expected raw water flow rate on e34-2 / m25xp ?

[phildogginit]

Does anyone know what the raw water flow rate should be on m25xp? (with oberdorfer pump)?

Has anyone measured it (at different rpms?)

My engine is running on the hot side and I'm troubleshooting.

 

[Christian Williams]

I'd say that if you put the outflow hose in a bucket, and the impeller is in good shape, then the flow is what it is. I think forum members have concluded that although other brands of pump have higher outputs, the Oberdorfer works well enough and its rate is not an issue.

More likely the overheating issue is the stuff downstream of the pump, notably the heat exchanger. They need to be serviced every few years result of mineral buildup. Lots of reports on how to do that yourself.

 

[Bolo]

I agree with Christian. I this year I changed from a Sherwood to a Oberdorfer pump on my m25xp and if anything the flow is better and I have no over heating problems. I too would check the heat exchanger.

 

[footrope]

Inspect the impeller, if you haven't already, as part of your troubleshooting.

 

[GrandpaSteve]

My Oberdorfer self primes anti-freeze from a bucket, and pumps 3 gallons in around a minute. Never really timed it though.

 

[Teranodon]

Raw water filter could be clogged.

 

[EGregerson]

If the impeller and heat exchanger are ok; check the raw water intake hose. If it's the original (1987 - 2021 let's see....) , it could be collapsing internally. disconnect raw water hose at sea cock; run (known good) hose to impeller pump; check flow.