White smoke

[ben holden]

Hi All,

I have a 2011 Rav4 150bhp (2AD-FAV I think). The problem I'm experiencing is, when warm, its intermittently chucking out a light white smoke from the exhaust. Can be while sat in traffic or giving it some poke. Doesn't happen all the time and sometimes only lasts a few minutes.

The smoke stinks of diesel and when it happens fumes can be smelt in the car and mpg drops. I've plugged it into techstream and no codes are stored. The only thing I can see is the maf has a test value of 1.2 and mine shows a value of 1.17 during test.

Anyone else experienced this? i'm thinking a bad 5th injector or faulty main injector?

[NASY]

Ben, as many would tell you white smoke is water.

[ben holden]

not using any water and smells of diesel

[Cyker]

It may be the 5th injector, assuming yours has one, is clogged and spraying a jet of diesel into the DPF instead of a fine mist and it's just coming out as airshow smoke.

Could try running some fuel system cleaner (e.g. redex, bg245) or a few tanks of super diesel through it to see if that cleans it, but because the 5th injector doesn't fire much it'll take a while to get enough cleaning agent through it.

[philip42h]

12 hours ago, ben holden said:

Hi All,

I have a 2011 Rav4 150bhp (2AD-FAV I think). The problem I'm experiencing is, when warm, its intermittently chucking out a light white smoke from the exhaust. Can be while sat in traffic or giving it some poke. Doesn't happen all the time and sometimes only lasts a few minutes.

The smoke stinks of diesel and when it happens fumes can be smelt in the car and mpg drops. I've plugged it into techstream and no codes are stored. The only thing I can see is the maf has a test value of 1.2 and mine shows a value of 1.17 during test.

Anyone else experienced this? i'm thinking a bad 5th injector or faulty main injector?

Oh no, not another "white smoke" thread! If you search the forum, you'll find that you are not alone ...

First, we need to clarify which engine you have - I don't believe the 2AD-FAV exists. Which country are you in? Which model do you have? Is it manual or automatic? If you were in the UK, a 2011 car would be either a manual with the 2AD-FTV D-4D engine or an automatic with the 2AD-FHV D-CAT engine. Can you clarify?

Unless I am very much mistaken, the 2AD-FTV does not have a fifth injector.

The 2AD-FHV / D-CAT is blessed with a "clean diesel system with the DPNR four-way catalyst, the engine to achieve exceptionally low combined NOx and particulates emissions". It was introduced to reduce the emissions from higher output engines and cars equipped with an automatic transmission. This system includes the fifth injector to regenerate the DPNR as it gets 'full' of soot.

If this system actives at the wrong time - i.e. when the engine is still too cold or below 2000 rpm - the result will be a "white smoke" comprising unburned diesel - which seems t align with what you describe but it is by no means the only possible cause of white smoke.

I had a D-CAT equipped 2009 SR180 that would occasionally puff white smoke - the cure was simply to take it on a long run to get the DPNR properly cleaned and the regen complete.

So, assuming that you have a D-CAT, the next question relates to your journey profile - do you take the car on regular longer journeys at higher speeds or does the car just potter about town? An hour on the motorway once a week would count as "regular longer journeys at higher speeds" ...

[GBgraham]

Don't worry about the MAF, that is absolutely fine but obviously there is an excess fuel issue, if you can't hear a change in the engine tone or power when it decides to throw out white smoke I would rule out main injectors.

Initially try the recommendations already given on here and go from there.    

[ben holden]

Thanks for the reply's.

Its a UK 2AD-FTV DPF with 5th injector (confirmed by Toyota). Runs mainly consist of around town with a couple of longer drives (30min+) per week

I've had it plugged into Techstream again today and typically it wouldn't smoke!

screen shots attached. couldn't see anything out of the ordinary apart from the DPF pressure jumping around. at idle it was between 0.175 & 1.925 kpa and at 3000rpm anywhere between 2.0 & 4.6 kpa. is this normal?

[GBgraham]

As suggested, take a closer look at the 5th injector and probably the EGR valve

[Nick72]

21 hours ago, ben holden said:

Hi All,

I have a 2011 Rav4 150bhp (2AD-FAV I think). The problem I'm experiencing is, when warm, its intermittently chucking out a light white smoke from the exhaust. Can be while sat in traffic or giving it some poke. Doesn't happen all the time and sometimes only lasts a few minutes.

The smoke stinks of diesel and when it happens fumes can be smelt in the car and mpg drops. I've plugged it into techstream and no codes are stored. The only thing I can see is the maf has a test value of 1.2 and mine shows a value of 1.17 during test.

Anyone else experienced this? i'm thinking a bad 5th injector or faulty main injector?

Only time I had this was on my Nova. I suspected the head gasket. Cooling water getting into the cylinders.

That's what it was. Fortunately a mate of mine skimmed the head and fixed it for a couple hundred quid. That was 1992 I think. Expensive job these days. 

