Coolant disappearing - intake gaskets?
#1
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Car: 1988 Trans AM GTA
Engine: 350 TPI
Transmission: TH700
Axle/Gears: 3.23
Coolant disappearing - intake gaskets?
Hi guys,
I have a 1988 trans am gta with the 350 TPI. I have owned it for four months and it has always had a slight coolant leak. I have maybe added two three pints of coolant during the 300 miles or so I have driven it
There is not really signs of any leaks apart from some tiny puddles on the passenger side of the intake manifold. Do you think this is the intake manifold gasket that is leaking or could it be something else? Car otherwise run fine and doesn't overheat. And no sign of water in the oil or white smoke from the exhaust.
Thanks!
Picture below of the manifold.
I have a 1988 trans am gta with the 350 TPI. I have owned it for four months and it has always had a slight coolant leak. I have maybe added two three pints of coolant during the 300 miles or so I have driven it
There is not really signs of any leaks apart from some tiny puddles on the passenger side of the intake manifold. Do you think this is the intake manifold gasket that is leaking or could it be something else? Car otherwise run fine and doesn't overheat. And no sign of water in the oil or white smoke from the exhaust.
Thanks!
Picture below of the manifold.
#2
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Car: 1986 IROC Z
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Axle/Gears: 3.23 Posi
Re: Coolant disappearing - intake gaskets?
Could be a head gasket or an intake gasket leaking into an intake port. Such a small amount of loss would be tough to track down.
#3
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Re: Coolant disappearing - intake gaskets?
tiny puddles on the passenger side of the intake manifold
Head gaskets rarely leak coolant invisibly, without other FAR MORE SERIOUS consequences. Coolant passages there can leak coolant only 3 ways: into the crankcase, in which case (no pun intended) you'd see your oil turning into grayish powdery gloppy gook; into cylinders (combustion), which the leak going the opposite way (combustion into the coolant) would be obvious; or externally, such as down the side of the block. In NO CASE can they possibly put coolant on top of the manifold. I'd save those for the VERY LAST suspect.
Far more likely, after the problem you already know you have, would be: the head bolts, specifically the row under the exhaust ports (the other 10 would leak into the crankcase and produce the above described coolant-in-the-oil symptom); the water pump (vent hole for the bearings weeping, which the coolant ends up on the inside of the pulley and gets slung everywhere as a fine mist); the heater core or radiator, butt you'd probably smell it, or worse, if it was the HC, or see/smell it from the radiator; or the coolant recovery bottle (cracked).
Get up under the front of the car and look up at the bottom of the lower rad hose. If there's signs of a drip running down the bottom of it, you need a water pump.
Intake gaskets almost never leak from coolant to ports. There's like 4 times as much gasket that it would have to go through horizontally to get there, than to get to the outside world. By the time one gets bad enough to leak into the ports there'd be coolant dripping EVERYWHERE. Kinda like, what you've got.
Based on the concept in my signature, I'd start by quarter-car-washing the motor after soaking it for a bit in spray-can engine degreaser (NOT the "foaming" kind) so that all old dried-up grungy crustified leakage from prior centuries is cleaned up. Then I'd fix the problem(s) I ALREADY KNOW OF, namely intake gaskets, which will be far less unpleasant when you don't have to wallow in the 10,000 years of funk all over everything. Put some thread sealer (NOT RTV) on the 2 center bolts on each side, and wire-brush the bolts real good and run a thread chaser down the 2 bolt holes at each coolant port, and use anti-seize on those. Then, if new intake gaskets didn't completely cure it, and when I could actually see what I'm doing, I'd inspect the radiator and cap and bottom of the coolant bottle, then if all that is OK look at the WP.
Save head gaskets for after doing all that. Save alien abduction, and their clandestine consumption of your particular car's coolant as a powerful aphrodisiac intoxicant, for even later.
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#4
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Car: 1988 Trans AM GTA
Engine: 350 TPI
Transmission: TH700
Axle/Gears: 3.23
Re: Coolant disappearing - intake gaskets?
@sofakingdom Huuge thanks for this and for the weekend plans, lol. I needed to hear this. I actually allready have the intake gasket set from Fel Pro waiting on the shelf.
The car is my project car so I'll see when I get the time to fix it, two small kids at home so time is a luxury. But I will return and tell you how it goes.
The car is my project car so I'll see when I get the time to fix it, two small kids at home so time is a luxury. But I will return and tell you how it goes.
#5
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Re: Coolant disappearing - intake gaskets?
Pull the heads & see if u can locate anarea where the gasket has failed. At this point, u could choose to have the heads planed especially if u have a lot of miles on the engine.
I replaced the head gaskets on my 1972 Buick GS 350 once & when leak appear 8 year later, I had the heads planed & rebuilt.
Before u reinstall heads, be sure all surfaces are super cleaned then reinstall with new ARP head bolts, which I did. I also used a thread chaser to clean the threads before installing the head bolts.
Goo luck
I replaced the head gaskets on my 1972 Buick GS 350 once & when leak appear 8 year later, I had the heads planed & rebuilt.
Before u reinstall heads, be sure all surfaces are super cleaned then reinstall with new ARP head bolts, which I did. I also used a thread chaser to clean the threads before installing the head bolts.
Goo luck
#6
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Re: Coolant disappearing - intake gaskets?
Did you verify the hose that comes out of the throttle bottle area is not leaking, that leak appears to be in the general area. lots of hoses in that area in fact. I'd pressurize the cooling system and look for leaks. easiest way to find it.
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#7
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Car: 89' Firebird / 87' Formula
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Re: Coolant disappearing - intake gaskets?
"tiny puddles on the passenger side of the intake manifold"
Where you see coolant, there is a leak!!!
Thats a pretty big job though unfortunately.
Where you see coolant, there is a leak!!!
Thats a pretty big job though unfortunately.
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#8
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Re: Coolant disappearing - intake gaskets?
It's not the heads or head gaskets. Head gaskets can't leak up on top of the intake manifold.
Don't worry about head gaskets or pay any attention to anyone who talks about them.
Blue's idea about the hoses is worth checking out though. I kind of assumed you had already looked at those and not found a problem. Butt we all know what happens when you break the word "assume" down into its 3 basic component parts...
Don't worry about head gaskets or pay any attention to anyone who talks about them.
Blue's idea about the hoses is worth checking out though. I kind of assumed you had already looked at those and not found a problem. Butt we all know what happens when you break the word "assume" down into its 3 basic component parts...
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