John3seventeen
Full Access Member
It's not opening , good you caught it!
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
...It's been single digits and negative the past three days so working on it is a no go haha
Got it backwards,I know for a fact since I have done more coolant flushes then I can count on 3.7's/4.7's.We use a short piece of clear hose in place of the machine while bleeding/getting the system at operating temps(t-stat open) so I know the direction of coolant flow.To answer the other question posed: the upper hose returns the coolant from the radiator to the block and the lower hose sends hot coolant from the block to the radiator.
Bob
Need a scanner to see what the PCM is seeing as far a coolant temps,the electric fan should not engage till the coolant temp reaches 219(+/- 2 or so degrees),the fan will engage when any selection that involves AC operation and that does include defrost(both modes for the '02's).UPDATE: So, took another shot at it. The thermostat is good, the original thermostat we decided to test too and that was good. They weren't the issue. The water pump is good to go, the impeller and everything is good and works.
Newest thought though, the fan. Obviously the purpose of the fan would be to cool down the coolant once it comes back out of the block into the radiator to cool it and put it back into the block and then it heats up again and repeat. So the fan should only be on once that thermostat opens and that hot coolant flows into the radiator, but my fan is on almost the full time. It'll kick on for about 60 seconds when i start the jeep, but it will come back on most of the time, even before the temp is up and anything and without that thermostat opening....any idea if this could possibly cause an issue?
Got it backwards,I know for a fact since I have done more coolant flushes then I can count on 3.7's/4.7's.We use a short piece of clear hose in place of the machine while bleeding/getting the system at operating temps(t-stat open) so I know the direction of coolant flow.
I had a "Doh" moment - thanks for the correction Troy. The upper hose gets hot first so of course it's sending hot coolant to the radiator.
My bad :shrug:
Bob
I've been here!! Replaced my radiator which had a pin hole leak, thermostat and flushed system only to still have no heat. Culprit-heater core. Even though it was circulating, it was actually bypassing the core cause it was clogged. My mechanic did the job in 6 hours and charges $30.00/hr. Not even worth the headache imo to save a $180.00 plus an $80.00 core from NAPA. I'd find someone local that might do work on the side that knows what they are doing and save yourself the hassle.
Well luckily my uncle has worked on cars for 30 years and he's the one who has been pretty much troubleshooting everything. I've just been watching, have to learn somewhere. But he'll be the one doing everything. All I'll have to do is buy the heater core! haha
I'm also a big fan of learning how to do things myself too. Manuals. youtube videos. Doing it myself or helping/watching are my ways to learn so I'd much rather watch it be done/help! :waytogo:
The t-stat just blocks flow through the radiator,it can be placed on either end for the same effect.Hmm...well i guess given everything that we've done i just will have to wait until summer and do the job and a half that is replacing the heater core. Probably take a couple days of leave to do that haha
one last question though, can somebody explain how the tstat works then, if the top hose is block to radiator and bottom is radiator to block...that confuses me haha Since the tstat is facing into the block i figured once the coolant heats up to temp, the tstat triggers and opens, and that hot coolant flows to the radiator and the top hose brings the cold coolant in and once that cold stuff reaches the tstat it closes?
Thanks again everybody for all of the help! From everything it sounds it's just that we flushed part of the core, but it's still plugged so i'll just have to do that come summer. I have better heat after the flush. Doesn't seem as though i have any sort of leak. I don't smell coolant nor do i have the dampness/fogging issue that i believe comes with a leaking heater core, correct?