Hi,
I read through the whole "Diesel Forum" tonight but didnt find the answer I need !

I recently bought a 1986 F-250 6.9 truck from a guy that brought it back from the US in 1999 ( By the way, I live in France).
I have to admit it has almost been rebuilt completely and a good job at that.
Problem is, for those who have never driven in France, the roads are narrow and the stop-lights in town are real close to each other.

This brings me to my problem:

After starting the engine the oil pressure gauge is right smack in the middle and stays about in the same range until the engine is at temperature, then,after driving awhile, at idle it drops way low, even sometimes beyond the lowest reading ! It goes back to the middle as soon as I go up into the revs.

There are no unusual noises or knocking and the engine doesn't overheat.


I read in the shop manual that I have to "ground" the sending-unit wire to test the guage but I cant find the darned thing, where is it?

Also, is there any plug located somewhere where I can plug in a pressure tester just to be sure I am getting enough pressure?

I use Castrol 20W40 Diesel oil which is pretty good "and expensive" so I dont think this is the problem.

Thanks,

Mike

 

The sending unit is in the back (top) of the engine block just in front of where the bell housing bolts on. From your discription it sounds like the sending unit is at fault.

 

Thanks,
I'll check it out.

Mike

 

 

Got the unit from the States, all is OK now,
Thanks,



Mike