So me and a buddy are working on this 86 s4 na and we are getting bubbles in the coolant. We checked the coolant seals by removing the spark plugs to see if it would shoot water on start up and it didn't. We then checked the water pump and it seems fine. What we think it is now is the intake manifold gasket. Is this a possibility? Also when we we're removing the throttle body to get to the intake manifold we found water/coolant in the butterflies.

Can anyone offer any suggestions?

 

How did you start a car with no spark plugs?

The S4 NA has no coolant passages through the intake manifold.

There is a cooling passage through the throttle body and BAC valve but I can't imagine any of them getting into the intake tract. To do so would require a massive crack in multiple locations.

What do you mean by "bubbles in the coolant"?

 

Well the car didnt start. I read somewhere that if your coolant seals are blown then you can take out a spark plug and see coolant on them? So we tried to see if without a plug then water would come out...which it didn't. We were going to just pressure test but we don't have the one for rotary engines.

By bubbles in the coolant (which is water right now because everything has leaked out from a blown heater hose) i mean when you take the cap off then you can see a constant flow of bubbles.

And ****...we just ordered the intake manifold gaskets yesterday! Well i guess it won't hurt to replace them...

 

Make sure the coolant system is full, try and burp the system by squeezing the hoses (top and bottom) while filling the radiator.

When my coolant seals went it was pretty noticable, open up the radiator cap, and start the car or at least crank it... if coolant shoots about a foot out of the top of the radiator, then your compression from your rotors/housings is going into your coolant chambers which at 100psi or so will shoot coolant out of your radiator.

The water in your tb could be from the accelerated warm up thermowax gizmo which helps you car warm up faster, but revs to like 2-3k which is bad for a cold motor... but it shouldn't be inside the tb...?