Engine cooling question.................
09-01-2004, 11:43 PM
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Engine cooling question................. What on earth can be making my engine hot?
FACTS:
There is nothing stuck up in front of my radiator
The coolant is totally full
The coolant starts to flow after I let it idle for awhile
The fans are working just fine, they were checked thoroughly
My air dam in front is perfect
Symptoms:
If I drive in the city on a hot day (A/C OFF), the temp will go right up to the 210 mark, which in my engine equals about 230 degrees, according to the scanner.
If I put the air on it will quickly go right past the 210 mark and keep on going if I let it. I have to then put the heat on full blast to get it to come back down.
If I'm on the HWY on a hot day the temp will rise to about 215 degrees(scanner). If I put the A/C "on" it will go up to the 210 mark and maybe a little past.
The engine before rebuild never went above the 155 degree mark no matter where or how I drove it with the A/C OFF. With the A/C ON in the city on a hot day the most it would ever go is about 185 on the gauge. It never once saw the 210 mark.
It seems that when I turn the A/C 'on" all hell breaks loose. Because sometimes it'll stabilize and not climb, but as soon as I turn the A/C "on", BAM!!! The needle moves like a widshield wiper.
Could the thermostat be sticking open?
Can a water pump that does not leak, not pump water properly?
Can a failing bearing on the compressor be dragging my engine down when the A/C is "off", and then just totally killing it when its "on"?
Any ideas? I'm getting pissed now
FACTS:
There is nothing stuck up in front of my radiator
The coolant is totally full
The coolant starts to flow after I let it idle for awhile
The fans are working just fine, they were checked thoroughly
My air dam in front is perfect
Symptoms:
If I drive in the city on a hot day (A/C OFF), the temp will go right up to the 210 mark, which in my engine equals about 230 degrees, according to the scanner.
If I put the air on it will quickly go right past the 210 mark and keep on going if I let it. I have to then put the heat on full blast to get it to come back down.
If I'm on the HWY on a hot day the temp will rise to about 215 degrees(scanner). If I put the A/C "on" it will go up to the 210 mark and maybe a little past.
The engine before rebuild never went above the 155 degree mark no matter where or how I drove it with the A/C OFF. With the A/C ON in the city on a hot day the most it would ever go is about 185 on the gauge. It never once saw the 210 mark.
It seems that when I turn the A/C 'on" all hell breaks loose. Because sometimes it'll stabilize and not climb, but as soon as I turn the A/C "on", BAM!!! The needle moves like a widshield wiper.
Could the thermostat be sticking open?
Can a water pump that does not leak, not pump water properly?
Can a failing bearing on the compressor be dragging my engine down when the A/C is "off", and then just totally killing it when its "on"?
Any ideas? I'm getting pissed now
09-02-2004, 12:01 AM
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A/C puts a big heat load on the cooling stack.
There is some stuff I see in HPTuners about
whether climate control overrides fans (force
them on?). Have not messed with this but there
could have been something set wrong there.
I would be looking at ECT as seen by the PCM.
and relay control signals, against what you know
the PCM fan settings are. If the fans themselves
have checked out then I would suspect a problem
with controls - either not heard or not asserted
or misguided.
There is some stuff I see in HPTuners about
whether climate control overrides fans (force
them on?). Have not messed with this but there
could have been something set wrong there.
I would be looking at ECT as seen by the PCM.
and relay control signals, against what you know
the PCM fan settings are. If the fans themselves
have checked out then I would suspect a problem
with controls - either not heard or not asserted
or misguided.
09-02-2004, 12:21 AM
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Originally Posted by jimmyblue
A/C puts a big heat load on the cooling stack.
There is some stuff I see in HPTuners about
whether climate control overrides fans (force
them on?). Have not messed with this but there
could have been something set wrong there.
I would be looking at ECT as seen by the PCM.
and relay control signals, against what you know
the PCM fan settings are. If the fans themselves
have checked out then I would suspect a problem
with controls - either not heard or not asserted
or misguided.
There is some stuff I see in HPTuners about
whether climate control overrides fans (force
them on?). Have not messed with this but there
could have been something set wrong there.
I would be looking at ECT as seen by the PCM.
and relay control signals, against what you know
the PCM fan settings are. If the fans themselves
have checked out then I would suspect a problem
with controls - either not heard or not asserted
or misguided.
Is there a way I can check to see if the PCM is set wrong with ATAP or some other way before I drive 220 miles?