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my 84' needs help on lowering engine temp. any ideas? .. any ways to create better air flow into the engine?.... thanks!
 

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Several ways.
Lower thermostat- 160
Better water pump-High output.
Clean your radiator!
Have you flushed your current radiator in the past year or so?
There are more ways, such as elec. fan etc. but I'm sure a few more members will chime in.
Matt383
 

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Make sure you clean out along the bottom of the radiator, a lot of debris collects there. Flush the system, put in a lower temp thermostat. Try some water wetter, it lowered my temps approximately 10 degrees. Ecklers and Mid america sell a coolant sensor that turns your fans on at a lower temp, only costs about $12. :)
 

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I pulled out a empty potato chip bag out of in front of the radiator. Not sure where that came from. I think that I gained 5hp for this mod.:rolleyes:
 

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custom fan controller-
low temp,t-stat.
i would not use water wetter(i actually have).it did nothing for my cooling and a little slime came out when i drained it.only had it in ther for a week.sometimes that does not mix well with dex-cool and water pumps.but others claim it does,not for me.
 

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The factory engine temp is FINE for your car.

But, if you think it's running too hot, then definitely try to figure out the problem first.

Things to look for are the secondary fans not coming on, radiator blockages, bad or removed thermostats, air in the system or incorrect coolant/water ratio.

If all of those things are fine, then I would first go with a lower stat and the coolant sensor to kick the second fan on sooner.:thumbsup:
 

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My '84 has a 190 thermostat, which to me, in my climate, seems a little high. But it is a California spec car so I would have figured that was pretty similar. I'm assuming Chev knew what they were doing.

The cooling system does nothing until the thermostat opens, so you would expect your temp readings to be a few degrees above what the thermostat is rated at. If it is, then I would suggest that everything is fine. If the temp reading is consistantly way above the thermostat rating, then I would suggest there is a problem.

Blocked radiator, knackered thermostat, low coolant level, etc, etc. I've also heard that the cooling fins on the aluminium radiators can become damaged over time. Not enough so the radiator looks particularly damaged but enough that the fins can impair the air flow through the radiator. Straightening them out is painful and time consuming, but apparently well worth the effort.

I would suggest that a lower temp thermostat will not solve anythng if there are other issues like a blocked radiator. (Unless of course it is the thermostat that is stuffed and you would have fixed the problem inadvertantly, just by using a new thermostat!)

Remember that the cooling fan only runs when the car is stationary or only moving very slowly (I think up to 10mph?? may be wrong) so a custom fan controller will do nothing if the issue is consistant regardless of speed.

Before messing with the factory settings, I would check that everything else is up to scratch. If your temp sits consistantly and reliably somewhere between the thermostat rating (probably 190F/88C) and the fan cut-in temp (approx 212F/100C - please correct me if I'm wrong, I just made that one up) then I would suggest your system is fine. But I too think that 190F is too high.

I also believe that going too low can upset the EFI, in that it never runs in it's most efficient temp range. Someone else can fill in the blanks here.
 

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not sure on a 84,but my 89 the fans came on at a set temp,i think 220*,then off at 190*.had nothing to do if the car was moving or not,or if the a/c is on the fans will run constantly.look in the tech manual for your car and it tells you what temp the fans kick on and of.i put in a 160*t-stat and had the chip programmed for fans on at 195* and off at 160*,the car never got over 200* in heavy trafic with a/c on.it's the same with the c5,change t-stat and fan controlls and run it at whatever temp you want.it's tuff to keep it under 170* unless you get a bigger radiator.180* to 190*,no sweat.and thats a good temp.the stock c5 fans don't kick on high until 235* :surprised ,thats a power killer at the track.....the car will knock much sooner at high temps....
but like others said,if it's higher than usual,there might be a blockage.i have lowered the tepms on all 3 vettes iv'e owned,and my buddy's too.....:smokin:
 

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hawaii-5-lo said:
not sure on a 84,but my 89 the fans came on at a set temp,i think 220*,then off at 190*.had nothing to do if the car was moving or not,
I do not own an '89 so I'm prepared to be wrong, but I would be very surprised if the standard factory cooling fan setup ran regardless of vehicle speed. Having the A/C on is a different story altogether, so forget that scenario. The fan has one purpose, to move air through the radiator. The motion of the car through the air at anything more than 10-20mph is far more effective at doing this than a fan. So above a certain speed, which is not very high, the fan becomes redundant, whether it is running or not. In fact, a fan can become a hinderance to air flow.

