overheats at idle

[jombe 2]

Ok, this is my first post and I wanted to ask a question regarding engine temp. I have a 1998 SeaRay 195 with the 4.3 V-6 and Alpha One drive. My question is this.
When I start it up and get to temp. (usually runs at 170 deg.) I can idle in or out of gear and slowly the temp starts to rise till the engine warning alarm goes off.
If I rev the engine in neutral or start moving at rpm the temp runs normal. What could this be? If something was stopped up why would the temp go back to normal when I rev or run?
Hope I have given you enough info. Oh, this happened just after winter storage (winterized with antifreeze) on first trip out...
Thanks,
J-2

 

[Sundancer]

Have you replaced the impellar in your lower unit lately? It's showing the classic signs of being worn out. It's not pumping efficiently at low speeds and reving it up slightly pumps enough water to cool it back down. When you return to idle, it's not pumping enough water again and it heats back up.

Depending on where you boat it can last 1 to 3 years, but every other year is probably the safest bet.

 

[tdappleman]

Yep - water pump in the lower unit needs replacing. When the RPM's increase it will compensate slightly for a worn out pump but you should replace it before you use the boat again. If you let it go you can get engine damage and you could also have an impeller fall apart and the rubber pieces will go through the motor and potentially clog a cooling passage. It's not a difficult replacement if you decide to do it yourself.

 

[jombe 2]

Have you replaced the impellar in your lower unit lately? It's showing the classic signs of being worn out. It's not pumping efficiently at low speeds and reving it up slightly pumps enough water to cool it back down. When you return to idle, it's not pumping enough water again and it heats back up.

Depending on where you boat it can last 1 to 3 years, but every other year is probably the safest bet.

Heck, I didn't know this....it hasn't been replaced in ten years!:smt009 This problem just started to show itself though as I haven't had any overheating issues till now. Thanks!

 

[jombe 2]

Yep - water pump in the lower unit needs replacing. When the RPM's increase it will compensate slightly for a worn out pump but you should replace it before you use the boat again. If you let it go you can get engine damage and you could also have an impeller fall apart and the rubber pieces will go through the motor and potentially clog a cooling passage. It's not a difficult replacement if you decide to do it yourself.

Thanks Travis...as it turns out I have an employee that stated the same today and said if I get the parts he would help me do the install. He said it would take about 2hrs.

Fred

 

[Sundancer]

Keep us posted and we will cross our fingers that ALL of the vanes are still attached to the hub! If they are missing, then you might have to back flush to get the pieces out of the motor. You MIGHT get lucky and they may not clog a passage somewhere, but you never know. Keep us posted! A 10 year old impellar has to be some kind of record!!

 

[Lazy Daze]

Jombe, I'm not making fun of you, but I've noticed over the years that the guy who says "I didn't know I had to do that" usually lucks out! If I tried to squeeze an extra 2 weeks out of an impeller, I'd probably end up having to replace the block. Why is that? :huh:

I have a "friend of a friend" who didn't know he had to winterize his engine - most importantly, not knowing he had to drain the block. It got pretty cold here in eastern PA this winter. Guess what? His block didn't crack, all freeze plugs are still seated... absolutely no problems!!!! I tried to explain to him how lucky he was and to be sure and do it next year. He listened to me, but I could tell he didn't believe me.

 

[jombe 2]

Jombe, I'm not making fun of you, but I've noticed over the years that the guy who says "I didn't know I had to do that" usually lucks out! If I tried to squeeze an extra 2 weeks out of an impeller, I'd probably end up having to replace the block. Why is that? :huh:

I have a "friend of a friend" who didn't know he had to winterize his engine - most importantly, not knowing he had to drain the block. It got pretty cold here in eastern PA this winter. Guess what? His block didn't crack, all freeze plugs are still seated... absolutely no problems!!!! I tried to explain to him how lucky he was and to be sure and do it next year. He listened to me, but I could tell he didn't believe me.

Heck, I won't take it the wrong way....shame on me. I am all about maintenance, so why didn't the local boat dealer say something when I bring her in for her yearly maintenance. ( not selling dealer) Duhh. You would think they would "upsell" me on whatever I need. It is not like I go in and say save me $$ don't do everthing needed.
My employee has done this repair many times before and he said the same thing you did.....any ideas on where to get good prices on parts. Local boat guy quoted $146 for the pump kit or he said I could buy the impeller only for $24. Thanks for your input.

 

[Nehalennia]

Yep. Sounds like an impeller with a "set" to it. Best of luck.