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w2kracing
06-10-2010, 12:24 AM
I Idled across a shallow sandy bottom,sucked sand of course,nose cone pick-up.Temp started climbing at high speed ,shut it down just before 180 deg. Limped it back to the trailer.I'll start at the begining of my attempted remedies.Pulled all hoses,pulled t-stat housing flushed clean.flushed fuel cooler,and oil cooler-which i found enough pebbles to plug those small holes about 70%.Okay, so then I purchased the sea pump impellar/body kit and rebuilt it.After back flushing the block for what seems like days now,it's been on the garden hose running and in the lake and the right side still seems considerabley hotter than the other.The temp still climbs and would go past 180 if I kept on it.I've also disassembled the exhaust riser/manifold,It's clear just expected rust.I also used compressed air in the water jacket drains to try to agitate the sand.I'm almost positive that when the sand was pumped into the engine the pebbles that half-assed plugged the oil cooler, restricted the flow enough that the finer particles packed into smaller water jackets or in the head,and could not flush away.Obviously a sea strainer may have helped.I've run the motor with the plugs out, it seems to be clear.When coming off plane and back to an idle I noticed some steam from the right exhaust,gotta be starving for water flow somewhere.When I start the engine cold ,the temp slowly rises to about 160,then I can see on the gauge that the stat opens and temp drops to 140-150.Like I said it will climb at high speed,past180.It's kinda weird cause we idled through a half mile long channel earlier that day and the temp sat at 120-130.Now once up to temp it wont go below 150. Both sides are dumping the same amount of water just the right side gets hot.The right exhaust manifold gets much, much hotter.I really wish I could figure out the flow path of the t-stat housing.My next step will be a new stat,even though it opens ,it may not be all the way.After that I'll pop a frost plug out towards the back and check for a blockage.I really don't want to pull the heads.Anyone knows any thing that I have not covered,PLEASE REPLY, WE HAVE A POKER RUN SATURDAY.Thanks Dave

MOP
06-10-2010, 07:36 AM
The sand is worse then mud to get out of the block, it builds up high at the ends of the block. I have had to pull the casting plugs (wrongly called freeze plugs) out to get enough water to the ends of the block to flush them out through the drain. Muck has no place to go except out the tiny center drains!

BigGrizzly
06-10-2010, 10:45 AM
I am with phil on this one. Note the port side is hotter then the starboard. Another note, i do not like low water pickups.

Planetwarmer
06-10-2010, 04:57 PM
If you pulled the heads to flush the engine, that would be a huge mess!!! You couldnt keep water out of the engine.

I would pull the freeze plugs (may be the wrong name, but I'm stubborn) and flush it that way if nothing else works. Maybe there is some sand trapped in the water jackets in the exhaust.?. But , then again, you said you have equal flow out each pipe. My guess is you have sand built up on the hot side of the exhaust and need to really flush it out well.

Pop a freeze plug like these guys said (or casting plug), and give that a try. Flush it for an hour or so. Flush then back flush time and time again till its clean.

Thats my 2cents.

BUIZILLA
06-10-2010, 05:17 PM
i'm going to throw out a stupid, really off the wall suggestion, before you bang out a core plug... get some salt-a-way, a lot of it... run the engine on it until you run out, then just cool water as high a feed pressure as possible... the water and steam holes in the head gaskets in the right rear and center ports kinda get the least pressure in the flow stream.. if you have a recirc pump and not an aftermarket crossover with the recirc eliminated, this can be the case and the crud jams up.. with that said, the salt sometimes coagulates the sand in tight and minimum flow areas and the salt-a-way may just loosen up things for it to pass... once you start, run the engine at 1200-1400 rpm for a least 30 minutes or about 20 minutes after the salt-a-way is used up... can't hurt to try..

TBroccoli
06-11-2010, 01:24 PM
Is 180F too hot? I have a 165F stat that allows the engine to run around 180F. When I run hard the temp may creap a little over that. When slowing down I get a small amount of steam. No problem. Cooling of the engine is never the same from side to side. Mercruiser states that the right side is usually the hotter side. I'm not saying you are out of the woods, but you may be ok if you flushed and found all impeller parts.

w2kracing
06-15-2010, 12:59 PM
Thanks to all for the info.I pulled the casing plug in the rear above the starter and found no sand.Looking again at the exhaust elbows.Thanks again Dave 1999 22zx .l

Cuda
06-15-2010, 02:43 PM
Is 180F too hot? I have a 165F stat that allows the engine to run around 180F. When I run hard the temp may creap a little over that. When slowing down I get a small amount of steam. No problem. Cooling of the engine is never the same from side to side. Mercruiser states that the right side is usually the hotter side. I'm not saying you are out of the woods, but you may be ok if you flushed and found all impeller parts.
No, it won't hurt the heads, the block, or the pistons.

gcarter
06-15-2010, 03:22 PM
After you figure this out, if you add a transom pickup and a good sized sea strainer, it won't happen again.
That is, unless you run the hull about 6" into the sand, or mud, or have you!
I've filled my sea strainer w/the transom pickup, but it wasn't easy to do. You really have to work at it.