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Water In Oil - HELP

chevyaddict

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Tucson, AZ USA
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1990 Convertible
Well, my worst fears are confirmed - there is definitely water in my oil. Don't you just love it when you pull the drain plug and the milky mess comes out. I put new head gaskets on the car about 20,000 miles ago - at that time the head gasket on driver's side was leaking out the back toward the fire wall - result of electrolysis during those years where they didn't install the right head gaskets. Well, I installed the right ones, and now this.

Here is my question. Yes, I have been losing water mysteriously.... mystery solved. So this is leaking internally. Is there ANY OTHER PLACE water can get in to the oil BESIDES through a head gasket breach? I suppose it technically could from an intake manifold gasket, correct? I guess I'm just trying to assess how severe this situation is.

Another question: I have probably been driving it with mixed oil/water for about 1000 miles. How much damage did I do?

Just discovered this, of course, two days after selling my 68 corvette (because of financial hardship) so least to say, this is a massively huge blow. :mad
 

chevyaddict

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Messages
894
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Tucson, AZ USA
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1990 Convertible
Actually I just read this could be a failure of the oil cooler itself.... has anyone had that happen? I guess if that has happened I would have oil in my coolant too, yes? Also, just an FYI, it has NOT been sucking water from the overflow (despite me putting a new radiator cap on it) which tells me there is some other decent place where vacuum/pressure can escape, correct?
 

DonB

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Chicago
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2019 ZO6 in Elkhart Lake Blue
The aluminum heads are also prone to cracking especially since the engine runs at such high temperatures. I had that happen on my '90 too. Have the heads checked at a machine shop. They can be repaired. Then when you rebuild it install the cooling switch to engage the fans at an earlier temp. Stock, the fans come on at 230* That's awful hot for an Aluminum head on a Cast Iron Block. Corvette Central sells the kit reasonably. It works great. Mine stays at 190-200*.
 

chevyaddict

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Joined
Jun 12, 2002
Messages
894
Location
Tucson, AZ USA
Corvette
1990 Convertible
The aluminum heads are also prone to cracking especially since the engine runs at such high temperatures. I had that happen on my '90 too. Have the heads checked at a machine shop. They can be repaired. Then when you rebuild it install the cooling switch to engage the fans at an earlier temp. Stock, the fans come on at 230* That's awful hot for an Aluminum head on a Cast Iron Block. Corvette Central sells the kit reasonably. It works great. Mine stays at 190-200*.

I have wired my fans to run all the time... living in Tucson with summer heat around 115 degrees you have to do this so the car doesn't normally get above 180 BUT I did overheat it once about a year ago. I also put an oversized aluminum 4 row radiator in it so got the cooling covered. But with the overheating I did (ran out of water because of a hose break), would it take so long for a crack to finally start leaking? I drove the car regularly another six to eight months before mysteriously losing the water.

I need to determine if a compression check can differentiate from a crack in the block/head from a gasket breach. Do you know if it can?
 

hcbph

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Minneapolis, Mn.
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86 Red Convertible
I won't claim to be a mechanic but having done repairs and rebuilds in the past, I'd do a couple tests first. One would be pressurize the cooling system to normal operating pressure and see if it holds pressure or not for an extended period of time. That should hopefully tell you if you have another head gasket issue again or not. It could also indicate if there's a crack in the head around a coolant passage or not. Next would be arrange the cylinders one at a time so the valves are closed on a cylinder and pressurize the cylinder and see if it holds pressure or not.
Another is to run the engine to operating temp and with the radiator cap off see if there are bubbles present in the coolant. Bubbles would be an indication of combustion gasses present in the coolant, an indication of either a blown gasket or cracked head.
I would think between the tests it would give an indication of where the potential leak might be (including which side of the engine) without tearing into the engine initially. Once you have that much, then you should be able to determine where to go next to narrow it down further.
There are places that will test an coolant and oil samples to determine if there are hydrocarbons present in the oil or coolant but I'm not sure that would be as useful at this time nor the cost of having it done.

My thoughts. Good luck.
 
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gmjunkie

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Old Fort NC/Vero Beach FL
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03 Z-51,78 L82 Coupe
I need to determine if a compression check can differentiate from a crack in the block/head from a gasket breach. Do you know if it can?

Dawn..........If the leak is bad enough to put coolant in the oil,You should be able to see it on a spark plug/s if it's a cracked head or bad head gasket!:thumb
If not you can pressurize each cylinder with a air hose attachment to about 150 lbs psi and see which cylinder/s makes it bubble back through the coolant tank!:thumb:thumb

Hope this helps!