After-market fan units, that are commonly installed on cars that were originally supplied with mechanical fans, tend to work solely on engine temp, but factory units like that in the C4s & 5s are more intelligent than that.

hawaii-5-lo said:
the stock c5 fans don't kick on high until 235
God that's high. Especially for an alloy engine. Why is it set so high? What do they hope to gain? Like I said, I s'pose Chev know what they're doing. I know I'd be very uncomfortable watching my temp gauge head towards 112*C while sitting in traffic!
 

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OzC4 said:
God that's high. Especially for an alloy engine. Why is it set so high? What do they hope to gain? Like I said, I s'pose Chev know what they're doing. I know I'd be very uncomfortable watching my temp gauge head towards 112*C while sitting in traffic! [/B]
the factory c4/c5 fans are controlled by temperature settings in the computer,period.(when a/c is off)i will print it out of the manual if you want me too.you can even change these setting with a hypertech hand held programer.
the c5 temp setting is that high,i think it's that high because it helps burn off junk for emissions.
the fans have temp setting for a few reasons.but thats to long,on the freeway the temps come down to the point were maybe they will shut off because there is enough air-flow,(not in hawaii).
now the other side of that,what if your working on your car and just installed a cam.now you have to raise the rpms for 20 minutes to break in the cam(non-roller).or your working on the a/c and need the car running for 15 minutes or more.the thing would overheat while idling if the car was waiting to move before fans come on.go outside turn on your car and let it idle until the fan comes on.thats the same temp the manual probably says the fan comes on.sorry i keep saying"fans",but after 90 or whenever,they went to duel fans.my c5 has duel fans,and they go high and low speeds also.
in hawaii the fans never shut off NEVER.even on the way home from the track at 1 in the morning,it's still to humid.the only time i see my fans off,is in the morning if the car is warming up.
plus lowering the underhood temps helps the vacuum hoses and wires from turning brittle.take care....:buhbye:
 

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In traffic my 87 will do the 200 to 230 and back routine. When I first got the car I was worried about it. Then I took a look at the temp gages in my other car.

In my Blazer the temp gauge goes from 100 to 260. The thing is when the it is reading in the middle of the range it is at 210, with 110 degrees on the left and 50 on the right. I never bothered to look at what it was actually reading, only that it was in the middle and not in the red part on the right.

After being on a few C4 lists I think there are a lot of people out there worried about nothing. The problem, IMHO, is no one is used to seeing a digital readout with 230 degrees on it or the rate at which it climbs from 200 to 230.

If it were a needle gauge with 215 in the middle l don't think anyone woud notice.
 

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hawaii-5-lo said:
what if your working on your car and just installed a cam.now you have to raise the rpms for 20 minutes to break in the cam(non-roller).or your working on the a/c and need the car running for 15 minutes or more.the thing would overheat while idling if the car was waiting to move before fans come on.
Err . . . I think you've misunderstood. The fans WILL run while the car is stationary. That's what it/they are for. I'm saying they won't run at higher speeds. Not engine speeds, but vehicle speeds.

I'm not sure I would rely solely on the factory fan(s) while breaking in a new cam, anyway. A dyno shop will run a large electric fan in front of the car while doing that or running it on a dyno. And running it on a dyno WILL confuse the thing. It thinks it's doing 60mph, but it's actually stationary. So the fans wont run.

I'm also not sure that humidity would bother a cooling system's efficiency. Outside air temp will, but not humidity. Like I said before, having the AC on will change things completely. The fans probably do stay on all the time. The ECM has no ability to know what the humidity is, or even the outside air temp, only the engine coolant temp.
 

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Discussion Starter #13
what would happen if i get a custom fan controller (turn on fans at will) and turn it on the whole time i drive ?
 

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I think I read somewhere that for LT1/4's the higher temp. somehow helps increase the compression ratio, too. Still scares the crap out of me sometimes!

Don't know about the crossfire.
 

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stu said:
If it were a needle gauge with 215 in the middle l don't think anyone woud notice.
I think you're probably spot on. Most factory analogue temp gauges don't even have numbers on them. They usually have a blue section with a 'C' and a red section with a 'H', and bit called 'NORMAL' in the middle, and as long as the needle points to 'NORMAL' everyone is happy, without ever knowing what the temperature actually is.
 

