My wife was driving my '07 MS3 a couple months ago and thought she saw smoke coming from the exhaust at idle although she wasn't 100% sure. The CEL also came on. She rarely drives my car and I thought maybe it was initial condensation burn off. I took it to the shop and they didn't see any signs of smoke and the code was a P0300. They didn't find any misfire so they put in 44k fuel additive and said the misfire code might be slight buildup on the valves. A week or so later, I did see slight smoke and called the shop. They said it's probably the 44k additive doing it's thing because they checked everything and didn't see any smoke so I didn't think anything of it. Then the CEL came back on. I brought it back into the shop and it was the P0300 again which they said isn't really giving them much direction. They suggested starting with a compression test and all of the cylinders checked out perfectly. Then they said more times than not it's the ignition system. Even though the plugs only had 14k miles on them, they suggested I change them out along with all new coils. The CEL went away and the car felt great. Then all of a sudden I saw smoke again, this time more significantly, and the CEL is back. And to clarify, it's smells more of burning oil than antifreeze. From what I've been reading, it sounds like bad turbo seals or a bad turbo, but from my research I haven't seen much about a P0300 attributed to a bad turbo. I'm concerned the shop is going to give me "this random misfire code isn't giving us any specific direction" because I'm already out of pocket on the compression test, plugs and coils and now those things might not be fixing the original issue.
P0300 code bad turbo?
- Thread starter MVSDKC
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Take off your downpipe and check the backside of the turbine blades/housing for oil residue. What were your plugs gapped at? Is the P0300 code only setting on cold start or randomly throughout the day?
The code has been random. After the plugs and coils were replaced, the CEL went away but came back instantly once smoke started coming out of the exhaust. I'll have to check on the plug gap.
I'm sure it did go away cause the plugs were fresh and not fouled with oil. Check your turbo for oil residue. Is the issue on cold starts that goes away once it warms up?
At first, the smoke came after the car was warm and idling. When it came back the other day, I had driven it around town and on the highway for about 15-20min and noticed the smoke on my way home while at a stop light. Yesterday I drove only about 2 miles from my house and it started smoking so now it seems like it's constantly there. I'm taking it back to the shop on Monday and having them specifically look at the turbo.
Update: The shop dug into the car and said it's definitely not the turbo, zero oil on either the input or output and not even residue. It was running rich so they cleaned the MAF and replaced the air/fuel ratio sensor and crankcase vent valve. The numbers all came back great which is good but it didn't solve the smoking problem. At this point they're certain it's not an engine issue because the compression test came back perfect and it's not a turbo issue. Next step is a cylinder leak down test. They're stumped at the moment because they can't see where the car is burning oil and continuing to smoke.
If the engine ran rich excessively then the oil could be diluted and allow it to be burned easier. Was the oil changed recently? Is the smoke blue or white in tint?
Ask the shop to replace the PCV valve, cost around $15-25
Located behind the Intake manifold
(I just reread your reply seems like you said they changed that crankcase valve)
theres also the band aid fix of turbo banjo/restrictor bolt.
-and/or using thicker oil e.g 5w40
to summarize your problem:
seems like your burning oil (smoke in exhaust) but all your compression and turbo seem good.
If youre worried about the P0300 random misfire code
then it is because the oil that is getting burn inside the engine (smoke in exhaust) is fouling the sparkplugs and causing it to misifire. Also it reduces the octane of the fuel burning.
Oil catch can between the line is also good.
PS people over here HATES wall of text so make sure you put spaces between.
grouchy old people......
Located behind the Intake manifold
(I just reread your reply seems like you said they changed that crankcase valve)
theres also the band aid fix of turbo banjo/restrictor bolt.
-and/or using thicker oil e.g 5w40
to summarize your problem:
seems like your burning oil (smoke in exhaust) but all your compression and turbo seem good.
If youre worried about the P0300 random misfire code
then it is because the oil that is getting burn inside the engine (smoke in exhaust) is fouling the sparkplugs and causing it to misifire. Also it reduces the octane of the fuel burning.
