I, like most C4 owners, have heat issues with my 87 auto. I have done a few small things to try and improve the issue. I have the heavy duty radiator and boost fan options. I have added Water Wetter to the coolant, changed to a high flow 180° thermostat and last summer I modified the boost fan so that it turns on at 195°, off at 180°. Still I often saw 220° in city traffic on 70° days.

This summer I will likely install the Hypertech Thermomaster chip. This allows the use of the 160° thermostats as well as activates the main fan at a lower temp, but I have read running a 160° thermostat can cause increased engine wear versus using a 180°.

The engine is stock except a few small bolt-ons.

My question...

Has anyone found the Thermomaster and 180° thermostat to solve their heat issue or has the Thermomaster with the 160° been needed?

Is there a better brand chip?

 

I doubt if the 160 will change the scenario. It just opens sooner. These cars need to run hot. The biggest help would be to vent the hood. Or try and pull the center splash shields out to see if that helps.

 

All the generic chips are equally worthless for anything except changing the fan settings. I'd have someone just reprogram the stocker.
Changing those settings in addition to the lower stat will fix the overheating problems, it fixed mine. My 160 still allows me to get the car warm in winter, but I'm sure you dont drive the vette in winter up there.

If i were you, I'd get the 180 and have the chip reprogrammed. Dont buy one of these hypercraps unless you can get it for less than $50 american.

 

I installed A Hypertech Thermomaster chip in my car along with the 160* stat and my car ran slower in the 1/4 mile. It was the chip, not the stat. Forget the 160* stat unless you take it to the track, often, and go to the trouble to cool it between rounds. On the street, a cooler stat will not make the car run cooler. It will only serve to make it take longer to warm up. Think about what it is that a stat does. My guess is that for your usage, the 195* stat and earlier fan on temps would work very well. The 180* would be OK. Don't go to a 160* stat unless you have a dedicated purpose, understand the consequences, and alter your maintenance schedule accordingly

RACE ON!!!

 

Hypertech also claims a wot HP increase, I assume that you did not find that true? Or do you have other reasons for disliking the hypertech chips?

The HP increase would be a nice bonus, I have not heard from anyone who has had the stock chip re-programmed (except a ricer buddy who shipped his chip to California and paid $1000 CDN to get 15 HP for his Type R-- stupid ricers more money than brains). Would I be able to get the stock chip reprogrammed with the lower fan activation and still get some bonus HP programmed in? What is the average price for something like this?

The hypertech will cost about $200 USD

 

Looks like the chip really isn't the way to go for any increase in HP. I am really leaning toward keeping the 180°. I am actually holding back on bringing the car out to play until I solve this.

I know I can always wire the main fan to a switch but I'd prefer not to.

 

I am sure you have, but let me ask anyway. Have you pulled and cleaned the Rad and all the junk that accumulates between it and the AC condensor?

Have you had the Rad flushed to eliminate internal scale that reduces heat transfer efficiency?

I run a 180 thermo in my 88 and have a "clean" system along with the switch to turn fans on at 205 and off at 190. I am in Va where it gets hot in the summer. I cruise at about 185 in the summer and rarely get over 205 even stuck in traffic

seeya

 

Finally a sensible answer to the thermostat question.

 

I have an 87 4+3 and with all orig eqt (195 stat) and a manual fan switch on at a stoplight in summer the coolant temp would go to 220. My water pump needed replacement and I chose a Stuart pump which has higher flow and now it will only go to 200 and drops as soon as I get underway. Several times a year I use a garden hose set for its highest flow (small diameter stream) and blast water backwards through the radiator to remove the debris that blocks cooling airflow. It is better to remove the radiator and clean the junk out of the front of the radiator.
220 F will not harm your engine and a 160 stat will do nothing to your coolant temps when you are below 35 mph. C4 radiators are sized to maintain 195 F for L98's above 35 mph so a 160 stat will merely stay wide open unless the air temp is low enough (winter) to get rid of heat fast enough to allow the 160 stat to just open and control the coolant temp to 160 F. 160 is too low a temp to operate an engine.

