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So we removed radiator today, was pretty clean, washed it anyway. Then we decided to check to see if both fans were working .Left side fan was not turning on at all. So we unplugged the other fan, and made car run to 240° to see if it engaged the left side fan would turn on .it did not .so we grounded it out and it engaged. I now have a switch under the driver side knee cover thingy. I can turn it off and on as I please. Car ran at 178 All the way home. Feels good .
Nice! Fans are often overlooked but glad you found the problem.
Yes, I'm a noob. Great thread here.
I have a 92 which temps just continue to climb as I drive. It will run in the 240's even on the highway and it got up to 250 once. I'm going to get into the shroud and clean the rad and ac coils pretty soon (when I get some time).
For now I'm just driving to and from work which isn't too bad as it's just under a 15 minute drive without much stop and go on all county roads. It will get up to about 220f which I can live with for now.
I am curious though. In comparison to the Dewitts 2 core at about $500 - there's the Champion 3 core sold on Jegs and Ecklers for around $230ish. The Champion looks well constructed and the price is reasonable.
Does anyone have an opinion on the Champion?
If I decide to replace the radiator, since this is a 26 year old car and I can reasonably assume this is the original radiator in it (Not a bad idea to replace it), I would think the 3 core would be better, and closer to $200 seems very reasonable to me for a radiator.
Yes, I'm a noob. Great thread here.
I have a 92 which temps just continue to climb as I drive. It will run in the 240's even on the highway and it got up to 250 once. I'm going to get into the shroud and clean the rad and ac coils pretty soon (when I get some time).
For now I'm just driving to and from work which isn't too bad as it's just under a 15 minute drive without much stop and go on all county roads. It will get up to about 220f which I can live with for now.
I am curious though. In comparison to the Dewitts 2 core at about $500 - there's the Champion 3 core sold on Jegs and Ecklers for around $230ish. The Champion looks well constructed and the price is reasonable.
Does anyone have an opinion on the Champion?
If I decide to replace the radiator, since this is a 26 year old car and I can reasonably assume this is the original radiator in it (Not a bad idea to replace it), I would think the 3 core would be better, and closer to $200 seems very reasonable to me for a radiator.
I asked the same question in the Tech forum. everyone said go with DeWitts.
ebay has sales all the time, just make sure you catch one
I'm waiting for the next sale.
as for the temp issue, make sure your 2nd fan is coming on. mine wasnt and I had to run a switch to turn it on manually. now its on all time. with no traffic I cruise at 194. during traffic it climbs up to 238 (stop and go)
oh I also have a 160 thermostat
ill try and remove it tomorrow to washout the current radiator and I'll install the new thermostat. Been busy this entire week with work and changing the valve seals on it.
I opened mine up to clean the radiator as this is a very common cause of these cars running hot. Attached pic shows just how clogged mine was. I then discovered the radiator was leaking. Not surprising for a 26 year old vehicle. So I bought the Champion 2 core economy for $180 something. I'm very pleased with it so far. Runs in the mid 190's with a 180 thermostat. Pretty normal operating temperature if you ask me.
After doing my front air dam repair ( see: https://www.corvetteforum.com/forums...t-spoiler.html). I have not experienced any temp above 210 even on surface streets w/90+ temps (AC on normal or off) or on a 100+ highway trip. AC seems cooler also. Check out the thread and if your air dam looks like the upper pic or is completely missing I suggest the repair or upgrade. This only applies to certain earlier C4. And as always YMMV. Thanks for looking.
I have a 1991 6sp conv,...just got her running new fuel (everything). Cannot get the primary cooling fan to come on, the AC/secondary fan comes on at about 138 F or so, I jumped terminals A & B on the under dash connector, both fans came as advertised, I swaped the fan relays, same issue, so I hot wired the cooling fan to a switch i mounted in the cab, works great, I flip the switch at about 220 F and it stays cool in traffic.
1) I want to fix it right but am stumped,,,,,,
2) are the fans two speeds on the 1991 C4 base model?, 6 speed conv....
3) I have 12 volts to the fan, is it running on high speed? What can I hurt by hot wiriring my fan, (i did put an in-line) fuse, It stays below the 220s F now........
Since my 1995 LT1 always ran about 196F on the highway, I assumed my thermostat is working properly.
During a recent cooling system service, I replaced the thermostat, just because. I used a standard temperature 180F MotoRad thermostat. I am happy to report that my temperatures have dropped 8-10 degrees overall. In the city I’m now around 190 when previously I was around 198-200. (our ambient temps have been much lower recently which I'm sure has a big affect here - we will see how it goes next summer.) And on the highway I’m now about 188 instead of 196. The car is completely stock and I can't say there was anything wrong with the old unit, or if the brand name of the new unit has any impact...? And I did not test the new thermostat before installing. All I know is I'm much happier with my digital temp readouts.
So don’t underestimate the effect of a new thermostat, I know I will never do it again!
EDIT: after a spirited drive this evening, it seems like the slightly cooler running temperature is allowing more spark advance -- I've had this car for 5 years and it has never pulled so hard! Wheeeee...