The Junk!:D
 

gmjunkie

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PS Checking the oil cooler will be a little harder to detect!:thumb
 

DonB

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Messages
339
Location
Chicago
Corvette
2019 ZO6 in Elkhart Lake Blue
I have wired my fans to run all the time... living in Tucson with summer heat around 115 degrees you have to do this so the car doesn't normally get above 180 BUT I did overheat it once about a year ago. I also put an oversized aluminum 4 row radiator in it so got the cooling covered. But with the overheating I did (ran out of water because of a hose break), would it take so long for a crack to finally start leaking? I drove the car regularly another six to eight months before mysteriously losing the water.

I need to determine if a compression check can differentiate from a crack in the block/head from a gasket breach. Do you know if it can?

It depends on where physically the crack/leak is. Many times the head gasket can leak without affecting cylinder compression. A good way to tell is to run the engine and see if bubbles are coming up into the surge tank. Remove the radiator cap and bring the engine(at idle) up to operating temperature. If there are bubbles coming up(about the size of a pea) consistently, it indicates the engine is pushing cylinder gas into the cooling system via a crack or bad gasket.

In your case I would run a cooling system pressure check to determine where the water is coming from first! Just off the top of my head, I would suspect the cooling runners at the corners of the intake manifold. When I built mine last year the front right runner was nasty at the gasket and the manifold bolt was ceased in there. The corner bolts are very close to the water jacket/runner. I also had a crack at the top center of the head near where it mates to the intake.
Keep me posted. Good Luck.
 
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chevyaddict

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Messages
894
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Tucson, AZ USA
Corvette
1990 Convertible
Thanks guys! I'm gonna pull the plugs first today and see what story they tell. The more I think about it the more I'm remembering some other things... like rough idling (although the car has been running great). Makes me think more and more it might be a cracked head. I've never done a compression check or filled the cylinders with air. I'll run to autozone and rent me a compression tester and also start there. It was a job and a half the last time I replaced the head gaskets... was pretty careful putting it back together because I never wanted to do that job again with the engine in the car... but this is certainly making me think its a crack somewhere. Oiy. Its my driver so this one hits hard at the moment!
 

LLC5

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98 black 6spd convert.
Thanks guys! I'm gonna pull the plugs first today and see what story they tell. The more I think about it the more I'm remembering some other things... like rough idling (although the car has been running great). Makes me think more and more it might be a cracked head. I've never done a compression check or filled the cylinders with air. I'll run to autozone and rent me a compression tester and also start there. It was a job and a half the last time I replaced the head gaskets... was pretty careful putting it back together because I never wanted to do that job again with the engine in the car... but this is certainly making me think its a crack somewhere. Oiy. Its my driver so this one hits hard at the moment!



When you did the head gaskets, did you have the heads resurfaced and pressure checked?

Also, the head gaskets that are being used need to be checked to make sure that they match up perfectly with the cylinder head and block openings BEFORE being installed. Often over looked, but vitally important as part numbers change and are combined.


As Junkie stated, a cylinder leak down should be performed with the radiator cap off and radiator filled to the top of the filler neck while looking for any air bubbles. Each cylinder being tested needs to be on TDC and on the compression stroke. Good luck with it. :)
 

Heyblue

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Aug 8, 2015
Messages
50
Location
Felton, CA
Corvette
1984
Water in the oil is almost always a result of damaged head or head gasket. The mentioned tests might point you to the area i.e. which head. There are two things you posted which may be clues to the cause. Over heated once and recent head gasket replacement. Overheating can usually cause cracked OR warped head/s. Installation of a head gasket that fails usually indicates you may have a warped head or the head was not torqued down properly. If it was a cracked head the first time the gasket would not have solved the problem. You mentioned corrosion on the first head repair, is it possible there was pitting on the block or head that was not fixed?
As posted elsewhere cracked heads can be repaired, also warped heads can be resurfaced, then there is the more costly option of buying new or re-manufactured ones.
I had an old Rambler that had a crack in the crankcase which caused water in the oil, but that is a very very rare.
If we were betting on what you will need to do, my money is on pulling the head/s.
BTW Usually you can tell which cylinder it is, hence which head, by looking at the spark plugs. One or two of them will probably look a lot cleaner, being you are washing them in coolant.;)
 

chevyaddict

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Joined
Jun 12, 2002
Messages
894
Location
Tucson, AZ USA
Corvette
1990 Convertible
Water in the oil is almost always a result of damaged head or head gasket. The mentioned tests might point you to the area i.e. which head. There are two things you posted which may be clues to the cause. Over heated once and recent head gasket replacement. Overheating can usually cause cracked OR warped head/s. Installation of a head gasket that fails usually indicates you may have a warped head or the head was not torqued down properly. If it was a cracked head the first time the gasket would not have solved the problem. You mentioned corrosion on the first head repair, is it possible there was pitting on the block or head that was not fixed?
As posted elsewhere cracked heads can be repaired, also warped heads can be resurfaced, then there is the more costly option of buying new or re-manufactured ones.
I had an old Rambler that had a crack in the crankcase which caused water in the oil, but that is a very very rare.
If we were betting on what you will need to do, my money is on pulling the head/s.
BTW Usually you can tell which cylinder it is, hence which head, by looking at the spark plugs. One or two of them will probably look a lot cleaner, being you are washing them in coolant.;)

