Need the think tank on this one
 

Ok, here's my deal. I own this beautiful 1993 RX-7, Touring with approx 48K miles on it, original. I bought is in 2001 for $16,500 with only 42K. I've spend the last 5 yrs just basically trying to get the car "right" in terms of fixing little things and getting some reliability mods. Also there were some big things such as having the AC all rebuilt and new clutch as well as tranny rebuilt (the tranny is a long story for another thread).

Here's the thing. My mechanic did a test on the cooling system and says that his test shows that exhaust gases are pressurizing it and it means the O ring is defective. But it runs beautifully. Starts right up in the morning and after a 5 min warmup runs smooth with clean exhaust and no smoke. Has plenty of power when put the pedal down and does not lose any coolant since I changed to Evans MPG Coolant. BTW, I also use TCW3 2-stroke oil with every fillup and run Mobil 1 20-50w in the crankcase.

I'm wondering if the mechanics test was faulty or just what's going on. How can the engine run so well if it is in need of a re-build? Does this make any sense?

Sorry to suggest the bad news but, it is quite possible to have a great running engine with slighly leaking O-rings. You can have minute amounts of combustion gasses pass into the coolant where you will not feel the loss of power in everyday driving. The car may continue to run like that for quite a while before getting significantly worse. Leaky O-rings appear to be a common problem for FDs, even at low mileages, particularly if the engine is still original.

Albert

Thanks Albert,
Yes, it would be too much luck if my mechanic was wrong. Using Evans coolant has stopped the coolant loss problem. I'm hoping to get by a few more years without the re-build. This car is trying to bleed me dry :wallbash:

Really, if you aren't getting any smoking, aren't losing coolant, car runs fine, I wouldn't worry about it. I have seen with rotaries you can get some exhaust into the coolant with a perfectly healthy engine.

In other words, I wouldn't lose a lot of sleep over it. Keep doing what you're doing - treat the car right, keep the temps in check, and I have a feeling you'll have a LOT more life left in that engine.

Dale

I agree with Dale. Yes, your car's coolant seals are going, but without any other symptoms it's reasonable to leave it alone until other things start happening. You probably have 1000s more miles on this engine.

Dave

I put about 15,000 miles on an engine just like this. And then I block-sealed it and got another 10,000 once the leak just got to be too much hassle, i.e. putting in a pint of coolant every other day or so.
And my car RAN perfect. NO smoke on start-up, great power, etc.
As other sage and seasoned FD owners have already said, you shouldn't worry too much right yet. Yes, you DO have a rebuild in your not-too-distant future, but you can likely get thousands of miles, which for you might mean years of service before you have to do this.