C1 Cooling/Heating question

[J60FI]

I just had the water pump rebult on my 60... been driving the car today.. pretty nice day her in southern ontario..

Last weekend was the first time I was able to drive the car... so I stuck close to home.. and after a couple of hours of short trips in the neighbor hood.. the water pump gasket went..

So today I finally got the chance to do some more driving..

I have noticed last weekend and today, that my temperature gauge steadily climbs when I am driving.. today it was between 200 to 220... when i come to a stop it seems to drop to anywhere between 180 to 190..

From what I know it should be the other way around.

I cant figure out why this happens.. After a while I was looking forward to get stuck at a red light for a while..

I was thinking of replacing the thermostat....

Any other ideas or suggestions...

Thanks

Joe

 

[JohnZ]

The thermostat has no effect on operating temperature unless it's stuck; it only regulates the MINIMUM temperature. However, if you don't know how long it's been in there or what kind it is, replace it (with a 180* 'stat) and let us know if anything changes. Have you checked your temp gauge reading against an I.R. gun "shot" of the upper radiator hose just above the thermostat housing so you know what the gauge is really telling you?

 

[J60FI]

The thermostat has no effect on operating temperature unless it's stuck; it only regulates the MINIMUM temperature. However, if you don't know how long it's been in there or what kind it is, replace it (with a 180* 'stat) and let us know if anything changes. Have you checked your temp gauge reading against an I.R. gun "shot" of the upper radiator hose just above the thermostat housing so you know what the gauge is really telling you?

Thanks John.. I will have to borrow a IR gun.. I took the car for a quick spin tonight.. I drove around the neighbourhood.... I was out no more than 10 minutes.. i could smell that rad fluid smell again... I was at the end of my street so i looked behind and there was a trail of flluid.. I looked at the temp gauge it was reading 220..

Popped the hood and green rad fluid all over.. it looked like it was coming from the cap.. looked for rad leaks but couldnt find any.. Yesterday i drove it quite a bit and it was between 210 and 220 and no leaks..

I cleaned it all up.. started teh car and the temp dropped to 100.. ran it in the driveway it got up to 180.. finally took it around the neighbourhood again.. didn't get over 210..

I did notice something this time.. when I reved the engine i could see the fan belt speed up.. but the fan didnt seem to speed up.. then when i turned the ignition the fan blades continued to spin for about 5 seconds.. Could the clutch fan be the problem...

I don't know about the thermostat.. but since that is an easy thing to do .. i will change that tomorrow.

The car has a 283 solid lifter engine .. the rad is copper with no overflow tank.


Thanks..
Joe

:bash

 

[Stan's Customs]

Most likely is the fan clutch from your description....in fact almost for sure.

Changing the thermostat is a good idea even though it won't fix anything. Chances are it's getting old..newer is better, less likely to fail..


Stan...

 

[magicv8]

If it works in the city and not on the highway you don't have enough rad or rad airflow to eject the extra heat of higher rpm running. IMO the factory fan is irrelevant at highway speeds.

 

[Stan's Customs]

Joe.. was last week the first time you have driven the car "ever" ? ....or just since you installed the new pump.

You should be able to hear the fan noise increase when the fan clutch is working...as when the temperature climbs for instance. ( without an increase in RPM...although it will "sound" like the motor has sped up)

Not to be argumentative Magic......but sometime remove the fan and try driving at highway speeds, I'll bet that you will reconsider that it doesn't matter if you have one or not. Especially with the borderline radiators that come in corvettes ...and poor airflow by the design.

This is not to say that a clogged or too small radiator won't cause problems...it would of course, as you said. If his car has been sitting a long time or..?? I was under the impression that it just started this problem..if that is in error then the radiator may well be the problem..

I have repaired several heating problems that just had the radiator cleaned and/or a new fan clutch installed...and still were overheating. Almost very time it was a bad or cheap fan clutch instead of GM or like quality. They had the symptoms that Joe describes.

Timing could be an issue too.

Stan...

 

[J60FI]

Joe.. was last week the first time you have driven the car "ever" ? ....or just since you installed the new pump.

You should be able to hear the fan noise increase when the fan clutch is working...as when the temperature climbs for instance. ( without an increase in RPM...although it will "sound" like the motor has sped up)

Not to be argumentative Magic......but sometime remove the fan and try driving at highway speeds, I'll bet that you will reconsider that it doesn't matter if you have one or not. Especially with the borderline radiators that come in corvettes ...and poor airflow by the design.

This is not to say that a clogged or too small radiator won't cause problems...it would of course, as you said. If his car has been sitting a long time or..?? I was under the impression that it just started this problem..if that is in error then the radiator may well be the problem..

I have repaired several heating problems that just had the radiator cleaned and/or a new fan clutch installed...and still were overheating. Almost very time it was a bad or cheap fan clutch instead of GM or like quality. They had the symptoms that Joe describes.

Timing could be an issue too.

Stan...

Thanks..

