Odd turbo response

[kaganb]

I have an 09 MS3 and have owned it for just under a year, with it also being my first turbo vehicle. I normally keep the car under 3000 rpms to conserve gas during normal driving.

Lately, if I give the car enough gas to get the turbo to kick in after the car has been off for a decent period of time, the boost kind of hiccups (boost goes in and out real quick 2-3 times) and white smoke bursts out the tail pipe. It's not consistent either and I can only make it happen once per sitting period (ie. overnight or while at work). The rest of the drive, I can beat on the car the whole time and nothing. The car is also warmed up when this happens.

This morning I was speeding up to get into traffic and there was a pop with a cloud of white smoke and that was it. Didn't hiccup this time.

Anyone have an idea what might be causing it? Is this normal for a turbo?

 

[SallySpeed3]

I know its normal to sometimes get a puff of grey/black smoke with this car because it tends to run very rich, although I never did. Does your tailpipe emit this smoke if its been idle for a long time?

 

[Darth Vader]

Stop namby-pambying the engine so much. You are loading up the plugs with all your low rev driving and that's likely what's causing the hiccups when you get on it after that. You are forcing the engine to operate in a range it isn't very efficient in. A little more revs drops the load and actually saves you gas, to a point.

 

[SallySpeed3]

Yeah he's actually right, if you keep an eye on current mpg's you'll see them improve if you stay a little over 3000 rpms. I cruise in 4th gear around 3100 rpms and get much better mpg's than I would in 5th at 2500 rpms.

 

[matsuda]

You need to do an Italian tune-up on a regular basis.

 

[Darth Vader]

Avvio la cosa....(yes)

 

[kaganb]

Okay, I'll give it a shot using higher revs and see if that takes care of it.

Another factor to toss in is that I recently started using the AC again (hasn't been warm enough to justify it) the past couple of weeks which seems to coincide with the issues I've been having. I don't think they are related though, but I'm going to keep an eye on it to see what the AC status is when the hiccup occurs again.

Thanks for the suggestions =)

 

[Darth Vader]

The AC places even more load on the engine when the compressor is on. Since you're lugging the engine badly and then the ac switches on, yep, that could cause some weird feelings. The AC is on with any setting bar face vents, face vents/footwell and footwell indicated, if you have the climate control setup.

 

[kaganb]

Update on this...

Hiccups still occur, but less often. 3 times since the original post. One of those times it was a huge black cloud of smoke. The other thing I am noticing is that my mpg actually went down if I cruised at 3000 vs 2500, so I am shifting just above 3000 and cruising at 2500.

Also, this is about 2500 miles after I changed my oil from 5w30 Pennzoil Platinum to 5w30 Mobil 1 fully synthetic (couldn't buy PP locally). Going to order some PP online for my next oil change and see if that helps at all.

 

[MSMS3]

Oil choice and selection is not your issue, and full synthetic is the best protection for your turbo you can have. You are going to occasionally hickup and have the occasional puff of smoke going on boost from cruise on this engine.

Did you buy the car new? Is it completely stock or does it have mods, if so what? If you are not the original owner, there is no telling what plugs might be in it, or what other mods may have been made. Just trying to eliminate diagnostic dead ends or follow reasonable leads based on more information.

 

[79535]

Update on this...

Hiccups still occur, but less often. 3 times since the original post. One of those times it was a huge black cloud of smoke. The other thing I am noticing is that my mpg actually went down if I cruised at 3000 vs 2500, so I am shifting just above 3000 and cruising at 2500.

Also, this is about 2500 miles after I changed my oil from 5w30 Pennzoil Platinum to 5w30 Mobil 1 fully synthetic (couldn't buy PP locally). Going to order some PP online for my next oil change and see if that helps at all.

You may want to inspect/replace your plugs. They may be fouled.

 

[kaganb]

Oil choice and selection is not your issue, and full synthetic is the best protection for your turbo you can have. You are going to occasionally hickup and have the occasional puff of smoke going on boost from cruise on this engine.

Did you buy the car new? Is it completely stock or does it have mods, if so what? If you are not the original owner, there is no telling what plugs might be in it, or what other mods may have been made. Just trying to eliminate diagnostic dead ends or follow reasonable leads based on more information.

Bought the car new as the original owner. Car is completely stock. I never had this issue until a few weeks before my original post and have had the car for just under a year now. I can't imagine it should be a normal occurance with it not happening for the first 10 or so months.

In regards to the sparkplugs possibly being fouled, is that at all likely with about 13,500 miles on them? I was pretty sure platinum ones are supposed to be good for 90-100k miles. What should I be looking for on them to confirm they are going bad? I am quite awful with car maintenance.

Thanks for the help with the issue. Appreciate the ideas.

 

[79535]

The plugs should be a nice tan color on the end. Look for chips/blackening around the electrode and check the gap to ensure they meet the stock specifications in your manual.

Have you inspected your hose clamps yet? It is common to find the hose clamp on the compressor side inlet loose. This usually causes a lean condition though I believe.

 

[kaganb]

More information on this. Had brought my car into Mazda for the 15,000 maintenance and explained what was going on with the hesitation and the response from the mechanic was exactly what Darth Vader had said. Even with me shifting at 3000 and cruising at 2500, it was hesitating slightly.

The mechanic said that I need to stop granny'ing the car and drive it harder. That the car was tuned to be driven hard from the factory and what was causing the hesitation was buildup of gas on the way to the turbo, but that it wasn't being burned off because I wasn't activating the turbo and once I punched it, it would have issues with the amount of gas and cause the smoking by burning off the excess gas according to the computer's calculations. I've started shifting at 3500 and cruising at 3000 and there is no more hesitations at all.

Thanks all =)

Oh, he also mentioned continued driving with that type of shifting would eventually lead to premature spark plug failure.