In a message dated 4/11/06 10:07:18 PM Eastern Daylight Time,
spamiam@comcast.net writes:
<< Oh, man. I REALLY don't want to have to strip the engine. I can't afford
a
rebuild!
>>
Before things get out of hand here. Use a known good temp gauge. Know any
racers that have a tire temp pyrometer?
Sediment at the bottom of the block will not cause the engine to overheat.
Very little heat is transferred from the bottom of the cylinders to the cooling
system. Most of the heat from this area is transferred to the oil. Having a
drain valve clogged is common to many engines and nothing to worry about.
For years drag racers have filled most of the block ( like within 1" of the
top ) with a substance called "Hard Block" this is done to stabilize the
cylinders and prevent them from splitting. Some people use the cars on the
street
and have reported no change in cooling temp. If they had a oil temp gauge
however the oil temps would be elevated.
As for the heads,most of the heat is transferred here. I know of no engine
that has a sediment problem, I suspect yours does not either.
Running water through a cooling system does remove loose silt. I tend not to
like chemical cleaners as any clogging is likely to be in the radiator and
the only real fix is to remove a tank and rod it out. Your car has a couple
year old rad correct? It is unlikely is is clogged so soon.
Next up is to check the head gasket. The only external way is to use
compressed air. All other methods are a waste of time.
Make sure the car is in neutral and your hands are away from the fan and
belts. Remove the rad cap. Turn the engine until # 1 is TDC on the firing
stroke.
Remove the spark plug and install a air fitting ( there is a adapter made for
this or use a compression gauge with the check valve removed ) Apply air in a
short burst, if the motor rotates turn it backwards to TDC. When the motor
is at TDC it will not rotate.
Apply full air ( 100 PSI is enough, more is OK ) stand clear of the rad cap
flange, if the head gasket is sufficiently bad, coolant will spray from the
rad. If coolant does not spray, leave the air attached and look for small
bubbles. Continue to the other cylinders, following the firing order saves
time
here.
You will get a hissing sound from the crank case due to piston ring leakage.
Some leakage out the exhaust is semi normal on a older or high mile motor.
Leakage from the intake manifold sometimes occurs, if this is the case a valve
grind is looming on the horizon. None of these leakages will cause a overheat.
Lastly you might have fins corroded away from the waterpump. I've only seen
this a couple of times in all my years of working/running a shop.
Harold
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