Stan the car was a project car that was put on the road two weeks ago... after a few hours of driving the water pump gasket blew.. turns out the bearings went.. so i had the water pump rebuilt and reinstalled.. drove the car this past saturday quite a bit with no problems other than it was running hot.. 210..

Then sunday went around the neighbourhood.. didnt get over 40 mph and with in 10 minutes it was over 220.. and rad fluid was coming from the cap.. I am not sure of the thermostat, .. pretty sure the clutch fan needs to be changed from the feedback.. since it kept running for 5 seconds after the engine was shut off.. and i have never heard the fan speed increase while driving or sitting still... so I ordered the GM #: 3916141 clutch fan and thermostat.. so i plan to change those this weekend..

I have only owned the project for about a year.. the rad could be an original harrison copper rad # 3411674 dated 59D.. the engine is the 290 HP.. but according to what i can find the copper rad was also used on this engine..

So if its not the water pump, thermostat, or clutch fan.. then it must be the rad... By process of elimination..

Would the timing cause this in 10 minutes at no more than 40mpg?

Is there any way to tell easily if the rad is clogged?

Thanks

Joe

 

[Stan's Customs]

What's the history of the engine...fresh build, old engine revived...?

Stan..

 

[J60FI]

Most likely is the fan clutch from your description....in fact almost for sure.

Changing the thermostat is a good idea even though it won't fix anything. Chances are it's getting old..newer is better, less likely to fail..


Stan...

I am not sure if a new thermostat was put in.. so i will change it anyway.. The engine was rebuilt earlier this year. the engine ran in June for the first time since it was rebuilt early this year .. it is numbers matching CS block..

 

[Stan's Customs]

I am not sure if a new thermostat was put in.. so i will change it anyway.. The engine was rebuilt earlier this year. the engine ran in June for the first time since it was rebuilt early this year .. it is numbers matching CS block..

I'm trying to determine whether there is a new problem...or existing problem that has just been discovered.

A new engine build opens other possibilities. Was the car driven much when first started in June?...or not at all just started?

How long has the radiator been dormant...was it just sitting in the car for a few years and the engine rebuilt or...?

 

[J60FI]

I'm trying to determine whether there is a new problem...or existing problem that has just been discovered.

A new engine build opens other possibilities. Was the car driven much when first started in June?...or not at all just started?

How long has the radiator been dormant...was it just sitting in the car for a few years and the engine rebuilt or...?

Stan.. THe car was not driven only started in June.. the car was not driven until September.. debugging.. brakes, clutch, tuning ...etc..

I have really no idea how long the radiator sat around for... years probably.. I dont even know if this is the rad came with the car.. it was probably purchased seperately from the guy I got the car from..


Really appreciate your interest.. THanks.

 

[Stan's Customs]

Stan.. THe car was not driven only started in June.. the car was not driven until September.. debugging.. brakes, clutch, tuning ...etc..

I have really no idea how long the radiator sat around for... years probably.. I dont even know if this is the rad came with the car.. it was probably purchased seperately from the guy I got the car from..


Really appreciate your interest.. THanks.

Well this kinda sketchy...but

In the debugging tuning was mentioned..Assuming it was indeed tuned I would temporarily discount timing. Generally if it isn't clattering on acceleration and it starts real easy the timing is at least close...and probably not the problem (probably). We can get in to vacuum and mechanical advance problems later if this is an issue...

Replace the fan clutch and thermostat.

Actually..."First" Check the engine oil....make sure there is no white or milky appearance of oil. Or if it hasn't been driven far ...that it isn't mysteriously getting fuller (of oil). Remote chance on a new build...but an over looked crack in a head or leaking headgasket could cause the heating problem. Were the heads magnafluxed before the build?

Even if the heating problem is fixed with the fan clutch/thermostat...I would definitely pull the radiator and have it cleaned. If it has been sitting for years...no telling what shape it is in..and you have a new engine. It was probably tanked and clean inside...the radiator should be too.

If it fan clutch doesn't fix it and the oil looks OK then Magic V8 probably nailed the issue from the beginning. Poor circulating or dirty radiator...


You can tell if the radiator is circulating when the engine is at operating temperature by by removing the cap and watching the water flow in the neck of some radiators. Not sure if you can see in the neck of your 60...but I doubt it.

(Must be at operating temperature...not overheated! As the thermostat closes, it will stop circulating so you have to be patient and give time to open, or reach operating temp...and the engine has to be revved a little to keep the coolant from overflowing with the cap off.)

Even if it is circulating the old brass radiators leave something to be desired in efficiency when in top shape....and need to be kept up.

Stan...

 

[J60FI]

Well this kinda sketchy...but

In the debugging tuning was mentioned..Assuming it was indeed tuned I would temporarily discount timing. Generally if it isn't clattering on acceleration and it starts real easy the timing is at least close...and probably not the problem (probably). We can get in to vacuum and mechanical advance problems later if this is an issue...

Replace the fan clutch and thermostat.

