Cold Cylinder Advise
Thread Starter
Racer
Joined: Nov 2004
Posts: 422
Likes: 0
From: Owensboro Ky
Cold Cylinder Advise
Well after bragging a couple of weeks ago about how fast the 454 is in my 69 vert, I have found a problem. Decided to get out my IR gun and check header exhaust temps when I noticed #7 was 320 degrees and all others cylinders running at 550 deg. There is a noticable colored ring around the header tube close to the mount flange.
The motor idles and runs fine with none of the signs that coolant is entering the system. I removed both valve covers and found no signs of milkshake nor does it blow white smoke. My coolant, on the other hand, has a slight dark color and is surely the cause of exhaust gases escaping into the coolant.
I am finally enjoying the vette and taking off the head is the last thing I want to do. Any advise on narrowing down the culprit and alternative fixes.
Thanks
The motor idles and runs fine with none of the signs that coolant is entering the system. I removed both valve covers and found no signs of milkshake nor does it blow white smoke. My coolant, on the other hand, has a slight dark color and is surely the cause of exhaust gases escaping into the coolant.
I am finally enjoying the vette and taking off the head is the last thing I want to do. Any advise on narrowing down the culprit and alternative fixes.
Thanks
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
If you have shop air, get a spark plug adapter so you can pressurize the cylinder. With the cylinder pressurized, take the rad cap off. If the gasket is bad you'll see bubbles.
Any decent shop can also do this for you if you don't have shop air.
Any decent shop can also do this for you if you don't have shop air.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Your looking to hard.
Don't trust that IR gun - not the way you are using it. Better read the instructions.
Nothing wrong with dark coolant - could be from block, heater core, radiator or some obsure part in coolant sys. If you cange it be sure to drain the block (plugs just above oil pan) too.
Only way to verify header pipe temps is with a thermal couple - hose clamp it on. Many digital multimeters will read TC temps but u need to use the correct type TC wire for your meter - try an electrical supply or maybe even Radio Shack.
What i'm saying is don't rip that mtr apart just from using that gun (which is not correct for that application) or dirt in your coolant. U may not have any problem at all. A dead cyl should give you a small/tiny miss at least at idle. Try a sthesescope at idle?
cardo0
Nothing wrong with dark coolant - could be from block, heater core, radiator or some obsure part in coolant sys. If you cange it be sure to drain the block (plugs just above oil pan) too.
Only way to verify header pipe temps is with a thermal couple - hose clamp it on. Many digital multimeters will read TC temps but u need to use the correct type TC wire for your meter - try an electrical supply or maybe even Radio Shack.
What i'm saying is don't rip that mtr apart just from using that gun (which is not correct for that application) or dirt in your coolant. U may not have any problem at all. A dead cyl should give you a small/tiny miss at least at idle. Try a sthesescope at idle?
cardo0
Thread Starter
Racer
Joined: Nov 2004
Posts: 422
Likes: 0
From: Owensboro Ky
Originally Posted by cardo0
Don't trust that IR gun - not the way you are using it. Better read the instructions.
Nothing wrong with dark coolant - could be from block, heater core, radiator or some obsure part in coolant sys. If you cange it be sure to drain the block (plugs just above oil pan) too.
Only way to verify header pipe temps is with a thermal couple - hose clamp it on. Many digital multimeters will read TC temps but u need to use the correct type TC wire for your meter - try an electrical supply or maybe even Radio Shack.
What i'm saying is don't rip that mtr apart just from using that gun (which is not correct for that application) or dirt in your coolant. U may not have any problem at all. A dead cyl should give you a small/tiny miss at least at idle. Try a sthesescope at idle?
cardo0
Nothing wrong with dark coolant - could be from block, heater core, radiator or some obsure part in coolant sys. If you cange it be sure to drain the block (plugs just above oil pan) too.
Only way to verify header pipe temps is with a thermal couple - hose clamp it on. Many digital multimeters will read TC temps but u need to use the correct type TC wire for your meter - try an electrical supply or maybe even Radio Shack.
What i'm saying is don't rip that mtr apart just from using that gun (which is not correct for that application) or dirt in your coolant. U may not have any problem at all. A dead cyl should give you a small/tiny miss at least at idle. Try a sthesescope at idle?
cardo0
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