Puff of white smoke starting?

[TheRedHorace]

HI all. Newbie here and to Toyotas, I could use a little help.

My 07 Auris with the 2.0 D4D engine was having trouble starting, three or four goes on which it would fire up then die, then start a bit rough but be fine once warm. Reading through here I found Cuba Libre's post about the SCV and have changed it, but just a stock replacement as I can't afford to pay Toyota to remap my ECU just for a new SCV. I also gave the MAF sensor a good clean as it was covered in sooty oil (just a coating not clogged or anything, the air filter looks fine and is only 9 month old).

The car now starts on the first turn of the key, but still runs quite rough for a second, emitting a puff of white unburned diesel (you can smell it) before idling up to 900rpm, and is then fine after that. I've put a mini-OBD monitor on and there are no fault codes. When driving it returns an EGR% error between +/-30% once moving, so I'm going to clean that soon, but that doesn't explain the startup smoke.(OBD tool was cheap off eBay but OK for just reading the ECU on my phone, I used it on previous car to clear codes when I had a turbo wastegate sticking). The glow plugs were replaced about 2 years / 20,000 miles ago so should be OK.

Has anyone got any suggestions or ideas for what to look for to diagnose this please? It doesn't seem to be a big problem, but I'd rather do some preventative maintenance that have an unexpected failure 8-) Are there any common issues or things to check?

Thank you.

[Mike169]

Hi Adam, I hopefully wish you haven't blown the head gasket as if your car is a 2007 diesel it falls right into the batch of a bad 3 year batch of of engines and can be very costly to repair. 

Regards, Mike.

[TheRedHorace]

Me too! 😞 . However, there's no sign of water in the oil, nor of oil in the coolant, and it's not overheating, which are all the signs I'd normally look for. Does this engine have some sort of stealth failure ability or have I missed something?

[Mike169]

Hi, between 2006 to 2009 Toyota made a bad batch of diesel 2.0/2.2 engines, basically the gap in between the pistons and the valves/cylinder head was too small and for about 7 years or about 100,000 miles Toyota would repair it for free costing up to £7K but i'm afraid to say yours has gone past it's 'repair by' date.

Sometimes you can get away with having the head gasket changed, for a thicker one or at the worst a new engine, that's the £7k part.

I politely siggest you take your car to any half decent garage for what's known as a 'sniff test' when basically they put a special bottle in your header water tank and some special fluid and then it detects any exhaust fumes in the water system.

Once this is done, costing about £50, you will know where you stand. 

Regards, Mike.

[TheRedHorace]

OK, so I'm guessing piston/valve contact resulting in bent valves, holed crowns or at best worn valve guides? This car's done 101k (so is just past that repair-by as well), but seems to run fine in all other respects. I think I'll take your advice; I have a friendly local independent who seem a lot more knowledgeable than a lot of main dealers I can think of. Maybe they can have a quick sniff :).

Thanks for the responses as well. 👍

[Mike169]

Hi, you are welcome mate, I was politely just trying to tell you the worst case scenario.

Get the sniff test done and take things from there.

Officially the cylinder heads are not skim able and personably I think it's the carbon that deposits on the piston crown on your engine that causes the problem reducing the tolerance between the pistons and cylinder head/valves. 

Come back to me anytime.

All the best to you.

Mike.

[Heidfirst]

Hi Adam, what Michael is referring to is largely found within this long thread below. Toyota's Customer Service Campaign for the small % of AD series engines that developed the issue was for 7 years or 111k, whichever came first. As a 2007 your car went outwith that 6 years ago.