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weird issue with overheating

S

sigtauenus

Active Member
So I'm still shaking down the car. Had a tach issue, posted that in the electrical board.


Had the car outside the garage today idling to get the engine up to temperature, which it did normally after about 5 minutes or so. All indications normal, fuel, tach, temp all working fine.


I had the radiator out of the car to install the a/c condenser, and filled it back up with coolant and overfilled it. My car likes a lower than normal coolant level, so I just top it off, let it burp out via the overflow whatever it doesn't want (another reason I had the car in the driveway vice inside to warm up).


So the radiator started pushing out the extra coolant, which is normal, but then the temp gauge went up to high. That is very weird, I've never had an issue with overheating with this thing. I went around to the radiator and the radiator was cool to the touch. It didn't make sense to me that the temp gauge would be showing hot but the radiator would be cool.


Combined with the tach issue, I'm not sure if I have an electrical/sender issue or an actual overheating issue. Water pump and thermostat are new, well, they are 2-3 years old now, but have less than 100 miles on them.


Suggestions?
 
Sounds to me like your thermostat was stuck closed. The temp sending unit is behind it, in the intake manifold. There's a route for high pressure through the water pump and lower radiator hose with a stuck thermostat that can push water out the radiator.
 
That's what I was thinking too. Damn what a mess. I just hate ripping into it again, but might as well yank the thermostat, put it in a pot of boiling water, verify it, and try again.
 
right now im having the same problem.. just changed the water pump, thermostat all the hoses plus the sender unit.. gauge still reads high.. but i have one of those cool radiator caps which tells me the temperature and it reads fine so im pretty sure mines the gauge at this point..
 
OK, so I changed out the thermostat, that was definitely the problem (and I bought one that fails open). However, I put in a 180* vice the stock 195* and the temp now barely comes off the peg. I added a/c, and a 24" 4 core radiator, and the engine is running really, really cool now. I had the heat on this morning and it barely felt hot.

Should I go back to the 195* thermostat?
 
Muffy,
Are you running stock gauges? Sounds like you are since you mentioned it barely comes off the "peg". If it was infact recently re calibrated I wonder what temp the middle peg reflects. I use 180 stats in both Red and Shag who use autometer gauges and both run dead on at 180.
 
Right off the peg isn't quite accurate. I'll post a pic here in the next couple days. Done with the car tonight.
 
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