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MG MGB Technical - Blown Head Gasket?

I will try and condense this story a bit. In Feb. I had pulled the engine and trans to install a new transmission and I used the valuable insight of all o f you here to accomplish that. After I was up and running again I had another problem when one of the bolts used to hold the intake and exhaust manifolds on stripped. I was able to Helli-coil it and again got back on the road. A week later I heard a very tell tell sound of exhaust leak at the manifold again and it was due to irregular shaped after market exhaust headers....so again I changed the gasket and compensated for the irregularity. At the time of getting up and running (yet again) I still heard a small sound of leak...did tests with soap bubbles and a non lit propane torch and was unable to find it. Yesterday morning I was checking the oil and i see the remnants of coolant on the alternator side of the motor appearing from under the head between the third and Fourth cylinders. I wiped it clean, check my coolant level and then go for a 100 mile ride. When I returned, the size of the stain had increased, all coolant was gone and i suspect head gasket. Today i pull the head and the gasket is as pristine as the day it was installed. At this point I will mention this is an aluminum head and i as wondering if there were any thoughts about this. I will answer any and all questions I can... I am worried about putting a new gasket in and experiencing the same problem. I should also mention I had not seen a leak from this side of the engine before any of the other work was done. Any help will be appreciated!!
Peter Murray

Have you checked to make sure the heater valve is not leaking?
Kimberly

A standard B-series engine will leak at this point without the head gasket actually burning through round the cylinders themselves. A smear of Hylomar or any other gasket compound along this edge should clear up this problem on a cast iron head. I imagine it will work on alloy too.

Mike
Mike Standring

I had a heater valve drip down the block and run the line between the head and block. I also first suspected head gasket. Another point to check is the Thermostat housing, it could drip down the front of the head and then run down to that seam. I aslo run an aluminum head, it has never gave any trouble.
Bryan

Peter,
my last 2¢, forgot to mention above. While the head is off it may not hurt to carry it to a machine shop and have them check it to make sure it is perfectly flat. If is not it may not seal off properly. They can surface it if it needs it.
Bryan

Peter-
I have to agree with Bryan. Get the head checked for warpage. If your head is from Pierce, then be aware that they have a reputation for often being warped when they arrive new in the box!
Steve S.

Thank you all for your comments. I did not install the aluminum head, I bought the car with it on.Is there away i can find out the manufacturer? is it stamped on the head somewhere? And lastly, Can you have an aluminum head surfaced?
Peter Murray

Hi Peter,
Another potential cause of water leakage - I had a new aluminium head which was porous. I sent it to someone who treated it with locktite and it has been OK ever since (20 years).
M Wellard

Peter, Aluminum heads can easily be re-surfaced in a short period of time. In N.CA the cost is around $40. RAY
RAY

This thread was discussed between 24/04/2008 and 25/04/2008

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