Low oil pressure at full RPMs

[Rich Waugh]

Quicksandfarmer,

It is recommended that every time you go to use the tractor you first take ten minutes to check things like the fan belt, fluid levels, lug nuts, bolts in general, steering components and tires. That ten minutes will save you hundreds of dollars and hours of frustration if it catches just one thing out of spec.:thumbsup:

 

[Meadowbrook Equipment]

In the past I had a problem with a couple of 385 engines. The oil journals were not cleaned properly during manufacturing and it caused a lack of oil flow to the upper engine. You would notice a lot of wear in the valve rockers from lack of oil and then the cam bearings will fail.You will also notice the oil pressure will be low. This may not be your case, but I would pull the valve cover and look for metal fillings on the head. Just my two cents.
Regards,
Meadowbrook Equipment

 

[quicksandfarmer]

Another follow-up: I did a pressure test today and everything was OK in the cooling system. So I'm going to conclude that the problem was that the fan belt was slipping on the water pump, which was causing poor coolant circulation, leading to poor cooling, coolant loss, and inaccurate temperature measurement. At high RPM the belt was slipping more; the low oil pressure was a symptom of elevated engine temperature.

I didn't mow today because it was raining, but since I tightened the belt I have not lost any coolant

I did have a devil of a time putting the fan cowling back on the alternator after tightening the belt. I ended up having to bend it to my will.

 

[quicksandfarmer]

I want to follow up with this year-old thread because I often find useful information when searching the archives.

Over the winter I started losing coolant at an alarming rate. In June I replaced the head gasket, which was blown. I also replaced the fan belt with a Harbor Freight link belt: Vibration Free Link Belt

About 25 hours later the oil pump failed. I replaced it this week. I just finished mowing ten acres and the engine is stronger than I remember it being when new. Temperature is consistent, oil pressure about twice as high with the new pump.