Hello
I have ann overheating problem on a 5.7 gxi-e engine. It has 250 hr approx. Yr 2003 - row water cooled. Boat has been in fresh water until last season.
Looks like when going over 2,000 rpm the engine quickly overheats. I had the gaude and the alarm going on. Looks almost independent from boat speed but related to engine rpm.when tested on the dock there is no overheating.
At the beginning changed raw water pump impeller and thermostat. Still overheats.
Per vp overheating diagnostic connected clear hoses and gauges to raw water pump.tested the boat stationary on the dock. Found low depression value (10 "Hg instead of 19) and low pressure (7 psi instead of 10). No trace of air in the inlet or outfeed.
According to vp this leads to issue with the raw water pump.
Impeller was replaced and I cannot see how it could slip.any checks on the pump housing i shall perform?
I have a plan: run the test with boat on the run ( as requested by vp...) and then repeat it on the other engine (I have twins...) to validate the measure. If the numbers are still the same I am p panning to swap the water pump to see how it goes.
Do you think I shall swap the entire water pump or only the impeller+impeller housing?
Does anyone experienced issues with original VP impellers?
Thanks in advance fo all your help
GP
328 Vista
I have ann overheating problem on a 5.7 gxi-e engine. It has 250 hr approx. Yr 2003 - row water cooled. Boat has been in fresh water until last season.
Looks like when going over 2,000 rpm the engine quickly overheats. I had the gaude and the alarm going on. Looks almost independent from boat speed but related to engine rpm.when tested on the dock there is no overheating.
At the beginning changed raw water pump impeller and thermostat. Still overheats.
Per vp overheating diagnostic connected clear hoses and gauges to raw water pump.tested the boat stationary on the dock. Found low depression value (10 "Hg instead of 19) and low pressure (7 psi instead of 10). No trace of air in the inlet or outfeed.
According to vp this leads to issue with the raw water pump.
Impeller was replaced and I cannot see how it could slip.any checks on the pump housing i shall perform?
I have a plan: run the test with boat on the run ( as requested by vp...) and then repeat it on the other engine (I have twins...) to validate the measure. If the numbers are still the same I am p panning to swap the water pump to see how it goes.
Do you think I shall swap the entire water pump or only the impeller+impeller housing?
Does anyone experienced issues with original VP impellers?
Thanks in advance fo all your help
GP
328 Vista