thermostat housing.

[Case1]

2005 5.0 mpi. Looking to replace this plastic plug on the thermostat housing. Is there a better choice than plastic ? Also , are there other plugs of this type on the engine I should look for and replace ?
Thanks ,
Pete

 

[Fill Ess]

Those are the standard ones (blue plastic with the o-ring). I'm not sure I've ever seen anything else on this era of MPI.

Are you trying to replace a broken one? Or just want something other than plastic?

 

[Fill Ess]

Also , are there other plugs of this type on the engine I should look for and replace ?

There's a few -- I don't want to say for sure without seeing it but besides the one on the t-stat housing there's 2 or 3 more near the bottom.

 

[HawkX66]

I replaced the plastic ones on the block with brass. You can see them in these pics:

 

[Case1]

There's a few -- I don't want to say for sure without seeing it but besides the one on the t-stat housing there's 2 or 3 more near the bottom.

The one on the t housing was dripping while underway yesterday and went to give it a little twist and and it snapped of with me just touching it. Some of the plastic was still in the threads. Small screw with electrical tape plug it up and got us home. i may just go with brass. i have never seed a brass plug Break ! thanks

 

[AeroNick]

Hardin sells stainless steel versions. High quality and after same mishap of the plastic one falling apart I installed the new one and it’s fantastic now knowing it”ll never break or leak.

https://www.hardin-marine.com/p-810...-plugs-mercruiser-22-806608a02-8m2000874.aspx

 

[Case1]

Hardin sells stainless steel versions. High quality and after same mishap of the plastic one falling apart I installed the new one and it’s fantastic now knowing it”ll never break or leak.

https://www.hardin-marine.com/p-810...-plugs-mercruiser-22-806608a02-8m2000874.aspx

I like those ! Thanks

 

[Espos4]

You could also run a tap through there to clean up the threads. They usually get a little rough over time and that makes the plug hard to remove. If a plastic plug gets stuck, it’s an easy thing to drill out. A metal plug, not so easy.

 

[DWABoat]

I have run the plastic ones in three engines for years without an issue. (Mine are 1989 and 2001 models.) I keep several spares on hand, but really in case I drop one. I did change the Orings a couple of years ago.

I like the brass and stainless ones, however, I am concerned long-term about dissimilar metals immersed in a conductive liquid - we all know how that works out. Any corrosion issues?

 

[Lazy Daze]

Keep it simple - just get some more blue ones and you'll get another 16 years out of them... replace them at year 15 next time and you'll be good.

You likely have more, but it depends on your current cooling setup. Look straight down... check block/manifold... check fuel filter/cooler... check raw water pump.

 

[Fill Ess]

I replaced the plastic ones on the block with brass. You can see them in these pics:

Are those quick release drains? If so do you find they drain well? Just wondering because sometimes with the bottom drain you have to get up in there with something to clear the hole if it's not draining well enough.

 

[pyro]

Mine were getting extrmeely difficult to turn. Needed vice grips on them, and I was concerned about snapping the ears off the plug. Bought some new plastic plugs and they go in, nice and easy. Seems like the plastic was just a bit banged up on the old ones. Which makes sense, the plastic certainly isn't going to damage the metal threads. Try new plastic ones and I bet you'll be happy.

 

[HawkX66]

Are those quick release drains? If so do you find they drain well? Just wondering because sometimes with the bottom drain you have to get up in there with something to clear the hole if it's not draining well enough.

You can either loosen them and the block will drain through the hole in the T or if you needed to you can remove the T like you do with the plastic ones. You can easily push something through to clear any obstructions.