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Mikey said:
what would happen if i get a custom fan controller (turn on fans at will) and turn it on the whole time i drive ?
Mike,
It is not necessary, at all. The fan running ALL the time will do nothing to solve your problem. If indeed you do have a problem. It'll probably just wear your fan out faster. What makes you think it needs to be lowered?

If the temp is within the guidelines that Chev have defined then why worry. If it is running hotter than the Chev guidelines then you have a problem. Getting a colder thermostat wont fix it. Getting a custom fan controller won't fix it. Check out why the temp is higher than it should be, as defined by Chev. Clean your radiator, inside and out. Straighten the fins. Top up the coolant. But if it just because you think the little digital number is too high, compare it to the book. If the book says it's okay, then it's okay.

I too would have said that 200 was too high, but like Stu said, it's probably quite normal and nothing to be concerned about. Chev would not have installed a 190* thermstat and set the fans at 212* or 220* or whatever if they thought they'd destroy engines. Imagine they warranty work they would have had.
 

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oops,i mis read the part when you said the fans run when the car is,my fans run all the time,they never shut off.i took out my thermostat,cut the springs,and reinstalled,now its a 180* t-stat.my fans are set by a adjustable controller to come on at 190* and off at 180*.thats the only way to keep the car in that temp range.thats ok.i will use my extended warranty for new fans if they burn up.
i have scanned my car with auto-tap at various temps,in the c5,anything over 200*,there was knocking,then the computer pulls timing.at 220* the car was down like 15 % horsepower.at 185* the car ran good with 28* timing and pulled hard.i drag race pretty regularly,and sitting in the staging lines watching your temp climb is a killer.i have made runs with the temps over 200* and the car is a couple tenths slower.Hawaiin Punch(on this forum) has watched me go thru this over a 2 year period.
bottom line-heat sucks/the fix-change your t-stat and fan settings.it's that easy:thumbsup:
 

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Tempture

My 1996 Lt4 runs much cooler with a 160 degree stat and a Hyper-tech power programmer, turns on the fans sooner and I use a air hose and blow out all the trash that gets sucked up in the radiator. The Lt4 runs a little hotter than the LT1 because of the Higher performance cam and increased compression ratio. My neighbor installed the G.M. Hot Cam optional for the 1996 LT4 and he gained some H.P. and some more heat to go with it. A bigger radiator is a option for LT4 engines that have been modified big time.:cheers:
 

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Let me share with you.
I have an '84. With the 160' thermostat. and using the 185' fan switch, on the pass side of the head.
My vette runs to 200 degrees, then the fan goes on, runs till it gets to 185', then the fan goes off.
I'm also using a ADS Chip.
My vette runs cool, and great.
Hope this helps you.
tony
 

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OzC4 said:
I do not own an '89 so I'm prepared to be wrong, but I would be very surprised if the standard factory cooling fan setup ran regardless of vehicle speed. Having the A/C on is a different story altogether, so forget that scenario. The fan has one purpose, to move air through the radiator. The motion of the car through the air at anything more than 10-20mph is far more effective at doing this than a fan. So above a certain speed, which is not very high, the fan becomes redundant, whether it is running or not. In fact, a fan can become a hinderance to air flow.

After-market fan units, that are commonly installed on cars that were originally supplied with mechanical fans, tend to work solely on engine temp, but factory units like that in the C4s & 5s are more intelligent than that.



God that's high. Especially for an alloy engine. Why is it set so high? What do they hope to gain? Like I said, I s'pose Chev know what they're doing. I know I'd be very uncomfortable watching my temp gauge head towards 112*C while sitting in traffic!

My '93 LT! has dual fans. If I Set on A/C one fan comes on immediatley and stays on as long as I hva A/C on. Under normal operation the temp is about 200F/93c. The fans only come on when the temp reaches 228F/109c and then go off at 118F/104c. This only accurrs when in traffic or stopped at idle. Normal operating temp goes from 194F/92c to 197F/94c which is a result of the thermostat opening and closing to limit flow. As far as I know, these are within designed operating range from GM?

If your rad cap is set a 15psi, the boiling point of water is around 245F/120c. You should not have a boilover under that temp with a good rad cap. Rad caps are specifically designed to maintain 15psi to raise the boiling point because vehicles routinely run in temps over 212F/100c. Whats the worry? Dont neglect to replace your rad cap if you have ANY suspicion that it is not functioning properly. ALso, a minor leak in the system will result in a lower operating pressure and possible boilover.
 
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