Marco

After doing the ATF trick I'm having problems with the coolant levels in my car. With help of this forum the diagnosis is "bad water seals". Even after the use of a mild stop leak product (bars leak) I have A LOT OF EXHAUST fumes in the overflow tank (it's like a very thick fog in there).

Weird about this is that my car has never had as much power as it has now and it still starts immidiately after two or three cranks and idles smoothly direct after starting so I'm pretty sure there is no coolant in the combustion chambers. So where is a leak so big that lets this much exhaust fumes in the overflow tank and stop leak has no effect on it but lets no coolant in the combustion chamber.

I don't think that there is a part of the exhaust system that is beeing cooled by the coolingsystem but maybe I'm wrong, the symtoms would indicate that the problem (leak) is somewhere after the combustion.(This would make it understandable that the stop leak does not work, the exhaust fumes are blowing it away from the leak).

Marco.

hypntyz7

Unusual problem, might be totally unrelated tot he atf trick. ON the other hand, the atf may have cleared out some crap trapped in teh corner of the chamber where the coolant seal meets the chamber and re-opened an old leak or weak area exposiing it to compression pressure again.

That stuff doenst do real well in a rotary anyway. There is a procedure and certain brand of sealer that is said to work well for this problem, its pretty involved though like draining adn filling the system 3 or 4 times, running the car for a while, repeat, etc. ITs floating around here somewhere, maybe do a search, but I dont remember what topic it was under. Search water seals and see if you can find it.

The coolant system runs on 13-20psi of pressure, while compression pressure is 90-125 psi, not even accounting for the massive pressure released while combustion is occuring. SO if youve got a open swinging door, with water pressing on one sid, and combustion pressing on another, which side do you think is gonna win? Combustion gases are pushing into the colant system and pushing coolant out as it goes, either out the exhaust or overflow.

Combustion occurs inside the engine from the area where the plugs are down around to the exhaust ports, so you can bet your leak is in that area internally. There's not much pressure internally up att he top part of the engine where the intake comes through until the rotor swings around to the plugs and makes its compression, which is why most failures occur between the area where the plugs are and the exhaus ports, where that pressure gets released.

Vroomaster

if it were your water seals, water would leak into the combustion chamber when you turned the motor off...Any white, sweet-smelling smoke on start-up?

Marco

No, nothing at all. That's what I'm calling weird.

Marco.

hypntyz7

Youd like to think so, but not necessarily the case.

Like I said, the cooling system is under very little pressure. If it is a small leak, just beginning, then there wouldnt be enough pressure on the water at rest(gravity only) to push it through the hole, but conversely when the engine is running, the compression forces might be enough to push through it then because theyre so much stronger. Over time, it will get worse, unless you try to fix it now with stopleak as that procedure describes.

Marco

This makes sense. You're probably right. I would have thought that on such a small leak a stop leak would have had some more effect but allas. I will have to go and find a shop that will do the flush and stuff method, because rebuilds are very very expensive overhere (about what the car is worth in good shape) in europe.

Marco.

gotorx7

If that's the case, I would expect to see lots of bubbles in the coolant, too (whilst the motor is running)...

Marco

When cold there are no bubbles and when pushing the throttle (still with a cold engine) coolant gets sucked in the engine instead of blown out (which is one of the symptoms of a blown seal). When the engine is hot there are so much exhaustfumes in the overflow tank that I can't see if there are bubbles or not but I think there should be a lot, cause there is so much exhaust flowing thru it.

Marco.

peejay

When it's cold the air is probably getting trapped under the thermostat.

The reason I swore of piston engines was a bastard of an Isuzu I owned... the engines in those cars had very poorly designed cylinder heads and would crack if you looked at 'em funny. Run great for 5-10 minutes then they'd crack and the engine would overheat, blow coolant everywhere, etc. Never once did it leak coolant into the engine, it only blew combustion gases into the cooling system.

You know, Ih ad that thing running perfectly once, ran just long enough for me to get it smogged and registered... then it ate another cylinder head. No more boingers for me, thanks!

Marco

I forgot to mention something else important. I do not see any overheating. Could this be that the temp-sensor is not in the coolant anymore or that there is no flow of coolant anymore.

Besides that, the coolant is pushed out to a certain level and after that there is only exhaust fumes coming out of the overflow tank.

Marco.

tmak26b

There's a trick on how to do a temporay fix on the water seal. It's around some where, dig it up and do that to try to seal the water seal

Marco

Just got my car back from the shop. Cooling system has been checked, flushed, cleaned and refilled. I still have the problem that the coolant overflow tank is filling up, but no way as fast as before. There aren't any fumes anymore. I seems that there was coolant in the system that cannot be mixed with antifreeze and I did that
.

Anyways now I noticed something else, coolant is coming from the overflow line with pulses, like one or two per second (I'm certain it is not more often). There are still about ten to fifty pulses after the engine has been stopped. It only happens when I'm driving the car as it should be driven (fast driving with shifting at 5500-6000 rpm). When I'm shifting at 3000 rpm and cruising at 2500 rpm there are no problems.

Marco.