86 Ranger 2.9l Oil Pressure drop Motor temp rise

[KatyBob]

Okay. 86 Ranger. 2.9ltre, 300k, new oil and filter, when warm; oil pressure drop and motor temp rise in city and highway driving. Why? Help please.
Thanks,
Katy

 

[kimcrwbr1]

300K thats why. As long as it is not overheating you should be OK. you can change the t-stat and flush the cooling system but the hotter the engine gets the oil pressure will drop. A new radiator might help also along with a thermostat but as long as it holds fluids you should be safe to drive it. The fan clutch could also be weak causing it to get hot at lower speeds flick it and if it spins free put a new one on and see if it makes a difference.

 

[dave2575]

My 88 had the same thing going on and it had over 225 on it and I ended up replacing the whole cooling system and the oil pump (pain in the a$$) that is when I found that the pan was caked with thick sludge/build up. I cleaned the pan and had to do the valve covers (even worse), the rocker arms and the inside of the push rods (two were almost plugged up), ending up with the oil passages on the heads. I am not saying thats what you have to do but I would suggest to check for build up in the valve covers (if bad check the push rods oil passages). I wish I new about this site first before doing all that work, even though I am glad I did (no problems sense and runs great). good luck.

 

[rusty70f100]

The 2.9L doesn't oil through the pushrods...

I'd consider a slightly thicker oil (maybe 10w40 instead of 10w30 for instance), an Explorer radiator (thicker, direct swap), and long term a rebuild.

 

[RustedRanger]

I agree with rusty. My 2.9L likes 10W40 and it has 160,000 mi.

 

[kimcrwbr1]

The cheapest way to flush the engine oil is with ATF. Put a quart in about 100 miles before you change the oil. My 83 2.8 seems to do best with 10W30 and use the motorcraft filter. Use that treatment a few times before oil changes and it will dissolve all the sludge in it. You may need to drain a little oil out so you dont overfill it and the oil level will rise as the sludge falls into the oil pan so dont run it very long with the tranny fluid in it. let us know what you find out