Hi Guys,

Hope someone can help me with this.

Just reBuilt a Mk2 Cooper S engine. There seems to be a large quantity of oil entering the cooling system from somewhere and I have run out of ideas as what is happening. First I thought it was a head gasket. Have tried two different gasket in addition to the original one, and re-newed all the studs with comp. one in case the originals had stretched. No luck. There is no water entering the sump at all, just oil entering the cooling system, so I'm convinced its not the head or block face, both of which were machined before re-assembly.

Cylinder compression is good so I don't think its at cracked head either.

Any suggestions gratefully received.

Cheers.

_________________
1967 Cooper S - new front bearings to do.
1965 Cooper S shell - all painted up, ready for fit out.
1969 Cooper S Mk2 - claimed by 2nd. born
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

Sometimes engines will do funny things and you can get oil in water and not water in oil or vise-versa. Obviously if you track the oil system there is the pressure feed side and drain side. For the oil to make it into the radiator in vast quantities i would be focusing on the pressure side.

Pressurising the radiator to about 15psi with a test kit and with the engine off might give you water in the oil to help diagnose the leak. Check the pots, rocker area or crankcase for water or hissing.

Oil in the coolant can take a while to flush out. Is there any chance it has been fixed and its just the remaining oil in the cooling system?

Sorry i cant be of much more help. I just hope its not something serious like a crack or corrosion in the block.

Did you put engine coolant in straight away

There are some pics here that track the oil circuit - http://www.nonlintec.com/sprite/lubrication/

Some times the brass plugs in head face give dramas too

Yes, as you normally would when starting up after a rebuild. Thanks.

_________________
1967 Cooper S - new front bearings to do.
1965 Cooper S shell - all painted up, ready for fit out.
1969 Cooper S Mk2 - claimed by 2nd. born
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

Yes I did consider that. Perhaps I should have got it pressure tested before, but was hoping a fresh head gasket would solve it.

_________________
1967 Cooper S - new front bearings to do.
1965 Cooper S shell - all painted up, ready for fit out.
1969 Cooper S Mk2 - claimed by 2nd. born
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

Thanks mate. Given the qty. of oil involved, I don't believe its due to a crack, The block was fine before re-honing. A pressure test of the cooling system is a good thought.

I appreciate the responses.

Pete

_________________
1967 Cooper S - new front bearings to do.
1965 Cooper S shell - all painted up, ready for fit out.
1969 Cooper S Mk2 - claimed by 2nd. born
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

A engine builder told me a similar scenario they left the coolant out and water only to settle the head gasket for a little bit then put coolant back in

I do this too, and the gasket makers suggest the same. Fill with water for the break in period and then drain and swap to coolant

_________________

Used ordinary water for the past to reinstallation of the head, rather than red coolant. So it does not appear to be the problem.
May try a pressure test on the cooling system next, as GTO suggested.

Thanks again guys.

_________________
1967 Cooper S - new front bearings to do.
1965 Cooper S shell - all painted up, ready for fit out.
1969 Cooper S Mk2 - claimed by 2nd. born
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.