Jump to content
Do Not Sell My Personal Information


Very high fuel consumption on 2009 RAV4 D-CAT


laukejas
 Share

Recommended Posts

Hi,

 

I bought a 2009 Rav4 with just 154,000 km under the hood and full VIN history. Paid 7000€ for it, spent another 1000€ to do a full maintenance and fix minor issues. It is truly a terrific car, I love it. However, there is a huge issue - the fuel consumption is WAY above the official specs. This is a 3rd gen Rav4 after the facelift, with the new diesel engine (D-CAT, 2.2l, 130 kW). According to official specs, this engine should get 8.4 l/100 km urban, 6.1 l/100 km extra urban. However, the actual fuel consumption is 11 l/100 km urban, 8.5 l/100 km extra urban - a very significant difference. With a full fuel tank, I struggle to get 600km range.

Now, I'm aware that official specs are usually a bit difficult to achieve, but with my driving style, I always managed to get within 0.2 l/100km of the official specs with my previous cars. With Rav4, I can't even get close.

For reference, with a warmed-up engine, on a straight, level road, going 70 km/h, AC off, I am getting 7.7 l/100km. Any acceleration or a slight incline - and I'm way past 8 l already.

Now, I already put a lot of time and effort into finding and fixing the issue. My car spent almost 2 months in service shop. What has been checked and done already:

  1. Gasket inspected - pristine condition

  2. Fuel, air and oil filters replaced

  3. Oil replaced

  4. Fuel injectors replaced (originals were in pretty bad shape)

  5. DPF inspected - no clogs, perfect condition

  6. Clutch and transmission inspected - no issues

  7. Brakes replaced, suspension checked for alignment, some worn out parts replaced

  8. Tires replaced, pressure checked, wheel alignment checked and balanced

  9. Went to the ECU tuning guys - they tweaked engine a bit to get it closer to actual 130 kW (it didn't feel like 130 kW before), and the fuel consumption went down by around 0.5 l/100 km (the consumption I quoted before in this post is after the ECU tuning)

And after all that - still not even close to the official fuel consumption specs. Service shop guys are out of ideas. I am too.

TLDR - fuel consumption way 2 l/100km higher that norm on 2009 RAV4 with D-CAT, full maintenance on engine, suspension, ECU tuning, didn't help, can't find the issue.

Can anyone help? How do I diagnose why the heck is this engine so hungry? Any advice on how to bring the fuel consumption to <7l/100km?

P.S. now that the winter is approaching, I also noticed that the car has difficulty starting - if it sits outside overnight at 0C (32F), it takes like 10 seconds to start next morning. And that's not even that cold. Battery is just 2 weeks old, pristine condition. This might or might not be related, not sure.

Link to comment
Share on other sites


From what you say, I understand that you have your local equivalent of a SR180? I.e. the 4.3 with the 177 bhp D-CAT engine and a 6-speed manual gearbox. I had one of those ...

From the manufacturer's figures it claims a 40.4 mpg combined (so ~7 L/100km). The Honest John Real MPG site suggests a realistic average of 31.5 mpg - i.e. ~9 L/100km. On this basis to expect better than 7 L/100km would be extremely optimistic ...

How are you measuring fuel consumption? From experience, the only way to get any form of realistic figure is from brim-to-brim calculations and, thus, measuring consumption across many 'tankfuls' of fuel. Figures taken from instantaneous readouts aren't dependable.

From personal experience I achieved an average of 37.2 mpg over 56,000 miles (so ~ 7.6 L/100km) which I consider pretty good for the car. Consumption per tank varied between 44.3 mpg (~ 6.4 L/100km) for long journey at very modest cruising speeds along the motorway (probably in the summer) right down to 29.7 mpg (~ 9.5 L/100km) ...

I averaged around 334 miles between fills (so 540 km) - so a 600 km range sounds about right.

  • Like 1
Link to comment
Share on other sites

Hi, i understand there has been a number of comments on the D-Cat relating to poor MPG.

Have you tried this method to access MPG.

