So I got back from a work trip yesterday and drove the truck an hour back from the airport with no issues. But when I went somewhere last night the oil pressure dropped down near the red line several times while I wasn't on the and had the clutch in. The light would come on and then it would go back up. I have been meaning to perform a compression test but haven't had time.

What are common causes of a loss in oil pressure?

Thanks for any help.

 

Low fluid level. (common.... unfortunately)

Sending unit going bad.

Pickup tube clogging up.

Failing oil pump........

 

+1 check out your oil first

Does it only happen when you are slowing down to come to a stop? Then once you hit the gas you gain pressure again?

It is fairly common for the Oil pressure sending unit to go bad on these trucks, (located next to the distrubutor, +/- $25) BUT you could end up like me and go buy one at the auto parts store then on the way home have the motor self destruct due to what you late pinpoint as a failed oil pump...

If theres no issues with the oil level i would still start with the sensor first.

 

It was a little low but this is the first time it's done this. I am already starting an engine build do I may just accelerate the process.

 

Check sender first, and if it is good ....build away! If you just start on the engine, and the fault is pump related, you could toast the engine going to work one day, and then have a towing bill, miss work, and not have engine ready yet. Too many Oh Craps for me personally.

 

I'm buying all new inside components. But I will still check the sender. I'm learning a lot thanks to this truck...

 

It may be as simple as a failing oil pump. After you check the pressure(if it's not the sending unit), it's pretty easy to do the pump. And not that hard of a job. Who knows , maybe you'll get tons more miles out of the motor. And if that's not it, you'll still have a new pump for the rebuild.

 

Good point on the oil pump. Can I do that from the bottom or do I have to disassemble the top as well?

 

From the bottom. Pan will come out without jacking the engine on a 2wd....don't know how much room on a 4x4. There are a couple of threads here on changing oil pump. I think they mention doing rear main as well (oil pump bolts to main) and make sure you prime the pump with oil before installing.

 

This will give you idea of what is involved. Fairly easy. http://www.pavementsucks.com/tech-article-31.html