Volvo Exhaust Bellow

[rjlipscomb]

Can someone describe the cooling and exhaust systems for a 2005 Volvo 5.7 Gi-E w/ DP-SM or point me to a diagram which fully details the systems.

Where does water enter the exhaust system?
Where does the exhaust exit?
Where does the water exit?
My "exhaust bellow(?)" has what appears to be some small pin holes shooting water out along the length of the bellow. Does mean it needs replacing?
Water comes out at front of the drive unit, through a hole in the drive unit and a little in what I thought was the exhaust above the props. Is this normal?
Exhaust appears to be coming out at the front of the drive unit. Is this correct?

 

[Maclin]

Re: Volvo Exhaust Bellow

Exhaust bellows have drain holes along the bottom, that is normal. There is no reason for them to be water or air proof.

Raw water gets picked up at the intake slots on the outdrive lower leg, sucked up by the raw water pump that is on the front of the engine for your Volvo (most Mercs have it in the outdrive). The raw water then goes thru the thermostat housing on the top of the engine, this is the traffic director for the raw water. The engine's coolant curculating pump gets fed from that housing, and any excess water is bypassed directly to the exhaust manifolds (the exhaust manifolds have two passages inside, exhaust and cooling). The thermostat is a major part of the water directing, when the engine needs more cooling it opens and less water is bypassed, as it closes more water is bypassed. The water entering the manifolds is directed up at the back of the manifold into the exhaust riser. The exhaust riser then directs the water into the exhaust gas stream, that is where the exiting coolant water meets exhaust. The exhaust goes thru hoses and piping into the outdrive then out the exhaust bellows and on out either thru the prop or thru the anti-cav plate just above the prop depending on model.

There are idle relief ports on the bottom of the transom plate on the outdrive below the exhaust bellows. Exhaust/water will exit there also at idle and lower rpms.

The major plumbing described is for a raw water cooling system, not a closed cooling system with a heat exchanger/radiator, but the raw water flow out the exhaust is relatively the same.

 

[rjlipscomb]

Re: Volvo Exhaust Bellow

Maclin, Thanks, that explains what I observed. In my driveway, with the hose hooked up to fresh water flush connection, I ran the engine at idle for 30 minutes today, never got to 175. I throttled up to 1200, 1500 and 2000 rpms for a couple minutes. Runs good.