 The next time you go to a petrol station, fill to the top the car with fuel.

 Make a note of your mileage before pulling away. Alternatively, reset your car's trip computer to zero so it keeps a record of how far you drive.

 Drive as normal until the fuel gauge tells you that you only have half a tank remaining and return to a petrol station to top the tank up again.

 Once you've topped up the tank for a second time, make a record of how many litres the fuel pump says you put in your car.

 Convert litres to gallons. 

Record how many miles you travelled between the two refills by checking your previous note or the trip computer.

 Divide the miles you travelled by gallons put into the tank on the second visit. The result will be your cars average miles per gallon for that particular period.

  • Like 1
Link to comment
Share on other sites

48 minutes ago, debrun said:

Might be worth checking your heater plugs for your slow starting issue.

I'll look it up, thank you.

34 minutes ago, philip42h said:

From what you say, I understand that you have your local equivalent of a SR180? I.e. the 4.3 with the 177 bhp D-CAT engine and a 6-speed manual gearbox. I had one of those ...

[...]

You mean Toyota Auris SR180? Not sure why you mentioned it, my Rav4 is a very different car. Like I mentioned, it is 2.2l diesel with 130kW D-CAT and 6-speed manual gearbox.

36 minutes ago, philip42h said:

How are you measuring fuel consumption? From experience, the only way to get any form of realistic figure is from brim-to-brim calculations and, thus, measuring consumption across many 'tankfuls' of fuel. Figures taken from instantaneous readouts aren't dependable.

22 minutes ago, Bper said:

Have you tried this method to access MPG.

I am using two methods. First one - just reset the onboard long-term fuel consumption calculator on the dashboard by holding down the Trip key, let it run for a few hours, and then check. Second - what you suggested, measuring how much fuel I add up from last fuel-up (I always fill to brim), and then do the math based on the mileage since that refuel. Both results match, indicating that car's automatic consumption calculator is showing accurate results.

 

The official specs I mentioned, along with engine and car data, are found here: https://www.autodata1.com/en/car/toyota/rav4/rav4-iii-xa30-22-d-cat-177-hp-4wd They are stating 28.0 mpg city driving, 38.6 mpg highway driving. But what I get is 21 mpg / 28 mpg respectively.

Like I said, I know that official figures are optimistic, but with all my previous cars (and I had quite a few), I was always within 0.2l/100km within the official figures. Like, for example, if the specs stated 5l/100km (47mpg), I could actually achieve 5.2l/100km (45mpg).

But with this car... I can't even get close. Something is very wrong here.

  • Like 1
Link to comment
Share on other sites

19 minutes ago, laukejas said:

You mean Toyota Auris SR180? Not sure why you mentioned it, my RAV4 is a very different car.

No, I mean a Toyota Rav4 SR180 ... In the UK the 177 bhp D-CAT diesel appeared in the Rav4 as a T180 and, later, as a SR180. Mine was a 2009 registered Rav4 SR180.

  • Like 1
Link to comment
Share on other sites

1 minute ago, philip42h said:

No, I mean a Toyota RAV4 SR180 ... In the UK the 177 bhp D-CAT diesel appeared in the RAV4 as a T180 and, later, as a SR180. Mine was a 2009 registered RAV4 SR180.

Oh, sorry, my google didn't turn that one up. Not sure if it is the same engine or not. But like I said, in any case my engine clearly has an issue... It's ways off from what it should be consuming. And with the fuel prices right now, you can understand my wish to reach that 7l/100km that the manufacturer claims possible.

Link to comment
Share on other sites

OK, so forget the manufacturer's NEDC figures. There's ample empirical evidence out there that you won't get anywhere close. A realistic target is somewhere around 9 L/100km - if you drive gently you may be able to beat that but your car is already at 154,000 km so hardly a spring chicken.

What are your last three brim-to-brim consumption figures?

  • Like 1
Link to comment
Share on other sites

2 minutes ago, philip42h said:

OK, so forget the manufacturer's NEDC figures. There's ample empirical evidence out there that you won't get anywhere close. A realistic target is somewhere around 9 L/100km - if you drive gently you may be able to beat that but your car is already at 154,000 km so hardly a spring chicken.

