Operating temps for my '84 C4.

[elkabong]

This has probably been asked a zillion times. My '84 runs at 205* to 215* while cruising and in traffic it runs up to 230*. I just had h the cooling system serviced and there is basically no change. My fans turn on at 230* and stop at 220*. I have purchased a 160* thermostat and new temp sensor for the thermostat but I am hesitant on putting it in because I am not sure if it will help or not. I have been told that the new thermostat and sensor really won't help and I should just wire a manual switch to turn on the fan, which I plan on doing.

The car has 36K miles. I live in AZ and I may be a tad over sensitive to temperatures but I don't want my little beasty to overheat and potentially cause any damage so I am being extra cautious. Any recommendations?

Thanks

 

[vader86]

Put the 160 in before the real AZ summer sets in, that and the fan switch and youre good to go.

 

[JonM]

Did you buy the new temp switch that makes the fans come on sooner? The manuel fan switch is a good idea also...just ground the green/white stripped wire on the relay (on drivers inner front fender) to ground with a toggle between. If you do have the correct temp switch the fan switch isn't really needed.

 

[elkabong]

Yes I purchased a new temp sensor. It was the conversion kit from Zip to go along with the 160* thermostat. My main concern is there seems to be a difference of opinion based on the other threads I have read. I do not want to cook my motor. If any place will cook a motor it is AZ in the summer.

Thanks for the wiring tips.

 

[ejrempel]

Hey, Elkabong, don't buy a Jet switch whatever you do. Still comes on at 190, and the inner is not affected because it is computer run. So I think that we are going to run another relay. When the front fan comes on at 190, it will trigger the relay to feed power to the inner fan. Should work, no switch.

 

[iron cross]

The recomended stat is a 195, on this subject your going to get so many different thoughts on what others have done to their cars it may drive you nuts. All I can tell you is that if you walked in the door and asked for a stat for a 84 Vette, I would sell you the 195 and be comfortable you will not be back for the same problem. We have a unique auto supply, we sell the part, and also offer service to install it. Just to show you this is not BS, go to our site and enjoy starting our engine on the A990 hemi Cuda as one of our subjects. We also offer the best interiors available for Vettes. Take a little tour and see for yourself at http://www.nitroalley.net CHECK your radiator cap, it`s designed to raise the boiling point as a pressure cooker.

 

[geekinavette]

Jim,

Did you get the "on at 200 off at 185" fan temp switch? If so install that and a 180 stat and you'll be fine as long as the rest of the cooling system is operating properly. Make sure you don't have a bunch of trash buildup between the radiator and the AC condensor (or whatever that thing's called).

I've also been meaning to ask you if you ever got one of those 7747 adapter boards installed?

Bill

 

[never2nd]

I own an 86. Just installed a 180 thermostat as part of head gasket replacement. Removed radiator and cleaned out the passages, ran water through the system until clear, then filled with 50/50 anti freeze/water. Fan comes on about 225 and cools the engine without any trouble.
Withs the proper water anti-freeze ratio and a system maintaining pressure your engine should not boil until 260 or so.

 

[elkabong]

Well here it goes. I replace the thermostat with the 160* - it works great while the AC is not running. I have the temp sensor that turns the fan on @ 200* and off at 185*. It works great as long as the AC is not on. When the AC is on the temp just climbs and climbs and then I get paranoid and turn the AC off at about 225* - 230* when the temp goes back down to 190* I turn the AC back on until it climbs and then I repeat the cycle. I am thinking of trying the 180* thermostat with the present temp sensor. My big question is does the AC have that big of a influence? or am I looking in the wrong area. I realize there will be a difference and with the AC going the heat generated is transfered to the radiator and it has to be cooled.


Thoughts?

Bill - unfortunately I have not been able to put in the 7747 yet. Between AC, helping my daugher move, couch shopping for my daughter, 60+ hr workweeks, visiting family ................. You get the picture.

 

[handstjg]

I just purchased my 86 convertible with 20k miles so I am no expert, but I do live in the Valley and dry heat or not 108 degrees is no picnic in our traffic.

