tell me if these are related - low oil pressure and high temp

[cmoore207]

Hey all, after an extended break from Rovers, I just picked up a 1995 RRC with the 4.2

Just had head gaskets and valve job done. Oil pressure switch was done about 3-4 months ago by previous owner.

After 30-45 minutes of stop and go in city traffic, the temp gauge creeps up to the very top of the "safe" range. When this happens, I also get a flickering oil pressure light at idle when in drive. If I pop the truck into neutral while I sit at stop lights, or just give it touch of gas while on the brake, the idle goes up just enough to turn off the oil pressure light. The flickering oil pressure light only happens when the temp gauge is in this high zone.

I've read plenty of threads about overheating, and plenty of threads about oil pressure, but my theory is that these two issues are related in this case. Just wondering if anybody else has experienced this, and what your solution was.

Project for the weekend will be to make sure the coolant is burped and check the fan clutch. Any other ideas? My other theory on possible culprit is the engine oil itself - was refilled with 5w-30 after the heads were done. Too thin for the hot weather we have been having in DC (upper 90s)?

 

[57loboy]

5W-30 is pretty light oil for that engine. I ran 15W-40 in mine, Rotella actually. Had 156k on it when I sold it. Lots of opinions about oil in various discussions elsewhere here. I'd change the oil for something thicker, just sayin'...

 

[Keanan]

Run a heavier weight oil. Check your fan clutch, replace your thermostat and radiator. Then you should be set.

 

[cmoore207]

Drained the 5w-30 and replaced with 10w-40. Problem seems to be solved, although weather has been slightly cooler past few days, so hoping it stays "fixed" on the next 95+ degree day.

 

[5x6.5]

Sounds like you got the oil pressure problem fixed, I have been running 15/40 Rotella T for the last 8 years. Not only does it bring the oil pressure up but it keeps the engine clean. I would also drop the oil pan and clean the pick-up screen. As far as the cooling issue, The thermostate might fix some problems but it doesnt sound like this is the problem with yours. It sounds like you have a flow problem. I would check the water pump and the radiator for flow. Even if the radiator doesnt leak it could have some massive gunk built up inside. Check with your local shop and have the radiator checked for flow.