Need advice on a high mileage '91.

[rrobby]

I have a beautiful '91 XLT with close to 240K miles. I have all records since new. I have 2 big concerns; low oil pressure and timing gear/chain wear. In re: oil pressure, the dummy light (even in the 0 degree weather) goes out after just a couple of cranks from the starter. I am running 15w40 Shell Rotella plus 1 pt. STP for extra viscosity. The oil gauge never registers above the 'n and o'. I never notice any unusual noises but am concerned about low pressure. Would this be because of general wear in the engine or could it be improved with a new oil pump? In perusing the folder full of records, I find that the chain/gear set has never been replaced. I think that should be done no matter what. What do you all think?

 

[Maniak]

1st thing.. ignore that oil pressure gauge. The factory gauge is just an analog idiot light.. < 5psi is no oil pressure.. > 5psi is "normal" on the gauge. It only moves when the voltage in the dash changes

There is a thread on here about your fake oil pressure gauge. Basically you change the sending unit out to the older ford style (its wider than your current one) and then you short a 20 ohm resister on the back of your gauge cluster (just put a wire across the resistor).. Now your gauge will be real and will move with oil pressure...

Also, to change the oil pump the motor comes out... As for timing chain wear.. We rebuilt our motor at 355k miles (cracked head) and the timing chain look decent..

 

[xzotictech]

its ok but keep a close eye

i know u like your truck and has a lot of miles.the oil pump is going to wear out no matter what oil u put in it or how often u changed it.u can start with the oil pump but before u do that pu a thinner oil and take off the sending unit attach a oil pressure gauge and see if the dash gauge is telling the truth.if the pressure is low then replace the pump but if its a 4x4 might as well pull out the engine and get it rebuild because there is no point in doing all that work to get the same result

 

[Sams01XplrSprt]

welcome

 

[BrooklynBay]

Welcome to this forum! I've moved your thread to the stock 91-94 section. The sound of the engine will get louder if you use a thinner oil, but if you have leaks, it will leak faster.

 

[Masterd]

Ive done the oil pressure gauge mod. Not too bad. Worst part was taking the gauge cluster out, but its worth the peace of mind in seeing the gauge moving.