One manifold running warmer than the other
 

Hey there, I was wondering if anybody had any advice for me? I have a Merc 502 mag mpi with a Bravo 1. One of my manifolds is running warmer than the other. Engine temp maintains at speed around 150, oil pressure and everything else is fine. After getting some sand in the cooling system, I flushed it completely: put in a new t-stat, water impeller and cleaned the strainer basket on the water intake line. I have the riser and the manifold off right now and can find absolutely no obstructions. Are there any suggestions as to what I should look at next, or do I even need to worry about it?

Cheerio, Trevor...

Re: One manifold running warmer than the other
 

Hey Trevor,

try a search on the subject. I think that there may be some posts from a few months back that you could find. I want to say that the consesus was that to a small degree, you will have that phenomenon.

See what the search yields.

Re: One manifold running warmer than the other
 

Hotter at idle or after up and running for awhile? I have always noticed at idle the STBD. side to be a little warm.

Re: One manifold running warmer than the other
 

I sucked up sand and the motor started overheating. I spent a lot of time, replaced manifolds, risers, impeller, etc. I found the problem to be the impeller housing. There was no obvious sign of damage to the impeller housing so I thought it was OK. After replacing the impeller and housing the problem was completely gone. I had the exact same problem you have described and did the exact same things you have done all to find out it was the impeller housing!! Good luck.

Re: One manifold running warmer than the other
 

My starboard side also runs hotter at idle on my 502 mag, especially on the hose. Also produces more steam.

Re: One manifold running warmer than the other
 

I completely agree with Julie & Matt.
Had the same symptoms, spent far too long messing around trying to track it, but new impeller & housing fixed it immediately. There were some slight signs of wear beforehand, but nothing significant.

Re: One manifold running warmer than the other
 

Yah, I replaced the T-Stat, impeller and its housing after getting the sand in the cooling system. Flushed it completely and still, STBD side still runs a little warmer than port after running it at speed for a while. I believe that I have been chasing a ghost around!! Oh well, I'd rather pull the exhaust off one side of my engine to learn that there was no problem at all, then spend 11K on a new engine!!! Thanx for the input, we're going back in the water tomorrow.

Cheers, Trevor...