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Discussion Starter · #1 ·
Hi fellow drivers,

Having this problem for a long time already. checked with Mazda dealer and they suggest:
1/ change O2 sensor
2/ change catalytic converter
3/ clean fuel tank
4/ change spark-plugs
5/ change fuel filter

1/, 4/ and 5/ already completed. 2/ is very expensive. Shall I do 3/ to solve this problem. BTW, there has beean leakage for engine-oil from 2 main seals which I never deal with over the past 5 years. Is this related to the above problem? Please kindly advise. Thank you.

Denny
 

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id say its the catalytic converter..

also if your main seals are leaking, that is very bad. Its repairable, but id suggest an overhaul while doing it.
If your meaning the valve cover gaskets, that should be repaired also, but its not as bad.

I dont believe there is a way to clean the fuel tank, nor is it needed.
 

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If it's a petrol smell I wouldn't say its the catalytic converter, cause that would be a sulfur rotten egg smell. Are you really talking about the main seals? The ones at both ends of the crankshaft, or are you talking about something else. If it's some seal that lets oil get into the exhaust somehow then I'd say that is the cause of your problem. Any smoke coming from the muffler? When accelerating from a stop? Color? You don't have to get a Mazda original catalytic converter. If you can find a muffler shop they should be able to weld up a new one to your pipes.

Hey 我是 ABC! Wow在香港有汽車?! 不是大部份人民坐公共汽車嗎
 

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He doesn't necessarily have a JDM MX6. He's in Hong Kong, China and they might have some sort of emissions test considering the air there being so bad but I doubt it LOL. Taiwan is also wierd like that, they have a mix of USDM, JDM, Espec parts on 6s.
 

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Discussion Starter · #6 ·
M(y)x6gr8RiDe said:
If it's a petrol smell I wouldn't say its the catalytic converter, cause that would be a sulfur rotten egg smell. Are you really talking about the main seals? The ones at both ends of the crankshaft, or are you talking about something else. If it's some seal that lets oil get into the exhaust somehow then I'd say that is the cause of your problem. Any smoke coming from the muffler? When accelerating from a stop? Color? You don't have to get a Mazda original catalytic converter. If you can find a muffler shop they should be able to weld up a new one to your pipes.

Hey 我是 ABC! Wow在香港有汽車?! 不是大部份人民坐公共汽車嗎
Dear friend,
Thank you. Agree that it is not rotten egg smell and not catalytic converter (even if it is I don't maind because this does not affect the performance of my car). BTW, your are right that there is some white smoke coming out when I stop in front of the traffic lights (the mechanic say that it is water vapour but I think it is not).
Moreover, someone has suggested that I can change all the fuel-injectors (6 in total). Is that useful?
 

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No the fuel injectors really have nothing to do with your problem I don't think. Unless your car is hard to start after it sits overnight or you notice a large amount of unburnt petrol coming out of your tailpipe. That might indicate they are leaking and not holding pressure. But i doubt that is your problem.

I would give your car a good tune up and change the spark plugs, pcv valve, ignition cap and rotor, and ignition wires if you don't remember ever changing them. Maybe your weak ignition isn't igniting all of the petrol. Also which two main seals are you talking about? If they allow oil to get into the engine cylinders, that may be causing your smell.
 

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The catalytic isnt that expensive just get a universal off of ebay.
 

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Get an AFPR. My car's fuel pressure is too high with the sotck FPR, so i put a check valve on it, to hold vacuum and kep prssure at its lowest... runs much better throughout the RPMs!
 

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DennyTang said:
Hi fellow drivers,

Having this problem for a long time already. checked with Mazda dealer and they suggest:
1/ change O2 sensor
2/ change catalytic converter
3/ clean fuel tank
4/ change spark-plugs
5/ change fuel filter

1/, 4/ and 5/ already completed. 2/ is very expensive. Shall I do 3/ to solve this problem. BTW, there has beean leakage for engine-oil from 2 main seals which I never deal with over the past 5 years. Is this related to the above problem? Please kindly advise. Thank you.

Denny
Listen man, give us some more info, does the car start and run fine? when warmed up what is your engine idle speed? any othe rproblems with it? has it started using more fuel than normal?
 

