I just changed my oil saturday 6-24-06 to amsoil 15w40 in my 91.5 12 v with a donaldson extended oil filter that is also sold by amsoil and fired it up to do usual leak checks and all is well. I drove it today sunday 6-25-06 and oil guage dropped to L (stock guage) pulled over and shut engine off checked for leaks and oil level and all is good. Fired engine up and pressure came up but a little below normal. I just drove up the road late this afternoon and needle came up and then pegged to below L. My question is has anyone changed to this oil and had this problem and what was solution? Do you think i have bad sending unit? I also ran a flush thru engine before dropping oil as recommended and pressure was good while i was doing this. I am totally at a loss. Any suggestions?

 

well the sending units are known for going bad. the one in my 92 did something similar on a long trip. we had just changed the fuel filter, exhaust housing, and tapped the KDP. but nothing different with the oil. mine seems to be a ground issue or something, sending unit is new but it drops all the way to low sometimes. i don't really plan on fixing the problem, the stock gauge is a guess at best. i am going to plumb a mechanical oil pressure gauge and know that many others have done that.

 

Almost definitely the sending unit.

 

Mine did the same when the sending unit went. If I were you, I'd simply invest in an actual mechanical gauge, that way you get a real number and it's less likely to fail. You can probably get the gauge and tubing for under $60 - any 0-100psi pressure gauge should work.

 

Been running Amsoil in everything for years without any problems. It's been in this truck all most a year. The sending unit is right under the IP. That should fix your problem. If oil pressure was as low as indicated I would think the lifters would be rattling.

 

Mine was reading low (below the 1st mark) until I cleaned the contacts on the sender by just unplugging it, spraying some WD40 and re-plugging it a few times. Now it usually reads just below the halfway point. Normal, I suspect.

 

Ya no mine would go to 0 at idle when hot and i just repaced the sensor but at the time i had a good leak from that area......brake cleaner and some WD40 just might fix it Good thought, ACE

 

Want to update everyone on my oil pressure problem. I left the next day 6-26 feeling the problem was due to bad sending unit/guage and relying on all of your experienced advice. So the results are the guage started to work when i fired the truck up and and headed down the road to Myrtle Beach, SC. for a few days of camping. It is still working but my new concern was what seemed to be a lack of power. She is still stock but my gut instinct says TC and loss of power through that weak link. My next project is to adress this issue before BOMBING this work horse. Thanks for the reply's Alan