The first head gasket replacement was not because of overheating... it just spring a leak because of electrolysis and the factory not putting on the correct type of head gasket to buffer against that. I guess this was a common problem. That leak was out the back toward the firewall. I did not check the heads as there really was no reason to check the heads. When I took them off it was very obvious what had happen. Just a gasket failure. The gasket actually completely eroded against the head/block. BUT, about three - four years later I did have a water leak that was too fast for me to notice and she got up to about 240 degrees.... now, I'm not sure if that is enough overheating to warp/crack. I don't think it is. So..... I will do as some have suggested if/when I get the heads off and have them checked. I haven't had a chance to get the plugs out yet (very unfortunately had to spend yesterday getting my 68 vette ready to be shipped) but will do so today and see where that leads me. I'll post what I find! All I know is this job was HORRENDOUS on this car because there just isn't much room so I'm not looking forward to doing it, yet again!

BTW, I did torque down the heads (and all the bolts) to specifications last time I did the job, as well as was EXTREMELY careful with the install as I didn't want to have to do this again so.... I'm guessing something went wrong instead of just loose bolts. We will see!
 

Heyblue

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Messages
50
Location
Felton, CA
Corvette
1984
Been rethinking what I posted and what others have. Much of the testing relating to cylinders and spark plugs more relates to leaks around the cylinder, not necessarily leaks between water jacket and oil system. Like bubbling in water would indicate a breach between a cylinder and water but would not likely be anything to do with water in oil problem.
On overheating. Sometimes the temp gauge will not tell you the real temp because once you loose water it is hanging in the air and the engine can get very much hotter than the gauge shows. Second, the reason most heads get cracked with a overheat (depending of course just how hot you got it) is people try to add water before the engine cools down, and the cold water hitting a hot head spells trouble.
p.s. Had to pull a head on a 98 Volvo, that is the definition of horrendous. Makes working on my Corvette a walk in the park by comparison.
Good luck
 

LLC5

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Sep 28, 2004
Messages
2,299
Location
Wa.
Corvette
98 black 6spd convert.
Been rethinking what I posted and what others have. Much of the testing relating to cylinders and spark plugs more relates to leaks around the cylinder, not necessarily leaks between water jacket and oil system. Like bubbling in water would indicate a breach between a cylinder and water but would not likely be anything to do with water in oil problem.
On overheating. Sometimes the temp gauge will not tell you the real temp because once you loose water it is hanging in the air and the engine can get very much hotter than the gauge shows. Second, the reason most heads get cracked with a overheat (depending of course just how hot you got it) is people try to add water before the engine cools down, and the cold water hitting a hot head spells trouble.
p.s. Had to pull a head on a 98 Volvo, that is the definition of horrendous. Makes working on my Corvette a walk in the park by comparison.
Good luck



Exactly how many successful cylinder head gasket diagnosis's and repairs do you have under your belt?

A proper cylinder leak down that shows bubbles in a radiator can certainly show a bad head gasket or cracked cylinder head, and yes if the breach is severe enough coolant will indeed make it into the crankcase. Seen it may times.

"The reason most heads get cracked with a overheat is people trying to add water before the engine cools down and the cold water hitting the head spells trouble"? I guarantee you that if you tried to add water to a hot engine, the cold water would never make it to the cylinder head before it blew back in your face. Even if the "cold" water made it to the cylinder head it would be very hot by the time it got there. The most common reason for head gaskets go bad and cylinder heads to crack is from severe overheating. Period.
 

gmjunkie

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Messages
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Old Fort NC/Vero Beach FL
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03 Z-51,78 L82 Coupe
Exactly how many successful cylinder head gasket diagnosis's and repairs do you have under your belt?

A proper cylinder leak down that shows bubbles in a radiator can certainly show a bad head gasket or cracked cylinder head, and yes if the breach is severe enough coolant will indeed make it into the crankcase. Seen it may times.

"The reason most heads get cracked with a overheat is people trying to add water before the engine cools down and the cold water hitting the head spells trouble"? I guarantee you that if you tried to add water to a hot engine, the cold water would never make it to the cylinder head before it blew back in your face. Even if the "cold" water made it to the cylinder head it would be very hot by the time it got there. The most common reason for head gaskets go bad and cylinder heads to crack is from severe overheating. Period.

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