I will not attempt to guess history of car nor full evidence of symptoms not told.
this is the answer on all cars. water cooled, for sure jeeps
pasted : (my personal logs)
all causes of Jeep overheating and tests. (my personal journal)
first are signs:
Evidence/symptoms !??????
steam blasting from rad cap or recovery side tank.
dash guage, reads too high or is erratic.. (and can lie to you,easy see why below)
ECT bad or air in the loop it reads wrong,fix air in loop first.
The scan tool shows. erratic ECT sensor. or DTC for over heating or ECT errors.
engine power drops.
engine pings/knocks/detonation, (under load)(too hot)
Coolant boils at 265F
the coolant must never be just water, it must be 50% AF, antifreeze or it will boil.
engine stalls. (some modern cars shut down too hot via PCM controls smarter)
Only over heats at stop signs, never moving fast.(or both)
Only overheats moving fast or only pulling a huge boat up hills.?
Only overheats A/c cab HVAC turned on.?
leaks to ground. Antifreeze 50%AF leaking.seen hot engine.
leaks to front passenger toes, foot well,heater core/hoses leaking
leaks to engine oil pan, it dipsticked looks like chocolate milk.
leaks to A/T, ATF oil pan. (dip-sticked just like above) skip for manual trans (m/t)
leaks , if it leaks coolant, this is repaired first.
CAUSES:
First are simple and cheap checks.
air in the coolant loop, not burped the correct way. makes gauge go crazy with lies.
The RAD always shows (eyes) full, dead cold cap off, does it? and no oil drops seen here.
No water in the oil pan (dip stick looks like chocolate milk shake ,bad) bad head gasket.
no steam under hood or at tail pipe end.
water pump witness hole drips coolant, the pump is bad.
on min last month the pump gasket was bad. 2008 jeep, jK. where you can not see it,directly. oops
fixes and tests :
RADiator packed in dead bugs.
RAD cap bad. $5 fix.
fan belt loose, 100 pounds up on serp belt not less. jeep is 140 lbs min. (5 bolts on PS pump)
Thermostat bad, at 7 years old (normal life span) $20 cure, and loves to fail on old cars. does.
running 30 year old coolant still?
A bad Radiator., (leaks? none, the RAD tubes must be not clogged deep inside it, IR gun tool finds this super easy.
top fails for old cars for sure 30 years old.
bad hoses leak.(cheap fix to)
water pump failures and its gaskets too.
thermostat installed backwards or its bleed hole not upward side. (engine tilts front to rear)
Rad fan dead or its relay bad. The clutch fan MUST not slip at idle.
Idle RPM is 800 or more, never 500 RPM.
.
Tests
Dead cold engine (safe), RAD cap twisted off.
You see coolant missing at RAD filler NECK,or not full here is wrong.
It must be full ever time (each morning)you looked
RAD side overflow tank , at 1/2 full each cold engne(morning?) test.
if was low that means there was air in the loop now.
This air pocket makes most dash gauges read wrong and the thermostat fail even a new thermostat fails in air pockets.
The ECT tests must show 180f running, hot. 225F(par say driving up hill) if electric fan, the RAD fan kicks on. near 225F or A/c turned on.
The AF boils at 265F.
The ECT does not work in air pockets,only in Collant AF.
My page covers 3 decades, from clutch fans to dual fan cars at RAT.
Test#1 for leaks,etc.
A DEAD Cold engine.
RAD cap off neck to RAD is full of 50% AF mix.
cap back on.
Start engine hood up. and let idle for 15 to 30 minutes.
The dash gauge goes mid scale, normal like it did for ages.
The fully hot (normal) engine will now produce 15PSI, full pressure and when this happens (good RAD CAP) all leaks will now happen under this natural large pressure. For sure to the ground.
Go slow and look for leaks. to ground, at the pump tell-tale weep hole leaks, any leaks from any hose.
leaks to front passenger toes.(carpet wet)
the main RAD leaks , seen.
leaks can drop/dribble or squirt. (even squirt to things fully 100% good)!!!!
If coolant or steam blast to the overfill bottle tank, stop the engine.
This page is for discovery and evidence.
At this point you can get advice on what to do next.(report all evidence first)Good and bad.
Best is start with a new thermostat in most cases and new RAD cap.
And 50%AF, fresh.
A good tool to own is a laser IR thermal gun. ($15) even Harbor Fright (sic) has them.
And use it to find thermostat housing too hot over 225f is.
Use this IR thermal gun to check all small tubes in the Radiator. (all ends, checked, hot and cold side. A super easy test, at 30 minutes idling, fully hot testing. OMG the IR gun finds out my dash gauge is a liar . (lies like a gas meter my grandpa said) (and did)
End to end RAD tubes checked. if one is cold, that tube is clogged.(hot engine tests)
A good tube scanned, is hot on one end and grows colder as you scan the tupe and is 35-50f degrees
cooler at the other end (cold side). This is a hard test, it is child's play and no burned hands.
example:
My JK jeep ,08, the pump gasket rotted out, where we can not see it.(flange) the evidence was
seeing green Antifreeze dripping from 6sp tranny bell. ( lies to me,, but expected)
the windage factors did that + gravity !
best test is to make it leak parked, and find exact source hot and parked.
I have cold engine RAD pressure tester that found mine. At 20psi,on tools gauge. saw the pump leak.
this is not my first Rodeo. 1963 to now, direct hands on.
end.
Jargon (ASE)
RAD = Radiator main, front of car.
ECT = Engline coolant sensor.
DTC = Scanned errors, Diagnostic trouble codes. OBD2 scan tools.(hey man I got codes they say now)
A/T = automatic transmission 50%AF
AF = Antifreeze COOLANT 50% mix , and is antiboil too.
