coolant leak

[dpain]

Hello
My 2002 Duramax diesel has a slow coolant leak coming from the front of the engine. Any input on over the counter cooling system sealants. I don't have time right now to dig into the front of the engine to find the problem but will soon.
David

[DmaxMaverick]

At the most, try some Cadillac Pills (get at any GM dealership parts counter). The others (like Solder-Seal, Bars leak, etc.) should NOT be considered. You're better off using eggs. It's better to have a little leak than use a temporary repair, such as the sealers. Once that stuff is in, it's always in, and causes serious issues with the system later on. Most of the time, they don't work, anyway. The Cadillac Pills are organic, and easily cleaned out with a good coolant system flush, while the "Solder-Seal" types have metal powder in them, which can remain in the system forever (and isn't good for dynamic seals, like the water pump).

At the least, find the leak. It may be more simple than you think. The water pump has a weep hole. If it's leaking there, the pump seal is leaking, but may also be an indicator or bigger issues (head gasket failure, etc.). Look behind the fan pulley for a short section of 3/8" rubber hose, about 2.5" long. That's the turbo coolant return line, and easy to fix. If you see a bit of scale built up around or under it, then it is leaking.

If it's just a matter of a little time and/or short trips until you can get to repairing it, loosen the coolant reservoir cap to minimize system pressure (and the leaking), and keep it full of coolant. If this causes greater coolant loss via the tank overflow, then you have a combustion gas leak, which will usually cause other failures, like a water pump seal and/or hose connection leaks, caused by the increased/sustained system pressure. If the leak is small and external, with no other systemic issues, the repair can be delayed, but limit the load on the engine to minimize the leakage. If the coolant consumption increases, your options become more limited.

[dpain]

The leak is pretty small and slow but it will need attention shortly.
I'll locate the leak and plan for another project. As soon as I get the transmission back in.
David