Ok the car is an 84 camaro crate 350 mild cam. anyway the car gets hot when driving or sitting. It has coolant in it, the fan works 12" permacool puller, the system holds pressure, has a high flow water pump also still did it with the stocker, radiator is a be-cool aluminum dual core (big sucker), the thermostat opens is a 160*, have tried bypassing the heatercore to rule out restriction made no diff, timing is about 8* advanced nothing crazy there, car may be running slighty lean but not too lean I will try to richen it up but probly won't help, air dam is in place. The car will heat up just idleing or even cruising down the freeway at 70mph. I have block checked it to check for combustion gases in the coolant found nothing. I'm not really sure what to try now other than richen it up and maybe try a coolant restrictor instead of the t-stat. If anyone has any ideas to try or somehow knows what it is by reading this I would appreaciate the helps thanks. oh I have verified that the car is getting hot with 3 different gauges.

 

Are you using a fan switch? If you are, that is usually the culprit. If the air dams are in place and in good shape, have you checked the area between the radiator and condenser for leaves/debris blocking flow? Is your thermostat a high flow type? If it is one of the older styles with a flange around the outside edge, you can drill 4 - 1/4" holes to eliminate steam pockets and check your cap. You might check to see if you have the wrong rotation water pump, they changed rotation in `87 when GM started using the serpentine belt.Your lower radiator hose may be collapsing if it does`nt have a spring in it.Check your ratio of anti-freeze to distilled water, I would use about 30% anti-freeze and 1 bottle of water wetter. Time for dinner, let me know what you think.

 

That's a pretty small fan.

 

No fan switch I just grounded the signal wire to the realy fan kicks on with key on. Fan may be small but does not explain why it overheats cruising. there is no condensor, no debris. the t-stat is a high flow type are they problematic? it is a reverse rotaion pump for the serp kit. lower hose is new but I will check that. the coolant mix is about 50/50 with maybe a bit more water. I'll have to try drilling a thermo probly help get rid of any trapped air as well.

 

12" fan is the stock size on my `88 Iroc with dual fans. You don`t want your fan running over about 40 mph,it interferes with air flow through the radiator, that`s what the air dams are for. I used a 180 high flow thermostat and fan switch that starts the fan at 200 and turns off at 185 and my car runs 30-40 degrees cooler than stock. Next weekend I am changing to a 170 thermostat that I drilled and fan switch that comes on at 185 and off at 170. High flow thermostats are not a problem just some better than others. Double check your serpentine set-up and water pump rotation, I am thinking that may be where your problem is but I am having trouble coming up with the correct way to explain what I am thinking. TPI parts on E-Bay has the type of 170 thermostat I am talking about.

 

Question on the fan interfering with air flow at speed. The factory fan was electric and looking at the wiring diagram I don't see any ecm function controling that circuit. So would the factory fan not still be blowing at speeds above 40mph? I would think it would but maybe I am wrong I would think the car would need some kind of VSS or wheel speed sensor to turn it off unless it's using something like a fan clutch some kind of thermal gel.

 

One other thought on the fans being a restriction at speed is they are energized with the A/C compressor at any speed.This is how they are with factory controls and most aftermarket have this provision with thier controls.

Checking the lower hose is a good idea as I've had a similar problem and that was the culprit.I forgot to transfer the support spring from the old to new hose.And you may want to play with the timing and mixture as both can cause cooling problems.And air pockets can be a pain to get rid of in the cooling system.

 

whats the best way to check and see if the lower radiator hose is collapsing?

 

rev the engine while it's hot from the throttle body/carburetor while watching the lower hose to see if it's being distorted. This may work while it's cold too, not sure, you can try both ways.