Engine cooling issue Volvo Penta 5.0GXI-D

[NotToShabby]

Hi everyone,

I just recently bought a 2003 ebbtide with a 5.0GXI-D motor with SX drive. Only has 60 hrs on it. I replaced the water impeller. Ran it a week ago before changing impeller, ran fine until I went over 3500 rpm. Received engine alarm when I was running about 4-4500 rpm then gradually backed Down to about 2000. As soon as I slowed down temps rised and engine alarm started to beep. Temp got to 180. While I was cruising around the lake at 3500 rpm temps were about 170(what it normally runs at, is that high?). I took it yesterday after the impeller change and ran good all day until I opened it up to about 4500 rpm for a short distance then slowed down towards the no wake zone. Temps climbed up again little over 180 degrees alarm went off. First boat and don't know what it could be. Thermostat? Water tube inside the drive? Grommet? I will be grateful for any advice to figure this out.

FYI- only been in fresh water. I also tried locating someone with same issue on this forum and could not find anything.

 

[jackd1023]

Was the old impeller in pieces? Could be any number of things, have you checked oil? Is it over filled? Compression check? Checked plugs? Was it overheating before impeller change?

 

[Scott Danforth]

pull the drive, replace the water inlet fitting (the one that the hose connects to)

while you have the drive off, replace the bellows and backflush the lines from the raw water pump to the outdrive.

on another note. a boat that only got 4 hours of use per year for the past 15 years (60 hours) will need a lot of maintenance from just sitting.

boat maintenance is a calendar event not an hour of use event.

 

[tlewis1]

Agree with Scott...remove the drive and replace the inlet water seal. Make sure to flush any broken bits of the old impeller out of there as well.

 

[rhrose]

Did it cool down shortly after slowing down to 2000rpm for a minute or two? If it's sporadic at different speeds it could be the water inlet seal, hose between outdrive and transom or nipple on other side (as the boat trims up moving through the water, air could be getting sucked in whenever, whatever part has failed, cracked, seal broken.) Sometimes at fast enough speeds or if trimmed right it's just pushing enough water past that air point or temporarily binded component in a cracked hose/ fitting enough to get water to impeller.

I have a somewhat related question below that I started on a different thread, but no luck with answer yet. Would greatly appreciate anyone's thoughts. Thanks Rob

Replaced complete driveshaft / u-joint assembly on a Volvo DP-SM outdrive. Put on the water, ran great except for overheating at midrange rpms. Figured we must have forgot to tighten the plastic nipple nut and unit was sucking air when out of water. Pulled outdrive back off and yeah it was just hand tight. Tightened nut until saw threaded plastic nipple coming through (just started through nut - how far should it be). It was getting very tight and almost appeared to start stripping. At a glance looked like square portion on back side of housing would seat the way it was lined up. Put everything back together and there is still water leaking from the back of the housing (when on water muffs). Hard to tell but I guess it still isn't seated properly. I'm positive is more than tight enough and sealed between the housing and outdrive. My question is what is the purpose of the drain hole on the plastic nipple on the pivot housing the outdrive mounts to(even referenced in manual it should point down)? If I can dab some adhesive/sealant from the port on the back of the drive (4 bolts holding plate - can see hole with inspection scope) using a long screw driver. The nipple is only a couple years old, hose clamp tight on the back side, no visible cracks inside and Im sure it's sealed on the inside, so if I could seal the drain hole, there shouldn't be a way for water/air to escape??? What is the drain hole in middle bottom of plastic nipple purpose? Just really don't want to have to pull drive again, gimbal came out on shaft last pull and this last install on new bearing, we had a real tough time getting outdrive on - new shaft / bearing super tight. Thanks.

 

[NotToShabby]

My mechanic ended up replacing a lower case d gasket in the drive. It looked fine, then I removed the thermostat housing and noticed the thermostat was stuck closed hence high temps at high rpms. Which i did that first. Newbie mistake. Was told always check impeller and thermostat first. Live and learn.