Car getting hot while driving...

[68Bigred]

Question, car seems to run hot while up to speed. Everything is new you can name. I'm thinking maybe the lower hose may be collapsing at higher rpm. It's a direct fit molded hose but no spring inside it. Anyone know of a spring I could buy or the hose that comes with it? It was 80 today and almost 12 miles at less then 25mph stuck in traffic didn't see more then 190ish but as soon as traffic cleared it jumped to 205 at about 70 mph and stayed there and never dropped back down. Never got hotter but to me seemed hot. Motor has less then 2k on it, full rebuild. Have huge aluminum radiator dual electric fans (which are running). Any suggestions? Other thought maybe running lean? I don't know how to adjust the carb. It's a 750 elderbrock. Also fluid totally full and I have a recovery tank. Looking for suggestions.

 

[Fratzog]

Think I'm running a 160 degree thermostat and haven't any issues. Mild 440 in a 68 Monaco 500.

 

[68Bigred]

Thanks there is a 180 in it now. Maybe I should drop it down. It's a very mild 440.

 

[CanCritter]

running a fan shroud?

 

[68Bigred]

Here is ny radiator

 

[Mopars & Missiles]

A thermostat ONLY controls the minimum operating temperature, it has NOTHING to do with the maximum operating temperature of an engine. Only exception would be if the thermostat was not opening completely as it should and therefore restricting water flow. Lower hose spring is a good idea. Shroud is mostly effective at lower speeds, once up to highway speed the air is forced through the radiator, not pulled through by the fan. Upper and lower air seals are there to keep the airflow going "through" the radiator and not under or over (path of least resistance) instead, are they installed? How is your water pump driven? Electrically?? Is it working properly and at the correct RPM??

BTW, 205 degrees operating temp is not really overly "Hot".

 

[Fratzog]

A thermostat ONLY controls the minimum operating temperature, it has NOTHING to do with the maximum operating temperature of an engine. .....

I'm not pretending I know anything but doesn't a 160 open sooner therefore letting the rad do it's thing sooner and improve it's cooling efficiency?

 

[CanCritter]

......went pretty well same route as you...modded up a electric fan for my 91 gmc...


pulled 4600 cfm


threw in a electric water pump as well and eliminated fan...put alotta thought into that mod..
bottom line it failed to keep the engine cool despite everything...turned around and ripped electric waterpump out along with my modded fan and went back to basic edelbrock mechanical waterpump and mechanical fan and never had a issue after...sometimes its hard to outsmart a engineer...
btw those cheap electric waterpumps you see plastered everywhere..summit jegs ect are junk...
anyway just my experience ...dont know if this helps

 

[68Bigred]

My water pump is belt driven, all March serpentine system and it is tight. I guess I'll just keep an eye on it. If 205ish is ok I guess I won't worry about it. I really don't ever drive the car far. Just felt it should be lower. The coolant looks a bit dirty, very slight, I assume from the rebuild had some crap in the passeges. I'll flush it out and put some water wetter in it. Here is the pump...

 

[CanCritter]

that looks nice..like that ...205 isn't to high realy...are some older Camaros that run 220ish...personaly would run recommended thermostat and sort it out from there...going to a cooler thermostat not best idea imo...was wondering where you were at and seen texas..looks like your fighting heat on top of heat to

 

[68Bigred]

Thanks..in austin. I put a 180 in it when I put the motor in. I assume it is good. Traffic is aweful and in slow traffic which I would get stuck in doesn't run "hot" which Im better with that. Just was just looking for assurance 205 isn't hurting anything.

 

[CanCritter]

was gona ask you about your rad cap...new...preasure rateing?..know those silly things can cause issues when old

 

[saforwardlook]

Just a thought - in looking at your shroud and integrated dual fans, it almost appears that you might have too much restriction to air flow through the radiator at highway speeds. I wonder if those fans turning at a constant speed might actually impede airflow at higher speeds since all the air seems to have to go through those two fans and what appear to be some small flaps in the shroud to allow additional exit air (but not enough total airflow for higher speed driving). Most aluminum radiator set ups I have seen use a more conventional open shroud and usual belt driven fan with an auxillary electric fan in front of the radiator to help with low speed traffic crawl conditions. Usually higher speed increased temperature of the engine means restricted coolant flow through the radiator due to crud build up or insufficient air flow through the radiator. While 205F isn't too high an operating temperature, there is no reason at all why it should be above 180F with an aluminum radiator of that size if all is right.

 

[CanCritter]

My water pump is belt driven, all March serpentine system and it is tight. I guess I'll just keep an eye on it. If 205ish is ok I guess I won't worry about it. I really don't ever drive the car far. Just felt it should be lower. The coolant looks a bit dirty, very slight, I assume from the rebuild had some crap in the passeges. I'll flush it out and put some water wetter in it. Here is the pump...

looking at that setup would consider loseing the electric fans and putting a stock clutch fan and shroud back in if l continued to have heat issues..looks to be room to pull it off...as saforward said should be no issues with that size rad.
know when l was looking at doing my setup with fans like that and noticed alota those fans realy didn't push alota air...would check to see what they flow

 

[68Bigred]

That was another thought that the fans actually could be blocking airflow. Ugh hate to pull it off as I spent so much money on it there are actually 6 of those flaps, maybe I can pull that off and add more holes to it. The fans are not cheap ebay ones, they move alot of air. They will suck a tissue to the front of the grill! Also the cap is new as well and it is 16lbs. Is that to high?

 

[commando1]

I have come across this problem a few times when aftermarket electric fans have replaced belt driven fans.
1. Many of these fans are designed to be pusher and puller fans.
2. Many are shipped as pushers and to use them as pulllers, you simply reverse the wiring.
3. Here is where most people screw up: If changing from pusher to puller, in additon to reversing the wires, you also have to remove the blades and flip it around.

So were the fans as they were shipped, pushers or pullers.
If they were pushers, did you reverse the polarity and reverse the blade pitch

 

[rags]

at 70 mph it shouldn't need fans to stay cool. fans are for stop and go. saforwardlook has it right. know what a raytek gun is? those really help for checking hot and cold spots in radiators and coolant flow through the system. can be used to check exhaust manifold temps for individual cyl. diags. SG

 

[68Bigred]

Thanks stan..these are pullers. This rad/shroud /fans were bought as one unit from Griffen. Maybe I need more holes in the shroud.

 

[Big_John]

Are you sure the gauge is right? 205° isn't that high, but I would think that it should run cooler. I'd double check that before going too much farther.

 

[68Bigred]

I'll have to bring my temp gun home from work. Here is another question. My fans turn on at 180 and since the thermostat is 180 the fans always run. Should I find a switch that is higher? So maybe at highway speed the fans shut off and not actually act like a block? Basically they never cycle..