What are your last three brim-to-brim consumption figures?

Okay, forgive me, I just don't get it - then why was I able to (almost) reach manufacturer's NEDC figures with every other car I owned? When I look at these customer-reported figures, I assume most of them run their cars far harder than I do. I was always pretty darn good at driving my cars economically.

To answer your question, my last three figures were all 10.5-11 l/100km. As for the 154k range, you are right about that - but if so, what engine components might have worn out that I need to replace (except for what I already did that I mentioned in my initial post)? I would very much like to restore this engine to a condition where I could get the best mileage out of it.

Link to comment
Share on other sites

10.5-11 L/100km comes out as 25-27 mpg and you should be getting better than that if you are driving sensibly.

As you say, you've had a lot of work done on the car already so I'm limited to a couple of questions / suggestions before I'm completely out of my depth:

  • The D-CAT system includes a fifth injector that adds fuel to raise the temperature of the exhaust gases to periodically regenerate the DPF. Is the exhaust 'clean' and is the system regenerating correctly? This is a known 'problem area' on this engine but it's usually pretty obvious when things aren't working as they should.
  • As I understand replacement injectors need to be coded into the system (rather than just replaced) and it is also highly desirable to use OEM parts (Denso) rather than copies. Do you know whether this was done?
  • Like 4
Link to comment
Share on other sites

5 minutes ago, philip42h said:

10.5-11 L/100km comes out as 25-27 mpg and you should be getting better than that if you are driving sensibly.

As you say, you've had a lot of work done on the car already so I'm limited to a couple of questions / suggestions before I'm completely out of my depth:

  • The D-CAT system includes a fifth injector that adds fuel to raise the temperature of the exhaust gases to periodically regenerate the DPF. Is the exhaust 'clean' and is the system regenerating correctly? This is a known 'problem area' on this engine but it's usually pretty obvious when things aren't working as they should.
  • As I understand replacement injectors need to be coded into the system (rather than just replaced) and it is also highly desirable to use OEM parts (Denso) rather than copies. Do you know whether this was done?

Thank you for these additional suggestions.

  • I stressed this first point at the service shop. They checked the DPF system inside and out - said it is clean. I ran my own OBDII device - onboard computer does not report any errors. I am not sure if there are any other ways to diagnose possible issues here?
  • Service shop guys brought the car to ECU tuning people right after swapping out the injectors. I assume they coded these injectors, but I am not 100% sure. In any case, fuel consumption didn't worsen after injector change, it got a bit better, presumably because of ECU tuning. It should be noted that the injectors I got were from a 100kW version of the engine, because original injectors are not manufactured anymore. I was worrying that mis-matching injectors might cause issues, but like I said, this whole repair didn't do much to fuel consumption in either direction.
Link to comment
Share on other sites

7 minutes ago, laukejas said:

Thank you for these additional suggestions.

  • I stressed this first point at the service shop. They checked the DPF system inside and out - said it is clean. I ran my own OBDII device - onboard computer does not report any errors. I am not sure if there are any other ways to diagnose possible issues here?
  • Service shop guys brought the car to ECU tuning people right after swapping out the injectors. I assume they coded these injectors, but I am not 100% sure. In any case, fuel consumption didn't worsen after injector change, it got a bit better, presumably because of ECU tuning. It should be noted that the injectors I got were from a 100kW version of the engine, because original injectors are not manufactured anymore. I was worrying that mis-matching injectors might cause issues, but like I said, this whole repair didn't do much to fuel consumption in either direction.

Starting problem previous posts on this 

Toyota Rav 4 2.2 D-CAT starting problem/ problems https://www.toyotaownersclub.com/forums/topic/190665-toyota-rav-4-22-d-cat-starting-problem-problems/

Link to comment
Share on other sites

9 minutes ago, Bper said:

Starting problem previous posts on this 

Toyota Rav 4 2.2 D-CAT starting problem/ problems https://www.toyotaownersclub.com/forums/topic/190665-toyota-rav-4-22-d-cat-starting-problem-problems/

Thanks for that link. So according to that topic, starting issues might be due to glow plugs, spark plugs (which I swapped), air leak or EGR. I will look into this. I'm not sure about EGR - I thought Rav4 has DPF instead? Or does it have both?

