over heating at low RPM 230+ but good temp 170 at speeds over 25

[Rambling Wreck]

Two thoughts:

A marginal battery will go out on you when the weather warms up - the self discharge rate increases with higher temps. Get rid of the battery - it will give you all kind of problems. It could actually be the root cause of your guage issues.

Do you run your blower at low speed? When my blower is on - my temp reads much higher - something electrical as the second I shut it off, the temp gauge returns to normal. I darn near came out of my skin the first time I looked at it with the blower on but now just accept it.

[sailtl]

bullet1w If you have a water leak under drivers side motor mount on a V drive I would take a look at the transmission oil cooler and see if it is leaking at the seams.

[bullet1w]

Terri
1. How do I check the Transmission oil cooler? Run it and look for leaks?
2.  How do I fix the Tx Oil cooler if it's leaking?
Thanks
Dave

[masonlk]

Bullet, look for wet n' frugal's post about his trans. cooler repair.

[bullet1w]

Ran the neg wire today in hopes that my temp problem would go away.  Took the boat out this evening and it still heats up on the way out of the no wake zone.  Get it up to speed and the temp goes down.  Did a few pulls and temp stayed around 170.  Return to the house in the no wake zone and the temp stays at 170-175... 
As soon as I lowered the boat into the water (off the lift) I can see water flowing in from somewhere on the drivers side engine area and it ends up under the mount but I can't pinpoint it.  After about 5 minutes the water slows to a trickle.
Sound like a Transmission cooler issue? I will take a look at it this weekend and see if I can do what WNF did. 

[bartmaas]

Still dealing with this temp issue

Has anyone ever had a bad "Block Water Pump" Looks like there is the sea water pump and then another water pump on the front of the motor run by the serpentine belt. Dose that ever go bad or am I barking up the wrong tree?
Thanks Bart

[lesman01]

The manifold is hot but if felt about the same as when the temp gage read 170. I cant leave my hand on it its to hot but not hot enough to burn you over a couple of seconds. The rubber houses off the thermostat housing are warm to the touch, I could hold on to thouse. I will run the wire, do I run it to the gage itself?

Also a new development the depth finder is going crazy how do I stop it. I dont need it. also the battery was completely dead today but it held a charge all winter, any ideas.
Thanks for all your help Bart

Did you run the ground wire and still reading hot? From what you describe, it seems like electrical. THere is a terminal under the dash with 2 posts on it. THere are other ground wires plugged in to the termal as well, so it should not be too hard to find. There's a post on here somewhere if you search for ground wire.

[cyclone]

Bullet,
I think you have a water leak from the sea strainer or trans cooler or oil cooler. I had my trans cooler pop apart last spring, there is water in there unless you pull the tiny drain plug. I was able to take it off while the boat was in the water and get it repaired. It's very sturdy but the end cap will pop off if it freezes. I had a guy clean it up and glue it with JB Weld, it works fine. I had no leaks into my transmission fluid, if your trans fluid is cloudy then you might want to buy a new one from TMS.

[bullet1w]

Pete. Help. See my PM

[cyclone]

Dave,
Here are some pics. The first is from the passenger compartment looking back at the starboard side. Disconnect the hose clamp circled, follow the hose forward and disconnect it at the water pump. Disconnect the two brass cooler line fittings, try not to break or bend the lines or fittings. Plug them as the fluid will leak out.

The second shows the drain plug of the cooler behind the starboard (drivers) side exhaust manifold. Don't try to get the hose off that end of the cooler, it's too hard. There are one or two bolts holding the cooler body to the engine, once you disconnect them you should be able to snake the whole assy out towards the passenger compartment.

[bullet1w]

Thanks Pete.
I will take a crack at it on Friday.

[shawn]

Did you figure it out yet, I am still overheating.  It seems like the water is getting stuck in the block somewhere.  I can hear it blow thru once we get on the throttle, but the muffler is really loud until then.

[bullet1w]

I am still having the same issues.  I am replacing the thermostat this week.  Took the boat out last night and noticed that the temp indicated about 10 degrees higher when you turn on the nav lights.  I will recheck the ground wire that I ran and then hope that the Thermostat fixes it

[bullet1w]

I think I fixed the overheat problem.  I replaced the thermostat and tightened down the newly installed ground wire a little more.  It seems to be running like it did before I installed the perfect pass.  I can even turn on my lights without the temp indicating 220.  I want to check the impeller for signs of overheating and replace it with the defender impeller (http://www.defender.com/product.jsp?path=-1|311|53460|809302&id=809152) if required.