Intake Manifold Coolant Leak, not your typical...

[marsmann]

I have developed a coolant leak which appears to be coming from the underside of my 2tc intake manifold. It is not the coolant hose, nor is it leaking from the gasket where it meets the head. It appears to be leaking from the seam of the manifold itself. Anyone else ever have this happen? I attached a pic and circled the area/seam where it appears to be leaking from. Any thoughts? Not sure if I can just RTV seal this or .. ??

[BOBLOOK]

Is a gasket you can custom your own

[marsmann]

Thanks Boblook.

Ironically, I had just completed putting everything back together again since I just installed a new carb with all manifold gaskets. I'm going to try RTV type sealant around the edge to see if that works. I'll give this a shot before taking it all back apart and post results after a week or so. My fear of taking it apart, removing the bottom plate and replacing the gasket is that the nuts will break off. I had one nut holding a small emissions valve and when I went to take that off the nut snapped off. I fear the others might do the same...

[baldo]

There is a gasket that comes for that. You can try rtv but if it leaks and fear is the game JBweld is your friend. You can also eliminate that hose.

[BOBLOOK]

+1

There is a gasket that comes for that. You can try rtv but if it leaks and fear is the game JBweld is your friend. You can also eliminate that hose.

[marsmann]

coolant hose delete?

hmm. well, I do remember some guys doing this back in the early 80s. Some used to swear it even gave them a few extra horsepower, supposedly because it removed excess warm air going into the engine. I've always been on the fence about that. Are there any disadvantages?

I realize the primary reason for the engine coolant lines into the intake manifold is to heat up the intake manifold to allow for better atomization of fuel. This is especially helpful in cold climates or on cold days at start up. But I'm not concerned about that too much. Any other drawbacks besides maybe poor cold idle/startup?

[baldo]

If cold weather is not a factor then there is no problem doing it then. In my opinion, if your car is completely stock I would try to fix the leak. Once you start doing things with these cars you dont tend to stop!
If its not stock, then this is something to think about doing then. About the weather cold start idle and start up, its a carb. We all know once it gets cold its time to tune the carb! Depends how cold it gets you might also have to sit there and wait a minute or two. Some people find this a hassle, it consists about turning 3 screws and (listen) to the engine. Do you have a stock carb and do you know how to mess with them? Most people on here have been there and done that. Any problems you may have somebody will have the answer.

[marsmann]

Thanks baldo.

The car is stock. I'm not really into modifying. I am very comfortable with cars, carbs and general mechanics after 35 years of working on them I've just been away from these old toyotas for about 20 years or so and am refamiliarizing myself with them again. It's slowly coming back to me. Having a resource like this online certainly helps as you guys fill in my memory gaps.

My problem is being over into the engine bay for an extended time. My back isn't so auto-friendly these days... I'm going to pull it all out and install a new gasket. Thanks guys!

[Tizzon]

Had that same thing happen to me a decade ago. Found out it wasnt the gasket at all. I had to get the manifold flange trued up and flat. Eliminated the problem right off the bat, then regular intake mani gasket sealed the deal.

[73GTV]

You can also purchase a thicker gasket material and cut it out to match the opening. The additional thickness will compensate for the warpage within that steel plate without eliminating the coolant section of that manifold.