Hey guys I have been shopping for my 2nd corvette for awhile now. I had originally decided to get a 90 or 91 to avoid the optispark issues. However after reading this thread I just dont know lol. Pre 91 ive read that they suffer from intake manifold leaks causing head gasket failure typically in cylinder #7 I now know after reading this article what causes it and how the lt1 fixes the problem with reverse cooling. I have several questions, apparently there was a service bulletin in 1991 that supposedly fixed this issue what exactly was done on the 91 to alleviate this problem? My other questions basically what can be done to prevent this or help alleviate the problem aside from a cooler opening t stat and the dual aluminum radiator are there any other.tricks to help ? I ask this because typically I have the option to buy a 90 over a 91 quite often!! Also how common is the issue with the last couple years of L98 engines ... Should I just forget them and get a 95 or 96 with a vented opti???? Im glad I found this thread but now im second guessing what i want to do !! Also how do you know if the 95 vette has a vented opti for future refeerence is it based on sin number ?
What about taking the thermostat out and running water in the summer months?
No. Please don't do that to any car. Removing the thermostat would only be a temporary measure to keep an engine from blowing up in the event of a cooling system issue... when the issue is fixed, back in goes the T-stat.
I have a 84 Corvette and the issue i thought i fixed seems to show of acting up again. When driving after it warmed up and the temp outside is 95 plus i had my brake peddle get stiff and i was going slow in the parking lot and put it in neutral and the car slowed down like the brakes were being applied. The things i did thought fixed the issue Recently, new master cylinder, flushed complete break system with new fluid, new break pads and rebuild of calipers and rotors were freshly turned.
I would like anyone that had this this issue please share, and what you did to resolve the issue. Thanks
Keep in mind you don't want to over cool your engine. That engine need to get hot enough to "boil" away stuff that collects in your oil. Water from heat/cool lcycles ect.Also, as someone said, our engines are designed to run best in a certain temp range. Many times an oi cooler works well. Also, as was mentioned, Do NOT run yourcorvette without a thermos. The coolant simply runs to fast to really cool water down, In the old days racers removed the therm but REplaced it with a large washer with a hole in it. Thanks to who posted this, reminds me I need to do some work in that area. Drive safe, race at the track,
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Keep in mind you don't want to over cool your engine. That engine need to get hot enough to "boil" away stuff that collects in your oil. Water from heat/cool lcycles ect.Also, as someone said, our engines are designed to run best in a certain temp range. Many times an oi cooler works well. Also, as was mentioned, Do NOT run yourcorvette without a thermos. The coolant simply runs to fast to really cool water down, In the old days racers removed the therm but REplaced it with a large washer with a hole in it. Thanks to who posted this, reminds me I need to do some work in that area. Drive safe, race at the track,
.
I'm glad this is a sticky! when I first drove my '95 home I was freaking out about the temp! When I got home, I looked this site up, read this post and was immediately relieved that it was actually running normal. Thank goodness!! And a big thank you for taking the time to put that together. Something everyone should read!!
Since then, in the 3000 miles I've put on it in the last month, I'm getting a quick squealing noise, as if a clutch is trying to engage. It seems to be somewhere around 209-212 degrees according to the digital temp readout. Then it happens again shortly after, as if to disengage whatever was engaged, once it's cooled down a little. I thought at first it was a fan engaging, but they are already spinning. I heard it once with while parked with the hood up and it sounded like it came from the front of the engine. Is there a clutch on the impeller of the water pump? It isn't the A/C compressor, I know that. It seems weird. It's quite loud too. I literally jumped when I was listening for it to happen.
I will try to get a video to post to help with diagnosis, but until then, if anyone has any thoughts or insight, I'd love to hear it!!
Do you associate the noise with a specific temperature? There is no clutch in the waterpump. It is driven by a splined shaft that is connnected directly to the engine so if your belt breaks, your engine won't overheat. Remove the serpentine belt and feel all of the things it drives for any unusual resistance.
I drove it to work today. I heard the noise, either "turning on/off" at 209, 212 and 215 degree's, and in no particular order. The temp would fluctuate between 209 and 212 and I only heard it a few times. When I parked at work I lifted the hood and tried to record video for a little bit, but it never did it again and the temp was at 215 when I shut the engine down.
If the water pump is gear driven it almost has to be a fan clutch engaging, but they were both spinning when I parked this morning.
There are a number of things that can make squealing noises. Does your car have the AIR pump up by the driver's side headlight? My '92 has it and I suspected it was making noise but I haven't resolved that issue yet. My car has too many other more important things to fix currently. I'll get to that when there's time.
Even if your fans are spinning, that's not to say they couldn't be making the noise. But even something like your alternator could be doing it. Especially if it seems to be temperature related, it could be when that component gets to that temperature, it then squeals. You'll likely need to let it run with the hood open and when it happens, just listen around to pinpoint.
07-17-2018, 08:51 AM
Fans are often overlooked but glad you found the problem.
