3.0L Mercruiser Temp. Issue

J

johnboy68

Cadet
Joined
Jul 5, 2013
Messages
18
I have an 84 3.0L that I recently bought. First time out boat ran very hot, changed impeller (melted pretty bad), took boat out again ran very cool now. Checked and sure enough no thermostat, installed new one and off again I go, boat ran fine until coming back after getting on plane for a bit it went up again to 180???? Drove back slowly and it stayed there for awhile until I get into the dock area and boom right back down.

My next thing to check is the exhaust flapper thingy to see if that got stuck?? Is this difficult to remove??

Going to be a few more days before I go back down wanted to make sure if there is anything else I can check?

Thanx :)
 
alldodge

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,751
Re: 3.0L Mercruiser Temp. Issue

Need to find out if the overtemp is repeatable. You could have picked up a plastic bag over the inlet ports. It could also be the previous over heating could have caused some other damage of plastic parts in the drive. May want to pull some hoses and see if water flows freely. Double check to make sure the thermostat was installed correctly and is the right one.
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,525
Re: 3.0L Mercruiser Temp. Issue

johnboy68 said:
I have an 84 3.0L that I recently bought. First time out boat ran very hot, changed impeller (melted pretty bad), took boat out again ran very cool now. Checked and sure enough no thermostat, installed new one and off again I go, boat ran fine until coming back after getting on plane for a bit it went up again to 180???? Drove back slowly and it stayed there for awhile until I get into the dock area and boom right back down.

My next thing to check is the exhaust flapper thingy to see if that got stuck?? Is this difficult to remove??

Going to be a few more days before I go back down wanted to make sure if there is anything else I can check?

Thanx :)
Click to expand...

Ayuh,... Welcome Aboard,.... Did ya swap out the complete Kit, with the housin's,..??

Did ya find ALL the pieces of the burnt up impeller,..??
 
J

johnboy68

Cadet
Joined
Jul 5, 2013
Messages
18
Re: 3.0L Mercruiser Temp. Issue

Bond-o said:
Ayuh,... Welcome Aboard,.... Did ya swap out the complete Kit, with the housin's,..??

Did ya find ALL the pieces of the burnt up impeller,..??
Click to expand...

Thank You :)

I did swap complete kit minus the lower housing parts store gave me wrong one!!! The bottom did have some melting on it, but still looked usable.

I have not found any of the pieces, would they be in the engine by now?
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,525
Re: 3.0L Mercruiser Temp. Issue

johnboy68 said:
Thank You :)

I did swap complete kit minus the lower housing parts store gave me wrong one!!! The bottom did have some melting on it, but still looked usable.

I have not found any of the pieces, would they be in the engine by now?
Click to expand...

Ayuh,... Get the Right housin', 'n put it in,... The faces need to be Perfect, to function properly,...

While the drive is Off,... Back-flush from the T-stat housin', Back,...
Catch the flushin's, 'n ya should find the pieces,...

Ya might wanta get the T-stat housin' gasket set, 'n clean it out too,...
 
You must log in or register to reply here.
Top