oil pressure dropping while cruising

[Kurtis]

So I bought a truck that had been sitting a while fixed quite a bit but now its running great. The other day I took a run to the desert pulling my dirtbikes and quads and on the way the oil pressure gauge started acting a little wierd. Got there no problem. On the way back it started acting really strange.


Sitting at a light I get normal oil pressure, but cruising the gauge
drops to the bottom????

I got it back to my house and parked it and havent gotten a chance to check it out yet. I have owned it almost a year, I didn't get much chance to work on it until the beggining of this year. Got it up and running and everything going changed the oil and it has about 1500 miles on the oil and its not low or anything.

Well thats pretty much it, Any suggestions/ places to start. I'm thinking it might be the gauge because the truck didn't heat up nothing strange happened. I think i'll change the filter just in case but any suggestions?

 

[Radd Cruisers]

This has been covered numerous times:

The Toyota oil pressure gauge is not accurate at all. It is best to install a proper oil pressure gauge to monitor your oil pressure.

Once you have done that, you can get some realistic idea of what your oil pressure is doing.

~John

 

[lehiguy]

Two things I have both seen, and experienced first hand. The sending unit on my rig died. Suddenly I have no pressure after it fluctuated for a week. Second, has the motor been rebuilt? It seems that after-market oil pumps are too long. They smack the bottom of the pan and can't pick up enough oil that way. I had this happen and so did a friend of mine. Considering the amount of oil a Cruiser holds, you should have about 1/2 inch between the bottom of the pickup and the oil pan. This problem manifests itself just as you described; it shows good at idle and pressure drops as RPM increases becuase the pump actually starves. I had a machinist cut 1/2 inch out of my nifty new oil pump pickup tube. I also shimmed the blow-off spring with a small washer; that increased pressure a bit.

 

[REKCUT]

Install mechanical guages. Its a must. Its inexpensive. Its easy. It fixes the problem.

 

[roscoFJ73]

Sitting at a light I get normal oil pressure, but cruising the gauge
drops to the bottom????

?

Mine did that and got worse and died. Replaced the sender and no more problems.
The sender is the same as about 30 other toyotas use.

 

[Kurtis]

thanks

Thanks everyone I guess I'll replace the sender then get some mechanical guages when I have a chance to work on the truck a little more. Thanks for the advice though that put me at ease a little, the engine hasn't been rebuilt, as far as I know. I see no signs of a rebuild and it only has 150 something. on the clock. Thanks for all of the replies.