2002 mercury 150 hp overheating at low rpms

[mikeraz]

i have a 2002 mercury 150 saltwater that the temp starts creeping up at low rpms. at higher rpms temp goes back to normal. thermostats and impeller were replaced by merc dealer. any ideas ?
thanks mike

 

[Docksidemarineservices]

Did they service the water bypass.

What parts did they install with the water pump?

Post a serial number

 

[mikeraz]

sorry dont have serial handy. was told they installed new pump and housing. they didnt say anything about water bypass system

 

[mikeraz]

sorry for the delay the serial is 0t469517

 

[Docksidemarineservices]

Water bypass should be done when the pump is done. The t-stats are only for low rpm cooling. Did they change the complete pump? That is the upper and lower housings. I would pull the lower unit down and inspect the install.

 

[mikeraz]

i change the thermostats the dealer changed the impeller and housings maybe thermostats bad out of box

 

[Docksidemarineservices]

Did you get OEM tstats or aftermarket?

 

[mikeraz]

changed the thermostats again and problem cleared up. i guess they dont make them like they used to. thanks for your help.
mike

 

[Docksidemarineservices]

changed the thermostats again and problem cleared up. i guess they dont make them like they used to. thanks for your help.
mike

When you can, use OEM parts only.