Hi all,
Having an issue with my Mercruiser 5.7 spraying coolant from the spring-loaded heat exchanger cap. At idle, the engine will come up to temp nicely with no issues; however, as soon as I give it some throttle and put a load on it, coolant sprays out from under the cap. If I immediately come off the throttle, it stops. I replaced the cap, but the problem still happens.
While this is all happening, I've noticed there is little (if any) change in the expansion tank level...engine hot or cold, the coolant level never changes. There is a bubble in the line from the heat exchanger to the expansion tank and I've noticed that as the engine gets warmer and comes under load, the bubble slowly works it's way towards the heat exchanger. When the bubble reaches the heat exchanger, coolant sprays out from the cap...when I come off the throttle, the bubble reappears and sits about midway between the heat exchanger and the expansion tank.
Last night I was working on the boat and I removed the expansion tank to get access to another pump behind it, and as I lifted the expansion tank over the heat exchanger, the bubble moved down to the heat exchanger cap and coolant poured out from under the cap. This was with the engine off and completely cool.
Any thoughts? Let me know if more info. is needed.
Having an issue with my Mercruiser 5.7 spraying coolant from the spring-loaded heat exchanger cap. At idle, the engine will come up to temp nicely with no issues; however, as soon as I give it some throttle and put a load on it, coolant sprays out from under the cap. If I immediately come off the throttle, it stops. I replaced the cap, but the problem still happens.
While this is all happening, I've noticed there is little (if any) change in the expansion tank level...engine hot or cold, the coolant level never changes. There is a bubble in the line from the heat exchanger to the expansion tank and I've noticed that as the engine gets warmer and comes under load, the bubble slowly works it's way towards the heat exchanger. When the bubble reaches the heat exchanger, coolant sprays out from the cap...when I come off the throttle, the bubble reappears and sits about midway between the heat exchanger and the expansion tank.
Last night I was working on the boat and I removed the expansion tank to get access to another pump behind it, and as I lifted the expansion tank over the heat exchanger, the bubble moved down to the heat exchanger cap and coolant poured out from under the cap. This was with the engine off and completely cool.
Any thoughts? Let me know if more info. is needed.