Need Help, Overheating Problems
 

I have a 90 supra with brand new 7mge, and for some reason my car keeps overheating. I have already replaced both thermostats in the car, the radiator, the fan and the thermometer on the fan and my car still overheats. It usually only happens within the first ten minutes of running my car and it sometimes goes ack down but then sometimes it stays up. Anyone with any ideas on what this could be or has experienced any problems similar to this, could you please post a response. Thank you.

Is it really overheating? Are you getting boiling sounds in the hoses? It could be just a sending unit gone bad. I could also be your ignition timing, or even a blocked exhaust system.

I am sure there are other ideas out there too.

Russ

MDellboy420,

How about a blown water pump? Only other thing I could think of on top of Moswal's idea's.

Cheers,

-=Littlestan=-

yes it is overheating, when I pop the hood I can see smoke coming from underneath the fan but I cannot tell exactly where it is coming from. I also do hear the boiling sounds in my hoses every time I turn my car on. Oh, and I also forgot to mention that the sending unit has been replaced as well so I know it is not that. But thanks for the help. Any more ideas just let me know.

maybe air getting in the lines somehow?

maybe air getting in the lines somehow? is the water getting back to the radiator?

The exhaust being plugged would heat it up but unless you scrapped and bent it I dunno. Water pump replaced yet? Fan belts tight? Coolant system professionally flushed by someone you trust? Is the block brand new? Like completely rebuilt?

I will throw this out as I think of it. Mine turned out to be a TINY pinhole leak in the head gasket. It would pressurize my cooling system, but never sucked coolant into the cylinder.

I have seen some water pump impellors that were broken, so it wouldn't push enough water. And the piece blocked off the passage.

If the car will quickly accelerate to 80mph, and drive it steady for a little while (5 min), then the exhaust is OK.

Perhaps air in the system? Gurggling in the heater core???

When you start the car cold, Does the upper radiator hose get hard in a short amount of time without actually driving the car.??? It should NOT get hard until you drive the car for awhile.

Wire your fan to stay on all the time and see if it still gets hot.

New radiator cap??? Does coolant boil over to the bottle??

Thanks for the input fellas, I will check the water pump and test the exhaust, Im pretty sure it's nothing with the engine because the engine has about 3000 miles on it and was built by jasper, also I had the coolant system pressure checked so I know there is no leaks but I will check the water pump and exhaust since those are the only things I haven't checked yet, again, thanks for the input

Dont right off the engine as being a problem. It sound like it is your head gasket considering what you say you;ve replaced, and the fact it has over heated on you a few times, it may be a head gasket now if it was'nt before. Heat is the 7Ms worst enemy, it is a long alloy head, which theres nothing wrong with till you COOK IT.
I hope for your sake its not, but check if it is before you replace more stuff you may not need to.