Hi all,

Its getting hot here in GA....and humid.....and my temp gauge is climbing.
Its about 205 while going 35 MPH but as soon as I start to accelerate and get to highway speeds it starts to climb.......
I read some posts about the fan clutch and how to diagnose it , and I think it is okay.
My car is getting up to 220 on the highway.
When I came home at that temp ( 220 ) and stopped the car , the fan spun about 2 or 3 times after the pulley stopped and then it stopped.
I let the car cool down to about 200 , ran ir for a bit and stopped it. This time the fan stopped almost instantly as the pulley stopped. I can turn the fan by hand but it has some drag on it.
If I spin it by hand it will go around about 1 time and stop.
So , anyways, I think the fan is operating correctly..

I popped open the radiator and drained it out. All my little port holes in there are caked with white corrosion. ......I bet this is my problem

Water pump has been replaced already....as well as new radiator hoses.

Soooooo, my question ( finally ) is this:

Should I have my radiator taken apart and cleaned.?...OR...should I buy a new one?

AND ........who has the best price.

its an 81 Automatic....

Thanks

Kevin



[Modified by ksems, 8:38 AM 5/9/2002]

 

also - one more thing....


every once and a while lately ..... I get a brief howl from something ,right when I start the car..
it only lasts about 1 second......then its gone...I can shut the car off and start it again and it may or may not happen.
I tightened all the belts up and didnt hear it after that for a few starts.....then I heard it again :(

I would say it happens once every 10 starts.

Kevin


[Modified by ksems, 8:44 AM 5/9/2002]

 

Hi Kevin,
I had my rad re-cored (much cheaper than new). I STILL haven't driven it, but it runs much cooler (when breaking the cam in the temp got nowhere near where it used to if it just sat idling for a while). If you get it re-cored, measure the size of the rad b4 & after the job. Mine has come back about 1/8" wider than it should be. It still fits OK, but it doesn't sit on the rubbers(?) properly.
I also suspect my fan clutch. The manual says 1/4" movement back & forward at the fan tips is OK (which mine does) but doesn't mention if the hub should have any fore or aft play on the shaft (mine does :( ). Mine won't spin a whole turn whatever it's temp - it always stops after about 1/2 turn.
Is the howl a bit like a roar?! Hard to describe noises, but my Ford fan clutch siezed solid & the fan made a noise between a roar & a howl!
Does your aux. fan cut in OK?
:cheers:

 

Sorry, forgot to say: Have you tried having the system reverse flushed? That might clean it out enough to do the job :)
Paul

 

Hi, Kevin!
The carbonate scale that's covering and probably somewhat clogging the tubes is almost certainly the problem. That's why you should only use distilled water when mixing up your coolant.

As for replace/recore/clean, I'd pull the rad and take it to a good shop. They'll pressure test it in a tank, and tell you what your options are. If there are few or no leaks, they might just suggest having the tubes rodded out; or if there are leaks, they'll tell you what it will cost to have it recored. And of course they'll tell you what a replacement will cost.

When I bought my car, 9 years ago I think, the cooling system was probably the car's worst problem. For some reason, for a lot of people, when a vehicle is only driven in summer weather, it never occurs to them to change the coolant/anti-freeze. I had noticed a small leak in the rad, so I pulled it and took it to the shop. The pressurized it with air in a big water tank, and there must have been 40 streams of bubbles coming up from all the little pinholes! :eek: The recore cost was about 1/2 of the cost of a new one, but I also had a loose upper hose neck, which would require repair, so I just opted for a replacement. Can't remember for sure, but it seems like it was around $200.

The new rad plus a good hi-perf pump and only distilled water plus Prestone in a 50/50 mix, and my car runs a steady 180-190 in the hottest weather (with a 180 stat).

Good luck! :seeya

 

Sounds like the Radiator needs to be cleaned....I would do that before buying a new one...It is GETTING HOT IN GA!!! :cheers:

 

looking at some old posts I saw an address for http://www.radiators.com

they have a new replacement for $179....and they are 5 miles from me...

thats pretty tempting.

I also saw some old posts about re-coring problems......

what to do , what to do.......

BTW , I confess, Im as guilty as anyone in using tap water in the radiator....
wont do it again though ....promise :D

Kevin

[Modified by ksems, 9:43 AM 5/9/2002]


[Modified by ksems, 9:44 AM 5/9/2002]

 

they also said that the stock replacement was a 3 row for $179
they also had a 4 row that would require some mounting modification for $250.

does this sound right?

Kevin

 

also :)

how can I check the aux fan operation?....its hard to see if it turns on.....

