ZZ4 getting hot!
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,186
Likes: 156
From: Toosoon Arizona
ZZ4 getting hot!
developed a cooling issue . I checked the easy stuff (timing, sender accuracy), and did a coolant flush, changed the thermostat and 13# cap but it did not resolve..
The car has always run (9000 mi) in the 180*, it gets up to temp as usual and then it spikes up to 250*
When it is heating up I can see on the gauge open and go back down when it takes the cooler water from the rad
It stays at 108* for a few miles than spikes to hot!
The rad went thru a few cycles so I believe the air bubbles were out of the pockets as I added a bit of water each time it cooled down.
The engine is a crate ZZ4 with everything and a new copper/brass rad except for a short water pump (9000mi).
I have checked with an IRgun and it agrees with the temp gauge....hot!
The engine and rad were clean when the flush was taking place
The car has always run (9000 mi) in the 180*, it gets up to temp as usual and then it spikes up to 250*
When it is heating up I can see on the gauge open and go back down when it takes the cooler water from the rad
It stays at 108* for a few miles than spikes to hot!
The rad went thru a few cycles so I believe the air bubbles were out of the pockets as I added a bit of water each time it cooled down.
The engine is a crate ZZ4 with everything and a new copper/brass rad except for a short water pump (9000mi).
I have checked with an IRgun and it agrees with the temp gauge....hot!
The engine and rad were clean when the flush was taking place
Le Mans Master
Joined: Feb 2012
Posts: 5,371
Likes: 2,878
From: Western Massachusetts
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developed a cooling issue . I checked the easy stuff (timing, sender accuracy), and did a coolant flush, changed the thermostat and 13# cap but it did not resolve..
The car has always run (9000 mi) in the 180*, it gets up to temp as usual and then it spikes up to 250*
When it is heating up I can see on the gauge open and go back down when it takes the cooler water from the rad
It stays at 108* for a few miles than spikes to hot!
The rad went thru a few cycles so I believe the air bubbles were out of the pockets as I added a bit of water each time it cooled down.
The engine is a crate ZZ4 with everything and a new copper/brass rad except for a short water pump (9000mi).
I have checked with an IRgun and it agrees with the temp gauge....hot!
The engine and rad were clean when the flush was taking place
The car has always run (9000 mi) in the 180*, it gets up to temp as usual and then it spikes up to 250*
When it is heating up I can see on the gauge open and go back down when it takes the cooler water from the rad
It stays at 108* for a few miles than spikes to hot!
The rad went thru a few cycles so I believe the air bubbles were out of the pockets as I added a bit of water each time it cooled down.
The engine is a crate ZZ4 with everything and a new copper/brass rad except for a short water pump (9000mi).
I have checked with an IRgun and it agrees with the temp gauge....hot!
The engine and rad were clean when the flush was taking place
Dan
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,186
Likes: 156
From: Toosoon Arizona
Yesone day to the next!
O K, I will do that this AM
I guess I am looking for a leak or.......
My rad tester pump is old like me!
I hope I can get 20* out of it!
Thanks folk!
what ABOUT USING A VACUUM PUMP AND SEE IF IT WILL HOLD VACUUM (unlock caps!!!)
O K, I will do that this AM
I guess I am looking for a leak or.......
My rad tester pump is old like me!
I hope I can get 20* out of it!
Thanks folk!
what ABOUT USING A VACUUM PUMP AND SEE IF IT WILL HOLD VACUUM (unlock caps!!!)
Last edited by solidaxel; Sep 5, 2019 at 12:38 PM.
Le Mans Master
Joined: Feb 2012
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From: Western Massachusetts
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Dan
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,186
Likes: 156
From: Toosoon Arizona
Well I don't like the results!
From 20# to 7# in 30 min damn!
Is there a carbon monoxide test that I can perform at the rad ?
I have heard of a "kit" as I don't think I can drive it to a rad repair shop 12 miles to the closest one
From 20# to 7# in 30 min damn!
Is there a carbon monoxide test that I can perform at the rad ?
