My '88 IROC 305 TBI is running hot. Drove it the other day had significant power loss. Fan is working wondering if it wasn't thermostat. Temp gauge wasn't climbing to normal temp. Have aftermarket temp control probe that sticks into rad fins. Help please.

 

What does the temp gauge say the temperature is? Get an IR temp gun and check the temperatures at the water neck and radiator cap.

is it getting hot in traffic or on the highway?

is the air dam in good shape?

225* is when the factory fans turn on so that is "normal".

 

when was the last time the thermostat was changed?
when was the last time water pump was replaced?

winter time i use 195*
summer time i use 160* (i use the ac alot when going to phoenix Az )

have you inspected the oil for a milky looking water color? (oil in water/antifreeze)
to rule out head gasket issue?

 

Temp gauge was only reading like 150 maybe running down the highway. Put new sensor on it last year so shouldn't be that. Air dam?

 

Well I tried thermostat but broke one of the bolts so have to get it out first. Water pump quite a while. Haven't checked oil yet. That's 2 different thermostats you mean?

 

you broke the thermostat housing bolt? (2 bolts that hold down the housing)




1 is a temp sensor that tells you the temp on your gauges
1 is a thermostat that installs on your intake manifold from upper rad hose to intake

you would know if the water pump is bad pretty quick it be leaking either from pin hole or other places around it.





thermostat housing

 

the air damn is what keeps our cars cool when we are driving, air hits the dam which brings up air to the rad

 

Yes snapped the head off one of the bolts.

 

Water pump doesn't appear to be leaking that I noticed. Haven't lost any coolant.

 

ouchie!! i so would have cryed n yelled an said some choice words loudly.lol

if u can get the other bolt off easy u should be able to remove that bolt thats broken..doesnt take much force to remove or install the bolts. go part store n get a replacement or junk yard typical bolt from chevy engine v8. grab a few from few diff engine just to be safe..

thermostats get stuck open or stuck shut which causes over heating issues
fan coming on ?

 

Yes bigtime. Ya steel bolt and aluminum head though. Bad combination. I have new bolts to replace just have to get broken one out.


Fan is coming on yes

 

yea check your oil for possible coolant mix
and change thermostat

you can check the stat by heating up a bowl of water an drop the stat in the water to see if shes opening or not..not accurate by any means but does help to see if its working. there cheap personally id just replace it.

so recap
check oil
change stat.

then let her run n watch temps
without ac on you shouldnt even hit 220 (depending how your area is) or stop at 220.

i have a 160* stat in my car, temps in my area are 90*F++ i dont even hit 220 unless my AC is on..

 

Hmm, I've always heard it creates a low pressure point just right after the dam, thereby pulling hot air out from the radiator and down underneath. Definately a unique critical piece for proper 3rd gen cooling.

 

yea im sure

if you think about it, when your driving air is being cycled through the engine bay from underneath the car pushing air in n out, only thing sucks is hot weather, 115* weather in Tempe az highways lol

 

No Air Dam = Hot running car.....This is a FACT and NOT FICTION.

 

This is correct.

The air dam creates a low pressure area behind the radiator that pulls air up and through the radiator. This must be in-place and functional to remain cool at highway speeds.