see it going down even further over time. One thing for sure from past experience is that the motor shuts off at 15 psi or at least the buzzer and light will come on indicating low presure. If that's the case, I don't see it being safe to be idling at 5 to 7 psi above shut down presure. All it takes with a bit clogged oil filter even if nothing else to go down to 15psi and trigger a shut down.

 

I know this is an old thread, but if the oil pressure is low, idle it up. My C-13, hot, sits at 35 psi at dead idle. Set it at 1000 rpm and it comes up to 50 psi.

 

I appreciate your contribution but I could also throw 5 gallons of Lucas in it or run straight Lucas in place of rotella. I could, Put a 155 degree thermostat to keep the oil temp below 170 and increase presure at idle since oil will never thin out. At the end, you got to realized it didn't address the issue, all I did was put a bandaid on it which will be ok for a temporary fix.

 

First thing I'd change is get that rotella out unless it's T5 or T6. The white bottle 15-40 is garbage, highest volatility (burn off) oil on the market , 12% if i recall.... terrible.
Lucas isn't a great idea either, it's just a 60wt base oil with VI improver...no anti wear additive package.
Gotta remember too, pressure isn't a direct relationship to protection.. pressure is the result of restriction of flow. I'd rather have flow and a high quality oil with good wear protection. Flow keeps temps of lubricated parts more uniform too. Some of the low pressure concerns and the oil band-aid solutions will just cause more problems.

A better band-aid than Lucas would be 20-50 diesel oil that has the proper anti wear additives that Lucas doesn't.

 

Thanks. I've considered runing t6 synthetic, I run that on everything else I own. Its simply the best lube out there money can buy, better than amsoil in my book but I couldn't find much justification using it on the truck given the added cost. To run 44 quarts of synthetic long enough to get your moneys worth, its best to install additional/ remote oil filters or else oil will be getting contaminated prematurely. Its like pissing away money. However, I don't think cat build these specifically for synthetic oil. Not that it hurts anything runing one but it shouldn't hurt not runing it. Anyway, It seems like no one got to the end of this problem. Probably will start pulling the cam and rockers bushings, that's the next logical thing to do.

 

Agreed, it's one of the best off the shelf you can buy. Very good oil !
Bypass filtration would certainly be wise if you want to run longer drain intervals plus it just keeps the engine cleaner. Kits are relatively inexpensive too.
Don't have to worry about the engine being built for synthetic though. Pretty much everything made since the 80s is compatible with the current CK-4 specs.... (Conventional, Semi syn, Full Synthetic)

FA-4 is a different story though....