aight, make this short and sweet. Took the gasser in to get a check up. Picked it up today (mechanic was gone) left the note with the truck saying that the engines shot. Something about 3/4 compression in the 4 and 7 cylinders. What causes low compression?

 

Usually the cause is poor cylinder sealing either because of worn rings/cylinder wall, or valves. A cylinder leak down test is more accurate and will tell more of the story as far as where the leakage is occuring. The poor man's leak test is to squirt a few shots of oil into the cylinder and redo the compression test. If the compression jumps back up, it is most likely a ring problem. If it does not, it is most likely a valve problem.

 

I havent done that test per say, but now if i changed the oil and put in the additives that are soposed to stop oil ussage, and it runs correct, and after a few miles it runs weak again, could that work in the same way? Thanks for that info

 

I wouldn't call that an accurate test, but you know that. If you wanted to try something like that, it certainly won't hurt anything. Worth a shot I guess.

 

are you talking about a gas eng. for sure????

 

I am for sure yes, im hopin he is haha. Ill have to try that test. Maybe take just take it apart and check it out. The reason id always change the oil is it would sound like the valve and the piston would hit, like the valve wasnt shutting and when i changed the oil it went away haha. My simple answers i tell ya


One quick question. neighbor has a 99 single cab that was wrecked. Took a school bus( bus fault) in the rear and pretty much ripped it off. And now im sure torque wise the Trany wouldnt handle it but would the 46re out of my 1500 bolt up to the 24v cummins? Hes got the front axle and everything id need there, And the local tranny shop, owner owes me some money so im sure i could trade that off on upgrades to handle the power. Maybe thats a solution since the Mech thinks replacement may be nessacery. who knows.

 

[quote author=kingofdodge7131 link=board=4;threadid=22779;start=0#msg213296 date=1069645377]
And now im sure torque wise the Trany wouldnt handle it but would the 46re out of my 1500 bolt up to the 24v cummins? [/quote]

Not a chance...

 

personally I would go out and get a good comp. guage and test it my self...leak dwn. testers are notourius for being woofully inacurate-its not the tool its the sys. the comp. guage will give a more accurate reading and i could wast yours and my time with details but thats the fax

 

I like to use the leakdown tester with colored smoke and the pan dropped- you see where it blows by and can turn the engine the whole compression stroke and see whether it changes or not- with the exhaust and intake disconnected you see where it goes.

Just my 2 c

AlpineRAM