I always had a bit of an issue but now with the summer in florida it is way worse: The car seems to get to operating temperature pretty quickly which I'm not to worried about around 190. The issue I am having is after that.

If the car is moving it stays 180-190 never really moves. The second it stops traffic light or traffic it starts coming up depending on how long 220-225. The other day I was stuck in traffic and it kept going to about 235-240 then we started to move. Once I start moving it comes back.

Before I start to throw parts at it I want to know what anyone would suggest to do to start. The car is a stroked 427 prc heads fast 102. It has a 160 t-stat in it. The fan has also been adjusted to come on 95% over 200. The car also has an slp underdrive pulley on it. Could that be causing the pump to spin 2 slow at idle(around 1k)

Thanks for any light you can shed on this. Its driving me nuts

 

Need more fan and possible upgraded radiator. Dewitts with d3 fans should fix that and keep it under 230.

220-235 is completely normal during hot summer months with AC on.

Yes underdrive could be causing a slight issue.

 

Thank you! I was more worried about how fast the temp got there and when it does it it slowly keeps creeping up.

 

Are you sure the fan is coming on. if it is try adjusting it to come on earlier It seems I remember its suppose to come on earlier anyway when the AC is on.

 

I'm not convinced that the fan is coming on or at least not coming on enough. It's variable speed, not on/off.

 

Check for blockages, grass clippings are the worse. Hard to properly clean without removing radiator. Check fan relays, fuses, and harness at the fan. It it's not running, the problem is obvious.

 

If your fan was not running, your temperature would rise quickly and never level off when you're stopped. Mine got to 265 when the connector melted, but would go under 200 as long as I was 35 mph or faster.

It was 107 here today and when on the freeway the temps never got over 190. Once on local streets it went into the 200-210 range. I didn't get tied up in traffic, which would have easily put it over 220.

I pretty much don't panic until 235+ and there is no place to get up some speed. The DIC warning happens at 256.

If you want to clean the crap out of the radiator/condenser, try this:
I use a water wand made from a 2' long section of 3/8" copper tube that attaches with some fittings to a hose spray nozzle. I crimped the far end and drilled 2 holes 1/8" diameter in the side of the tube about 1" from the crimped end.

Take off the air intake/filter and the radiator/condenser cover. I slip a thin sheet of plastic between the radiator and condenser and blow out the crap with the wand from the back of the radiator. The plastic keeps the junk from being pushed into the condenser. After the radiator is done, I use the wand in between the radiator and condenser to force the crap out the front. Removing the wand from the spray nozzle and lightly spraying the crap from the whole area finishes the job.

 

Should we assume the coolant was changed when the engine was done, and when was that?

 

The fan is coming on for sure. I adjusted the table my self by 200 the fan are on 95%. I can hear it running and I can see the voltage drop.

 

All brand new coolant from gm when it was changed maybe 8 months ago

 

I will try to see if I can get in there and clean it out. Thanks

 

HOX's suggestions may be the ticket! Let's hope so. Good luck (glad it's got new coolant).

 

Heavily modified engine.

Yes as above first steps make sure the front of the radiator is not clogged with leaves etc.
Yes check the fans are coming on.
Yes check the coolant system is not gummed up.

I bet the answer is installing a better radiator from your motor description.

Good luck.

 

Sounds like a plan. I knew I would have to upgrade the cooling system just wanted to make sure there wasnt a deeper problem.

 

I know that there are many PRO vs CON threads on installing a 160 degree thermostat...but Ill tell you what in 110 degree weather even at stop lights with the A/C blowing max.. I never get above 200 degrees...

And im not sure if you have noticed this yet....but under 200 degrees there isn't any temperature timing pulled so you should notice a bit more power....pay attention to the car when you are 180-190 and then feel the performance after it hits the 200 mark...you WILL notice a difference...

Freeway driving equals about 180ish night times and cooler 170

I'm not here to start a huge debut like you see on every-other 160 thread...

Just stating the facts in a hot state such as yours ...