4.3 still oveheating

[Bondo]

Ayuh,.... Did ya ever change the riser gaskets like ya said you were gonna,..?

Is there water flow out the exhaust,..??

Are the risers water dump ports plugged,..??

Yer puttin' water in, by the sounds of yer tests,....

It's gotta be able to get rid of it too,....

 

[johnnypac]

When you say "hot" what temp reading are you getting? You are certain the temp gauge is correct? Ill just ask, your engine oil level is good right?
Just thinking of anything other than exhaust.... Seems like you've covered that.

 

[UncleWillie]

When installing the thermostat, There is a plastic sleeve in the hole that need to be removed before installing the T-stat.
The thermostat goes in, then the sleeve goes in.
The thermostat will be in the bottom of the hole, not at the top.
If it is at the top, the block water just keeps recirculating, and the hot water isn't dumped overboard, allowing more cooling water into the mix.

Also the t-stat gasket has crushable brass rivets that electrically connect the removable part of the housing to the block.
If the rivets have been crushed from reuse you may get erratic readings if the mounting bolts do not want to carry the signal to the gauge.

 

[UncleWillie]

---

I remove my T-stat in the Fall to flush the engine.
I happened to be replacing it today, so took some pictures...

 

[jaybrassmonkey]

Sorry for the delay. I did change the riser gaskets to the free flow, no change. The exhaust is exiting out the rear. The new risers came with several plugs but they're all on the exterior? Where are the water dump ports? I've run it with the thermostat and it is still reading 130 consistently on the gauge. I know that is not the best situation but I'm on the water!

 

[Benny67]

I'd run a compression test...just to rule out a bad head gasket after all that overheating...and to see if you are possibly blowing exaust into the coolant/water

 

[jaybrassmonkey]

Wouldn't a blown head gasket not result in water getting somewhere it shouldn't? Or running rough? Motor runs REALLY well as far as I can tell.

 

[Benny67]

A blown head gasket can do a lot of different things. Not sayin that's your problem but it's just a thing I like to do to get a general idea on the health of the block and valves, ect.

A "really good running motor" does not need it's thermostat removed to operate correctly...something is wrong.

 

[Lucrative]

I am very new to all this, so be advised I don't know what I'm talking about.....but I just took apart the top end of my 7.4 and the block was all gunked up with rust flakes/sediment. Not sure how old your engine is, or if this might be a possible cause of your overheating. Check out this link http://home.comcast.net/~tpenfield/Web_Page/My_Power_Boat/Engine_Disassembly.html

 

[jaybrassmonkey]

No I just put this motor in, no chance of that, but thanks for the thought.