68 327 running cold
Thread Starter
Instructor
Joined: May 2011
Posts: 169
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From: petaluma california
68 327 running cold
I havent posted in awhile just like to say i picked up this 68 and a mechanic did a partial get running- driving--going after say possibly sitting for 15-18 years.. since it was outa state i didnt get an opportunity to drive or argue about the price..so i put high octane super in it and noticed tank was new..I also noticed the antifreeze and oil where changed. I replaced a few of the heater hose -ends that were kinked, plus thermostat..180 degree..The car is running at 110-120 deg after
thermostat was replaced.... I turn on heater full boor and was able to warm up cab...but not hot..When radiator cap was off I did not notice much circulation but the level did go down...the motor @ idle sounded fine but when i reeved
engine the right bank had lower compression than the left coming out of tailpipe..there is a diesel noise coming from right bank when under load and say around ,,,a guess... 1500 rpm...I have messed with timing to no avail,, maybe off a tooth? hopefully not a Wrist pin on one cylinder...got out my stethescope,, noisey 130k miles engine.....any ideas appreciated,,, GUMP
thermostat was replaced.... I turn on heater full boor and was able to warm up cab...but not hot..When radiator cap was off I did not notice much circulation but the level did go down...the motor @ idle sounded fine but when i reeved
engine the right bank had lower compression than the left coming out of tailpipe..there is a diesel noise coming from right bank when under load and say around ,,,a guess... 1500 rpm...I have messed with timing to no avail,, maybe off a tooth? hopefully not a Wrist pin on one cylinder...got out my stethescope,, noisey 130k miles engine.....any ideas appreciated,,, GUMP
Last edited by Gumpy; Feb 14, 2019 at 11:20 PM.
Melting Slicks
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From: Chapel Hill NC
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Running cold I would guess thermostat is bad.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
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if the water isnt heating up the thermostat is stuck open. Even if it is new it can be bad. I would pull it and see if it is open or closed. then test it in a pot of water and bring it up to boil.
You can also put a piece of cardboard on the intake side of the radiator to block air flow to see if engine temp increases. If anything is working the radiator is.
I would solve one problem at a time on an unknown engine. Get the temp to normal, then mess with timing. You may end up rebuilding the motor, but worry about that later. If the previous owner ran a sstraight 10/30 that was NOT ZDDP modified the cam could be toast, but again, one thing at a time.
You can also put a piece of cardboard on the intake side of the radiator to block air flow to see if engine temp increases. If anything is working the radiator is.
I would solve one problem at a time on an unknown engine. Get the temp to normal, then mess with timing. You may end up rebuilding the motor, but worry about that later. If the previous owner ran a sstraight 10/30 that was NOT ZDDP modified the cam could be toast, but again, one thing at a time.
Last edited by Rescue Rogers; Feb 15, 2019 at 11:22 AM.
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Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
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Take approximately 24 inch square piece of cardboard. Lay it on the outside of the radiator so the fan drawing air through the radiator will suck it onto the radiator. no air flow, no cooling.
Last edited by Rescue Rogers; Feb 15, 2019 at 11:20 AM.
Race Director
Joined: Oct 2008
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From: Long Island
Suspend the thermostat in a pot of hot water and see where it opens. I agree, many new one are junk..
Rev the engine while looking into the carb - see if both sides of the carb are feeding the engine.
Rev the engine while looking into the carb - see if both sides of the carb are feeding the engine.
Thread Starter
Instructor
Joined: May 2011
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From: petaluma california
update....help appreciated
Jebby you may be right but haven't gotten to that point yet...so i replaced thermostat 195 deg thouroughly cleaned therm housing installed new upper radiator hose the coolant that came out of the driver side of radiator appeared recent...ran the car with cardboard in front of radiator... while alternating between a/c and full heat,,,got it up to 135 degrees ,,,wow!...still think its timing ,,oil,, or heat riser,,,feel free to comment,,,,Steve
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
Jebby you may be right but haven't gotten to that point yet...so i replaced thermostat 195 deg thouroughly cleaned therm housing installed new upper radiator hose the coolant that came out of the driver side of radiator appeared recent...ran the car with cardboard in front of radiator... while alternating between a/c and full heat,,,got it up to 135 degrees ,,,wow!...still think its timing ,,oil,, or heat riser,,,feel free to comment,,,,Steve
Jebby
Team Owner
Joined: Jan 2006
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From: Crossville TN
You need to take Jebby's concern seriously. If the heat riser valve is CLOSED on the right bank, that head is OVERHEATING regardless of what the water temp is doing. You can crack a head, blow a gasket, whatever if the heat riser valve is shut when the engine is running.
I know of no way the engine can run that cold IF the thermostat valve is closed....which it should be, until it gets warmed up. Whatever you are using to measure engine temp is in error.
I know of no way the engine can run that cold IF the thermostat valve is closed....which it should be, until it gets warmed up. Whatever you are using to measure engine temp is in error.
Thread Starter
Instructor
Joined: May 2011
Posts: 169
Likes: 2
From: petaluma california
You need to take Jebby's concern seriously. If the heat riser valve is CLOSED on the right bank, that head is OVERHEATING regardless of what the water temp is doing. You can crack a head, blow a gasket, whatever if the heat riser valve is shut when the engine is running.
I know of no way the engine can run that cold IF the thermostat valve is closed....which it should be, until it gets warmed up. Whatever you are using to measure engine temp is in error.
I know of no way the engine can run that cold IF the thermostat valve is closed....which it should be, until it gets warmed up. Whatever you are using to measure engine temp is in error.
Thankyou i do take it serious and will pickup an infared today,,,had a death in family last night but iShall keep try trying to remedy this inconvience...which is always a challenge....thankyou for your input LT1vette!!!!~
