I'm getting excessively high coolant temps while driving around town. The hottest it got before I shut it down was 241, so I didn't hurt anything, but its obviously annoying to have two options:

1. Pull over and let the car sit for ten minutes every five minutes of driving
2. Run the auxiallary Radiator all the time at full blast(heater! Too hot!)

The oil temperature is staying down around 200-210, and everything thing else seems to be opperating fine.

At first I thought I had a fan problem(I'm running dual 12 inch fans), but now I'm not so sure. I get air(not much) through the radiator while sitting still, which is about what the stock fan did, but now I'm doing it at two positions.

When on the Freeway, temps range from 187-197. I'm running a 180* thermostat. I'm chaning the thermostat tomorrow because I think that although its sitting around 187 most of the time, its just a coincidence since it does occasionally go up. I think that the air getting sucked over the engine is working as an air cooling system and the water in the rad isn't making it through the engine. (If Hardly can do it, I don't see why a SB wouldn't react the same way)

It is a new water pump, I didn't dissasemble it to make sure its the right water pump, but it looked identical to the one that came off the motor. I'm wondering if possibly its spinning backwards...is there any way I can check this without pulling the hose and making sure water is being pumped? That sounds messy.

Any ideas? Thanks.

 

Don't sweat the waterpump. Its working fine. Your cruise temps sound okay too. The around town temp indicates that the fans are not doing well.

Let the car warm up and check out the air flow in and out of the radiator. Put your hands in front of the radiator and see if any warm air is coming in from the engine compartment. Find the sources and plug them. I doubt this is the problem but its worth checking. I am not sure how to check the out going air. Its possible that the two fans mess up the air flow path through the radiator that existed when the stock fan was there.

Make sure your radiator cap is okay. If its old, replace it. Check the water level too.

 

First thing I'd do is pull the shroud over the radiator and clean any accumulated sand, sticks, cig buts, candy wrappers and other assorted goodies that these engines suck up from the road.

If you are one of the very few who find little to nothing stuck directly behind the radiator, I'd flush the radiator. pull the lower hose off and run a lot of water through it. Sometimes gunk accumulates at the bottom of the radiator interferes with water flow.

You mentioned you are replacing the thermostat. That's fine, but if you are thinking of putting in a lower temp one, that isn't going to help.

These cars are bottom breathers and will get hot when run below 35-40 mph constantly. They were designed to run hot to meet emission specs. As long as your oil temp is staying between 200-210, you aren't going to hurt anything.

Finally, 34th anniversary coupe? Gotta be an '87 with a black bow, huh?

 

Thanks for the replies, I'm running the fans as pushers because they are too big to fit on the engine side of the radiator. I'm planning on adding something near stock(can't go stock, I cut up the shroud to make the new fans almost fit) in the immediate future.

I had most of the car apart, and I cleaned the cooling system out really well, I flushed the radiator and the heater core(with it still installed). Since the car is an Arizona car, I didn't have a lot of anything in there.

The thermostat in the car is nearly new, I got it last November, and decided not to change it with everything else in the engine. Its a 180 and I'm replacing it with a 180, as I had good luck with it before taking the car apart.

I read that alluminum heads don't like to get over 250 degrees, the head gaskets are brand new, and I spent quite a bit getting these heads reconditioned and I'd prefer not having to take the engine apart again for a long, long time.

I've been thinking about taking "34th Anniversary Coupe" out of my signature, because I've gotten four e-mails saying things to the effect, "They didn't make a 34th Anniversary Coupe, you got ripped off." The car started out as one of 397 Gold cars in 1987, I got it at a great deal because the gold paint was oxidizing all over the place. Next to go are the gold wheels. :)

Thanks again for the replies.

 

One more thing, I have overrides for both fans, so I know they're on.

 

Think you have a fan problem. Pusher fans are not as efficient as puller fans. Must have been a pain to rig those fans in front of the condenser? How did you fit that all in there? Do I understand correctly that you now have no fan on the engine side of the radiator?

Anyway, I think you will find that installing a standard puller fan arrangement where the stock one used to be will help alot!

 

When you installed the fans as pushers, did you swap the polarity from if you used them as a puller? If not, you are drawing heat from the engine compartment out the front into the airbox area. You probably know this, but if you just took the original fan and put it in front of the radiator, you gotta swap leads. -Matt-

 

This will GAURANTEE your car running below 200 all the time even in the hottest days in traffic.

1- 160-170 degree Thermostat
2- Clean the radiator. The Corvette radiator is VERY high tech and VERY small. So even the smallest junk makes your car run hot. Clean your radiator once a year, and flush the coolant. Also, a wise investment would to put "Redline Water Wetter" in your coolant/water when you refill it. (Get it from Mid America).
3- Auxillary Fan Override switch (you already have it... so there is one).

This will keep your car running PERFECT.
Go to the "Tech Tips" at the top right/middle of the forum, and click on "C4 Tech Tips". Then find Radiator Cleaning... and you will be perfect.

Once you clean your radiator and add water wetter, you won't believe the difference. Also, once your radiator is flushed, go ahead and do the "Coolant Bypass" on your Throttle Body.

