inlet manifold query...

[roon_VR]

hello people,

My car has been recently overheating close to the red zone. So i checked to see if the thermostat is playing up by feeling both radiator hoses. The upper hose would be scorching hot compared to the lower hose, which was at a reasonable temperature. I went to Super-cheap Auto and bought a new gasket and thermostat. I get home, take off the thermostat housing, scrape off the old gasket, install the new gasket on the housing, then tension up one of the bolts. When i got to the 2nd and last thermostat housing bolts, it seemed to be going in fine, until it started getting tighter and tighter. I kept tightening the bolt until i realized that the thread of the bolt completely demolished the thread inside the hole. I pull it out and noticed aluminum scrapings all over the thread of the bolt. I thought, "shit, this isn't good".

Now, I'm just wondering, is it possible to make a whole new thread into the thermostat housing hole and screw in a marginally larger bolt through? Or is it better to just go to the wreckers and purchase an inlet manifold from there? I've given the inlet manifold to my mate who will give it to his dad to check out. He knows anything and everything about metal, bolts, threads etc....

P.s. While we were taking out the inlet manifold, a bit of coolant went in the valley and down a hole. at the back end. Is this okay? I got some paper towels and soaked up all the coolant that fell in.

[cander24]

If your can replace the manifold with another one from the wreckers cheaply then i'd say that would probably be the neatest option. However, there is nothing wrong with going oversize in the thread size aslong is it still leaves enough metal around the thread walls to retain strength and you will probably have to also enlarge the hole in the top part if the thermostat housing so that the new 'larger' bold does not bind at all. As for the coolant, just soak up all that you can with a rag as you have done and then once its all installed again run the moror for a little while and do an oil change to get rid of any bit you've missed. Most times you remove an inlet manifold you are going to end up with a little bit of coolant in there.

[delcowizzid]

or get a helicoil put in the hole.its like a spring they thread in which makes a new thread for the bolt work great probabaly cost $6-$8 bucks for a mechanic or engineers shop to put one in for you

[goat]

yeha i'd get the heli coil if u want a cheaper way out, alot cheaper than buying the entire manifold, im sure your dads mate will help you out either way.. a tiny bit of coolant mixed in with your oil in your valley wont be to harmfull... i ran a blown head gasket with coolant mixed totally in with my oil lol...just check the oil, prob pay to change it..atleast it gets a service then too..

[danja]

You shouldn't take your engine apart while its still hot, because different metals (like steel bolts and aluminium alloy housings) expand at different rates when they heat up. You'll strip threads in no time like that

[roon_VR]

My mate's dad has re-threaded the hole and gave me a bolt to match it as well. He also made up a gasket for the thermostat housing which is good. Now it's all a matter of putting it all back together again. Thanks for all your advice people.

cheers,

[ScoHar]

just a note, im pretty sure the upper hose should be hot (if thermostat working) and lower hose not as hot. i think the water travels out engine through hot hose down radiator 'cooled' then back into engine through lower hose.

[roon_VR]

just a note, im pretty sure the upper hose should be hot (if thermostat working) and lower hose not as hot. i think the water travels out engine through hot hose down radiator 'cooled' then back into engine through lower hose.

both hoses should be at near temperature. If one is hotter than the other, it's a good sign that the thermostat is shat.

[ScoHar]

hmm strange, im talking slight difference in heat, as mine doesn't feel the same top to bottom and i've just changed thermostat, but before with the stuffed one the top hose was cold and bottom hot.

[delcowizzid]

top hose will allways be hotter