oil in cooling system

[johnea]

Hi all,

One day I found the antifreeze solution contaminated with engine oil on my BN6. I thought, a clear indication for headgasket trouble. I replaced the gasket, cleaned and flushed the cooling system, but the oil found a way back into the radiator. Then I've fitted a reconditioned head and again a new gasket, but the oil keeps coming back!
The inside of the valve cover however is clean, non of the white sludge that would indicate that coolingwater would get into the engine.
I'd greatly appreciate any advice on this one.
John

 

[Dave Russell]

Hi John,
There are not many places where oil can get into the cooling system. The most common would be the rocker arm feed passage to the water jacket via a leaking head gasket. It appears that you are sure that this is not the case?

A rare but possible leak could be in one of the internal oil passages. It's a long shot but Moss has a kit to correct this problem. See here:
https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=60214&SortOrder=1
Be sure to click on the instruction sheet also. It will stop a leak in the internal rocker arm feed & or a leak in the main oil gallery.

I sincerely hope that this is NOT the problem. It would require a considerable amount of precise work to install the repair kit.

This may be worth investigating? I hope someone else will have an "easier" idea.

Best to you,
D

 

[johnea]

Thanks Dave,

Maybe it's worth checking the rocker oilfeed/headgasket area again before considering fitting one of those oilway repair kits, wich I think is best left to a machine shop.
Is there any member out there who has ever fitted one?

John

 

[Bugeye58]

Thanks Dave,

Is there any member out there who has ever fitted one?

John

John, I've never done one on a Healey block, but I've sleeved oilways on other makes. I've done mine on a Bridgeport, drill the hole slightly undersize, and use an appropriate reamer for the final fitting. A smooth finish on the final bore size insures a good fit, and the best surface for the Loctite to adhere to.
I agree, unless you have a mill, and feel comfortable using it for this, it's best left to a machine shop that you trust. There's a very small margin for error.
Jeff

 

[why]

What is the downside to oil in the coolant, as long as it is just a bit each day, occasionally top up the oil and drain and refill coolant, sounds a lot easier than all this other stuff--especially if it is not a head gasket problem:"a difference that makes no difference is no difference"
Jay Glass

 

[vette]

Hi Why, if you want to drive it very much, how do you know when a difference that is no difference becomes a "BIG" difference. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif
I believe the contamination would have a significant negative influence on the cooling system.

 

[Dave Russell]

What is the downside to oil in the coolant, as long as it is just a bit each day,
Jay Glass

Not sure how much problem a little oil in the coolant would be. On the other hand, how much problem would coolant in the oil system be?

When the engine is shut down the pressure in the cooling system stays up long after the oil pressure is gone.
D

 

[johnea]

Hi all,
Dave is right about that. The pressure in the hot cooling system could force coolant into the oilway, plus that oil in the cooling system adheres to the inside of the radiator reducing the transfer of the heat, acting as an insulator.
Not good!

 

[Bugeye58]

Not good for the hoses and seals, either.
Jeff

 

[why]

Sound like an awful lot of hypothetical, other than getting water in oil which can of course be catastrophic, but so far that has not been mentioned. Hoses, seals, heat transfer for just a bit of oil in coolant?

 

[Bugeye58]

Sound like an awful lot of hypothetical, other than getting water in oil which can of course be catastrophic, but so far that has not been mentioned.

Yes it has, twice. Once by Dave Russell:

"Not sure how much problem a little oil in the coolant would be. On the other hand, how much problem would coolant in the oil system be?

When the engine is shut down the pressure in the cooling system stays up long after the oil pressure is gone."


And again by Johnea:

"Dave is right about that. The pressure in the hot cooling system could force coolant into the oilway"

Jeff

 

[johnea]

Hi Why,
Oil obviously does'nt mix with water/coolant, so it accumulates in the top radiator tank like thick whipped cream like sludge.

John