engine overheating

[ErikP]

has anyone ever heard of a bad ground causing an engine to run hot/overheat? if so, why does it happen? i've replaced the thermostat, is there any other reason the engine would overheat?

Thanks
Erik

[SafeAirOne]

has anyone ever heard of a bad ground causing an engine to run hot/overheat? if so, why does it happen? i've replaced the thermostat, is there any other reason the engine would overheat?

Thanks
Erik

Yeah--If you have an electric cooling fan with a bad ground you could overheat depending on the season and type of driving and type of engine.

[ktom300]

Mine used to overheat after I shut it off. I added some "water wetter" and it never happened again.

[jgkmmoore]

overheating

You may want to consider having your radiator inspected/tested at a radiator shop if it's really old, and you know it's never been out of the car. If it's old...have it rodded out, or get a newer one. Be sure your pressure cap is good(last thing everyone chks). Leaks? Look at the inside of the bonnet to see if it has been slinging water. Shake your fan blades to see if pump is ok. Could you have an air bubble in the heater circuit? Timing set right? How bad does it overheat? Clear into the nuclear area? or just below boil? Have you changed the coolant regularily? Backflushed it?
Gotta manual?

[scott]

ya gotta have a clogged rad. mine used to leak, hole was on the top so it ran about a gallon short almost all the time and cause i'm cheap i stopped adding coolant and with just a couple of gallons of water it still ran at normal temps

[greenmeanie]

I'll thradh my 88 down the freeway at 3800rpm for a couple of hours and she doesn't get over 3/4 up the temp gauge.

Things that affect temp other than the aforementioned clogged radiator and thermostat:
- Make sure you have a fan shroud. It makes a difference in forcing the fan to pull air through the rad instead of just churning it around in the engine bay.
- MAke sure the fan is on the right way round so you are pulling and not pushing air.
- Timing. Incorrect timing and a toolean fuel mixture will cause temps to rise.
- Wash the front and rear of the rad with a hose to unclog the fins.
- Replace any old hoses.
- Cracked head/block.

Do a search as there have been inumerable posts on overhaeting issues.

[ErikP]

overheating continued

the radiator is new

the fan is non correctly

the shroud is not on, but overheating occurs even on cold winter days in maine.

the timing is good (checked with a strobe).

the engine is almost maxed out on the temp gage, by the way.

what about mixture, does a lean engine run hot? would it cause it to completely red line?

Thanks all for the help.

[SafeAirOne]

Is the engine, in fact, running hot? Or is it just indicating hot?

Is the fan belt missing?

Is the cooling system full and free of air?

Was the onset of the problem sudden or gradual?

Is the coolant or the engine oil milky and coagulated?

[Sputnicker]

Are you sure it's actually running hot, or is it possible that the gauge is reading wrong?

[ErikP]

the engine has always run hot, ever since i rebuilt it.

the coolant is not milky.

the engine loses power when it redlines.

there is no squeeking, so i assume the belt is fine. i'll double check though.

if i open the radiator (cool engine) should i eventually see flow out of the top hose as the engine warms?

[badvibes]

the radiator is new

Why did you put a new radiator in? Old one shot/non-repairable? Did you put in a new thermostat at the same time? Was the truck overheating before the rad replacement? Just looking for more information.

Jeff

EDIT: Saw you stated you've installed a new thermostat. Have you run the truck witout a thermostat?

[ErikP]

Why did you put a new radiator in? Old one shot/non-repairable? Did you put in a new thermostat at the same time? Was the truck overheating before the rad replacement? Just looking for more information.

Jeff

EDIT: Saw you stated you've installed a new thermostat. Have you run the truck witout a thermostat?

the old rad leaked and was unrepairable (its free for anyone who picks it up). the engine was rebored(could grinding debris clog get in the water passages?) the thermostat is new and in correctly. How do i get air out of the engine if that is the problem? Hose? if engine is running hot because its set too lean, then would pulling the choke out cause the engine to cool down? Thanks.

[badvibes]

Erik-

What was the coolant like when you swapped rads? Clear, green, brown, sludge? Did you flush the system when you did the swap until you got clear running water? If the rad is new, thermostat is new, the only other piece I'd question is the water pump. By running the truck without the thermostat the flow is unrestricted and should not get hot, it may have trouble even getting warm enough. IF there is flow and no blockage in the system somewhere. If the coolant looked brown/rusty/sludgy when you did the swap and you didn't flush the system I'd try doing that, flush the entire system until you have clear running water coming out. What does your exhaust look like? Does it look whitish at all?

Jeff

[ErikP]

I think my problem is solved. put a hose to the rad while the engine was running and al of a sudden started to get flow out of the top of the rad hose (thermostat removed). looks like it was trapped air.

Thank you everyone for all of your help.

Erik

[badvibes]

Cool! (no pun intended) Glad you got it resolved.