94 LT1 drinking antifreeze
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From: Sitting in his Nowhere land Hanover Pa
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94 LT1 drinking antifreeze
on my 94 LT1 I replaced the intake gasket sometime back because it was leaking oil on the front and back. but now every so often the coolant level gets low. its not in the oil. so it must be going though the exhaust. when I put the bolts back in on the intake I never used the Teflon on the bolt threads. so you think that would be my problem. if so what bolts go into a blind hole in the head and what ones go into a coolant passage.
would it be best to drain the coolant a little and back one bolt at a time and put on the liquid Teflon on each bolt
would it be best to drain the coolant a little and back one bolt at a time and put on the liquid Teflon on each bolt
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
No coolant passages between the heads and the intake...
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
For there not to be any leaks on the floor, it's a head gasket or cracked cylinder head. However, C4s seem to have a knack for hiding leaks. Therefore I'd check around the waterpump and at the weephole as well as both sides of the radidator since the side tanks like to crack. Next I'd check the passenger side carpet. If it's wet, the heater core has failed.
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Joined: Oct 2010
Posts: 81
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From: Southwest Ohio
I had a similar issue, it was the water pump leaking onto the block, never dripped. I saw some splatter on the hood. The heat of the motor kept it from dripping. Pulled the pump and cleaned the old gasket off reinstalled, took care of it.
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Do you smell coolant at all?
Run the engine to temp and with a good flash light look for leaking coolant.
The WP weephole drops directly onto the serpentine belt, so it will spray around.
The throttle body hoses like to leak after being disturbed.
Check plastic tank on the radiator. You can inspect it though an opening.
If you're leaking, chances are that it is doing so when the system is pressured up. This means that the engine and bay are hot and the coolant may be evaporating before it reaches the ground. But you would definitely smell antifreeze.
Then there is the headgaskets. Though there may be no evidence of coolant going into the cylinders, perhaps leaking from a water jacket to the outside of the head? Is there eveidence of moisture where the head meets the block?
Run the engine to temp and with a good flash light look for leaking coolant.
The WP weephole drops directly onto the serpentine belt, so it will spray around.
The throttle body hoses like to leak after being disturbed.
Check plastic tank on the radiator. You can inspect it though an opening.
If you're leaking, chances are that it is doing so when the system is pressured up. This means that the engine and bay are hot and the coolant may be evaporating before it reaches the ground. But you would definitely smell antifreeze.
Then there is the headgaskets. Though there may be no evidence of coolant going into the cylinders, perhaps leaking from a water jacket to the outside of the head? Is there eveidence of moisture where the head meets the block?
Safety Car
Joined: Apr 2011
Posts: 3,660
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I'd do the simple stuff first...monitor and log how much, how often. It might just appear to be loosing coolant when its actually trying to find its balance between the hot/cold cycles. That can push excess out to the overflow tank, then partially draw it back. This can take several cycles or more to get the correct balance in the system. I used to believe that the rad had to be full..no voids and air spaces. Thats not true. When mine is hot and its full to the filler neck, that same liquid amount will go down to 1" below the neck once its stone cold. I would try to add water/coolant and only get 1/2 cup in before it would overflow..
Also check the cap. I recently had a scare with vanishing coolant. Could not find a leak, could not prove that a head gasket was the source. Finally heard a whispering after shut down and found that the cap was allowing coolant to escape to the recovery bottle wayyyyy easrly...and that was overfilling the tank and letting it vanish. That was caused by the spring in the cap getting soft. The rubber seal was intact, no tears or cuts. Just a weak spring in the cap. 16 lb cap ended up being a 6 lb cap...
Also check the cap. I recently had a scare with vanishing coolant. Could not find a leak, could not prove that a head gasket was the source. Finally heard a whispering after shut down and found that the cap was allowing coolant to escape to the recovery bottle wayyyyy easrly...and that was overfilling the tank and letting it vanish. That was caused by the spring in the cap getting soft. The rubber seal was intact, no tears or cuts. Just a weak spring in the cap. 16 lb cap ended up being a 6 lb cap...
Army Hoist Operator
Joined: Feb 2009
Posts: 836
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From: OK
You should also check the steam pipe on the back of the heads. See the black dots on the front of the heads in 96GS#007's picture? There are holes on the back of the heads in the same place where a little pipe is bolted with banjo fittings. The seals are notorious for leaking. Mine are leaking enough to vent steam and a little coolant when hot but not enough to pool on the floor. They're a bear to get to.
For a good look, see
http://ls1tech.com/forums/attachment...dvice-egr1.jpg
You'll see the banjo fitting under the EGR valve on the left head and just below the letter "o" in shbox.
For a good look, see
http://ls1tech.com/forums/attachment...dvice-egr1.jpg
You'll see the banjo fitting under the EGR valve on the left head and just below the letter "o" in shbox.