Oil catch can between the line is also good.
PS people over here HATES wall of text so make sure you put spaces between.
grouchy old people......
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I'm not due for my regular oil change interval for another 1k miles. I checked it 2 weeks ago and it was about .5 quart low so I topped it off. The smoke is more white than blue but smells more like oil burning than coolant.
Ask the shop to replace the PCV valve, cost around $15-25
Located behind the Intake manifold
(I just reread your reply seems like you said they changed that crankcase valve)
theres also the band aid fix of turbo banjo/restrictor bolt.
-and/or using thicker oil e.g 5w40
to summarize your problem:
seems like your burning oil (smoke in exhaust) but all your compression and turbo seem good.
If youre worried about the P0300 random misfire code
then it is because the oil that is getting burn inside the engine (smoke in exhaust) is fouling the sparkplugs and causing it to misifire. Also it reduces the octane of the fuel burning.
Oil catch can between the line is also good.
PS people over here HATES wall of text so make sure you put spaces between.
grouchy old people......
Ask the shop to replace the PCV valve, cost around $15-25
Located behind the Intake manifold
(I just reread your reply seems like you said they changed that crankcase valve)
theres also the band aid fix of turbo banjo/restrictor bolt.
-and/or using thicker oil e.g 5w40
to summarize your problem:
seems like your burning oil (smoke in exhaust) but all your compression and turbo seem good.
If youre worried about the P0300 random misfire code
then it is because the oil that is getting burn inside the engine (smoke in exhaust) is fouling the sparkplugs and causing it to misifire. Also it reduces the octane of the fuel burning.
Oil catch can between the line is also good.
PS people over here HATES wall of text so make sure you put spaces between.
grouchy old people......
I've printed out the response from Mazda regarding the smoking issue to give to the shop. Since they've checked everything from the MAF and PCV to the air/fuel sensor and compression, from what I've researched online the fix has to be either Mazda's ventilation (PCV) relocation kit or a new turbo. Although the shop's going to push back on the turbo thing because they didn't see oil residue on either the input or output of the turbo or the intercooler.
It could be a possible ring issue that we'll see after the leakdown test but if that checks out as well, by process of elimination, all signs lead to turbo. I'm concerned about the smoking because I'm trying to sell the car but don't want to unload it on somebody if it has an oil burning issue, that's bad juju. Other than that, the car is in great shape.
What intake do you have?
When you see the smoke how long are you idling? Does it go away if you use the throttle to hold the rpms at about 800?
When you see the smoke how long are you idling? Does it go away if you use the throttle to hold the rpms at about 800?
HPS intake. The smoke appears when the car is warm and idling for a while. As in driving the car for 15min and then letting it idle for over 5min. That’s when it starts to smoke pretty heavily.
It does seem to dissipate at higher RPMs.
Then you 100% have a crankcase pressure issue. Do not replace the turbo or install an oil restrictor bolt. Neither of these will solve the problem only potentially mask it
So start with an OCC since I just replaced the PCV? Or swap the new PCV for the L3Y2-13-S80B ventilation kit? Or do both, the OCC and ventilation kit?
Where is the nipple on the htp intake? Gen 2 revised it to be closer to the turbo generating more vacuum first step is to make sure you get enough suction from the intake
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That could be it, you want that bung to be in the tip close to the turbo
It's possible I have a crankcase pressure issue because of the wrong intake? If so, that's a much more cost effective change than a turbo which would be great.
So what's the fix, a different intake like a Cobb or Corksport? One that doesn't require tuning?
Honestly that intake isn't hurting anything. If I was you I would just start turning the car off instead of idling for long periods. Once you are moving there is enough vacuum being pulled on any intake.
Or of you need to idle just make sure to touch the gas and ring the rpms up a bit every once in a while
Or of you need to idle just make sure to touch the gas and ring the rpms up a bit every once in a while