Picked up my "new" '88 saturday. Car runs great and feels very strong, but in stop 'n go traffic today the coolant temp seemed (at least to me) to get quite high - 218-220. Once I got rolling she cooled down, and on the expressway she was perfectly happy at about 185.

Whats "normal" operating temps for the L98/Automatic. At what temp might you expect the fan to turn on? Assuming the fan is not coming on - any trouble shooting tips?

Thanks

 

That is around the correct factor operating temp I think. The main fan is controlled only by the ECM.

Do you have the booster fan in front of the radiator; it came with RPO Z51 & RPO Z52.

If your main fan is not comming on and you don't have the booster fan, temps would have gone much higher.

As a fan control test start the engine cold and turn on the A/C to max cool the main fan should come on in a few minutes if all is well there.

 

your temps are perfect for an L98

another way to test the fans (at least in my '85):
jumper the a and b sockets in the ALCL and turn the key to ON (do not start the car). The fans should come on... and this is also the procedure to display any engine codes you may have or could get...

 

Also, you can start the car let it idle with the hood open & see when the main fan comes on.
I think the factory setting is 228.

 

Thanks guys - I feel a bit better. The car (and 'vettes in general) is ALL NEW to me. Frankly - checking codes and things is the next thing I gotta learn to do - I'm sure there will be plenty of posts about that subject later.

I'll have to look and see if I have the booster fan - I'm almost certian it has the Z52 suspension (I've ordered a build sheet to get the specs - was purchased from a dealre that didn't know a lot about the car) becasue it has the 17" rims and 275/40's which its my understanding were part of that package.

This is going to be quite an adventure - thank God for the Forum.

 

Yeah...those temps are definitely normal for 'round town drivin'. If it were to get up into the low 240s, I'd get concerned, but not with your temps. Turning on your A/C when the car is sitting still (or driving slowly) will turn on your fans and cool the engine down. Glad we could help - that's what we're here for! There's lots to learn about these cars, and this place is a great vat of info...

 

got in traffic again - watched it climb to 228 and waited nervously to see what would happen - sure enough, 227, 226, down to about 212, cycled several times until traffic broke.

Given how many times I've been burned on used cars in the past, buying a used 'vette made me pretty nervous ($$$$$$$) but so far, everything seems to be functioning normally.

Man what a car! Just want to play hooky this afternoon and DRIVE!

 

The RPO codes are on a sticker under the console lid.

The 17" wheels came with either Z51 or Z52, as did the booster fan and quick ratio steering. RPO Z51 also brought HD suspension, HD radiator and HD front brakes.

BTW, the booster fan (in front of the radiator) is controlled only by the aux fan switch located in the block below #1 & #3 spark plugs; it comes on at 228deg F. So, you might want to verify that your main fan is indeed comming on in traffic and not just the booster fan.


Enjoy your new Vette.

 

I believe that fan was also included if you had the HD cooling RPO code... Cause I have it on my vette, and I don't believe I have either z51 or z52 options...

 

Head over to www.helminc.com and order a factory service manual. Besides all the poop on checking codes and the proper trouble shooting procedures for each, there is a wealth of general info and how various systems work.

RACE ON!!!

 

And for future reference-if you start running hotter, check for debris in front of the radiator-these cars are know as Hoovers(vacumn machines). I also went with a lower temp switch, about $25. fans on at 200, off at 185.But your temps are very normal now. Congrats on the new car and welcome

 

Looked up all the RPO's last night - WOW this car has all the cool stuff - Z52, FG3, booster fan - slick - I'm feeling better and better everyday about this decision.

Thanks everyone

 

65Z01 is correct as usual. The main fan is controlled by the ECM. It should come on when the coolant temp reaches 226F or 108C. The aux. fan is controlled seperately by the coolant fan temp switch and should turn on at 228F or 109C. This is spec. according to the 88 GM Factory Service Manual.

Rick brings up a very important point. The C4 will attract junk in front of the radiator which over time will degrade its ability to stay cool. My 88 used to hit 235 on hot days a lot when I first got it.

One Saturday morning I pulled the radiator on my 88 and cleaned out a bunch of junk. Then I washed the fins clean with a mild solution of dawn dish detergent and a soft brush. After that I CAREFULLY straightened every bent fin with a small flatblade screwdriver. I replaced the stock 195 thermostat with a 180 unit. Took all of one morning and is pretty easy on the L98. This made a significant impact on my cooling.

I also ordered the aftermarket aux. fan switch rick mentions. I got mine from midamerica for $20. It was a simple 3 minute replacement and the new switch turns the aux. fan on at 205 and off at 190. In the last 5 years I hev never seen coolant temps above 221. That includes driving in stop and stop again traffic on 100 degree days.

Congratulations on your new Vette.

 

Temps in the "normal" range were just too high for me. I put in a 170 degree thermostat, a Hyper Chip (to allow the lower temp in closed loop), and a manual fan bypass control. I just leave the fan on. My average summer time driving is about 185 and may go to 205 in traffic.

When checking for blockage in front of the radiator you need to pull the top shroud. Lots of stuff gets between the radiator and air conditioner coils. Mine was packed about 1/4 full with leaves and trash. When you look in from the front all you see is the AC coils and not the radiator.

 

Your temps are normal for a L98. The fans will come on automatically at around 228. If this makes you nervous, put in a cooler Tstat and re-program your computer for the fans to come on earlier.

 

Thanks everyone - looks like this weekend will be filled with all kinds of "vette check out stuff - including cleaning out the radiator area.

 

I have a 95 c4 Lt1 and installed a fan switch as well. It comes on at 200 but will not go off. It should go off at 185 but the temp never gets that low. I have replaced the thermostat which is 180 degree. Coolent was changed. also the radiator fins look fine. Is this normal ?

 

 

Bobby O.,
This I learned from the STANT thermostat people directly. The way a thermostat works is that it starts to open above the rated temp and is completely open about 20 degrees F above the rated temp. The goal of a 180 thermostat is to achieve a minimum temp of 180 degrees. For racing applications there are calibrated thermostats which open and close at exact temps, but for general use the 180 thermostat operates in a range of 180-200 degrees plus/minus about 1~2% or 2~4 degrees depending on the manufacturer. The aux switch probably has a similar degreee of tolerance for error.

In your case the aux coolant switch isn't seeing temps get to 185- in order to turn off, but that is to be expected since the thermostat's job is to block flow until it sees at least 180+. Given the allowable amount of error in the 2 units combined with the propensity of the C4 to run warmer than 185, even with a 180 thermostat you have 2 separate mechanisms the design of which both have some temperature overlap.

If the tolerance for error in both was just 1.5% or say 2.75 degrees F for both units, that would mean the aux coolant switch might want to see 182.25 before it turned off the fan and the thermotsat would shut completely at 182.75. They would overlap by one-half degree and the aux fan would never shut off unless the outside conditions were so cold as to prevent the thermostat being able to do its job of keeping a minimum temp of 182.75.

You either need a lower temp thermostat or a higher cut-off temp aux fan switch. I'd change out the aux fan switch. It costs more, but it is easier to do and I prefer to run a 180 thermostat to a 160/170 thermostat.

 

I have the same car, 1988 with automatic. I live in Northern California where it gets pretty hot in the summer, like over 105-110 June, July, Aug. My car runs at 195 to 200 almost all the time, all year round, except in summer when the air conditioning is turned on, then the temp spikes in stop and go traffic, but comes down to about 200 when I am on the highway.

It seems to me your temperature is a bit high for this time of year.