Also, that topic mentions priming pump. I can't seem to find one on my car. Where is it?

This also got me thinking about fuel consumption issue. There are 3 things that I haven't checked:

1) Air pump;

2) Fuel pump;

3) Fuel filter.

Could any of these cause higher than normal fuel consumption? What is the simplest/cheapest way to test these components?

Link to comment
Share on other sites

Err, diesels don't have spark plugs so what did you swap??

Rav4 has EGR and DPF (EGRs came first, so any vehicle with a DPF almost certainly has an EGR too)

Priming pump is in the engine bay - It looks like a button on top a cylinder a bit bigger than a coke can (IIRC) that you can just push down on a few times to prime the fuel system, but if the car is running you shouldn't need it. It's only really useful if you completely run out of fuel and need it to get some fuel into the fuel lines so the fuel pump can suck on something that isn't air.

What sort of driving are you doing, lots of start-stop city driving? Those engines don't really get efficient until they're nice and hot which usually requires longer journeys at higher speeds.

 

Link to comment
Share on other sites

17 minutes ago, Cyker said:

Err, diesels don't have spark plugs so what did you swap??

RAV4 has EGR and DPF (EGRs came first, so any vehicle with a DPF almost certainly has an EGR too)

Priming pump is in the engine bay - It looks like a button on top a cylinder a bit bigger than a coke can (IIRC) that you can just push down on a few times to prime the fuel system, but if the car is running you shouldn't need it. It's only really useful if you completely run out of fuel and need it to get some fuel into the fuel lines so the fuel pump can suck on something that isn't air.

What sort of driving are you doing, lots of start-stop city driving? Those engines don't really get efficient until they're nice and hot which usually requires longer journeys at higher speeds.

 

Sorry, brain !Removed!, I meant injectors, not spark plugs lol.

Okay, I will try the priming pump next time I have issues with starting, just to test.

As for driving, most of my miles are on the highway (90-100 km/h / 60-65 mph), and as for the city, there isn't much traffic here. I usually drive for an hour or two, engine gets warm in 10-15 minutes. If there was lot of start-stop, I would probably be looking at 15 l/100 km...

It pains me to say this, but when I was choosing a 4WD SUV, I was choosing between Rav4 and Skoda Yeti. Chose Rav4 because of higher clearance and proper LSD instead of some electronically controlled 4WD (because I occasionally do off-road). But with this fuel consumption so far from the specs, I wonder if I made a mistake...

  • Like 2
Link to comment
Share on other sites

Aha that makes more sense :laugh: 

Sounds like your journey should be good for that sort of engine so not sure what else to suggest... :sad: 

 

Link to comment
Share on other sites

1 minute ago, Cyker said:

Aha that makes more sense :laugh: 

Sounds like your journey should be good for that sort of engine so not sure what else to suggest... :sad: 

 

Isn't there a deductive, step-by-step way to find the reason behind too high fuel consumption, rather than guessing? I mean, the reason has to be there, engines are not magic 😄

Link to comment
Share on other sites

Guys, I have an update. Something very peculiar happened today. I had a non-stop 9 hour highway drive, starting with a full fuel tank (topped-off after near-empty). Temperature outside was 3°C. Traffic minimal (I could keep constant speed on speed autopilot all the time). Mostly flat road, no rise in elevation. I warmed up my engine for 30 minutes (driving), and then reset the onboard fuel consumption meter to start taking readings. I will remind at this point that I have triple-checked that meter during these last few weeks, and found it to be very accurate and reliable.

I drove at 90 km/h for 30km - fuel consumption averaged at 9.1 l/100km. Then I reset the meter.

Then I drove at 100 km/h for 30km - fuel consumption averaged at 10.5 l/100km. Afterwards, I reset the meter.

