Did the ole compression check today, I am both somewhat pleased but also sad at the same time. But it is a 207,000 mile 12 year old truck with a hard worked engine.

Here are the results
1-140
2- 120
3- 130
4- 150
5- 135
6- 130
7- 125
8- 90

Cylinder 8!! What happened!?!?

Well where should I go from here? Is it more likely to be a ring or the condition of the head and the valves?

Ive always wanted some new heads, maybe I just got my justification.

 

Do a leakdown test to determine what is not sealing.

 

Inform of this leak down test good sir

 

Heres a cheap way of doing it.

http://api.viglink.com/api/click?for...13535421732882

 

I can't weld

 

where is the wet test results? did you do this test with the engine hot and throttle open all the way?

you don't need to be able to weld to do a leak down test but you do need a compressor and a couple of fitting. spark plugs have the same thread count as a 1/4 in. NPT fitting but with the dumb head shields you can't just screw a fitting into the hole. you need an extension.

 

I didn't do the wet test. How much of what do I squirt in?

Why does the throttle have to be open?

Oh and welding refered to the link where the guy takes an old spark plug, knocks the porcelain out of it and then welds an air fitting to it.

I don't have a compressor either

 

i know. i have seen that video before. i tried knocking the porcelain out of a spark plug and it never really worked. plus i don't know if you would be able to get a airline on a fitting welded to sparkplug with the heat shield.

a shot or 2 of oil in the cylinder before testing will tell you how bad the rings are. if the rings are bad the oil will cause the compression to jump. i think holding the throttle all the way open allows the engine to suck up as much air as it can and give you more accurate numbers quicker. otherwise it is like sucking air through a straw.

 

Ahh I see, will do it again

 

Just curious, were there driveability symptoms that prompted the compression test?