possibly oil in coolant
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
possibly oil in coolant
I may be getting engine oil in my radiator but I'm not getting coolant in my oil in my '73 SB auto, a/c car.
At first I thought it might be a head gasket but now I'm thinking it isn't. I did an exhaust gas test for the presence of exhause gas in the radiator and it came back negative. The plugs look o.k. I don't think a compression test will help and I can't do a proper leak down test on each cylinder because I don't have the tool.
What are the chances the oil cooler lines within the radiator are leaking the oil into the coolant portion of the radiator end caps?
I'm almost ready to replace the radiator to solve the problem but they are so expensive and such a pain in the a** to install that I would kick my car in the fender if it didn't solve the problem.
At first I thought it might be a head gasket but now I'm thinking it isn't. I did an exhaust gas test for the presence of exhause gas in the radiator and it came back negative. The plugs look o.k. I don't think a compression test will help and I can't do a proper leak down test on each cylinder because I don't have the tool.
What are the chances the oil cooler lines within the radiator are leaking the oil into the coolant portion of the radiator end caps?
I'm almost ready to replace the radiator to solve the problem but they are so expensive and such a pain in the a** to install that I would kick my car in the fender if it didn't solve the problem.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
I recently purchased the car in Nov and drained, flushed and added 50/50 to be sure it was ready for the Michigan winter. The pan the old coolant was drained into, when emptied, was coated with "oil". The "scum" on the surface of the new coolant in the radiator looks like oil as well when wicked out with a rag.
The car is under wraps in the garage until spring so I don't have a chance to drive it at all. It starts, idles and runs well and does not overheat at all. No coolant or oil leaks. Here is a pic of the pan. Sure looks like oil.
Last edited by Bobz08C6; Jan 9, 2009 at 05:41 PM. Reason: Add photo
Drifting
Joined: May 2003
Posts: 1,634
Likes: 2
From: Melbourne, Victoria, Australia, the World
Heres a possible "Worst Case Scenario"
I had an engine which had engine oil in the cooling system. I had the heads checked out, they were fine. Head gaskets were fine. I ended up stripping the motor back to a bare block and putting kero in where the water should be, blocking off ports and such. I used kero because it is "thinner" than water and will dissolve any oil which got in it's way.
The first side was fine so I drained it and rotated the block to bring the other bank up level and filled it with Kero. After leaving it overnight there was a few drops on the catch paper I had put underneath.
What it was was a porosity between the cooling system and the oil gallery. I could see the track of the kero from near a cam bearing.
Oil under pressure could get to the water but water stayed out of the oil.
I replaced the block and had a great doorstop for the garage door.
I do hope this not your problem.
I had an engine which had engine oil in the cooling system. I had the heads checked out, they were fine. Head gaskets were fine. I ended up stripping the motor back to a bare block and putting kero in where the water should be, blocking off ports and such. I used kero because it is "thinner" than water and will dissolve any oil which got in it's way.
The first side was fine so I drained it and rotated the block to bring the other bank up level and filled it with Kero. After leaving it overnight there was a few drops on the catch paper I had put underneath.
What it was was a porosity between the cooling system and the oil gallery. I could see the track of the kero from near a cam bearing.
Oil under pressure could get to the water but water stayed out of the oil.
I replaced the block and had a great doorstop for the garage door.
I do hope this not your problem.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
Thanks for the input RHD. I hope you are wrong. If not I would then replace the engine with a ZZ4. The Vette is a '73 with the original engine so it probably isn't porosity but could be similar with a crack instead of porosity. The engine was rebuilt with some performance characteristics 1,170 miles ago before I owned the car. I have only put 3 miles on the car before it went in the garage for the winter.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Since this car has an automatic trans ... it has a trans cooler integrated into passenger side OE rad tank. You'd better check real close if there's a trans fluid leak into rad or vice versa. Lemme warn you ... check it ASAP ... because if you also have coolant leak into auto trans ... it will quickly wreck the trans ... the friction plates are designed to run in a petro-based bath (trans fluid) ... the coolant will dissolve the water-based glue that adheres the friction material to the friction plates ... it'll shuck the friction right off of the plates ... and only a few spoonfuls of water/coolant will wreck it ... quick too.
Racer
Joined: Feb 2008
Posts: 497
Likes: 0
From: Streator Illinois
Any chance you could contact the previous owner to find out if he noticed the problem (I'm betting he did) and what, if anything, he did to try to find the cause? Just a thought to keep you from covering the same ground.
Terry
Terry
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Well, looks like you definately got oil from somewhere. The tranny cooler is a possibilty, bypass it and flush the cooling system with GM system flush and see where ya are. Also pull the tranny pan and look in there, hopefully no coolant.
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Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
Thanks for all your help guys. Pretty scary stuff. I'm highly confident it's oil and not tranny fluid. I can see cooler lines attached to the right side rad end cap. I just hate to replace the rad only to find out it's an internal engine problem but I don't know how to diagnose the issue to be sure.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
That's actually not a bad idea. I went out and smelled the tranny dip stick and then the residue on the sides of the container. It doesn't smell like the tranny fluid and the tranny fluid on the dip stick is clear and red.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
I'm also going to disconnect and plug the oil cooling lines that connect to the radiator side tank and do an air pressure decay test on the oil cooling part of the radiator. If there is no pressure decay there is no leak.