At wits end with this motor.

[Okieboater1590]

Ok guys need some guidance here.

I have a 2004 Volvo penta gi-d in a crownline bowrider. I have been experiencing some overheating issues.

This is the sequence of events beginning last Tuesday.

1. Unwinterized boat (garden hose to inlet/no muffs)
2. Changed lower unit gear oil
3. Changed engine oil/filter

4. Boat ran a little warm so I replaced impeller.
5. Boat still ran warm and reached 195 degrees.
Checked all connections and assumed raw water
pump was bad.

6. Purchased rebuild kit and removed water pump.
7. Bearing was water damaged. Followed directions and rebuilt water pump and reinstalled.

During installation belt tensioner broke. Had to drive 6 hours to find part. Plano marine in Longview was only place that would overnight it. Thanks owe them a hi five.

Saturday.

8. Put boat on water. Within 5 min boat was overheating and alarm sounding. Immediately shut off engine. Took a few minute and my first admitted mess up. I had the hoses reversed on the water pump. Switched them and fired up boat. Immediately down to 150 degrees. GREAT day on the water. Boat ran better than ever before. Spent about 10 hours on water with wife no issues.

Sunday morning.

9. Unloaded boat in water. Immediate overheat with alarm. Checked all connections. Everything looked the same as I said boat ran immaculate the day before. I pulled the thermostat and it was stuck in the top of the housing and not down on the rim. I used some rtv and attempted to run the boat with no thermo to narrow down my problem with no avail. Boat still overheated.

10. Pulled boat out of water. NO WATER is being sucked in by raw water pump. I can blow air with compressor and see bubbles in lake at the lower unit.

Today.

I removed the lower unit and checked for any obstructions in water inlet from lower unit. I am able to blow air both directions from inside engine compartment and from lower unit back up. I also checked impeller again and it looks new still.

After reading and reading and more reading I've seen the help you guys offer and am lost.

I am afraid my cost searching and rebuilding the water pump was a bad idea and should have just replaced OEM.

Any help would be greatly appreciated.

 

[dypcdiver]

Quite simple I think!! The thermostat should be up in the top of the housing and be held in place with an "O" ring. Clean the stat housing internally and you will see the groove for the stat and the "O" ring. Secondly whilst running the boat with the pump hoses reversed you may very well have cooked the impeller, check that too. I know you say you have checked it but make sure the vanes are still flexible.

 

[Scott Danforth]

boat motors are not like car motors in their plumbing. the thermostat is required to regulate the water and how it is distributed within the motor (hence the multiple hoses coming off the T-stat housing)

dont run without a T-stat

Also, agree with dypcdiver, the T-stat needs to be located correctly within the housing.

I agree, running with the hoses backwards probably took out the impeller.

 

[bruceb58]

Impeller is toast. Replace it.

 

[Okieboater1590]

Ok guys thanks again for the help.

Replaced the impeller and still had the issue.

So I replaced the water pump and tstat. Put it on muffs and bam it warmed up and stayed at 150 degrees.

Noticed a water leak in the two rubber hoses on the exhaust elbows on both sides. I am assuming this is from the overheating. Ordered news hoses and they are on the way.

I took the boat out for a test run and it ran good. Could definitely tell the exhaust leak was an issue. I'm guessing this is the only issue now. Boat sputtered a small bit.