Overheating at idle?

[tonyjh63]

Hey folks, I went out to start my engine on the muffs before heading to the lake this afternoon...after about 10 minutes, I noticed the temp gauge was reading about 180 and climbing - it got up to around the 200 mark and that is when I shut it off. Also, there wasn't much, if any, water coming from the prop area - it just came out the sides of the muffs. Note that I had the drive trimmed up during this time. I've never noticed this before - is this normal, or is my impeller/water pump dead? Thanks!

 

[spoilsofwar]

What drive?

It's almost certainly the raw water pump. When was the last time the impeller was changed?

 

[tonyjh63]

It's a Alpha 1 Gen2 out drive. I've only had the boat since this past winter, so I don't know when/if the impeller has ever been changed.

 

[spoilsofwar]

I've only had the boat since this past winter, so I don't know when/if the impeller has ever been changed.

No offense, but wrong answer. Impeller should have been among the first things serviced when you got the boat. Pull the lower, and change the impeller.

 

[achris]

First question. Are you still about to select gears and have the prop spin? If so, check/change impeller. If not, you may have a broken shaft or spun coupler.

Second question. Are you sure it doesn't have a through hull water pick up? Have a look and see if you have an engine mounted raw water pump. (Post photo of the front of the engine showing lower crankshaft pulley and alternator. )

 

[tonyjh63]

Update: took the boat out yesterday afternoon (had a buddy standby for a tow, if necessary) and everything ran fine - temp gauge topped out at around 160-165 - idle, full throttle, didn't matter. So I'm still not sure what that was about yesterday in my yard...

One more thing, now that I have your attention: the little reservoir on the right front side of my engine (when looking at it from my back bench seat) is just a tad low on whatever fluid goes in there. Can someone tell me what fluid it needs, and where to get it? I "think" it may be the out drive fluid? Thanks for any help/advice!

 

[spoilsofwar]

Weak pump will usually work better with the boat in the water then on muffs. Or, you have an air leak upstream of the impeller which is underwater when the boat is in the water, but obviously exposed on muffs. Or, maybe you got lucky and there was just an obstruction that cleared itself and you're good to go now.

You're not off the hook though... You need to pull the lower off the drive and inspect the impeller condition. And since you're going in there anyway, just change it out for new. Cheap part, basic maintenance, easy job.

 

[achris]

One more thing, now that I have your attention: the little reservoir on the right front side of my engine (when looking at it from my back bench seat) is just a tad low on whatever fluid goes in there. Can someone tell me what fluid it needs, and where to get it? I "think" it may be the out drive fluid? Thanks for any help/advice!

First, what are we working on? in-line 4, V6, V8? Injected, carbed? Engine model, serial number and/or year would also be helpful (not concerned about what boat it's in)....

Reservoir on the port side of the engine with a blue fluid would probably be drive oil, yes. Only use Quicksilver High Performance Gear Oil....

Chris......

 

[tonyjh63]

First, what are we working on? in-line 4, V6, V8? Injected, carbed? Engine model, serial number and/or year would also be helpful (not concerned about what boat it's in)....

Reservoir on the port side of the engine with a blue fluid would probably be drive oil, yes. Only use Quicksilver High Performance Gear Oil....

Chris......

Duh, that was kinda stupid of me to assume y'all knew what kind of engine my boat has! LOL! Anyway, it's a Mercruiser 4.3L with a carb. And now that you mention it, it does look kinda blueish, so it must be the drive oil.
Also, I took the boat out again today, and she ran like a top! Temp gauge got up to about 165-170...