smoke from engine

Hello, I have 1992 Mazda Protégé with 140,000km (88k miles). Haven't yet replaced timing belt nor automatic transmission fluid.

Car has run fine, smoothly and quietly. Although it began shaming at stops about 5 years ago. Never found a mechanic who would try to fix it. Recently it has lost a bit of power; i;e;need to be bit more heavy-footed on the gas pedal sometimes to get it to accelerate it quickly. And the exhaust has sprung a leak immediately after the engines but upstream of the (new month ld) catalytic converter. It's releasing visible dark fumes with a cigarette smoke smell. Before the leak, little visible fumes were emitted at the tail pipe but the smell was of gas fumes.

Anyhow, my question is, if the engine is properly tuned and healthy, should there be no visible fumes coming out of the engine (upstream of the catalytic converter). Is this an opportunity for me to get a mechanic to first tune the engine properly then seal the exhaust pipe-- i.e. if no more visible fumes?

Besides the classic "tune-up" which I understand just means replacing spark plugs and checking the timing, what else should I expect the mechanics to try and tweak?

Note: my experience in about 15 years of dealing with mechanics is that they only want to easy stuff like replace exhaust pipes, tires, brakes, spark plugs. How do I find a real mechanic?

Reply to
Tom Staresinic
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typo fix: ...began shaking at stops...

Reply to
Tom Staresinic

The exhaust should still be fairly clean upstream of the cat. Only explanation I can think of is that the break is before the O2 sensor and it's forcing the car to run rich? otherwise you are either running rich for some reason that needs to be investigated, and/or the engine is burning oil. Either of those two possibilities would explain why you had to have the cat replaced, and should be addressed before your new cat dies too.

nate

Reply to
Nate Nagel

Thnx. But it ran rich before the break. Btw where is the O2 sensor? In the exhaust between the engine and the cat? This month was the first time I ever had to top up the engine with a bit of oil (1/2 litre). Yes, I would like to keep the cat alive.

Reply to
Tom Staresinic

yup, where, I don't know, it could be anywhere from the manifold to the inlet of the cat depending on the design of your car

nate

Reply to
Nate Nagel

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