Hope this helps,
Andy

 

I was wondering the same thing. If they are running as pullers, they are fighting against the high pressure area in the air-dam area as the car moves forward. Effectively canceling out the flow of air through the radiator.

 

Alright, I changed my thermostat with a 180 degree with three small holes in it. It obviously takes a little longer to warm up, but nothing too bad, and then it holds at 192 degrees with both fans on at idle. Outside air temp is 57 degrees(as per my mom's Blazer's thermometer).

I'm taking it to Phoenix right after the world series, I live right off the freeway, so I shouldn't have a problem. If I do have to stop at any stop lights and the fans won't keep the temperature down I will run the auxilliary radiator, which worked pretty well yesterday.

As for polarity of the fans, the instructions said to flip the whole blade around, which I did. They are definitely pushing air into the condensor, and I can feel a little bit making it through the radiator. They are almost perfectly up against the condensor, but I'm still getting a lot of blow back. They fit perfectly in front of the condensor, there was even two brackets on the side of the condensor that made mounting really easy. There was no way to mount them on the engine side, I tried for over 4 hours, I couldn't seal them, and I couldn't figure anything else out.

The car isn't my daily driver, so its ok if I can't drive it.

I'll try water wetter, I've heard mostly good things about it. I'm going to try to get another fan tomorrow, this Checker next to my house is as big as a Walmart, they'll probably have something. :) I'm starting to pull a lot of amps, but I got the big alternator, I'm not seeing any adverse effects yet.

Thanks for all the replies.

 

You really need to have a puller fan. Pushers alone won't cut it.

 

No worrie.. I had the EXACT same problem and this what I did... First I went to Dana Radiator on Country Club road in Mesa.. I think its like Country club and 8th.. im not sure.. anyways, Mike Dana does copious amounts of work for GM (at the proving grounds) anyways, the shop looks like a dump.. but he is terrific.. however, you need to pull the radiator and bring it to him...

what he does is pull the side tanks off of the core and "reams" the radiator.. hot tanks it a cleans it.. when you get it back you wallet is some only like 80 bucks lighter and the radiator like new!!!!!!! I run at 194 all day long..even this summer when it was 118 out in bumper to bumper traffic..

and i have my fans just as they came from the factor... because running both fans all the time is a band-aid not a solution ot the problem and will wear out your fan motors quicker!!!

Hope this helps
Chris

 

Getaway's got the right ideas. I opened up the fan shroud a month ago and guess what I've found? Leaves and crap covering up a quarter of the radiator!!! After taking a while to clean that stuff off, my '86 runs much cooler. The temp never rises above 190 in cruising speed.

 

Flipping the blades around won't reverse the airflow. You must reverse the rotation of the motor. Think about it. Take a look at any fan you may have around the house. Simply flipping the blade assembly in relation to the motor shaft will not reverse the air flow.

Unless you have reversed the motor rotation you are still pulling air through the radiator.... only you are pulling the air in the wrong direction.



From what I can make out in the picture above, the fans need to be running in a clockwise rotation to become pushers.




[Modified by LWesthaver, 12:05 PM 10/28/2001]

 

as for water wetter, i have used the stuff a long time ago,you might see some temp drop if you cut back to 25% anti 75%water, its really made to work in 100% water, quit using it in my race car with 100% water because it just didn't make much diff,just mho

Wayne
:seeya

 

Alright, I'm confused. They spin counterclock-wise, effectively acting as pullers.

The weird thing is that they don't feel like pullers. There is no air being pushed out of the front of the car. On the engine side of the radiator I feel air doing something. At first I thought it was so diffused from going through the condenser and radiator that it was just too little pressure, but now it feels like vacuum because I think I know what I'm feeling for.

I trusted the instructions when they said, "If used as a pusher, install with this side out. If used as a puller, install with other side out." It made sense when I was doing it. But now that was obviously wrong.

Since I'm not an electrician in the least(The most I know about wires is that they're attached to telephones(or in this case the internet), you use a telephone to call help), I don't know exactly how to switch the polarity. Does that just mean I switch the power going into the wire that is now ground, and ground the wire that is now power? Seems simple...is it that simple?

Thanks.

 

top

 

I have seen many valuable replys, but haven't seen some of these suggestions:

Is the coolant mixture correct?
Did you burp the system?
Did you remove and clean the radiator, including the surrounding areas?

It appears that there are two main possibilities to your problem, excluding the fan configuration; Not enough coolant in the system, or blocked radiator.
After making sure that the above is not your problem, check the lower radiator hose. Let the engine idle at operating temperature, then rev the engine. Does the lower radiator hose crush? If so, replace.

 

As stated earlier, reversing the fan blades does not change the direction of the airflow, you are still pulling air from the engine compartment. The picture tells the story, they must rotate clockwise or you are pulling air out of the engine compartment. Going down the road, the high pressure area in front of the car is overpowering the fans. Car would probably run cooler with them off when traveling a highway speeds.

THEDEVL :reddevil

 

The answer to your question on reversing polarity is yes. Ground becomes hot and hot becomes ground. This won't work with AC current, but for your car (DC) it is the answer. Sounds too simple huh.

THEDEVL :reddevil