I have a 85 RX-7 with the 1.1 engine. My front cover has developed a serious leak of engine coolant. The leak is right at the top of the engine and visible without taking anything off the motor. I'm guessing that the front cover is similar to the head on a boinger. I know that when a head gasket goes, it is also possible that the head gets warped. Is that also an issue with the front cover on a rotary? Maybe the front cover is not like a boinger head at all. Can I just replace the gasket/seal on the front cover or should I replace the front cover also?

On a different note, how long do these rotary engines last before they need to be rebuilt or replaced? Mine has 123,000 miles on it. It is a waste of time to put a lot of money into this motor? Should I look to replace it?

Thanks,

Dennis

 

It's very unlikely that the front cover would warp. I wouldn't say it's equivalent to the heads on piston engine either. The front/center/rear irons and the two housings are where the coolant passages are. Actually, the front cover doesn't have any coolant passages under it that I can think of (or at least on 13b engines). The front cover seals off the oil pump and sits above the front of the oil pan. If you actually mean you have a coolant leak from around the front iron, the only fix for that is a full or partial rebuild of the block. The coolant seals get replaced at the very least.

As far as engine life, I'm not a 1st gen guy, but in general, rotary engine life is not much different from your average piston engine.

 

Thanks for your response. My engine is a 12a instead of a 13b. But I suppose the coolant passages would be the same. Anyone out there who can confirm that for me? The leak is between the front iron and the front cover. The gasket/seal there has been compromised. I guess I was hoping that I could just take off the front cover, put on a new gasket/seal and be on my way.

Any idea, even roughly, what a rebuilt 12a is gonna cost?

Thanks,

Dennis

 

for starters, no part of a rotary engine resembles a piston engine in any way. the only way u'd have coolant leaking from the front cover is from bad freeze plugs and there would be water in the oil because the area behind the front cover goes directly to the oil pan. u sure it's not coming from the water pump housing to front iron gasket? and the coolant passages r the same for 12a and 13b.

 

Michael,

Thanks for your post. I can see the leak when I pour water in the radiator. Once the radiator begins to fill, water begins coming out of the top of the motor between the front cover and the front iron. I tried to take a picture, but my camera doesn't seem to be working. If you're standing on the driver's side of the car looking at the engine compartment and you look directly above the distributer cap and back in under the alternator, that is where the leak is. It is not on the front of the motor, but on top. It looks to me like the water pump housing does not connect directly to the front iron, but to the front cover. I do not know for certain there is no water in the oil. I have not drained it. The dipstick does not appear to show signs of water/coolant, but I had just changed the oil and it is very clean.

Dennis

 

Sounds like this is a water pump housing leak that appears to be coming from the front cover.

There are no water passages in the front cover.

 

Michael,

Here is a picture of where the leak is. Below the alternator and to the right, there is a small red elliptical shape. That is precisely where the leak is. I have described it as being between the front cover and the front iron. Is that incorrect?

Dennis

 

that's the gasket where the pump housing attaches to the front iron.

 

Michael,

Thanks for your post. So can I fix this just by replacing that gasket? Or does the engine need to be rebuilt?

Dennis

 

You can just replace the gasket. You'll need to pull the alternator, air pump, upper and lower coolant hoses, then unbolt the water pump and housing. Clean everything up, put sealant on the new gaskets and installation is reverse of the removal.

 

Aaron,

Thanks for the post. That is what I wanted to hear. Do you know what kind of sealant is normally used? Does it need to go on both sides of the gasket? It sounds like you have done this before.

Dennis

 

i use the gray rtv. and yes both sides.

 

Black or gray RTV will work fine. The area will never see more than ~200* F. Also, be very careful around the MOP/OMP (metering oil pump) lines when removing the housing. The bolts holding them onto the pump will need to be loosened and moved aside when you go to pull the housing forward off the studs. Because of their age, they are notorious for snapping off when the bolts break loose. Soak them in penetrant and carefully remove them.

 

Thanks everyone for answering my questions and the great tips. I guess there's nothing left but to get at it. This club is just what I needed.

Dennis