Looks like I have developed a leaky freeze plug at the rear, passenger side of the head (most glad to see the number 56, not 53, on the side of the engine!!).

While it looks miserable to replace, I think I have a handle on it, but can someone please explain this: With the cab heat (temp. control) turned all the way down, the plug doesn't seem to leak much if at all, and I can even turn the heat up to roughly half-way without much if any leak. But with the heat all the way up there's a tiny little stream that shoots straigth back to the firewall. I don't see how there could be that much difference in coolant pressure in the head between the two scenarios, unless maybe there's something wrong?

Question: the heater line that leads into the head (as opposed the the one that leads to the water pump) - is that the return line from the heater core or the supply line?

TIA.

CD

 

Does anyone know what size that freeze plug is? I saw some freeze plug install/removal kits on ebay that look like they'd make the job easier (something like $25), but the plug on my motor looks smaller than the kit accommodates.

 

Sorry nobody has responded. Not sure of the size, but, there is allot of plumbing over there with the heat exchanger, heater core lines, and all. Are you absolutely sure it is the freeze plug? I agree, your problem does not make much sense to me either. Good luck, Kevin

 

Freeze plug would leak all the time once it got hot, would it not? Pressure behind the plug remains aprox the same so leak would not be related to temp selection. The heater flow would change, sounds like heater related to me. Not an expert but thats where I would start looking. Good luck.

 

It's coming from the freeze plug. I can see it.

CD