Finally, I drove at 110 km/h for 30km - fuel consumption averaged at 11.3 l/100km. And reset the meter again.

Which, like I said, is way off from what this car should be consuming.

But then something happened. I returned back to 90 km/h, and continued the drive (consumption returned to 9.1 l/100km). After a few more hours, I noticed that the fuel meter readings are going down rapidly, even though nothing changed. Curious, I reset the meter again to see what is happening here. The fuel consumption dropped to 7.5 l/100km. And over the next 30 km or so, it continued dropping, until it finally stabilized at 6.5 l/100km - just a touch above what the manufacturer is claiming for this engine in an extra-urban driving.

I couldn't believe it, thought maybe the meter is wrong (even though it was always dead-on accurate before when I compared it to refuel amount between top-offs and distance driven). But every other instrument on the dashboard confirmed the same thing, even the analog fuel tank gauge. I still wondered if maybe the fuel tank float got stuck or something, but near the end of my drive, I had to stop at a gas station - and by then, I had driven 826 km since last refuel... Compared to my usual sub-600 km range. This confirms that the meter is still accurate.... But... what the heck??

I have absolutely no idea what happened here. It's almost as if the engine suddenly got unshackled from something. I had driven FAR too long since this sudden drop in fuel consumption happened, so it can't be engine warming up. No engine takes 3-4 hours to warm up after the temperature gauge is already in the the middle. DPF cleaning (hot burn) cycle ending? But it can't be that either, it would mean that the whole time I was driving this car up to this point, the DPF was cleaning itself all the time, and only completed it now. Unless there is some electronic/sensor malfunction, and it actually was..?

Or could it be something else? I have absolutely no idea what could cause such a sudden and massive drop in fuel consumption many hours into a non-stop drive at a constant speed and road conditions.

This, however, confirms beyond a doubt that the engine is capable of such efficiency, and I wasn't just imagining problems. There is definitely something there gulping up that extra fuel. Now all I need is to find it. I will take my car out again after a few more days, and see if the typical (high) fuel consumption returns. Somehow I have a feeling that it will. But today was a breakthrough.

Any ideas what the heck happened here? 😄

 

Link to comment
Share on other sites

It always takes a while for a accurate reading after reseting MPG on the car I only reset mine once a year after that I take the readings from my phone be it just one trip from 4  that day , a full day weekly or monthly or yearly.

Link to comment
Share on other sites

DPF Regen?
I wonder if the car was attempting DPF Regen (rightly or wrongly) and adding lots of extra fuel. At some point it may have decided that the regen is complete and stopped adding extra?

Clutching at straws really but all I can think of that would explain a large change in consumption on the move.

  • Like 1
Link to comment
Share on other sites

11 hours ago, laukejas said:

I drove at 90 km/h for 30km - fuel consumption averaged at 9.1 l/100km. Then I reset the meter.

Then I drove at 100 km/h for 30km - fuel consumption averaged at 10.5 l/100km. Afterwards, I reset the meter.

Finally, I drove at 110 km/h for 30km - fuel consumption averaged at 11.3 l/100km. And reset the meter again.

This is broadly what you would expect ... fuel consumption during cruising conditions is proportional to the speed you are travelling. Go 10% faster and your will consume 10% more fuel; go 10% slower and you will consume 10% less fuel. The figures you quote are broadly in line with that - at least to the level of experimental accuracy.

Link to comment
Share on other sites

From memory, an active DPF regen takes about 30 minutes from when the engine gets up to temperature and is running above 2000 rpm. Which is one of the reasons why this engine likes longer journeys and dislikes frequent short runs. Over 9 hours you'd be very disappointed if the regen cycle didn't complete.

With regular long runs the system should survive on passive regeneration alone - i.e. without adding extra fuel via the fifth injector to raise the temperature of the exhaust gasses. Certainly in the second part of your journey that should be the case. This could explain the improvement in fuel economy - but only if you accept that the car was stuck in an overdue regen cycle from the outset of the journey.

