vovlvo penta V8 Coolant Being pushed Out The Overflow....

[sat1425]

hey...hope someone can help

V8 Volvo Penta early Model. Engine runs fine, but when revs reach about 2000 rpms, water begins to come out the over flow tube on top the the heat exchanger. If I back off the throttle, water stops coming out of the overflow tube. Water in heater exchanger does not get very hot...can easily touch when I remove the cap. According to new temperature gauge, motor temp is not getting above 100-110 degrees. I suspect blockage somewhere but do not know enough about coolant flow.

Motor can be viewed here:

Library Slideshow by sat1425 | Photobucket

thanks for any advice.

 

[tpenfield]

Re: vovlvo penta V8 Coolant Being pushed Out The Overflow....

I am thinking that the first place to start would be replacing the cap, as it may be faulty and not holding any pressure.

 

[sat1425]

Re: vovlvo penta V8 Coolant Being pushed Out The Overflow....

That was the first thing I thought of as well. Changed it with new and no change. The overflow tube is about 1/8 inch below radiator cap. There is pressure against the cap but nothing coming out from the seal. All over flow is coming direct from the drain tube.

I drained the heat exchanger to about half full and start the engine......in just a few moment the water was spilling out through the tube. Remove the cap from the exchanger and it was full again. Don't know enough if that supposed to happen, but seem like water is backing up in the heat exchanger and not flowing.

 

[Don S]

Re: vovlvo penta V8 Coolant Being pushed Out The Overflow....

According to new temperature gauge, motor temp is not getting above 100-110 degrees.

Sounds like you have a missing thermostat. Install a new thermostat and see if your problem goes away. If not, then it's time to do a leakdown test on each cylinder with the heat exchanger cap off and see if you get bubbles or the level rises on one of the cylinders.