Overheating
Burning Brakes
Joined: Oct 2001
Posts: 911
Likes: 5
From: TN
Re: Overheating (JackCooper)
Have you determined what the black stuff is in the coolant system?
What you do as recommended by others is your decision. I am still driving my 70 Corvette that I bought new and it has the original cooling system. This includes the original fan clutch. My cars ability to maintain a safe operating temp impressed me in 1970 on a hot August day in downtown Dallas with the air conditioning on in stop and go traffic and never got above about 210.
If your cooling system is operating properly your car should be able to do the same. The best fan clutch you can buy for your car is still sold by GM and will do the job it was designed to do. When mine goes, if it ever does (have 165 thousand on it now) I will spend the extra money and get the one from GM.
Let us know how your problem gets solved.
What you do as recommended by others is your decision. I am still driving my 70 Corvette that I bought new and it has the original cooling system. This includes the original fan clutch. My cars ability to maintain a safe operating temp impressed me in 1970 on a hot August day in downtown Dallas with the air conditioning on in stop and go traffic and never got above about 210.
If your cooling system is operating properly your car should be able to do the same. The best fan clutch you can buy for your car is still sold by GM and will do the job it was designed to do. When mine goes, if it ever does (have 165 thousand on it now) I will spend the extra money and get the one from GM.
Let us know how your problem gets solved.
Instructor
Joined: Oct 2001
Posts: 216
Likes: 0
From: Kingston Tn
Re: Overheating (70ZZ3 96LT4)
Jack,
Just for the hell of it, why don't you put that old water pump (you decided to change it out even though it was working) back in? If you dropped it off for a core replacement maybe you can call them before it's sent out for rebuilding. 'luck PM
Just for the hell of it, why don't you put that old water pump (you decided to change it out even though it was working) back in? If you dropped it off for a core replacement maybe you can call them before it's sent out for rebuilding. 'luck PM
Thread Starter
Advanced
Joined: Nov 2001
Posts: 88
Likes: 0
From: North Myrtle Beach SC
Re: Overheating (JackCooper)
There isn't any water on the dipstick,
but I haven't yet identified the black
gunk.
How much is a new modine radiator?
Maybe I should just get a new one and
be done with it.
If the black residue turns out to be oil (I
don't believe it is), Then I can just pull the
heads and install new gaskets (a gasket kit
is only 50 bucks, chump change, and I do
my own work). But I doubt that its blown
a gasket.
Whats wrong with having the radiator rodded
out? If all it is is that its stopped up from sitting
up for a long time, then whats the problem?
but I haven't yet identified the black
gunk.
How much is a new modine radiator?
Maybe I should just get a new one and
be done with it.
If the black residue turns out to be oil (I
don't believe it is), Then I can just pull the
heads and install new gaskets (a gasket kit
is only 50 bucks, chump change, and I do
my own work). But I doubt that its blown
a gasket.
Whats wrong with having the radiator rodded
out? If all it is is that its stopped up from sitting
up for a long time, then whats the problem?
Instructor
Joined: Nov 2001
Posts: 175
Likes: 0
From: St Louis MO
Re: Overheating (JackCooper)
remove the thermostat. start car with radiator cap off and have someone increase the rpm while you watch level in the radiator. the level should drop as the rpm is increased and you should see a steady flow from the radiator tubes that are exposed. when you decrease the rpms the antifreeze could gush out of the radiator so be prepared for that. good flow then your water pump is probably o.k. . check to make sure that the front of the radiator is not blocked by some foreign object and make sure the little spoiler underneath the nose is there and intact.
Melting Slicks
Joined: Apr 2001
Posts: 2,280
Likes: 0
From: colorado springs CO
Re: Overheating (JackCooper)
jack, depends on the condition of the current core!!.....
man i played with that stupid radiator 3 times!!!
3 TIMES!!!!
argggggggghhh makes me mad just thinking of it...
pulled it once for a rodding......
again for a cleaning and check....
both times came back "good condition" by radiator shop......
:rolleyes: :rolleyes:
3rd time i said screw it after i limped home pushing high temps......
got it recored for 130 bux...
that was about 5 trouble free years ago!!
i guess it all depends on the radiator shop!!
if they say you have a high pressure leak dont get the header soldered...just recore it!!.....
my .02
man i played with that stupid radiator 3 times!!!
3 TIMES!!!!
argggggggghhh makes me mad just thinking of it...
pulled it once for a rodding......
again for a cleaning and check....
both times came back "good condition" by radiator shop......
:rolleyes: :rolleyes:
3rd time i said screw it after i limped home pushing high temps......
got it recored for 130 bux...
that was about 5 trouble free years ago!!
i guess it all depends on the radiator shop!!
if they say you have a high pressure leak dont get the header soldered...just recore it!!.....
my .02
Thread Starter
Advanced
Joined: Nov 2001
Posts: 88
Likes: 0
From: North Myrtle Beach SC
Re: Overheating
Well, I pulled the radiator, and its all stopped up
with goo-like material (which is not oil).
I'm gonna have it boiled and rodded out
Maybe that will fix my problem. :crazy:
I hope so.
If it doesn't, I may :U
with goo-like material (which is not oil).
I'm gonna have it boiled and rodded out
Maybe that will fix my problem. :crazy:
I hope so.
If it doesn't, I may :U
Burning Brakes
Joined: Dec 1999
Posts: 845
Likes: 0
From: Ventura Harbor CA California
Re: Overheating (JackCooper)
If the top hose is collapsing and the thermostat is good and the radiator is full, the cast iron is plugged. Flush the system with some of the cheap stuff from the chain auto stores before you spend any big bucks. It is pulling through the radiator or it wouldn't collapse the hose.
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Pro
Joined: Jun 2000
Posts: 569
Likes: 0
From: phoenix az
Re: Overheating (JackCooper)
If you have the radiator out, replace it with a nice aluminum unit. You can spend big bucks and get a custom fit one or with a little fiddleing and modification you can get a generic GM unit and save a ton of money. I bought mine from a local manufacturer here in Phoenix and It's run cool ever since. On the freeway, it barely gets off of the 180 stat. In the city it idles in traffic at about 200+-. Do yourself a favor and put the water pump back on after you put the shroud in.
Team Owner
Joined: Jul 2001
Posts: 61,410
Likes: 478
From: Here to make friends
St. Jude Donor '11, '16-'17
Re: Overheating (JackCooper)
My guess is the black gunk is Bar's Leak. This stuff works great at plugging holes in your radiator, but it can settle in the bottom and also plug your cooling system when it get's cold (don't ask me how I know). My guess is, that you either have a leak in your radiator or heater core and someone dumped in Bar's Leak to solve the problem. Flush your radiator and bypass your heater core and see what happens.
Thread Starter
Advanced
Joined: Nov 2001
Posts: 88
Likes: 0
From: North Myrtle Beach SC
Re: Overheating
Well, after cleaning the radiator, replacing the hoses, t-stat,
and radiator cap, and flushing the system three times, the
overheating problem is GONE!
Thanks guys! :cheers: :jester :chevy
and radiator cap, and flushing the system three times, the
overheating problem is GONE!
Thanks guys! :cheers: :jester :chevy
Racer
Joined: Oct 2001
Posts: 274
Likes: 2
From: Pampa Tx
Re: Overheating (JackCooper)
Agree with the reverse flow pump. Newer engines (serpentine belted) usually run the water pump the opposite direction of a v-belt engine. If you got a late model pump by mistake, it will do exactly what you are seeing. If it happens again after repairing the radiator , put the old pump back on.
Phlash
72 LS-5 Roadster
Phlash
72 LS-5 Roadster