 

Kevin,
There used to be some stuff that you could use to dissolve all the crud in the rad, etc. I don't know if it's available over there (or even here, these days) but you'd just drain the system, flush it through until all the loose stuff was out & then fill it with water & this cleaner. Then start the engine with the rad cap removed & let it warm up (don't let it boil over). The cleaner would dissolve the salts, etc & you'd just drain it all out, flush & fill with antifreeze & (distilled!) water. It worked well usually, & was a lot cheaper than a new or repaired rad. The only problem was that in some cases the deposits were filling holes in the rad, so when it was all dissolved & flushed out, the rad would leak like a seive. It might be worth seeing if you can still get it &, if so, give it a try.
:cheers:

 

UKPaul,

thanks

I tried the RADIATOR FLUSH stuff twice last summer.....you put it in...run the car to operating temp...drain it out.......repeat.........yadda yadda yadda....

Kevin

 

I found that the sensor in the p.side head only had one wire going to the 2 terminals - & that it went to ground!!! Upon pulling all the electrical tape off the harness I found a melted mess (long story which took most of last Saturday to sort out) with the wire to the sensor just cut off & taped up. After fitting it I ran the engine up to as hot as it would go, then turned it off & then turned the ignition on but with the engine stopped. As long as the engine is above the fan kick-in temp (which yours sounds like it will be) you should see the aux fan spinning (you should also be able to hear it when sitting in the car).
:cheers:

 

UKPaul -

ah ha - thanks ...I 'll give that a try

:)

 

Oh :(
In that case I'd pull it out & run it down to a rad. shop & see what they say. If it's anything like over here don't, whatever you do, let on it's out of a Vette! Their eyes just light up with £ ($) signs as they assume you're loaded! I just said it was out of a beaten up old Chevy I was trying to get running (well... it was partly true) ;)
What were the problems with getting rads re-cored that you saw? :( :eek:
Paul

 

I remember one person in particular had his recored and a little while later one side started to leak....
got that fixed and a few months later the other side started to leak......
went a bought a new radiator - has been fine for 2 years.....

it s getting toooo hot here in GA these days...I DONT want to be on the side of the road after paying someone to recore my radiator.....:mad:





[Modified by ksems, 10:20 AM 5/9/2002]

 

everyone i talked to said to replace rather than repair. here in jersey, repair shop's are going out! for what it costs, its a better option. try http://www.radiator.com. they ship for free overnite.

 

It will cost money, but you will never look back badly on the purchase: Get an aluminum radiator. It will keep your car cool for all occasions. Griffin and BeCool models come to mind. These will make a VERY nice upgrade to your car's cooling.

-Noel

 

thanks everybody...
I went ahead and got a new radiator from http://www.radiators.com
they are only 7 miles away from me and had a great price....$179.00
It is a 3 row, like the one originally in the car....and size and dimensions
are right on....havent put it in yet but so far I am pleased.
They would have delivered it for $10....:) .....I went ahead and drove to them
since I was out.

now I need to get the seals...probably go with Ecklers kit for $35...9 pieces.

about the aux fan....the manual says it doesnt kick on until 239 degrees...
my car never got that hot so I still dont know if it works.

Kevin




[Modified by ksems, 6:20 PM 5/11/2002]

 

UKPaul,

I tried the test for the aux fan like you said - mine didnt come on....
however, the manual says the aux fan doesnt kick on until 239 degrees...
my car never got that hot so I still dont know if it works.

:confused:

Kevin

 

Many of the Vette parts houses sell replacement sensors that kick the fan on at lower temps.
As far as the fan clutch. Get the car up to temp, then turn it off. Try and turn the fan by hand. If there is a lot of drag, then the clutch is ok. If there is little or no drag, replace it. My opinion, just replace it anyway, they don't cost that much.

Radiator -- if you can get a new 3 core for $179, get it. I had mine re-cored and it ran $150. The problem is most likely the radiator. If the car only overheats at stop and go traffic, then I would say it's a fan problem. But at highway speeds the car should be force fed air and should be more than enough to keep it cool.
Look at the A/C condensor. Are the fins all blocked with crap or bent? Yet another possible problem.
How about the seals ? There should be seals on both sides of the radiator, and at the top to meet up with the cold air intake for the air cleaner. The cold air intake is there, isn't it ? If not, that's another big problem. There should be a complete seal all the way around the radiator, both sides and the top. If not, air will go around the radiator instead of through it.

Make sure to use distilled water.
I live in Phoenix, so with no threat of freezing, I use distilled water and 2 bottles of Red Line Water Wetter, and that's it. Pure water cools best, period. However you need to lubricate the water pump. That is where Water Wetter or Anti-freeze comes in. If you have problems with boil over using pure water and water wetter, mix in some anti-freeze to raise the boiling temp of the mix. I have not had to do that, but I have had times that when I turn the motor off, I can hear the water pushing into the overflow tank. So I may try a minimal amount of anti-freeze to push the boiling temp up a little.

I drive in 100 degree temp, with the A/C running, and a 300+ HP motor. In stop and go traffic and on the highway I have no problems cooling with a stock 3 core radiator and dual electric fans. My ONLY problem is when I turn it off, but that is a minor issue.

Good luck.