Hi All, Firstly I apologies in advance if I have posted this in the wrong section. I am new to this forum and would like some advice on my Mazda5.
I have a 2007 Mazda5 Sport Diesel since brand new in 2007. It's done 56k miles and regularly serviced. The issues I have is this: 4 months ago, the DPF light came on - read the manual/internet and ran the car on the motorway over 2000 rpm and cleared out the filter, the DPF light went off. Job Done -or so I thought, the light came back on after a few days and took it on the motorway and repeated the cycle. Eventually (after a couple of weeks) the light started flashing - which is serious - so took it to my local garage - he cleaned the filter out, put it back, and the light was still flashing - Ended up, I had to replace the DPF - Ouch, that hurt!!! Anyway, car is back on the road. Then after 2 months, the car started smoking blue smoke when I was taking off at traffic lights - this didn't happen every time nor any kind of pattern - just random blue smoke when taking off from a standing start. Took it to the garage and did an early full service, including replacing the fuel filter. Car is back on the road, and the smoking is still happening - although not all the time, it still does. This car is supposed to be a Turbo Diesel, but I never feel a kick that a Turbo is meant to give you. My question to you guys, is this: Should I be looking at replacing the turbo - if not then why do I get blue smoke at random times when taking off from a standing start.
Any help is appreciated.
Thanks in advance.
ps - didn't understand why the DPF went on me as I do 60 miles every day (round trip) on the motorway every day - doing approx 70-80 mph (2000-2200 rpm) But I'm hoping that is now sorted - the light no longer comes on anyway.
JAKK.

 

Just a few thoughts on your problem.
I am not entirely clear in your train of thought. I would have thought blue smoke was more likely to indicate burning oil rather than poor combustion due to lack of air when with diesel it would be black. You do not say whether the lack of turbocharger surge is a new issue or has it always been like this? Or are you suggesting the blue smoke is from oil leaking across the seals of the turbocharger rather than from say a worn engine valve or seal allowing oil to pass into the engine combustion space. I would have thought low turbocharger pressure would be picked up by low pressure sensors and indicated as an engine management fault. Has your engine oil level rise remained consistent - if it is less it would suggest to me the problem is with the engine - not the turbocharger.

Good Luck.

 

Hi Rhodri,
Thanks for the reply - I have never felt the turbocharger from day one of having the car - I didn't relaise this car had a turbo in it, until the mechanic at Mazda told me all 2.0 diesels (of my car 07 plate) have a turbo. So in answer to your first question, I have never felt the turbo - as I am not a mechanic, I wouldn't even know where to look under the hood to see if it has one - I will ask my local garage when I next go there - maybe a few weeks time.
Engine oil has remaimed constant - at the Full level and no where near the "X". I had an issue with the DPF approx 4 months ago, The light stayed on - as the manual says, I took it on the motorway for 30 mins running over 2000 rpm. This cleared the light. This cycle was repeated a few times over a period of 3 weeks, then the light started flashing. The mechanic tried to clean the filter, this didn't work, so the DPF was replaced - ouch!!! SINCE this was replaced, I have been having issues, with the blue smoke. The smoking happens intermittently - but always from a standing start. The last time this happened was approx 1 week ago. When the car runs it runs perfectly, although I have noticed a significant drop in fuel consumption. I am at the point where I am not sure whether I am at the start of major issues with this car - so get rid now - or if the replacement of the DPF needed something within to clear it - so maybe I should not worry and keep it.
From what I understand the DPF is physically no where near the engine - as it's part of the exhaust. As for other explanations - the car has been serviced at regular intervals, so not sure how a seal could be leaking - unless the seal is faulty.
My question through all this, should I get rid or take the plunge and keep it. Mazda charge approx £100 to have a diagnostic done on it - although reading other peoples posts, the diagnostic does not always reveal a fault. Help !!!! I love the car, but don't want to spend £ hundreds keeping it on the road. Any advice/help is appreciated.
Thanks.
JAKK.

 

If it's definitely blue blue smoke then that will be indicative of engine oil burning.White or black could be diesel. White could also be coolant. So we can conclude it's engine oil. Turbos with leaking seals tend to produce blue smoke at idle, especially if the engine has been idling for some while. Blue smoke when pulling away can be valve stem seals. These tend to cause blue smoke as you pull away after the car has been idling for a while, for instance at a set of lights, or accelerating after coasting down a hill.
Blue smoke while driving under normal conditions is usually due to worn piston rings/bores/pistons etc.

If you're burning oil then it must either be entering the combustion chamber or the exhaust system before the DPF. I can't see any connection with blue smoke being produced after a DPF being replaced. However, if the car was burning oil beforehand, I can see that causing problems with oiling up and blocking the DPF.

You really need to have the problem properly diagnosed, it could be something as simple as a blocked breather pipe or it could be rather more serious.

As far as feeling a "kick" from the turbo I wouldn't be too concerned, if the turbo wasn't working you'd have trouble keeping up with traffic and you'd also have the engine management light coming on to warn you of low boost pressure.

 

Hi NickC

Many Thanks for this explantion. You are right, I should exclude the turbo being faulty - as I am able to keep up with traffic - it's no ferrari, but will stay with traffic.

As for the blue smoke, as I say, this happens intermittently, and hasn't done so for nearly two weeks now.

As you say, I think it's best if I take the hit and pay Mazda Main Dealer and let them do a diagnostics check on it. If their tests show anything then at least I can m,ake a decision as to whether to fix or get rid.

Many Thanks for the responses.
JAKK

 

Hey. I'm having something of a smoking issue with my 2007 Mazda 5 2.0 Diesel. Intermittent smoking. Had oil change and new filter, now seems to be smoking again. Oil level seems to be a little high again...

Wondering if you found a solution?

Thanks