It is a tough subject in the desert. Currently it is 9:30 pm and the temp is still near 102 F. I am having the same dilemma. The t stat is the hardest decision. The good radiator shops in the "Valley of the Sun" will tell you that you have to let the coolant stay long enough in the radiator to let it cool down. The 160 stat will open sooner, but MIGHT not slow down the coolant flow long enough to allow cooling to take place. The fan seems to be the best fix. Insure it is clean and free of debris. Getting it to turn on sooner and stay on longer would seem like the best fix. My turns on at 229F and immediately starts cooling, almost a degree every 15 seconds until it turns off near 215F. Let me know how you make out, I need the feed back. Thanks

 

[elkabong]

I hear ya. The Valley of the Sun will cook anything. I guess that is why I am real paranoid. I read the other posts regarding temperature, but there are a bunch of opinions. I already had the 160* so I decided what the heck. I just don't wanna cook the motor which around here will happen if I am not careful. I am going to keep the temp sensor and try a 180* thermostat.

I commute from Chandler to I17 & 101 and when the traffic stops before the Broadway curve going home - well things heat up in a hurry. I'll let ya know what happens.

 

[geekinavette]

Jim,

Does the fan turn on when the AC is on? It should run anytime the AC is on. I'll also mention again to make SURE there is no debris between the radiator and AC condenser, and make sure that you don't have a bunch of bent-up fins on either blocking air flow.

Bill

 

[elkabong]

Bill,

The fan does turn on when the AC is on. I cleaned as much as I could last night without taking the shroud off. I just used a hose and washed it out. I will work on it this weekend and replace the 160* tstat with a 180* tstat but keep the new temp sensor (on at 200* and off at 185*). It has to be related to the AC becasue I can turn it on and watch the temp rise to lets say 220* and then turn it off and watch the temp go down fairly quickly.

Ahh desert living - ain't it grand.

 

[elkabong]

Another question I have would I be better with the 180* tstat along with the sensor that turns the fans on @ 200* and off @185* or the 180* stat with the original stock sensor on at 230* and off @ 215* (if i remember correctly).

 

[elkabong]

Yesterday I pulled the radiator and cleaned out everything. What a mess. What a dinky radiator. It was pretty dirty in there. My Vette originally came from Indiana - I found maple leaves (i think), cig butts, sticks and just plain crap. I refilled the system with a 60/40 mix - glycol to water and decided to try water wetter (I have nothing to loose at this point). I went out for a little put last night and then let the lil beasty idle in the garage with the AC on for about 10 mins. The temp got to 210* and stayed there. Hopefully the results will be just as good in traffic with real temps of 103*-110*.

I am still considering the 180* tstat with the lower fan on/off sensor. Thoughts from anyone ?????????

I have also inquired about the new hi-zoot radiators, boy are they expensive $400-$600. I am also checking on the HD radiator for Vettes - Ecklers had 'em for $249 and I am picking up an aux fan out of an '86 Vette.

This is what I have done so far, any suggestions on what else to try if my efforts thus far are in vain?

 

[JonM]

Another option is to toss in a bottle of Water Weter



http://www.redlineoil.com/products.htm

 

[WhalePirot]

I run the 180 in my 406 and I believe it is the right choice.

My '84 Z-51 HD radiator was fine, but is available, shipped in my BeCool radiator box.

I think you have the problem whipped, but agree on the 180 stat. More fans won't do help, IMHO, beyond what you've done.

Mike

 

[elkabong]

Update. This is what I have done. The long and short is I replace the little radiator with one that has twice the surface area and is has an aluminum core. This was based on the recommendation from the 'ol codger that has been running a radiator shop for 35 years. The mfgr is Modine and the part number is 1R2051. The old radiator core width was 7/8 inches and the new one is 1 5/8 inches, almost twice the size.

The next item is to play with the fan on/off temps. Unfortunately, being an 84, there is not much I can do other than play with the temp sensor that screws into the head. I can't modify the on/off temps with the ecm. Does anyone have other ideas on how I can do this other than the temp switch in the head?

 

[JonM]

Just connect a wire to the Green/white wire on the relay. (don't disconnect the g/w wire just slide or splice into the wire. Then run this wire to a toggle switch mounted into the hush pad under the drivers side (Near the ALDL) then run from the toggle to ground. Then when you are sitting in traffic and you notice the temp climbing you can throw the switch and have the fan come on...cost about 3 bucks.

 

[elkabong]

I understand the part about wiring up a switch. I am looking for something that I can "set it and forget it". I purchased an aux fan with relay out of an 86 on eBay for $20. I plan to wire manually with a switch - a little insurance.