getting hot 170 hp.mercruiser

[edwardr]

i just had a impeller kit install now it will not get hot at a slow idle . but when i idle up to1500 RPM and higer it get hot. 220 hot . i idle down it cool down . I check the heat exchanger OK new t stat, it is pumping water up to the motor. buy the way the motor did get hot before . it starts good, not mix water in the moter oil. elbow and exagust on restristion . dont know what to check next. any body has any idea

 

[Faztbullet]

Re: getting hot 170 hp.mercruiser

Do you have antifreeze mixed at 50/50 in cooling system?? Have you checked heat exchanger for impeller part blockages??

 

[Don S]

Re: getting hot 170 hp.mercruiser

getting hot 170 hp.mercruiser

Assuming you are actually referring to a Mercruiser I/O and the engine is actually a 470 style engine, and since there is no such thing as a 170hp ouboard, I will move this over to the I/O forum for answers.

 

[Don S]

Re: getting hot 170 hp.mercruiser

Are you getting good flow of water out of the drive when running?

 

[edwardr]

Re: getting hot 170 hp.mercruiser

yes i am getting good flow of water out of the drive when running. and i clean out the heat exchanger . and yes 50/50 coolant . could a head or a head gasket cause this type of problum ? or the water pump ? how can i check the water pump . buy the way i did tell you the motor did over heat 2 or 3 times .

 

[Don S]

Re: getting hot 170 hp.mercruiser

buy the way i did tell you the motor did over heat 2 or 3 times .

No you didn't tell anyone about any overheats, or how bad they were, or anything else.

all you said was.

i just had a impeller kit install now it will not get hot at a slow idle . but when i idle up to1500 RPM and higer it get hot. 220 hot . i idle down it cool down . I check the heat exchanger OK new t stat, it is pumping water up to the motor. buy the way the motor did get hot before . it starts good, not mix water in the moter oil. elbow and exagust on restristion . dont know what to check next. any body has any idea

Kind of hard to understand what you meant.

 

[edwardr]

Re: getting hot 170 hp.mercruiser

it got 220 hot. it did get very hot 200, 2 times and the last time is when i found out that the motor gets hot at 1500 RPM and higer but under 1000RPM the motot Temp is 160 . I ran it over 1 Hr at that temp."slow"the boat was fine.I was testing It wrong in a bucket.I found out the water line is a lot higher than the whale tail. was not runned to long may be 2 or 3 min @220 . a local shop show me how it should me how to bucket test WRONG !!! after the first time they sold me a new impeller kit . the 2nd time i did not go back .i went some where else and that is where i was told i was doing it wrong !!!

 

[bomar76]

Re: getting hot 170 hp.mercruiser

1. Throw that bucket away
2. Buy another water pump kit (the whole kit,not just an impeller, you've FUBARed it)
3. Install the new pump correctly.
4. Buy a set of muffs and a hose.
5. Put the muffs on, turn on the water, and fire the engine up.
6. Try and determine what else you may have toasted.

 

[Don S]

Re: getting hot 170 hp.mercruiser

1. Throw that bucket away
2. Buy another water pump kit (the whole kit,not just an impeller, you've FUBARed it)
3. Install the new pump correctly.
4. Buy a set of muffs and a hose.
5. Put the muffs on, turn on the water, and fire the engine up.
6. Try and determine what else you may have toasted.

I agree with everything he said, plus will add a couple of items.
1. Get the oem manual for your engine and drive and read them BEFORE you mess with it so you know what you should and should not be doing. Better yet, find a friend or have a qualified Mercruiser dealer show and explain how to run the boat out of the water.
2. Check the exhaust hoses (from exhaust elbow to pipe in transom.

You need service manual #8 for your engine, you can find the manual #6 for your drive at the link below. Just scroll down to the outline and click on the section letter you want to view.

http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf

 

[edwardr]

Re: getting hot 170 hp.mercruiser

1. Throw that bucket away ( DONE IT )
2. Buy another water pump kit (the whole kit,not just an impeller, you've FUBARed it) ( DONE IT )
3. Install the new pump correctly. ( DONE IT )
4. Buy a set of muffs and a hose. ( DONE IT )
5. Put the muffs on, turn on the water, and fire the engine up ( DONE IT )
Done it all ! NOW I am lake houston
AT 1000 Rpm the motor Temp is 160
AT 1500 Rpm and higher Temp is 220
I lower the rpm the motor temp drop back to 160 i can run over a hr. at this rpm. with out getting hot !!! i did put a new "t stat"
Sent it out to have the heat exchanger ,elbow and exagust check for restristion. no big problum there . but is is gettin hot at a high rpm !

 

[billy51z]

Re: getting hot 170 hp.mercruiser

i also recently did my impeller. it was just by chance i noticed old impeller debrie that had fallen right to the bottom of the intake vent. most of the big chunks had fallen down. i had to take the intake vent cover off to get all the crap out. it would have surly caused a simmiler problem that your having. did you clan the old impeller bits out before putting it back together ?

your boating pal

larry

 

[CharlieB]

Re: getting hot 170 hp.mercruiser

Check the water tank for circulation at idle then throttle up and recheck.

The engine circ water pump impeller may be coming loose from the shaft

Also watch 'bubbles' coming up in the water tank, indicating a head gasket leak as engine speed/load increases.