Water pump test
Thread Starter
Instructor
Joined: Jun 2008
Posts: 233
Likes: 9
From: Marietta Ga
Water pump test
Is there a test for determining if a water pump impeller is worn?
My car temp increases from 185F to just over 210F with sustained RPM over 2500.
Idle speed temp is fine even on a hot day...temp stays down. Driving around up to 55 MPH slightly increases temp.to 200F. 70 Mph for an increased time on highway will get her too hot (over 220)
Seems it doesn't matter the temp outside .....I can increase engine temp on a cold day up over 210F just by driving in 3rd to keep the rpm's up.
Radiator recored
Lower hose spring installed
Radiator seals all in place
Lower air dam in place
Rad cap pressure tested OK
New thermostat 180F
Timing advanced to 14 Deg BTDC
My thought is a worn water pump impeller, but is there a way to tell?
73, 350 L82. Non AC, 4spd.
My car temp increases from 185F to just over 210F with sustained RPM over 2500.
Idle speed temp is fine even on a hot day...temp stays down. Driving around up to 55 MPH slightly increases temp.to 200F. 70 Mph for an increased time on highway will get her too hot (over 220)
Seems it doesn't matter the temp outside .....I can increase engine temp on a cold day up over 210F just by driving in 3rd to keep the rpm's up.
Radiator recored
Lower hose spring installed
Radiator seals all in place
Lower air dam in place
Rad cap pressure tested OK
New thermostat 180F
Timing advanced to 14 Deg BTDC
My thought is a worn water pump impeller, but is there a way to tell?
73, 350 L82. Non AC, 4spd.
Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
It could still be a clogged radiator. Happened to me same symptoms. Did the block have lots of rust...it could have fouled the rad again.
Is your temp gauge accurate, checked with IR gun?
Initial timing sounds OK, and check mech advance, and keep vacuum advance hooked up
Is your temp gauge accurate, checked with IR gun?
Initial timing sounds OK, and check mech advance, and keep vacuum advance hooked up
Race Director
Joined: May 2006
Posts: 18,736
Likes: 2,582
what is your total mechanical advance timing without vacuum?
how many additional degrees from vacuum?
did you test the thermostat to see if it really opens at 180?
is this a standard thermostat or a wide mouth? https://www.summitracing.com/parts/e...make/chevrolet
how many additional degrees from vacuum?
did you test the thermostat to see if it really opens at 180?
is this a standard thermostat or a wide mouth? https://www.summitracing.com/parts/e...make/chevrolet
Thread Starter
Instructor
Joined: Jun 2008
Posts: 233
Likes: 9
From: Marietta Ga
So I have 34 Deg all in. 14 Deg BTDC with the vac advance plugged. Its 20 mechanical plus 14 at 3,000 RPM.
I have a standard thermostat....didn't know there was a wide mouth!
Another interesting thing is my temp gauge runs up and peaks at 210 as it warms up. When the thermostat opens it quickly drops back down to 180 on the gauge and stays there at idle.
I flush the rad every year, but have never opened the block drains since I don't know what I'll get myself into ....maybe its time.
I have a standard thermostat....didn't know there was a wide mouth!
Another interesting thing is my temp gauge runs up and peaks at 210 as it warms up. When the thermostat opens it quickly drops back down to 180 on the gauge and stays there at idle.
I flush the rad every year, but have never opened the block drains since I don't know what I'll get myself into ....maybe its time.
Instructor
Joined: Nov 2014
Posts: 161
Likes: 17
From: Georgia
I replaced my original GM pump with a new aftermarket pump on my 73 just as a precaution with the idea of rebuilding the pump at a later date. I immediately noticed the new pump caused an increase of almost 10 degrees in temp. It still runs under 200 so no big deal. I'm not saying this is your problem, just sharing my recent experience .
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Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
Also would help hi speed cooling
Race Director
Joined: May 2006
Posts: 18,736
Likes: 2,582
Thermostat
So I have 34 Deg all in. 14 Deg BTDC with the vac advance plugged. Its 20 mechanical plus 14 at 3,000 RPM.
I have a standard thermostat....didn't know there was a wide mouth!
Another interesting thing is my temp gauge runs up and peaks at 210 as it warms up. When the thermostat opens it quickly drops back down to 180 on the gauge and stays there at idle.
I flush the rad every year, but have never opened the block drains since I don't know what I'll get myself into ....maybe its time.
I have a standard thermostat....didn't know there was a wide mouth!
Another interesting thing is my temp gauge runs up and peaks at 210 as it warms up. When the thermostat opens it quickly drops back down to 180 on the gauge and stays there at idle.
I flush the rad every year, but have never opened the block drains since I don't know what I'll get myself into ....maybe its time.
I would test that thermostat in a pot of heating water to see if it is really opening at 180
