A few days ago i posted up https://honda-tech.com/zerothread?id=333094, a thread about a headgasket we believe going bad on my friends car. Today we put his car up on jacks and i inspected the back of the block and i noticed coolant residue which looks like is coming from either the water pump or the coolant tube that connects from the thermostat housing to the water pump. Also, i see a slight bit of residue on the opposite side of the block. When parked, the car shows no leaking, it does not leak enough to actually form a puddle while parked (car is garage kept). So my assumption is it leaks only while running, but while letting idle we cant see the leak. Could this be a possibility of why he keeps dumping coolant into his reservoir? I do see the tiny bubbles in the coolant when the car is at idle as well as oil in the coolant however, so im about 99% sure its the headgasket. I wonder if his water pump seal is going bad as well? Has anyone had problems with ARP headstuds backing out at all? Before the head is pulled, i recommended him to check the torque on the studs...

 

I bet its the water pump. Most of them leak the most while sitting and not running, so it's probably seeping.

 

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