The symptoms.
The MPG is disgraceful this time last year we was averaging no less than 38mpg over a tank and around 42-45mpg when driven on a run with cruise control set at 70mph. Over Christmas we did approx 1500miles and have managed best on a run +4oc 31mpg driving with cruise control set at 70mph, when it was cold we was down to 21mpg and have now risen to around 30mpg driving like your gran going to church. These figures are a long way short of the figures that Toyota quote and of what we was achieving this time last year with similar temperatures, it may be worth noting the car makes a pinking sound at around 1800-2300rpm if you put your foot down and there is a small delay / flat spot in throttle response (not turbo lag) when you press the accelerator, I suspect this is the fly by wire throttle system but is it supposed to have a delay?
How to clean, I did have to borrow a few pictures as I had cleaned mine by the time I made this thread.
1. Remove the engine cover, this just pulls up and unclips.
2. Now you can see the EGR Valve, you will need a 12mm socket, Ratchet and extension to remove this.
3. Remove these 2 x bolts 1st for the pipe above the EGR valve.
4. Now undo the other 4 x 12mm nuts and bolts from the EGR valve and unplug this from the wiring loom, this can now be removed.
5. This is now what you will find.
Dirty manifold with 2 x blocked breathing holes.
Dirty EGR valve with restricted air flow.
6. I cleaned these using an old toothbrush, small screw driver, carburettor cleaner, old cloth and a dyson cleaner to suck the muck out. Try to scrape and brush out the thick carbon then use the carburettor cleaner to clean the finish this off.
Now once all this is cleaned out just simply refit, This took me a total of 15 minutes so I assure you this is very easy.
The results
This will vary for everyone but in my experience I did a 360mile round trip the next day with mainly cruise control set at 70mph, going there (more downhill) the roads where very very wet with poor visibility and approx 7oc and we averaged 41.1MPG by the time we got there. When we come home with mainly cruise control set at 70mph, slightly uphill most of the way the roads where dry and approx 3oc the average MPG had dropped to 40.0. When I filled up we got 37.4litres in the tank which I rounded up to 38 and worked out at 43MPG (I always brim the tank). This is now showing a big improvement / approx 20% for a 15minute job of cleaning the EGR valve. I will also note the slight flat spots in throttle response are a lot less than before.
I would like to say a big thank you to cabcurtains for bringing the EGR valve to my attention and to twingo69 as I borrowed a few pictures from his thread to make this guide.
UPDATE
Ok it has been nearly 5 months and around 4k since I did this do this morning I thought I would check the EGR valve. To be honest the manifold was very very clean maybe a small less than 1mm coating of carbon and the EGR valve had a little more, I did clean this again while it was removed but in my opinion looking at what I seen today I would recommend cleaning this around every 12months or 10k.
UPDATE
Well over the next 12 months the MPG just continued to drop, Toyota claimed there was no problems with the car but by Feb 11 we could only manage 28-32MPG at best. I had also noticed the car had started to do a lot of DPF recycle burns and suspect the DPF was maybe on its way out, we had no warrenty left on the car so had a shop around and exchanged for a 5 month old 500 mile CRZ. What can I say but for sure the CRZ is one of the best cars we ever owned and was fantastic on fuel (49MPG average for every turn of the key over 9 months and 9000 miles) but due to the birth of Lewis we needed a bigger car so exchanged this for a CTR (FN2), I will say that so far over 7000 miles this has returned 29MPG for us which puts a quicker petrol car in the same area as the T180 when we traded this in.
What never made sence was when we first bought the T180 we could get 40-44MPG no problem then at around 30'000 miles the MPG just started to drop while nothing really changed, we never found a cure for this or a fault but for sure this is problem and Toyota must know about this because they dropped the 2.2 and 2.0 Auris diesel cars and have now agreed to use BMW diesel engines from 2013. Why the worlds largest car manufacturer would need to use a BMW diesel engine is beyond me unless it shows they are struggling to get a modern diesel to be clean and efficient while being very driveable.
