Oil Pressure Question

[Digger276]

Ok Pros, 91 LC, 3fe, 154,150 miles.

The oil pressure gauge was just above the lower line, not fluctuating much at all. The PO put 3,000 miles in two years and I would guess didn't change the oil. I changed it every two thousand miles for 6,000 and the oil looked better.

I have added extra detergent to the last two oil changes and I have noticed the pressure going a needle higher than normal. I do think it has a little louder than normal upper engine tapping than it should. So before I jumo in and change the oil pump, where is the "normal" needle range for the oil pressure.

I do have a slight rear main seal leak and after I get My 84 CJ beater running this summer, I can have the time to pull the engine and replace the seal and may do the oil pump, any high volume options out there, is it needed in these 3fe's.

Thanks again

Cris

 

[tusk74]

Digger,
My '91's oil pressure gauge is always hovering around the first line (acutally the 2nd line if you count the very bottom line as #1). It doesn't seem to move much. Your oil leak might just be the pan gasket. I retorqued the pan bolts and it cured the leak. Some of the bolts were less than hand tight. The valve cover gasket is rubber and will crack over the years. Oil will pool on the top of the engine in the rear and drip down. Tapping COULD be the injectors clicking or the valves need adjusting. I adjusted my valves because I figured it was never done. I think I only needed to actually adjust one of them...the rest were within specs. Hope this info helps.
Tusk

 

[Digger276]

I adjusted my valves also, I think only one needed adjusting also. I know the sound of the injectors, it is definitely a top engine sound, not harsh but there. I will check the pan and valve cover, I haven't really checked it out. I think I may have tightened the pan before, but will double check.

Thanks for the input.

 

[loquito]

I had to tighten my pan bolts to.

 

[Cruiserdrew]

Digger-Don't do anything until you do a mechanical oil pressure test. The Land Cruisers of all vintages have notoriously unreliable oil pressure guages. Hook up a mechanical guage and if it's within factory specs, forget about it. Oil pumps almost never go bad in Cruisers and I'll bet everything is fine in your truck.

The leak can be anywhere, but rear main is a good bet. Eliminate all the other possibilities first, like valve cover gasket, side cover gasket and oil pan gasket. The oil pan gasket in particular leaks frequently at the round area at the back of the engine and mimics a rear main leak.

 

[photogod]

Just my .02. I have a 91 with 170,000. I had the same indication on the oil pressure guage till I stopped using Mobil 1 as the prevoius owner had been using it for 140,000 mi. The engine was full of sludge and ran very rough. I put in a can of Pyrotec engine cleaner and three oil changes later the engine is running much better and the sludg has been reduced to a very thin coating. The pressure guage is rideing dead center at idle and third line up at highway. I am using Castrol GTX 10-30 in the summer and 5-30 in winter. I tightened all the oil pan bolts as well as the valve cover bolts and have stopped 90% of the leaks. I do have a somewhat loud cilck in the engine but only after a local mechanic did a valve adjustment. I don't think it is the injectors but a poorly done valve adjustment.

 

[Digger276]

Yeah, I have seen an improvement in the pressure with adding more detergent to the oil changes. This is a tough engine so hopefully it will bounce back. Good to know about the rear pan leaking, I just may srop the pan and see what the inside looks like and do a good cleaning and new gaskets.

Thanks All