thermostat assembly removal problems

[Cptkid570]

Hey everyone…<br /><br />1985 Mercruiser. Chevy 350 V8 engine. 260hp.<br />I was trying to remove the thermostat housing assembly (the whole thing) and one of the bolts broke (the bolt on the port side of the motor – if facing into the engine compartment, it’s the right bolt). I was able to remove the other bolt, and the bolt didn’t come out because it was frozen somewhere inside of the thermostat housing assemble. It’s not frozen where the bolt goes into the intake manifold because I can remove the other bolt and I’m able to move the housing from side to side. I put a lot of pressure on the bolt before it broke, so I don’t have much confidence that I can get this bolt out.<br /><br />1st question: If I remove the carburetor, will I have enough space to be able to turn the entire housing all the way around and just unscrew the entire housing or will the housing bump into the manifold?<br /><br />Any suggestions as to what to do?

 

[Haut Medoc]

Re: thermostat assembly removal problems

How much is broken off? (They are pretty long)If the majority has broken off, I would try something like wd or pb blaster down the hole & let it soak.....& then see if it will loosen by tightening slightly by hand.....For the price of a carb gasket you could give the other option a try....If nothing else, you would increase the range of motion & hopefully break it loose, & it might screw off as you suggest...But i think it will hit.....Of course, salt water won't make it any easier....Good Luck....JK

 

[Cptkid570]

Re: thermostat assembly removal problems

It broke off right at the head of the bolt, so, I could probaby get a tap into it, but it's frozen pretty good.<br /><br />I'm half thinking that my best option is going to be to take a circular saw with a metal cutting blade and just hack the crap out of my housing and chop it so that it is skinny enough that I can just rotate it around and unscrew the whole thing. Then just replace the thermostat housing. (I think they are like $130). I'm going to try to get some pb blaster in there..or maybe use some heat and see if I can some how get the housing to lift off of the screw..but, that's the part that was frozen up (where the screw is inside of the housing. If I could get the whole assembly to turn, then I could pound the screw out from the other side.

 

[tashasdaddy]

Re: thermostat assembly removal problems

no expert but you might try taking a center punch type tool and taping the bolt to see if it wiil jar loose.

 

[Haut Medoc]

Re: thermostat assembly removal problems

If it is broken that far up, but will unscrew from the manifold, I would loosen it as far as it will go, and try to break the bolt at the manifold & retrieve what's left of the bolt with an easy out.....But, if you are willing to sacrifice the housing, I would just cut it off as close to the manifold as possible, and again, drill & remove whats left of the bolt with an EZ out....It should come out easy if it is already loosened......If that is a 20 year old salt water motor, I would cut it off & go with a new housing, with that much bolt stuck in the old one, it probably won't be worth the time & effort trying to save it.....Post back with your results.....JK

 

[Cptkid570]

Re: thermostat assembly removal problems

I didn't have a hammer with me... but, I've been thinking about it and maybe I can bang around on the current housing and maybe I can knock something loose...also, I can try the punch thing and see if that will knock it loose.. Worst case scenario is that I can always just cut it all away.

 

[Haut Medoc]

Re: thermostat assembly removal problems

I would try a mallet... Or at least a block of wood....I don't see how a punch will help you.....JK

 

[hudman]

Re: thermostat assembly removal problems

the housing is not threaded... you need to soak it in oil and it will free up... sounds like its just severely rusted....

 

[ron7000]

Re: thermostat assembly removal problems

this might be a little more work but it may be a lot easier if take the whole intake manifold off and get it on a bench where you can work on it. Get the carb off, and use an acetylene torch to unfreeze the bolt and housing. If you don't have a torch, this way to can take it to someone who does and it's a 5 minute hjob. Intake gaskets are cheap for a 350. If everything hasn't been touched in 20 years, might not be a bad idea to go through it with new gaskets. Oil seepage always happens at the front and back of the intake where it seals to the block anyway.<br /><br />Trying to just unscrew the whole thermo housing with the intake on the motor, in the boat, is probably going to hit something and fustrate you. I've been there, it hits the carb, so you take that off. Then it hits the water pump pulley, take that off. If it's a ford, you have to pull the distributor. Before you know it, it's easier to have pulled the intake off. <br />This way, you can work on the whole thing on a bench, then when it's ready (with carb and thermo already on) just drop the intake back on and it's an easy reinstall.

 

[Haut Medoc]

Re: thermostat assembly removal problems

I do agree wih hudman, the housing is not threaded & if you have the time & patience to let it soak, that would be the way to go.....That is why I suggested a tightening motion to break it free .....JK

 

[Cptkid570]

Re: thermostat assembly removal problems

This is just one project of many projects to come..so, time and patience to let is soak is no problem! Thank you for all of the suggestions. I'll keep you posted on the progress. Hopefully I'll have a chance to work on it this weekend.