92 ford bronco compression

[rogmit]

i checked the compression on my motor because i've been having idling problems, i took the suggestions that have been given and so i decided to buy a compression guage, i found out that for the most part the cylinders had a 135 to 150lbs compression accept the #8 cylinder, it had only 50lbs, i guess that means the #8 cylinder is bad or does that mean i've got a burnt valve---any ideas?

 

[rubberdust]

squirt a shot or two of oil in that cylinder, if the compression comes up it's most likely rings, piston, cylinder walls etc. If it doesn't change your most likely looking at a burnt valve

 

[Bully Bob]

Best case senerio....a bad head gasket...

Any tailpipe smoke or continued loss of water in rad. overflo bottle..?

 

[BLADE262US]

I dont know what guage you have but my snap on one has removable hoses for different size spark plugs so what I do to see if its a bad valve is on the tester hose that fits the heads I take the valve stem out of the end of it and ***** it in the head then roll the motor over to top dead center compression stroke for the cylinder Im working on then I plug the shop air hose into my tester hose as it uses the same plug now if you have a burnt exhaust valve there will be air shooting out the exhaust and if you have a bad intake valve it will be coming out the intake and also if you have a leaking head gasket into a water jacket you will have antifreeze coming out of the cap . /emoticons/[email protected] 2x" width="20" height="20" />