Intermittent power loss Avensis diesel

[Pavarotti]

Hi Guys

Was on motorway and the car experience a noticeable loss of power.  Put peddle to the floor but nothing happened.  When I changed down a gear or two the power came back. No lights came up on the dash.  Coming up a hill recently the same thing happened. The engine was not responding to the peddle.  Had to pull over.  When I restarted the car it was fine.  It doesn't seem to be a consistent problem but it is a bit worrying not having precise power response when on a slip road or joining a lane of traffic.

 

Any suggestions on what it can be and where to look before I book it in.

 

Thanks   AG

 

[Heidfirst]

Hi Aldo, welcome to TOC 

Diesel? possibly SCV.

 

P.s. if you edit your profile with a bit more info on your car it will help people to help you as they won't have to ask the question first ...

[Pavarotti]

Hi

Yes its 2004 diesel  D4D.  The mileage is fairly high . About 211000.    A diagnostic machine couldn't find the problem as it is intermittent.

Thanks  AG

 

ps  what is a SCV?

[Heidfirst]

your profile says 2004, your profile says 2007 - which is it as they would be different engine series?

scv= suction control valve

[furtula]

Can it be the pedal potentiometer?

 

[Verdi]

Finally sorted the power loss problem on my 2004 Avensis estate D4D.

It was losing power and would not respond properly to the accelerator.  If I shifted down a gear the power would suddenly come back but a large cloud of black smoke was ejected..  Strangely nothing showed on the dash in terms of warning lights.. A diagnostic check failed to find the problem due to it being an intermittent fault.  Trawling through the forum I enevtaully pinned it down to the EGR unit.

In my car it is located on the engine block to the left of the air filter.  Had to remove filter and box and undo three stubborn bolts.  The bottom one I couldn't see. Had to be done by feel.  Took the unit off which was quite sooty. Cleaned it with WD40 and some petrol.  I think the problem wasn't the soot but the fact that a spring loaded piston wasn't operating properly because of the soot build up.  Having cleaned it and replace it back. The car now drive as before.

Hope this is of use to anyone with a similar problem.  Stuff on the web and on this forum is invaluable.

 

Thanks   AG

 

[DiscoStoo]

Yes I have the same issue on mine, and normally make a point of manually servicing that part every year (6 months ideally). It can be quite a stiff spring on the valve and only takes a bit of buildup for it to cause lumpiness and such - you should find you'll get a few extra MPG on motorway journeys as a bonus. 👍