Mysterious overheating

gregwenn · #1 08-22-2010, 08:44 PM

2001, 2.3l stock XLT, 120K miles
I have an overheating engine that the Ford dealers can't diagnosis or fix (except for experimental diagnostic replacement...).

To make a long story short:
Truck runs fine for about 15mi, normal temp.
Then temp starts to rise up to 7/8 (1/2, mid gauge is normal).
Very pronounced rise if steep grade.
Two separate dealers have replaced T-stat/housing (second under warranty on a trip).
Passed blue water test.
Said temp was even across radiator (no hot spots)
Dealer re-evaluated and replaced pressure tank cap.

Still same problem. Dealer indicated maybe fan clutch problem.
I replaced fan clutch, temp rise is a bit slower but still a problem.
Dealer said they couldn't do anything unless I wanted them to start replacing parts as a diagnosis method. No Thanks.

I'm about to start replacing parts, starting with water pump.

Any thoughts or suggestions welcome.
Thanks in Advance

gregwenn · #2 08-22-2010, 08:55 PM

A tad more info after reading Dealer write-ups:
- Engine code saying Intake manifold runners not opening fully.
- Mentioned possible head gasket failing due to overheat

How likely would either be the cause?

gregwenn · #3 10-04-2010, 09:26 PM

Replaced fan clutch and problem is reduced.
Looks like water pump replace next.
Hope its not head gasket failing.

Coleosis · #4 10-05-2010, 04:26 AM

If you're losing coolant it is most likely the HG (assuming you obviously cant see a leak or you would have checked that)

If you are not losing coolant, sounds like you got a clog somewhere....before you buy a waterpump, try bypassing the heatercore...Its worth a shot

I remember my 93 overheating and smelling like puppybreath in the cab...bypassed the heatercore and it was better....when I got home I ran some water through the heatercore and mud lookin shit came out. Thats when I flushed every bit of that FORD specific coolant out (it was orange and mucky looking) flushed it like 10 times before everything was nothing but water...then switched to the green stuff.

mossyoak03 · #5 10-05-2010, 04:47 AM

are you gettin water in your oil? is any smoke coming out of your exhaust?

FireRanger · #6 10-05-2010, 06:05 AM

Replace your water pump. This fits 100% the symptoms of rotted out impeller vanes causing insufficient water flow. It can pump enough at low RPM and low heat load. But climbing hills and such is more than it can compensate for. If you aren't losing coolant, and you aren't boiling over constantly, and you haven't baked the engine into oblivion, there is no reason to suspect a head gasket leak. The symptoms do not fit.

mossyoak03 · #7 10-05-2010, 06:06 AM

Quote:

Originally Posted by FireRanger

is more than it can compensate for.

thats what she said