Mercruiser Plastic Water Pump Pulley Water in Cylinders

[sightsearok]

e just had the hub on the PLASTIC pulley for the raw water pump crack and break. This is on a 1997 7.4L Mercruiser 454 Mag Bravo Three. The belt jumped off, the engine overheated, and now there is water in the cylinders, but none in the oil. When we pulled the pump off, the impeller looks slightly worn, but is intact. It will be tomorrow before we can get a compression check done. We really don't want to replace the pulley with another plastic one and we're not certain how to proceed if the compression check is ok. Has this happened to anyone else???? Kathy

 

[12Footer]

Re: Mercruiser Plastic Water Pump Pulley Water in Cylinders

I agree, do the compression test first. Chances are good it has a blown head gasket, but there is also a small possability that the block has cracked, so even after head gasket replacemnt, do another test for commpression. If it has good comp, then replace the water pump pulley. They do make metal pulleys,and entire water pump can be upgraded on those engines. But your plan of attack sounds like the best one at this point.