haven't checked that yet, what is normal operating param? doesn't show up on my scanner. ill have to borrow a gauge. measured off the fuel rail I assume?

 

do you have your fan shroud on cause i had the same problem when i busted a belt it torn my fan shroud up so i took it off and it get high up there. Also look into a fan clutch and maybe hood vents, it helped me

 

thanks for the advice but all three are new.

 

Air pocket in one of the hoses. same thing happened to me.

I cut open the highest hose... (AIR RISES to the higest point)



Google picture... (the jeep I did this too is long gone.)

I put in a fitting... no clue what it was called.


Anyway, what the problem is... from what I can tell... your OPEN cooling system has a problem. Open cooling system are "self burping" from air pockets. What I did was manually "burp" my system? Ultimately my system wasn't breathing well due to a later found clogged line running from the overflow jug to the radiator. A bad rad cap would do the same thing.


99% sure you have/had air locked somewhere. This may sound weird, but try blowing into lines at different places, but it sound like the rad cap did the trick.

 

ummm wow idk what to say, you ever think it was just the coolant temp sensor or the coolant gauge sensor on back of intake? thats the one that tell guage what to say might not even have a problem with your engine at all..

 

Ok this might sound really stupid but I was having the same problem with my 88 cherokee and come to find out a mechanic told me to take the filler hose off at the thermostat housing and then refilling the radiator. For some reason it does not burp and with an air pocket in the back of the engine it will over heat every time. Sounds cheesy but after fighting with it over a yr I did it and I dont overheat anymore.

 

why dont people read before posting

 

On level ground, the back of the motor is lower than the front. Air rises in a liquid so it seems logical that air would naturally move to the front/higher part of the motor. Both air and water exit at the front of the motor which is also the highest point, no?

 

I won't lie, I haven't read every post but I have skimmed most of them.

Have you pressure tested the system? If not there is a real easy way. Take a bike tire tube and cut it through in one spot. Take the two ends and clamp them off to the inlet and outlet of the radiator. pump it up to 15 or so pounds and see if it leaks off. You can do the same to the engine but unless you have a hole drilled in the t-stat you will need to remove it.

If this has all been tried then I'm sorry and best of luck to you.

 

ok i have never heard of bike tube thing, well i think i have an idea how to do it ill try it out

 

Any update on this? I'm just extremely baffled by your situation and want to see if you've figured it out yet.

 

no real changes. i cant explain why but i seem to have dropped 4 degrees overall by clamping the upper heater hose shut but this could also just be attributed to slightly cooler ambient temperatures here the last few days.

I dont know what else to do. I guess i am just going to run it hot till it blows and swap in a 5.3 Ls motor.

 

I bet ur fine , I mentioned before and did not notice about changing the coolant temp sensor sender on the back of the block that actually reads the temp and sends it to the gauge, as long as it doesn't go up i would just run it if ur gunna save for that upgrade anyway

 

He's getting his actual temperature reading from a different, more reliable source than the usually crappy, inaccurate XJ gauge.

 

Wow try and look at pig tail connectors on the coolant temp sensor connector make sure there not worn out, this happened to me and I cut the line and spliced in new connector works fine! 10 bucks tops