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Discussion Starter · #11 ·
M(y)x6gr8RiDe said:
No the fuel injectors really have nothing to do with your problem I don't think. Unless your car is hard to start after it sits overnight or you notice a large amount of unburnt petrol coming out of your tailpipe. That might indicate they are leaking and not holding pressure. But i doubt that is your problem.

I would give your car a good tune up and change the spark plugs, pcv valve, ignition cap and rotor, and ignition wires if you don't remember ever changing them. Maybe your weak ignition isn't igniting all of the petrol. Also which two main seals are you talking about? If they allow oil to get into the engine cylinders, that may be causing your smell.
Thank you.
I think you are probably right that it's not the fuel-injectors. There is no problem in starting the engine. But still not sure whether it is unburnt petrol or burnt engine oil. Maybe both.
According to the mechanic, the 2 seals of the 2 cylinder heads are leaking. Maybe I need to deal with both the leaking first and then the fuel presuure valve second.
BTW, have already changed ignition wires, the distributor has al
 

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Discussion Starter · #12 ·
kman said:
Listen man, give us some more info, does the car start and run fine? when warmed up what is your engine idle speed? any othe rproblems witt? has it started using more fuel than normal?
The car starts and runs fine. idle speed =700rpm. Fuel consumption is not particularly very high in view of the age of the car, or at least no great increase over the past few years (actually this petrol smell has been there for years).

Have changed all spark plugs, fuel filter, distributor, ignition wires etc. Problem already improved 50 to 60% but still there. Maybe the seal-leak is the main problem so that there is engine oil being combusted. How do you think?
 

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Discussion Starter · #14 ·
M(y)x6gr8RiDe said:
If it's a petrol smell I wouldn't say its the catalytic converter, cause that would be a sulfur rotten egg smell. Are you really talking about the main seals? The ones at both ends of the crankshaft, or are you talking about something else. If it's some seal that lets oil get into the exhaust somehow then I'd say that is the cause of your problem. Any smoke coming from the muffler? When accelerating from a stop? Color? You don't have to get a Mazda original catalytic converter. If you can find a muffler shop they should be able to weld up a new one to your pipes.

Hey 我是 ABC! Wow在香港有汽車?! 不是大部份人民坐公共汽車嗎
You are right. There is some "smoke" when I vew the exhaust in the rear-miror and the "smoke" becomes obvious in front of the light-beams of the car behind. The mechanic said it is water vapor but I do not feel it is.

BTW, in HK there are still a lot of private cars but many owners are week-end dirivers (me too). Petrol is very expensive here. US$1.5 per litre.
 

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AFPR= adjustable fuel pressure regulator and I doubt you need it!

Again what seals are you talking about? Are they the ones that seal the valve cover to the head? Yes those seals leaking letting oil into the engine is definitely your problem. Change those and your smoking problem should go away.

 

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Discussion Starter · #16 ·
M(y)x6gr8RiDe said:
AFPR= adjustable fuel pressure regulator and I doubt you need it!

Again what seals are you talking about? Are they the ones that seal the valve cover to the head? Yes those seals leaking letting oil into the engine is definitely your problem. Change those and your smoking problem should go away.


Yes, exactly. Thanks so much. I'll do it.
 

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Discussion Starter · #17 ·
M(y)x6gr8RiDe said:
AFPR= adjustable fuel pressure regulator and I doubt you need it!

Again what seals are you talking about? Are they the ones that seal the valve cover to the head? Yes those seals leaking letting oil into the engine is definitely your problem. Change those and your smoking problem should go away.


BTW, have you had the same problem before?
 

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Discussion Starter · #18 ·
M(y)x6gr8RiDe said:
AFPR= adjustable fuel pressure regulator and I doubt you need it!

Again what seals are you talking about? Are they the ones that seal the valve cover to the head? Yes those seals leaking letting oil into the engine is definitely your problem. Change those and your smoking problem should go away.


Have asked around. How about changing the whole engine so that all seals are changed as well as having a 'younger' engine? There are second-hand engine (3 to 4 year old) in from Japan. inexpensive.
 

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No because if you get a used engine, the smart thing to do is to change all those belts and gaskets(timing belt,water pump, valve cover gaskets) anyways unless you want to do it again later. What engine do you have? Unless you want the higher horsepower Japanese engine, I say just change your gaskets and drive the car until the engine blows up.

If you got the money to spend do it keke.
 
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