E120 Hatchback Bad Fuel Economy

[Eero]

Hello

I got a new car for myself. Sold the 2000 Avensis and bought 2006 Corolla 2.0 D4D hatchback.

Everything is nice and fine. Just enough electronics, but not too much. I kinda like it. 

But one Big problem. Fuel economy is real bad. Worst than my Avensis wagon. I have changed heat plugs, front wheel bearings, front brake pads and disks. Nothing fancy. But I have like 8 litres per 100km. Avensis with the same 2 liter engine took 5.5 😄 

Any ideas, suggestions etc?

Thanks in advance.

Eero

[oldcodger]

In old UK  money thats 35mpg for the Corolla and 51mpg for the Avensis.

If you search the web/forum on "corolla d4d poor mpg" you will find a few similar threads that might help, though would start with a clean air filter, if its the original housing and check that the rear pads are not sticking or the handbrake shoes dragging badly , perhap try a top end fuel line cleaner like Redex.

[Cyker]

My brother's one hauled like a truck and got 50-55mpg on average with mixed urban and motorway driving so it definitely could be doing better!!

I believe that's the 1CD-FTV so pre-DPF which is the usual go-to for worse-than-expected mpg.

If the previous owner didn't drive it much, it could be the injectors and engine are just full of crud from being run at low temperatures all the time. I found in my old diesel Yaris, when I was babying it through stop-start traffic and such it started to loose power, feel a bit sluggish etc.

I gave it a full tank of V-Power diesel and then thrashed the smeg out of it on some fast roads and hills - Got the engine good and hot, and that seemed to do the trick, and it felt nice and loose and responsive again afterwards! I think that's what started off my occasional weekend hoons, as every time the car started feeling a bit laggy I'd do the same thing and it always felt better for it afterwards.

Other things that might be worth checking is the servicing on it -  Oil and oil filter, air filter etc. changed regularly? Also, the Fuel filter is one that likely hasn't been changed in a while.

Also check the tyres as low pressures can drop a few mpg.

I can't remember if that car had a solid flywheel or a dual-mass one, but if it's dual-mass and hasn't been changed for a while that can also affect mpg as it soaks up power instead of transmitting it to the wheels, but usually you find other issues first like knocking sounds and a slippy clutch so less likely.

 

[Eero]

Injectors tested, all good there. Diagnostics did not showed any faults. Testing fuel additives now. Thinking cleaning MAF sensor. Will update this post and thanks for replys.

[Trewithy]

I don't know if an additive called Cataclean is available where you are, it is well regarded. Cleans the whole fuel system, injectors, valves and cylinder head.

[Eero]

Well I bought fuel additive made by Liqui-Moly. Hope that works. I tried to clean MAF with contact cleaner but the result was awful. Corrosion maybe? 

[Eero]

Ok more info. At idle MAF reading is 6,4g/s. Engine load when driving is always 100%. At idle 96,6%. Totaly weird.