Volvo Penta 5.0 GXI-E overheating....please help

[mha7514932]

I have a 2003 Volvo penta engine in my deck boat and it is overheating at idle speed, if rpm are at 2000 or better every thing is fine. We replaced the impeller inside the water pump twice, and the t-stat as well, but the problem keeps happening intermittently. We can put it in neutral and raise the rpm and it cools right down, but I can't imagine the change of temps is good for the engine. A really good suggestion would be welcomed because my boat mechanic is scratching his head. Thanks Mark

 

[aerobat]

Re: Volvo Penta 5.0 GXI-E overheating....please help

i have three ideas :

1) a partially blocked cooling system where enough flow is only reached after rising the rpms, so rising the flow of the pump.

2) a slipping pulley of the raw water pump at idle speed.

3) a strange fault in the gauge which for whatever reason occours only at idle speed.

 

[Lou C]

Re: Volvo Penta 5.0 GXI-E overheating....please help

Volvo has a whole section in their manual on overheat diagnosis, using gauges and clear hoses to troubleshoot where the problem is. You should make sure your mechanic follows this....

 

[MNBrent]

Re: Volvo Penta 5.0 GXI-E overheating....please help

I just ran through a similar problem, but overheated at idle up to 1K RPM and overheat over 2K rpm, but at about 1200-1400rpm, the engine cooled down to ~160 degrees. It was the square block grommet seal between the upper and lower gearcase in the lower unit that wasn't sealing the water inlet pipe. VP part: 3854595.

Are your exhaust manifolds getting hot or do they stay as cool as your engine block. If they start getting hot fast, then that is a sign that you are not pulling enough water in to keep your engine cool.

Also the Volvo Penta overheat diagnosis doc with the clear tube set-up was absolutely the best help I could get, compliments of Don here at iboats.

Good luck.

 

[tcharlie]

Re: Volvo Penta 5.0 GXI-E overheating....please help

I just ran through a similar problem, but overheated at idle up to 1K RPM and overheat over 2K rpm, but at about 1200-1400rpm, the engine cooled down to ~160 degrees. It was the square block grommet seal between the upper and lower gearcase in the lower unit that wasn't sealing the water inlet pipe. VP part: 3854595.

Are your exhaust manifolds getting hot or do they stay as cool as your engine block. If they start getting hot fast, then that is a sign that you are not pulling enough water in to keep your engine cool.

Also the Volvo Penta overheat diagnosis doc with the clear tube set-up was absolutely the best help I could get, compliments of Don here at iboats.

Good luck.

I had similar problems, had neautra system connected to power steering cooling system, and had some errossion at the joint where neutra system was connected taking air. replaced it and now problem is fixed. Looks like you could have this issue due to various reasons and need thorough trouble shooting.