Actually..."First" Check the engine oil....make sure there is no white or milky appearance of oil. Or if it hasn't been driven far ...that it isn't mysteriously getting fuller (of oil). Remote chance on a new build...but an over looked crack in a head or leaking headgasket could cause the heating problem. Were the heads magnafluxed before the build?

Even if the heating problem is fixed with the fan clutch/thermostat...I would definitely pull the radiator and have it cleaned. If it has been sitting for years...no telling what shape it is in..and you have a new engine. It was probably tanked and clean inside...the radiator should be too.

If it fan clutch doesn't fix it and the oil looks OK then Magic V8 probably nailed the issue from the beginning. Poor circulating or dirty radiator...


You can tell if the radiator is circulating when the engine is at operating temperature by by removing the cap and watching the water flow in the neck of some radiators. Not sure if you can see in the neck of your 60...but I doubt it.

(Must be at operating temperature...not overheated! As the thermostat closes, it will stop circulating so you have to be patient and give time to open, or reach operating temp...and the engine has to be revved a little to keep the coolant from overflowing with the cap off.)

Even if it is circulating the old brass radiators leave something to be desired in efficiency when in top shape....and need to be kept up.

Stan...

Stan..

I will look at the oil in the morning..

I will replace the clutch fan and thermostat this weekend and let you know... how I make out..

 

[Stan's Customs]

Best of luck...hopefully it will be simple...

Stan..

 

[2X4's 60]

My buddies 59 had a very similar problem. It would idle in the driveway all day long but when you started to drive it, the temp. would slowly climb until you either stopped or it would boil over. Nothing had been done to the car other than it sitting for 6 months. He took it to a repair shop and they replaced the water pump, thermostat, boiled out the rad. but it still did the same thing. They installed a higher capacity rad., still the same thing. He finally gives me a call (out of desperation). He brings the car over and the problem is found in less than 10 mins. with a timing light. The weights in the dist. had corroded and it wasn't advancing the timing. Money spent on the problem - $2000+. money to fix the problem - $.01 worth of WD40. Start with the basics.

 

[J60FI]

My buddies 59 had a very similar problem. It would idle in the driveway all day long but when you started to drive it, the temp. would slowly climb until you either stopped or it would boil over. Nothing had been done to the car other than it sitting for 6 months. He took it to a repair shop and they replaced the water pump, thermostat, boiled out the rad. but it still did the same thing. They installed a higher capacity rad., still the same thing. He finally gives me a call (out of desperation). He brings the car over and the problem is found in less than 10 mins. with a timing light. The weights in the dist. had corroded and it wasn't advancing the timing. Money spent on the problem - $2000+. money to fix the problem - $.01 worth of WD40. Start with the basics.

I understand how your buddy could feel,, wish it could be this simple for me. I will definetly give it a try...

THanks.:Twist

 

[Stan's Customs]

Hey Joe..

How did the heating problem turn out...

Stan..

 

[J60FI]

Hey Joe..

How did the heating problem turn out...

Stan..

Thanks for asking.. on Friday i changed the thermostat... the one that was in was a 160degree.. so i swaped it out with a GM 180 Degree..

I replace the clutch fan with a GM one from Paragon.. i could feel a difference jsut standing beside the car with the hood open.. much more air movement.. i took the car for a spin for about 10 minutes.. the temp gauge got upto 190.. had to park it cause it started raining...

I still have some fluid leaking out of the rad cap.. must have the wrong cap.. even though i ordered it new.. going to try another rad cap.. the one i have feels loose even when its tight..

Had some pretty good thunderstorms here on saturday.. I was away yester day... Today i am going to go for a good drive and test it out fully..

I checked under the distributor cap .. no corrosion everything seems loose.. chnged the thermostat, water pump was rebuilt, new clutch fan.. if this doesnt work... then it can only be the radiator must be plugged. or timing issues...

Will keep you posted..

Joehnoes

 

[Stan's Customs]

I still have some fluid leaking out of the rad cap.. must have the wrong cap.. even though i ordered it new.. going to try another rad cap.. the one i have feels loose even when its tight..
Quote::



Well maybe a dry day will give you a real chance to test it after getting the proper cap.

The radiator cap is extremely important. Pressure loss will result in coolant boil at a lower temperature.....also probably the cause for leaving a water trail you mentioned the other day ... Pressurized fluid boils at a higher temp.

I don't know who manufactures Paragons fan clutches...remember I have repaired several that overheated with new fan clutches (and other repairs) only to discover the fan clutch, even though new, wasn't up to par. I installed the best available and the heating problems ended...instantly.

Point being...make sure the Paragon clutch is top notch..


Cheers...Stan..

 

[JohnZ]

I don't know who manufactures Paragons fan clutches...remember I have repaired several that overheated with new fan clutches (and other repairs) only to discover the fan clutch, even though new, wasn't up to par. I installed the best available and the heating problems ended...instantly.

Point being...make sure the Paragon clutch is top notch..


Cheers...Stan..

The fan clutch Paragon sells is the GM #3916141 - they're brand-new GM parts, made by Eaton.