Hi, My intake manifolds leak coolant (slightly) where they bolt onto the head. Of course I decided I could not live with it and have pulled the manifolds and cleaned up the surfaces and am wondering what sealant or coating I should use in addition to the new gaskets which I have ordered? They were assembled with what looks to be a blue RTV silicone and leaked. Any help or recommendations would be appreciated. Thanx Don
i just did my intakes on my 308 gtsi i use the ultra gray RTV a thin coat of RTV on both sides of the gasket will be fine.
the intake manifolds do not have any coolent in them--if they do--you have BIG problems--it if is the coolent rails that are below them then you just need new gaskets, rtv sealant, and a wire brush to clean things up
the early cars actually do have a coolant passage with the intake manifold. later cars have the separate coolant manifold.
on my 1980 308 gtsi on the intakes ther is 2 hose that conect the 2 intakes and water pass in them for cooling the hads and on. a thin coat of RTV ultra gray is to be use .
Quite right on the water passages in the 2 valve motors, as they have a passage that runs along the flange, and exits in the center. I would surmise that it is a remnant from the Carb models, as a means of helping keep the carbs from iceing up. I often find that they can be quite corroded, often to the point that a gasket sealing may be questionable. I cure the problem by a thorough cleaning, followed by a layer of good ol' JB Weld, applied with a flat blade. They can be carefully hand filed if there are any high spots once it is cured,so that the surface is flat, and true. HTH Kermit
Thanx all, I will try a bit of JB weld on some of the pitted surfaces on the head and the manifold flange. The manifold castings have a surprising number of voids or low spots in the casting, none near the edge but close enough that I think that I will fill them with JB weld and then sand/file smooth. While it seems that gray RTV is the goop of choice, has anyone ever used the liquid copper gasket sealant made by Permatex for this application? It is formulated to seal head gaskets so it might just stop the collant leaks. Again, thanx Don
Right on Don. I'm with Ria on the Ultra Grey. SPAREINGLY. Any axcess that squeezes out should be left untouched, as after it cures, it wil peel off, leaveing no traces of sealant, and a clean looking job. Any yhat may end up in the runner will be washed off by the petrol over time, and will not hurt the internals on the motor. The coolant passage is a different story, as it will end up in the radiator, causeing havoc, hence the SPAREINGLY. Kermit
Permatex makes a grey colored RTV just for waterpump/coolant sealing applications. It's called: PERMATEX® Water Pump & Thermostat RTV Silicone Gasket Maker http://www.permatex.com/auto/autouh.asp?automotive=yes&f_call=get_item&item_no=22071 Spec sheet says it's much more resistant to coolant than the other RTVs & it's rated for 600 degrees F continuous. http://www.permatex.com/MSDS_data/tds_files/22071.pdf The copper gasket sealant is good for high temp applications, but I don't think it's a good fit for here.
