Thursday, September 15, 2011

Overheating more slowly after thermostat, radiator hose change, and radiator flush...Whats the deal?

Alright, 1997 Chrysler Concorde. Took off the radiator and flushed it, changed both upper and lower radiator hoses. At the time, I figured I would see if I could also flush the flow of water through the engine. I stuck a hose in the thermostat housing and it flowed through...So I took it off to change the thermostat, and someone had removed it totally. So I put a new thermostat, new thermostat housing, both radiator hoses, and flushed the radiator. The coolant reservoir isn't leaking, but the cap is. However, it is still overheating, just not as quickly. The water pump is working, the top hose gets hot. I am thinking there is a possible clog in the return line from the reservoir to the engine/radiator, but does anyone else have any ideas? After changing everything (also new coolant, 1gal concentrated, rest water) it idled for a while, but the coolant bottle never dropped the level. It stayed full completely. Any ideas? Fans work, thermostat is within temp range. Properly bled radiator.Overheating more slowly after thermostat, radiator hose change, and radiator flush...Whats the deal?One more simple thing that people never think of is the radiator cap. I had this happen to me once. The cap no longer held the pressure and let the water out at the overflow. It didn't show up in the pressure test because the cap was not there.



Worth a try....Overheating more slowly after thermostat, radiator hose change, and radiator flush...Whats the deal?Your heads are warped. Need to have them shaved. ( It would be cheaper to buy a new motor.Overheating more slowly after thermostat, radiator hose change, and radiator flush...Whats the deal?You took the necessary least expensive home troubleshooting steps first. Now it's time to have your cooling system pressure checked at a car dealer or independent mechanic who has the hand pressure pump tool.



It looks very similar to a very short hand bicycle air pump with a plum-med radiator cap on the end with a pressure gage. He'll pressurize your complete system and hopefully it'll hold the minimum (cooling system pressure ) overnight. If not and there are no visible external leaks. The cause will most likely be a partially leaking head gasket or worse case a crack in a cylinder head or block. In that case the heads will need to come off, a very close inspection for cracks between the valve seats or and cylinder block. If the head gaskets are leaking internally they should be cheked at an engine shop for absolute flatness.



A slight warp on the head face can re-machined. A new set of head gaskets will be all you need. If necessary you can pick up another set of heads completely re-manufactured or at an auto parts re-cycling yard.



Inspect the used heads for cracks before you buy them. Have them inspected for flatness and do a valve job is necessary.Overheating more slowly after thermostat, radiator hose change, and radiator flush...Whats the deal?could be blown headgasket or worse yet a bad head. either one is major work and expensive. white smoke coming out the tail pipe would confirm this. the coolant reservoir is just to collect coolant due to exspansion. fill radiator to one inch of filler neck. recheck coolant level after comming up to operating temp. leave the reservoir empty. even though you fushed radiator, it could still be plugged. take it to a radiator shop for a real flush and flow test before you spend any more money. also what is the prior history of this car ? is this a new problem just developed ? or did you buy car this way ?Overheating more slowly after thermostat, radiator hose change, and radiator flush...Whats the deal?I had a similar problem with my camaro. Guess what was wrong...I had a corroded terminal under my fuse box and the electric fan wouldnt kick on when it was supposed to. I sprayed some electrical contact cleaner and everything is fine now. Do you have an electrical fan or mechanical fan?