I have been trying to track down an internal coolant leak on my 03 cooper s.I tore in to it to verify that my water pump and gears are good,which they are.When taking off the last plastic air tube that bolts to the supercharger under the water pump,when a little puddle of coolant dripped out when I removed it.The coolant didn't come from the water pump,and I am not sure if there are any coolant passages in the intake manifold or supercharger.I am thinking a crack in the head in a low pressure area due to the fact that it is not chugging water out of the coolant bottle.Or could it still be the head gasket,or something else I am missing?Also is there any kind of sealant needed for re-installing the rear supercharger gear cover? Do I need special tools for removing the head,for the timing chain? I am a ford tech so I have the basic tools available.

 

ok,so I'll answer myself.Removed the head,found .003 warpage.Sent the head to get milled and pressure tested for peace of mind.Looks as though it were leaking between water jacket and timing chain area.Will report later after re-assembly.

 

The 1st Gen cars are noted for leaking thermostat gaskets.
Many threads about this problem.
.003 is not alot of warpage but since you are getting head milled/decked anyway that should solve that possible issue.
Use a OEM head gasket.
The aftermarket gaskets just don't work very well on a MINI.
You will need a cam sprocket holder to torque down cam sprocket nut.
Hope this helps you out some.

 

Thanks Vollgas! I bought a new thermostat and housing just for insurance even though it didn't show signs of leakage.Also bought an oem gasket.Couldn't I torque the cam sprocket bolt by holding the crank pulley!I have done it on toyotas that way,just need an extra set of hands.

 

You could probally do it that way.
Wasn't thinking of that.
I think you'll solve the problem.
What did the oil look like?
Was it foamy or milky in any way?

 

oil was milky,and upon inspection when the head was off I saw coolant trail coming from #9 head bolt area( from torque sequence).Apparently coolant leaked passed the gasket to the head bolt and wicked up the bolt and into the top of the head and down the timing chain area.Didn't look like the previous mechanic took the time to clean things up properly either.So I made all of the surfaces surgically clean and ran some 2000 grit across the resurfaced head and top of the block to remove any sand scratches.I also sprayed some permatex copper sealant onto the gasket before installing it,due to the fact that there was minor pitting around the water jacket in question on the block.Alot of techs don't use the stuff,but I have used it for over 20 years with no problems as well as the tech that showed me had been using this method for 40 years.This has been a learning experience working on the mini,but I hope I can bring my experience and knowledge to this brand and help others resolve their problems and issues with the mini coopers because it truly sucks to have a problem with no answer and a dealer that rips your head off with labor expenses that are absurd and unjustified.Will report back when she's back on the road.

 

Sounds like you are doing a very professional and complete job.
Been useing Permatex for years myself.
Trying to keep compression and oil seperate from each other on BSA, Norton and Trimuph's.
Also worked on all British cars.
Good luck with the job.

 

I'd carefuly look around for the leak....I would hate to reassemble it,just to find it was a crack in the block....
good luck...it sounds like you are pretty handy, and smart to avoid the dealer for heavy mantance work..their high overhead tends to make them uncompeteitive for all but highly specalized tasks....

 

I have done all I can to find any cracks,had the head pressure tested and cleaned the top of the block within an inch of it's life.If there were a crack it would have been in the #9 head bolt to water jacket,and there was nothing there at all.It seems as though the slight warpage in the head made things go bad,or at least was the root cause.Have you seen very many cracked blocks in minis?

 

I have heard of a couple, but they were mostly do to a rod going through the block.
Blocks are pretty sturdy.
I'll bet you got the issue with decking the head.

 

It was the head! HUGE crack from the #9 head bolt hole down the head to the water jacket.

 

Head replaced,thanks to k-huevo for the parts and assistance.2 weeks running and not a drop lost,knock on wood she runs perfect.

 

Isn't that that truth!