countinued from "unusual [to me] over heating".

did a compression test today. First thing i notice were all 6 pugs where white from being to hot and they only a year old proble 6 months ago i started using 89 at the pump and am getting better mpg now so dont know if that could be it or not. I did replace the plugs and jeep started up nice and sounded smooth at idle again. but im thinkin the plugs well be white again in no time.
well test went:

cyl 1crank 7cranks

1) 90/150
2) 90/140
3) 95/150
4) 115/165
5) 115/170
6) 90/150

from what the books says high compression is from carbon build up...looking in side the holes looks like carbon is in all cylinders i guess in side 4 and 5 it was a little darker in there and the plugs were a little worse.

so what do these numbers mean to u guys? and still whats up with over heating like that going up hills, assuming its the root of all my problems.

 

The compression is within 15% which is acceptable.
White plugs can also indicate a lean condition. Check your intake manifold bolts for proper torque. Also check the TB mounting bolts, and all vacuum lines. JMO

 

when checkin the vaccum lines its nothing more then checkin for holes or rips in them right?
dont think 89 gas has anything to do with it?

 

Spray carb cleaner on the lines one at a time with it idling. If the RPMs change you've found a leak.
89 octane has nothing to do with it. Try another station though, as my Jeep runs better on gas from certain stations. At others it runs like crap. JMO

 

alright cool ill do that. thanks alot. you got anything for me on my over heating problem?

 

Running lean can cause it to run hotter than normal, but I've not read your other thread. What color is your coolant? If it's brown then you need to flush the system and hope that your radiator isn't clogged up.

As for the carbon causing the higher compression, yeah that's possible. Try seafoaming the motor, that removed a lot of carbon from my '93 (made a big old stinky mess, I was like James freaking Bond with a smokescreen ).

 

^ This guy! Lol.

Yeah, both Ol' Blue and CodeXJ know their stuff. Good news is, so long as your motor oil isn't milky, given your compression test I think you can rule out a head gasket.

Just an after thought - do you ever SMELL anything when its smoking up these inclines? Something as simple & rudimentary as a radiator cap may to blame. The rig I have now is my first Renix motor, so I'm still relatively new to them. (more of a HO & Powertech guy) but on my motor (90 vs your 91), the reservoir IS the radiator cap, and where it's located could easily allow fluid to pass through the cap without leaving much evidence. Then if say it fell on a hot exhaust...

And thank you for following through with forum advice and doing a compression test. Makes diagnosing over the interwebs easier for all.

Good luck!

 

coolant is green over flow tank gets some brown in the bottem sometimes but i clean it out. radiator is 2 two years dont know if its clogged or not.

Ive read about seafoam but never used it because it can be poured in every orfice of a vechicle and its suppose it fix something. just seemed like a bad thing. but maybe not...

 

no never smelled anything. no burnin anitfreeze.

just tryin to keep her goin. you guys and this forum are ther reason shes still runnin. thanks a lot.

 

Seafoam = mechanic in a bottle.

Besides adding "Restore Engine Treatment" at every oil change, this is the only other additive I use.