Head Gasket leak repair
Had been losing a lot of coolant on BMW 320i 1981 and also see traces of coolant on oil cap. NO steam from the tail pipe. Occasionally starts running a bit rough. My mechanic threw in some GM pellets which seem to have sealed the leak as there is only a minimal loss of coolant now. He said it was a temporary remedy. HOwever, I do see a little chocolate type of residue on the oil cap after I drive. Mechanic said it was likely the residue of coolant still remaining in the oil. However, dipstick doesn't show any chocolaty stuff.
Want to avoid replacing the head gasket as the car is old ( but in good condition) and I dont drive that much. Any thoughts on repairing the head gasket leak permanently or may be for a year or so? Any one used K@W nano technology Head gasket and block repair? Also, should I replace the oil before using the K@W repair? Directions do ask for a complete drainage of antifreeze. Thanks in advance for your prompt response.