Possible Head Gasket issue?
Vehicle : 1991 Ford Ranger 3.0L 151,000 miles
Recently I have been having a problem with the cooling system in my '91 Ranger. The truck was getting up there in age, and still running well so I decided to go ahead and go all out on the cooling system. (I had a stuck open thermostat also, so I figure it is time to put some money back into the Ranger) I went ahead and replaced the following:
Radiator Hoses Upper and Lower
It drove great for the first day, and she started overheating. So I figured that maybe the Thermostat I got was stuck closed. ( I used some Bars Leak a bit back to try and seal up the heater core awhile back, and I noticed it gunked up the system when I did the previous work) So I decided to remove the thermostat to see if that was the culprit. It is still overheating, and smoking a bit (Which it smoked a little before, but hey its an older vehicle they do that), and I am losing coolant.
I went out and bought a Compression gauge to take readings on the cylinders and got the follwing results. On the Passenger side of the Block starting closest to the radiator was 137, 145, and 145 psi. On the Drivers side of the block starting closest to the radiator was 125, 140, and 101. Now I took those readings when the motor was cold, and the 101 it was struggling to get there. When I drove it I noticed the smoke goes away a bit when the motor gets up to temp. I rechecked the compression in the lowest valued cylinder, and got a reading of 120. The cylinder in front of that still read 140.
The Truck is sputtering pretty bad and I probably lost about 10 ounces of collant test driving it yesterday and this morning. Its going somewhere, and there are no visible leaks under the truck. With the Chilton's or Haynes (can't remember which I have atm) the lowest value it said I should have is 101 psi in the cylinders. I didn't see anything in the write up on a certain % or tolerance it had to be in relation of the other cylinders. Am I in right thinking I need to replace the Head Gasket on that side? Any advice would be welcomed towards this. I have had this truck since '96 and it does hold a certain value to me. Even though people say they need a Tetnis shot after standing next to it. Thanks once again.