I'm working on a '89 Grand Marquis, 5.0L. A few days ago it basically overheated and I noticed the radiator was leaking a little bit at the top. So yesterday I go to
put a new radiator in it and when I go to drain the radiator...there was practically no coolant in it at all. I replaced the radiator and put in a new 195* thermostat and upper/lower hoses as well.

My problem now is after idling for like 10 minutes then driving it for about 15 minutes the thermostat is not opening ( the upper radiator hose is easy to compress and does not feel like it has hot coolant flowing through it).

There is also practically no heat in the car and I would like to get that fixed before winter!!
I visually checked the water pump and did not see any coolant coming out of the weep hole.


Any ideas on what I should do next? Should I replace the water pump and try to flush out the heater core or replace both? The heater core is cheap, about $28; water pump about $45.

it sounds like you just have air pockets in the system. do any of the lines have bleeder screws?

if so, you need to open them up to let the air out

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My problem now is after idling for like 10 minutes then driving it for about 15 minutes the thermostat is not opening ( the upper radiator hose is easy to compress and does not feel like it has hot coolant flowing through it).

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If what you say is true.....it must be severely overheating after the 15 minute run??????
Is that how your determining that the thermostat isn't opening??

If you have no other leaks, and there is no flow through the system, I would try a run with NO thermostat to ascertain that there is flow.........and that can be determined easily enough with no radiator cap on while idling and running up the rpms right in the driveway......

Check for 'hot' hoses through the whole system after warming up.......

The water pump 'may' be the culprit, but they usually give some indication of going bad......bearing noise, shaft wobble, etc.

Tongue in cheek question - was the thermostat installed correctly? - not upside down??



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The car is not overheating at all now. I drove it to work today, about 15minutes/ 10 miles.

I believe the thermostat is installed correctly, "spring into the manifold, as the haynes manual indicates"

The uppper radiator hose does not have fluid running through it after what I would think would be a long enough running time for it to be up to temperature.

I cannot tell what the exact temp's are because there is no temperature gauge in the dash....kind of dumb if you ask me.

I am going to inspect the water pump a little closer today and see if there is any shaft wobble.

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Well, there's one problem......."I cannot tell what temps.....etc."


Dash gauges are notoriously WRONG, and/or the span shows a temp between 120 and 240......so we're supposed to
"Guess" what the temp is when the needle is between the two lines?? Hello????

Go to Wallymart and get a cheep meat thermometer........and stick it in the radiator when the engine gets up to temperature....(actually before, so you don't burn anything off getting the cap off)

It's the ONLY......ONLY way you're gonna know exactly what temperature it's running at ! ! ! !

It seems odd that the upper hose has no fluid running through it, with the engine at temperature, so the fact that the hose is "soft" may only indicate that no pressure is being built up in the system..........for that I would say there could be a problem with the radiator CAP not holding pressure. Hmmmmmmmm........

But, as you say, it's not overheating now, so if it's running correctly, and maintaining the recommended thermostat temperature, any lack of heat from the heater core could be due to - clogged core - bad control valve - or other items like closed vent doors, bad vacuum line to heater, etc., etc., .............


One last note, make sure the heater is FULL ON, and check to see if both hoses going TO and coming FROM the heater core are hot.........if not, there's no circulation....for some reason.



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