Compression

[tekjones83]

My 89 2.6L is running a bit raggy lately (exclude the tune up and filters changed) but I did a compression test on it. I am only getting between 90 to 120Psi across the board for each cylinder will I need a head gasket and have the head checked at a machine shop?

[LiL Bastard]

That depends, how close is each cylinder ? How many miles on the engine ?? What is leading you in the direction of the head ??

[tekjones83]

its a constant 92 to 120 lbs each time for each cylinder. 128,000 and it makes water boil out of the overflow and i cant keep water or antifreeze in it all i am having to refill it each day.

[camoit]

have you changed the thermostat and cleaned the radiator first? If the head was bad or gasket bad it will run like shit or loose water overnight. Many times if you fill the radiator to the top and leave the cap off then start the truck it will bubble air continuously. You can also put on a pressure tester on the radiator and start up the truck. If it makes pressure nearly instantly then the head or gasket has a problem. Never reuse the head bolts.

Please keep it cool as you can destroy the head. The compression looks OK from what you are saying. Another thing mine would do is run on 3 cylinders when started then get better. But that would happen every time. But at that point it was done.

[tekjones83]

O ok I will have to do that. No I haven't replaced the thermostat yet. The temp gauge never gets hot but I am not sure if it has a thermostat. I am going to check it out. Thanks everybody. Help is always needed.

[camoit]

OK, thats the first step. 2 bolts 1 gasket and some flush and a new lever right cap 13 Lbs. Change the T stat drain the radiator. Fill it with water and flush. Run it, get it hot, drain all the water fill with clean water run it some more and flush with the hose tell water is clean. OH,, turn on the heater.. You can leave the drain open when doing the final flushing. Just keep water flowing into it. Clean out the plastic overflow tank also. Then fill it, put on the cap and check for over heating one last time, drive it around the block or so. Then drain it one last time then mix 50 / 50 with antifreeze or stronger if you are in a place that freezing is a factor. Change any hose that might be looking bad or suffering from Elephantiasis.