I have heard of a "kit" as I don't think I can drive it to a rad repair shop 12 miles to the closest one
Le Mans Master
Joined: Jan 2007
Posts: 6,003
Likes: 1,509
From: Prescott Arizona
Universal Block Tester
I've used this kit to check for Combustion Gases present in the Coolant/Radiator. Works well and was available at NAPA. Can't find the specific pic, no doubt because I had it stored on Photobucket but did find an old thread where I posted the pic. Hope this comes out.
https://www.corvetteforum.com/forums...post1586934490
When you use this kit, it typically helps to lower the coolant level so there is no wet-splash up against the tester but if your car has an expansion tank, there should be ample distance between the bottom of the tester and the coolant.
If after a minute of squeezing the bulb, the blue liquid turns yellow, that's not good and indicates the presence of combustion gases and therefore a ruptured/blown head gasket or ???
Good luck,
Mike T - Prescott AZ
https://www.corvetteforum.com/forums...post1586934490
When you use this kit, it typically helps to lower the coolant level so there is no wet-splash up against the tester but if your car has an expansion tank, there should be ample distance between the bottom of the tester and the coolant.
If after a minute of squeezing the bulb, the blue liquid turns yellow, that's not good and indicates the presence of combustion gases and therefore a ruptured/blown head gasket or ???
Good luck,
Mike T - Prescott AZ
Le Mans Master
Joined: Feb 2012
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From: Western Massachusetts
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That would be enough for me right there but regardless of what the combustion test says, the fix is in the motor and not the external cooling system. I would do both gaskets and anything else worthwhile while the hood is up and you are dirty.
Dan
Dan
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Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,186
Likes: 156
From: Toosoon Arizona
You make it sound "so easy"!
I am going to try and source a test kit...........just so I can procrastinate longer!
Le Mans Master
Joined: Feb 2012
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From: Western Massachusetts
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Good luck.
Dan
Race Director
Joined: Aug 2004
Posts: 15,304
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From: NorCal
I agree with the head gasket issue
Well, sorry to say I've been there, done that! The ZZ4 has an iron block and aluminum heads, and experiences different expansion and contraction between the two. Mine came with a sandwich type head gasket which sheared over time from the effect of the different expansion and contraction between the heads and the block. I replaced mine with a solid gasket; no problems since.
Two pieces of advice -
First, replace both head gaskets even if only one is leaking - you do not want to do this again, and since the intake is already off you're most of the way towards the second one..
Secondly, be sure to use new rocker arm nuts when you put it back together. The originals are basically single use and some do not hold when reused. I learned that one the hard way.......
Best Wishes,
Glenn
Two pieces of advice -
First, replace both head gaskets even if only one is leaking - you do not want to do this again, and since the intake is already off you're most of the way towards the second one..
Secondly, be sure to use new rocker arm nuts when you put it back together. The originals are basically single use and some do not hold when reused. I learned that one the hard way.......
Best Wishes,
Glenn
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,186
Likes: 156
From: Toosoon Arizona
Upon further inspection and an after the 20# pressure test and 8 hose connections, I have found three AF leaks!
Today I am going to address the hose connections and try using 15# of pressure and look for more AF leaks
I sure hope I did not compromise the heater core!
Today I am going to address the hose connections and try using 15# of pressure and look for more AF leaks
I sure hope I did not compromise the heater core!
Safety Car
Joined: Oct 2016
Posts: 4,617
Likes: 1,547
From: Olive branch Ms
Slow down and verify. They'll have you changing the rear end. The pressure loss could come from anywhere in the cooling system. Are you losing water with no apparent leaks, i.e. water under the car or in the oil. I hope it's minor.
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,186
Likes: 156
From: Toosoon Arizona
No A F on the floor or in the oil
I think I have addressed the hose leaks and it will hold 15# for 30+ min
Today I removed the thermostat to see if I could keep it at operating temp with ram air but same results
it stayed in the -180* for a short time then started climbing to 250*
Time to remove the rad and have it serviced, I have procrastinated long enough!
I think I have addressed the hose leaks and it will hold 15# for 30+ min
Today I removed the thermostat to see if I could keep it at operating temp with ram air but same results
it stayed in the -180* for a short time then started climbing to 250*
Time to remove the rad and have it serviced, I have procrastinated long enough!