HVAC,heating, vent and air condidtioning.
this is the answer on all cars. water cooled, for sure jeeps
pasted : (my personal logs)
all causes of Jeep overheating and tests. (my personal journal)
first are signs:
Evidence/symptoms !??????
steam blasting from rad cap or recovery side tank.
dash guage, reads too high or is erratic.. (and can lie to you,easy see why below)
ECT bad or air in the loop it reads wrong,fix air in loop first.
The scan tool shows. erratic ECT sensor. or DTC for over heating or ECT errors.
engine power drops.
engine pings/knocks/detonation, (under load)(too hot)
Coolant boils at 265F
the coolant must never be just water, it must be 50% AF, antifreeze or it will boil.
engine stalls. (some modern cars shut down too hot via PCM controls smarter)
Only over heats at stop signs, never moving fast.(or both)
Only overheats moving fast or only pulling a huge boat up hills.?
Only overheats A/c cab HVAC turned on.?
leaks to ground. Antifreeze 50%AF leaking.seen hot engine.
leaks to front passenger toes, foot well,heater core/hoses leaking
leaks to engine oil pan, it dipsticked looks like chocolate milk.
leaks to A/T, ATF oil pan. (dip-sticked just like above) skip for manual trans (m/t)
leaks , if it leaks coolant, this is repaired first.
CAUSES:
First are simple and cheap checks.
air in the coolant loop, not burped the correct way. makes gauge go crazy with lies.
The RAD always shows (eyes) full, dead cold cap off, does it? and no oil drops seen here.
No water in the oil pan (dip stick looks like chocolate milk shake ,bad) bad head gasket.
no steam under hood or at tail pipe end.
water pump witness hole drips coolant, the pump is bad.
on min last month the pump gasket was bad. 2008 jeep, jK. where you can not see it,directly. oops
fixes and tests :
RADiator packed in dead bugs.
RAD cap bad. $5 fix.
fan belt loose, 100 pounds up on serp belt not less. jeep is 140 lbs min. (5 bolts on PS pump)
Thermostat bad, at 7 years old (normal life span) $20 cure, and loves to fail on old cars. does.
running 30 year old coolant still?
A bad Radiator., (leaks? none, the RAD tubes must be not clogged deep inside it, IR gun tool finds this super easy.
top fails for old cars for sure 30 years old.
bad hoses leak.(cheap fix to)
water pump failures and its gaskets too.
thermostat installed backwards or its bleed hole not upward side. (engine tilts front to rear)
Rad fan dead or its relay bad. The clutch fan MUST not slip at idle.
Idle RPM is 800 or more, never 500 RPM.
.
Tests
Dead cold engine (safe), RAD cap twisted off.
You see coolant missing at RAD filler NECK,or not full here is wrong.
It must be full ever time (each morning)you looked
RAD side overflow tank , at 1/2 full each cold engne(morning?) test.
if was low that means there was air in the loop now.
This air pocket makes most dash gauges read wrong and the thermostat fail even a new thermostat fails in air pockets.
The ECT tests must show 180f running, hot. 225F(par say driving up hill) if electric fan, the RAD fan kicks on. near 225F or A/c turned on.
The AF boils at 265F.
The ECT does not work in air pockets,only in Collant AF.
My page covers 3 decades, from clutch fans to dual fan cars at RAT.
Test#1 for leaks,etc.
A DEAD Cold engine.
RAD cap off neck to RAD is full of 50% AF mix.
cap back on.
Start engine hood up. and let idle for 15 to 30 minutes.
The dash gauge goes mid scale, normal like it did for ages.
The fully hot (normal) engine will now produce 15PSI, full pressure and when this happens (good RAD CAP) all leaks will now happen under this natural large pressure. For sure to the ground.
Go slow and look for leaks. to ground, at the pump tell-tale weep hole leaks, any leaks from any hose.
leaks to front passenger toes.(carpet wet)
the main RAD leaks , seen.
leaks can drop/dribble or squirt. (even squirt to things fully 100% good)!!!!
If coolant or steam blast to the overfill bottle tank, stop the engine.
This page is for discovery and evidence.
At this point you can get advice on what to do next.(report all evidence first)Good and bad.
Best is start with a new thermostat in most cases and new RAD cap.
And 50%AF, fresh.
A good tool to own is a laser IR thermal gun. ($15) even Harbor Fright (sic) has them.
And use it to find thermostat housing too hot over 225f is.
Use this IR thermal gun to check all small tubes in the Radiator. (all ends, checked, hot and cold side. A super easy test, at 30 minutes idling, fully hot testing. OMG the IR gun finds out my dash gauge is a liar . (lies like a gas meter my grandpa said) (and did)
End to end RAD tubes checked. if one is cold, that tube is clogged.(hot engine tests)
A good tube scanned, is hot on one end and grows colder as you scan the tupe and is 35-50f degrees
cooler at the other end (cold side). This is a hard test, it is child's play and no burned hands.
example:
My JK jeep ,08, the pump gasket rotted out, where we can not see it.(flange) the evidence was
seeing green Antifreeze dripping from 6sp tranny bell. ( lies to me,, but expected)
the windage factors did that + gravity !
best test is to make it leak parked, and find exact source hot and parked.
I have cold engine RAD pressure tester that found mine. At 20psi,on tools gauge. saw the pump leak.
this is not my first Rodeo. 1963 to now, direct hands on.
end.
Jargon (ASE)
RAD = Radiator main, front of car.
ECT = Engline coolant sensor.
DTC = Scanned errors, Diagnostic trouble codes. OBD2 scan tools.(hey man I got codes they say now)
A/T = automatic transmission 50%AF
AF = Antifreeze COOLANT 50% mix , and is antiboil too.
HVAC,heating, vent and air condidtioning.
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