Starboard side riser temperature creep.

[chris032188]

I noticed a few weeks ago when I was out that my starboard side was running much hotter then my port side (volvo penta 5.7 gsi). 150ish / and 120-130 on port. Little background - newer motor about 2 - 3 seasons on it - manifold and risers were new also (or believed to be - bought it from his wife and he is deceased). My boat mechanic ended up replacing the risers. After doing this the engine got worse.. Took it out for a water run and riser got up to 180 before i shut the boat down and let it cool. So then he replaced the raw water impeller, t-stat, and t-stat housing. I have only run the boat on the hose and there is still a temperature disparity. It isn't as drastic. The starboard side rises, but much slower then it initially did (approx 20 minutes on hose). I did the clear hose test and couldnt notice a drastic flow difference or any air bubbles. It did develop air bubbles when i revved it a few times. Not really sure what to look at next - I did notice that one of my risers does have a water hose running into side (port side / the cooler side) and that the starboard doesnt. Could this have something to do with it? or is that normal on these engines?

 

[Bondo]

Ayuh,..... Welcome Aboard,..... Risers rarely to never run the same temp, 'n 180* is not critical,.....

I think yer chasin' a ghost,....

 

[chris032188]

Ayuh,..... Welcome Aboard,..... Risers rarely to never run the same temp, 'n 180* is not critical,.....

I think yer chasin' a ghost,....

When I was coming back in pretty sure an alarm came on just as I hit the dock. I shut it at 180 but it was still rising and there was almost a 50+ degree difference

 

[stouchton]

Somewhere I thought I had read that the thermal switch for the riser temp activates at 210. I had one instance where I had the nipple clogged with an eel (try to figure that one out) - alarm went off and I lifted the hatch to see what was going on - had smoke rising off the riser and manifold, it was burning oil or paint off. So that is probably above 210.