Background first :

stock 2 core radiator was leaking replaced it, radiator cap, lower radiator hose. I ended up getting the $3 cheaper radiator which is a stock copper Heavy duty 3 core radiator. has 180* thermostat in it

Drove the car the same day i installed it sitting in traffic the thing started heating up so I turned the AC off and it dropped to the middle. I turned it back on and the temp never rose again.

Well the other day I drove it with ac off and it never went past the middle even when idling.

But today i drove it and three times i stopped at a redlight and the temp gauge pegged out to hot and the temp didnt drop quickly till I got the car moving.



Question now :

I took auto courses and I dont think its the thermostat cause the engine would not want to heat up (stuck open thermostat) or over heat (stuck close) but this engine cools down when you get moving. I thought water pump but I have some people tell me they leak when they go out but I have seen others say they havent. Then theres another issue that I think it could be not enough air flow over the radiator being a HD and I only have the stock 5 blade flex fan that came with the car (which came with a standard duty 2 core radiator).

So what does everyone think water pump or not enough air flow?

If its water pump I guess im **** out of luck cause I got a alternator bracket bolt that I tried to loosen up to adjust the bracket but the bolt wont turn and I kinda dont want to break it off in the block.

If its not enough air flow I got two options I can do which I dont know about.

Option 1. Go to a 6 blade steel clutch fan. The clutch spins at 70% water pump speed which means it will most likely pull the same amount of air as the 5 blade flex fan is spinning at 100% water pump speed.

Option 2. Go to a supplemental electric fan infront of the condesner. Issue with that is no one can answer me if there would be noise from the air the electric fan is blowing into the mechanical flex fan. Not to mention I need a way to mount them on brackes I dont want to use nylon zip ties like flex-a-lite wants me to use through the condesner.



So anyways, yea I know it lies between not enough air flow or water pump but i dont know if a water pump not moving enough water volume would cause over heating over air flow. The thing never over heated with the 2 core radiator after I flushed it all out and went to a 180* thermostat but now with the 3 core radiator it seems like the water volume isnt as much maybe I need a high flow. But considering high flow water pump is $90 and a electric fan is $80 its kinda one or the other for me at the moment not both.



~UPDATE~

I desided to duplicate the issue. Started the car up hood up engine idling in gear at 600ish rpm. Temp didnt want to move past the N in normal after idling for a good 5 mins. I closed the hood and then the temp rose up to the O then to the R in normal. I got a electric box fan I have and placed infront of the grill and plugged in with the car idling in park now at 1,050 rpm and the temp dropped down. Could have dropped from the faster spinning motor but I put my hand infront of the grill and theres not much air flow being pulled through the grill as I remember with the 2 core.

So I am guessing its a air flow problem since around 25ish mph or more the temp gauge drops real quick.

So I am not looking at a water pump I am looking at fan blades now. Might consider a 6 blade flex fan (if they dont make noise since my stock one doesnt) or a 6 blade clutch fan (dont know if it will pull more air since they spin slower than the water pump does).

So if anyone has any insight to this let me know. We didnt really cover cooling issues like this only cooling issues on computer cars and removing this steam plug or that to purge air out of the system and all that good extra work stuff.

 

How clean is the AC condenser core? Maybe try power washing it to remove any built-up dirt and see if that makes any differenece to airflow.

 

It was cleaned not too long ago. Every few months I bleach white the radiator and the condenser and hose it down from behind to front.

I am thinking the 5 bladed fan wasnt designed to pull air through the thicker 3 core radiator cause i never had a over heating problem with the old 2 core radiator. Even when i changed it I only replaced it cause the leak couldnt be repaired.

On my fan options I got a few fans I can go with. I have a spacer for the flex fan since thats what the car came with. I have to measure exactly how big mine is but summit listed a Flex-A-Lite 1318 seires 6 blade 18.25" ($38.95), a nylon 418 series 6 blade fan at 18.375" ($19.88), and a steel 5718 series 6 bladed steel clutch fan (which will cost me $75 for the fan and clutch).

Now they also carry a 1818 series 7 blade flex fan that is 18.0" but I dont know if it would work since summit didnt list this one like the ones above. They also listed in the description heavy steel hub. I dont know if they mean the hub is literally heavy steel or if its a heavy duty steel hub but its not heavy.

