Overheating 4.3 Volvo SX-A outdrive

[RKunka]

Hello
2017 19 ft Campion with 4.3l v6 SX-A outdrive, engine running hot , sea water impeller not pulling water from bottom of outdrive to transom hose with boat in lake , impeller cover hot, I’m not using ear muffs. However if I disconnect transom hose and place in bucket of water it pulls good ,impeller cover is cool and engine maintains 170-175F. Checked for blockage from cooling water pick up and plastic transom hose bib non found. Any assistance is greatly appreciated.

 

[alk]

Probably doesn’t help you any, but after years of issues getting my Mercruiser to draw water through the drive, I finally gave up and put a transom scoop on, and a drive shower. One of the best upgrades I’ve ever done.

It would seem that there must be an air leak, above the waterline, that is preventing the impeller from drawing water through the drive. Absent a clog, I can’t imagine what else it could be ?

 

[ddurand]

You could try to put some clear hose inline with the intake hose from outdrive to raw water pump. Look for air bubbles.

Then take the output hose from raw water pump and point it into a 5 gallon bucket. Time how long it takes to fill up the bucket with the intake hose in another bucket of water vs on the outdrive with boat in the water.

Why is the impeller getting hot? Is the intake hose also hot. You probably have an engine oil cooler or PS cooler inline with the intake hose.