my two cents....
ive skimmed through this thread and may have missed a few things but can you confirm you installed an Ebay water pump?
Many ebay and Repco pumps use inferior plastic impellers that are well known to break loose and spin freely at lower than needed rpms on their shafts at higher revs (so they dont match engine revs and will freewheel on the higher revving shaft reducing coolant flow). this would in effect produce higher temps at highway speeds with higher revs. the shaft spins higher matching engine rpm but the impeller spins much lower than required which reduces coolant flow. basically, the water pump impeller is not matching the required speed to pump coolant.
im not saying this is the culprit but from everything ive read about your issue a higher quality water pump would be where i would start. never trust ebay for water pumps. and Repco units are just as bad as they have usually have plastic impellers. i have seen this many times so maybe best to rule this out before going further
just seems you have a good working system aside from this and your t-stat. might be worth a changeout with a metal impeller pump.
having said all this, there are so many descriptions and cures being presented here it will only run you in circles. as far as running without a t-stat (a proper 195 degree t-stat) - that is a no no and will not get you any closer to finding the problem and not the way to diagnose this (sorry JJ but i disagree with your hypothesis toward diagnosis but i have considered your point). put the proper 195 stat in and leave it. at least you know this is not contributing to the problem. Stant and Gates brand t-stats are your best choice (or dealership).
most overheating is due to blockage or lack of coolant flow and i would suggest these contribute to around 75% of overheating cases. type of coolant has nothing to do with it if you are using something other than plain water. Coolant brands have nothing to do with this. just use a good brand name coolant with the proper mix and you should be fine as far as that goes (i usually use a 50/50 mix). even cheap coolant is better than nothing and will produce better results over straight water. never run straight water and never run without a 195 t-stat or the computer will make things too rich.
from my seat it looks like you have a good cooling system if not the correct parts. some folks will suggest extras like bonnet venting etc and i would also state the same but it depends where you live, your climate and what you use the car for. but first and foremost is making sure your existing cooling system is optimal. looks like youve done that but i question some of the parts you have used.
cheers, Rodge
__________________
there's Only One
Last edited by Rodgebone; 13-11-2015 at 04:32 PM.
|
1996 JEEP CHEROKEE
1996 Jeep XJ Cherokee