 

I dislike any manufacturer who advertises huge gains on stock engines when dyno results and track tests say otherwise.

No, there is no power increase.

 

I have a 160 thermostat in mine now, someone else put it in before I bought it. I'm going to change it to either a 180 or 195 when the weather improves a little and I have the time. I can say from experience the 160 will not make it run any cooler on warm days, and it keeps the engine from getting up to normal temperature cool days. In my opinion a 160 thermostat does no good, and can potentially cause harm.

 

I'd start with Jackdaroofer's recommendation. Get a small mag lite, find a good spot top side and try to visually inspect the area between the condensor and radiator. If this area looks bad, remove and clean the radiator.

Or, flag down the Snap On truck, ask him for the 22" long air gun(around $20). This long, small diameter tool will fit quite nicely between the radiator and condensor allowing you to get high pressure air to this area. I clean this area about once or twice a year. Never had a heating problem, except when one of my dual fans quit.

I would start with the simple stuff first. For stock engines, the stock cooling system should work just fine, assuming it is in top form. Anything less on a C4 will cause problems.

dlmeyers 90 coupe zf6 3 speed shocks

 

Found a guy that reprograms the chip. It'll cost $230 USD to make whatever programing changes I want. The $230 comes with lifetime changes to the programming for free. I think this is definitely the way to go. It's essentially the same $ as a Hypertech chip but I can modify only what I want to today and change more in the future as I modify the engine.

Does any one have suggestions on what improvements, in addition to the fan activation temp, I should do when reprogramming (ie. shift points, removal of EGR, etc)?

Stock L98 with throttle body airfoil, auto, 3:07 rear end

 

is this guy in calgary?? be warned about mail order CHIPS!!!

i would install 180*F with 205 on 185 off switch, (if you find one LET me know where you got it in Calgary)..also do manual fan switch..

 

I have everything on my 94 to cool at 160 deg .
The best I have seen is 185 deg,most of the time 210 deg.
I have my 86 set up for 160 deg the fan comes on when the engine starts and best I have seen is 171 deg,most of the time 195.
Good luck!

 

I agree with these 100%. For your L98, get a 180* and have the fans re-programmed to cycle on/off earlier from the factory programming, around the new 180* t-stat.

If you go 160*, then plan on changing your oil twice twice as much.

 

Davenport refered me to this guy in Brooks, I believe his name is Linden. He has a toll free number, 888-937-8371.

I will use a 180° thermostat, but I think I'm going to go with 200° on, 185° off. Right now my boost fan is 195° on, 180° off (it's on a lot).

 

Definitely clean out from under the shroud. You'll be surprised at the difference. Blasting some high pressure water from the backside of the radiator will get rid of tons of leaf particles stuck in the fins.

 

Davenport does great tunes, why would they send you to Linden. yes i know the guy in BROOKS. actually in TILLEY... save your money, thats pretty expensive for just turning your fans on earlier. unless this guy can tune your chip with the aid of a dyno, don't bother..

we have a small group of c4's here and in lethbridge, that are interested in programming our own. after what has been going on with mail order chips, we think it a better route. As least we will know what we're gonna burn to these chips!....

i had similiar problem just last week, i used 180*f t stat. drilled 1/8" into it near the side( to help with air escape). check your pressure cap. it should be 17 lbs..i replaced with 18lbs..also installed manual fan switch..

i have checked with most of the suppliers on the switch between 6&8 (main ecm) and the secondary 1&3 temp switch. No one has the replacements for lower temperature, but do carry the stock replacements. really do not want to order from ecklers, with the high deliverly charge. if you have found supplier Please let me know.

 

I'm with quisinartvette. If you're running 220* with the air temp only 70*, you're problem isn't with the thermostat or fans. You either have a lot of crap blocking the airflow or your radiator needs rodding-out. On a 70* day, I'm lucky if I hit 190*in traffic.