I was also told I could check out the junkyard and pick up a electric fan from some import and just mount it on the front as a supplmental fan as a fix. personally I prefer to have just one fan if I can get the air flow increased. Likewise I dont want to hurt my fuel economy, I figured a 7 blade might cause me to eat up more fuel than a 5 blade flex fan but I dont think it would be but maybe 1/2 mpg at the most.

 

Why not ditch the belt driven fan altogether and install an electric? It only cycles while the vehicle is stationary, with the bigger rad a fan isn't even needed once you're rolling so you loose that parasitic drag and gain HP. I have notice the same issue on my truck since I have begun changing cams and stuff, the motor generates more heat and the temp gets pretty high just sitting there idling but is drops immediately as soon as you're rolling, been thinking about an electric conversion myself.

 

I thought about electric but considering its a stock vehicle and not really using it for performance just a daily driver the power gains wouldnt be much to me. I have thought of a small add on electric fan to move more air to keep the ac cold since i converted it to R134a but I was looking at a fan with 1 or 2 more blades since I can get a flex fan for less than a electric fan. But I am keeping my options open.

one thing I would do if i got an electric is I would want it to help cool the engine when idling long times in traffic so I would have to in my eyes fix the overheating issues from lack of air movement at idle at a red light. I would also want it to supplement the ac when its on. That was my orignal plan when i still had the smaller thinner 2 core radiator add the electric fan to cool the engine down when started to over heat from excessive idling in traffic (not idling 30 seconds at a redlight) and when the ac is on. also cool the coolant down after shut down to make start up easier

 

Ok today I desided wouldnt hurt to wash the condesner coil.

I did and desided to go on a drive and see. Was on the road for 2 hours. Didnt peg the gauge out but it was cooler today compared to sunday (80ish today with cloud cover. Was near 100 without cloud cover sunday). Till near the end sun started coming out then the temp gauge started doing it again. It didnt peg out to hot but it did move to the high side of normal. So it might have helped but variables are different than sunday (ambient temp, sunlight condition, ect).

I think what I might do if I can get a clutch and steel fan cheap (i hear those eat up less power and not as much mpg as a flex fan) install that and then get a small electric fan infront of the condesner.

 

Something else you could do is remove the trans lines from the rad and install a dedicated tranny cooler maybe even with it's own electric fan. Any auto trans that doesn't have a lockup TC generates a ton of heat and that just gets transferred to the engine coolant in the rad.

 

True. Only thing is the car doesnt pull weight so I was never recomended a transmission cooler. Then it comes back to with the 2 core radiator I never had this problem of the temp shooting up after stopping I have drove the car for easily 4 hours one day in the city just driving around and the temp never did that with the old 2 core radiator. That is why I am worrying myself and obsessing over this cause it worked fine before and now I am wishing I just got the $6 more 2 core radiator to go back in.

 

Yeah I think you're fretting this too much, the simple solution now is simply install an electric fan in place of the belt fan with it's own temp sensor and forgetaboutit, or swap back to the smaller rad.

 

agree with the electric fan. put one in my truck not to long ago and all my heating/cooling issues vanished. i think i paid a total of 180 bucks and put about an hour into the install.

 

Yep but thing is I cant put the smaller radiator back in it leaks I had to buy new and this one was $163 for the 3 core but its $169 for the 2 core.

So I kinda dont want to spend alot more money. I am checking ebay right now for a cheap clutch fan I found a 6 bladed one out of a ford big block but I dont know if a ford small block clutch would bolt up to that fan. I am also keeping an eye out for cheap electric fans on there also to hook up. They got the temp controller for under $10 on ebay for the electric fans

 

does yours care have a fan spacer if i rember right theres a 2in and a 3in check the distace you have betwen the to radiator

 

also check the heater core could be pluged not leting the waer from the back of the block flow as it should try to by pass it and see if thing change

 

heater core is blocked got a hot water valve operated by vacuum. only opens and allows water when temp slider is slid over to heat and hot.

The spacer I have is a 2 3/4" spacer. Fan is a 5 bladed 18" diameter stock flex fan. Distance between the radiator cores and the fan is about 2 1/2 - 3" I would have to measure it in the morning to be exact but I want to say 2 1/2 - 3 maybe 3 1/2" at the most.

 

just asking because when i had my 302 60 0ver it ran real cool even when the fan belt broke it would get in the mildle but as soon as i got moven it cooled back off drove 20 mile that way