Annoyed... can't figure this one out

ric · **Posted:** Sat Nov 03, 2012 4:09 pm

4.3GL-J. Sometimes (not all the time) the temp will creep up. You could be cruising at 3200rpms and it's slowly rising from 175 to maybe 190.. kinda hovers there. Let off the throttle, it will start to run up even higher BUT, BUT, if you rev the throttle once or twice it will instantly cool back down to 175. Other times it will stick right at 175 and never falter.

I have no idea.

I replaced impeller, thermostat. Checked the pickup for obstructions. Checked the flush port to make sure it's not sucking air. The raw water is crank driven but the circulation pump is belt driven (serpentine). The belt looks shiny/slick and the pulley was polished for the circ pump. There's quite a bit of rubber dust everywhere. I sanded down the pulley good and rough and went out for a rip at WOT for 5 minutes, ran perfect but I slowed down and it started doing it's thing again. Tied to the dock, the circ pump pulley was shiny again. I'm thinking maybe I should replace the belt? That's my last ditch effort until I take it in for warranty. The circ pump itself will kinda squeak sometimes but it's not leaking out of the "weep" hole.

Ideas?

Backdraft · **Posted:** Sat Nov 03, 2012 4:30 pm

Ric,

I had something very similar happening on my 5.7 GXI-E. Check the manifolds/risers for any obstructions floating around in there? It could be causing an intermittent restriction in flow causing the temps to rise/drop without any rhyme or reason. I used the fresh-water flush port and removed the manifold plugs to force most of the crud out of it. Problem solved. Granted, my boat's almost 10 years old and is due for new risers and manifolds...

ric · **Posted:** Sat Nov 03, 2012 7:52 pm

I'll try that too. I can't find the length of the Volvo belt I'll have to go match it up. The part number on it doesn't correspond to anything about its size. They got smart

alanurt · **Posted:** Sat Nov 03, 2012 9:17 pm

I had an issue with my charging system. Pulled the alternator and had it tested. It was fine but he noticed black dust all over it. I re-installed with a new belt and all was fine. I kept the old one as a spare. Your issue may be a slipping belt and it's just manifesting itself differently than mine did.

ric · **Posted:** Sun Nov 04, 2012 11:05 am

Belt. Installed a new gatorback from the local bennetts and problem solved. It was slipping on the circulation pump since it rides on the smooth part of the belt (that was glazed over). The slight "bell ringing" sound I would hear is gone.

FYI, it takes a 91.5 inch 6 rib goodyear gatorback (factory VP belt is rebranded goodyear).

$45 for a goodyear branded belt. $20 cheaper than the VP branded belt.

ric · **Posted:** Mon Nov 05, 2012 8:09 am

Nevermind, it showed it's head again later on in the day. With the engine running I pulled out a drain out of a manifold and the water was just randomly dripping out. I was expecting a stream? I'll pull the boat this week it's gotta be an obstruction. My lake gets very weedy during summer months there could be something in there.

www.iFourWinns.com

Annoyed... can't figure this one out

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