Avensis 2.2 (150Bhp) Diesel Unstable Idle Revs

[Thisisjimmi]

Hi Guys

I have an Avensis 2.2 (150) diesel from 2007 with 130000 on the clock. The engines idle revs are unstable sometimes. I have made a sample recording (please see attache).

The revs are unstable typically at a bit high rpm say than in the video say in a region of 1000 – 1200 but I couldn’t catch that on the video now. I’ve had it for 6 months and I was expecting to get a better MPG from it. I am getting an average consumption approx. 5% worse in the same conditions as our previous car 406 HDI 110 is that normal?

Do you know what could be the reason for the unstable revs?

The car has 130000 on the clock and is due for a service today. I will do oil change, oil, air, fuel, cabin filters. I will also use one of the diesel injector cleaner products. Not sure which one is the best value.

People seem recommend the BG244 but it is expensive:

http://www.amazon.co.uk/gp/product/B0062KYGZC/ref=s9_simh_gw_p263_d0_g263_i2?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=center-2&pf_rd_r=0PA7F9264SN0DHTN180A&pf_rd_t=101&pf_rd_p=467128533&pf_rd_i=468294

Are the STPs any good, seem like much better value…

http://www.amazon.co.uk/gp/product/B0035QBP82/ref=s9_simh_gw_p263_d0_g263_i2?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=center-2&pf_rd_r=00FC4GYFE1ZQNBE6VQ2N&pf_rd_t=101&pf_rd_p=467128533&pf_rd_i=468294

http://www.amazon.co.uk/gp/product/B003PKFIK4/ref=s9_simh_gw_p263_d0_g263_i1?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=center-2&pf_rd_r=00FC4GYFE1ZQNBE6VQ2N&pf_rd_t=101&pf_rd_p=467128533&pf_rd_i=468294

Cheers

Jimmi

[igormus]

Do you know what could be the reason for the unstable revs? ---- air in the system or clogged fuel filter

have car serviced first

cheers/Igor

[Mistermena]

BG244 is the only one that I know works!...

[Heidfirst]

don't see an attachment/video?

whilst normal idle is ~800rpm when warm it's higher when the engine is cold or has extra load (heating, aircon, demist etc.) on it.

as for mpg it's a more powerful engine & being newer probably has more emissions equipment which usually negatively affects mpg.

Driving conditions/style have a noticeable effect - mine varies between middle 30s to over 50s depending on where/how I drive.

[T5NELtim]

Unstable revs at that mileage...If it is happening once the engine is up to temperature and the load is not changing.

I would want to check injectors (££££) and fuel filter(s) (p) and possibly obstuctions in intake/exhaust

[cabcurtains]

Might be worth cleaning the MAF with electrical contact cleaner as a cheap try. Check the EGR and clean if required, again no real cost.

If its done 130k though and is on the original injectors then they will be tired.

[pault38]

On the shelf in Halfords with all the additives is one made by comma, i cant remember the proper name of it but it's in a red/orange bottle, i think it's called power boost. its a one shot cleaner so you put the entire contents in your tank and its only 6 quid a pop and seems to work ok.