[ben holden]

1 hour ago, GBgraham said:

As suggested, take a closer look at the 5th injector and probably the EGR valve

Hi Graham. I'm thinking 5th injector or possibly DPF pressure sensor (causing random regens). EGR is new as the old one packed up (motor failed)

[GBgraham]

I don't think it will be the pressure sensor because I suspect this would throw up a fault code. If it is random regens it's more likely to be what is telling it to operate.

I'm sorry but I'm not au fait with this particular model, now if it was European and especially French we would be could be on to a winner. As an example a lot used to have magnetic switches in the fuel cap that used to instruct the ECU when it had a fill of fuel and then it would kick in and regen the DPF. 

 

[ben holden]

Should the DPF kpa value be jumping about so much? I would of thought the value should be consistent unless there's a change in engine rpm?

[GBgraham]

16 hours ago, ben holden said:

Should the DPF kpa value be jumping about so much? I would of thought the value should be consistent unless there's a change in engine rpm?

In an ideal world no, a constant would be expected at idle but the fluctuations are on such a small scale this may be acceptable But what would be causing it to fluctuate, a signal or a fault in the pressure sensor, blocked pipe lines or a blocked DPF, these need to be determined but if the pressures were too high and out of range I would expect a fault code.

A good place to start maybe, there are products out there for cleaning out DPF's and lines but I have absolutely no experience of such products.

Do you not have a good independent Toyota workshop in your area that may have had hands on experience with DPF problems on your model. Anyone on here can only pass on limited information and the expectations of remedying  remotely is about zilch.

 

[ben holden]

I'm starting to suspect the dpf sensor. It's showing readings between empty an 50% full in a matter of seconds. Maybe making the ecu think it needs to trigger a forced regen hence the unburnt diesel out of the exhaust?. I'll check the pipework for blockage tomorrow. The sensors relatively cheap so if it's possibly playing up it can be changed especially as it's mounted above the dpf and turbo so will be subjected to some serious heat

[GBgraham]

Now I've had more time to take my brain out of retirement and digesting your issue further, I have found this from a Pico (automotive oscilloscope test equipment) service page which may  . . . 

------------------------------------------------------------------------------------

"I have been thinking about DPF back-pressure and in particular, a Toyota formula used for checking DPF breathing efficiency.

The formula states that dividing DPF differential pressure by MAF should result in a value below 0.2 if the DPF is not restricted.

The formula uses serial data obtained during a road test with the DPF temperature stable > 450°C.

 For example:

 MAF = 25 gm/sec

 DPF differential pressure = 2 kPa

 Therefore 2 / 25 = 0.08 and so DPF is OK.

However, if DPF differential pressure was 6 kPa with MAF at 25 gm/sec then: 6 / 25 =0.24 meaning the DPF is restricted."

----------------------------------------------------------------------------------

From your supplied info of Techstream values  . . . . . . 

MAF = 64.62 gm/sec

DPF differential pressure = 4.679 kpa

I realise the base figures are different to the example but on this theory based on your print out figures the the DPF is okay. 

[GBgraham]

Sorry I forgot to finish off the math  . . . 4.679/64.62 = 0.0724

[ben holden]

Thanks Graham for the useful info. the values appear to show the DPF is ok but the car wants to regen.

 

I'm going to try a forced regen tomorrow and see what the pressure values are after that

[ben holden]

Have tried doing a forced regen in techstream and nothing happens!!! Exhaust temp stays at about 110 deg c, no change in rpm etc

[GBgraham]

12 hours ago, ben holden said:

Have tried doing a forced regen in techstream and nothing happens!!! Exhaust temp stays at about 110 deg c, no change in rpm etc

Okay then, no white smoke on regen then? 

If not, it's time to start to look elsewhere, white smoke is excess fuel so the injectors might the a good place to start.

[ben holden]

Wont do a regen which has made me dig further! looking through the Techstream data I keep finding the AFS voltage is always at 0v with a current of -10.98ma which makes me think the ECU is getting mixed messages about the air fuel ratio and its running rich

[GBgraham]

At idle you can expect a 0v reading but I see from your data sheet it's running just short of 2500rpm so you should expect voltage. 

The only problem with this assessment is that if the 02 is at fault or the ECU isn't detecting the expected values then I would fully expect that the car should then be showing a fault code. 

You may be able to glean enough by a digital meter at the O2 connection but ideally an oscilloscope is needed for a true picture of the O2 operation. 

I would also do the test at the ECU to make sure there isn't an anomaly appearing between the two connection points. 

While you are at the ECU, make sure all the pin connectors are fully home and locked in. I remember once a reasonably new Toyota giving me the run around of an intermittent fault because of such an issue and I have no idea whether it was caused at the time of production or man made at a later time but chasing faults as this can be a nightmare. Retirement is bliss😂