I've got an 87 2wd pickup that I can drive when outside temps are 70 or below and not have problems but when temps are higher my engine seems to run hotter and hotter corresponding to the outside air temp. I have a fairly new radiator w/shroud and a new fan clutch and t-stat (180 degree). I've tried running the heater to see if it had any effect but noticed no difference. I've had a dozen 22R's and 22RE's and never had one that acted like this. Any ideas???

 

Either your heater core is clogged up or your coolant passages in your block are clogged up. Both happend to me and did the same you are describing.

 

Maybe bad water pump.

 

I have noticed that my heater doesn't work very well, it could very well have a clogged core. As far as clogged block passages go I guess I might check with a radiator shop about getting the system "powerflushed"? I have drained the system and used the typical parts store sytem cleaner on it but it didn't seem to help. I'll check that out.

 

I had wondered about that, didn't know if a water pump could for some reason have a reduced flow. I guess maybe the impeller could be damaged maybe? It's not leaking and it doesn't seem to have any play in it when I try to wiggle the fan but I will check it out, thanks.