How long ago did you have the injectors changed and/or the ECU interfered with? If the ECU has been reset it will take some time to relearn the parameters of the car and resume normal service. This is a possible explanation if the change is relatively recent.

And then, as you note, if there is a fault with the fifth injector or the associated sensor(s) this could result in the fifth injector delivering fuel when there is no need to do so. If this were to be the case you could have an irritating, intermittent fault ...

Link to comment
Share on other sites

13 hours ago, laukejas said:

but near the end of my drive, I had to stop at a gas station - and by then, I had driven 826 km since last refuel...

How much fuel did you add at this point?

From what you say I am assuming that you burned a whole tank of fuel in one sitting (more or less) and at an average speed of around 92 kph ... ?

Link to comment
Share on other sites

15 hours ago, Derek.w said:

It always takes a while for a accurate reading after reseting MPG on the car I only reset mine once a year after that I take the readings from my phone be it just one trip from 4  that day , a full day weekly or monthly or yearly.

Yeah, well, I reset that meter very often to observe my MPG in certain set of conditions (I still like to drive at least 15-30km to let the average settle). But like I said, through comparisons with manual calculations, I found that meter to be accurate and reliable. I see no reason to doubt that it is telling the truth

4 hours ago, Strangely Brown said:

DPF Regen?
I wonder if the car was attempting DPF Regen (rightly or wrongly) and adding lots of extra fuel. At some point it may have decided that the regen is complete and stopped adding extra?

Clutching at straws really but all I can think of that would explain a large change in consumption on the move.

That is what I'm suspecting too. But I have been driving this car for nearly 2000 km now (mostly 1-3 hour highway drives, sometimes more), and this is the first time I observed such a huge and sudden drop in fuel consumption. Could it be that the car was stuck in DPF regen all this time until now?

4 hours ago, philip42h said:

From memory, an active DPF regen takes about 30 minutes from when the engine gets up to temperature and is running above 2000 rpm. Which is one of the reasons why this engine likes longer journeys and dislikes frequent short runs. Over 9 hours you'd be very disappointed if the regen cycle didn't complete.

With regular long runs the system should survive on passive regeneration alone - i.e. without adding extra fuel via the fifth injector to raise the temperature of the exhaust gasses. Certainly in the second part of your journey that should be the case. This could explain the improvement in fuel economy - but only if you accept that the car was stuck in an overdue regen cycle from the outset of the journey.

How long ago did you have the injectors changed and/or the ECU interfered with? If the ECU has been reset it will take some time to relearn the parameters of the car and resume normal service. This is a possible explanation if the change is relatively recent.

And then, as you note, if there is a fault with the fifth injector or the associated sensor(s) this could result in the fifth injector delivering fuel when there is no need to do so. If this were to be the case you could have an irritating, intermittent fault ...

Thank you, these are very acute observations. My injectors were changed around 1000 km ago. Since then, I only had long drives, definitely long enough to perform DPF regen. But it feels like it was stuck on that regen all the time, and completed it only mid-way through that 9 hour drive.

I will definitely look into that fifth injector.

2 hours ago, philip42h said:

How much fuel did you add at this point?

From what you say I am assuming that you burned a whole tank of fuel in one sitting (more or less) and at an average speed of around 92 kph ... ?

I added 57.54 liters. So yes, I burned almost the entire tank. I can't say what the average speed was (didn't reset that meter after previous refuel unfortunately), but almost all out of these 826 km were done on this 9 hour trip. Probably averaging 90 km/h of actual driving (I had a few short stops). I didn't measure time very accurately here, but distance and fuel added is dead-on accurate. So the actual average between refuelings was 7 l/100km.

 

Okay, so now my main question is, how exactly does the car decide when to do a DPF regen? Is there some kind of sensor? Or is it done based on distance/time since last regen? Is this logic documented somewhere?

Also, how do I access DPF regen status (meaning, is it regenerating or not at any specific moment) through OBDII? I have a BAFX OBDII scanner that I can connect to via my phone. I tried several apps for reading the data, but I can't find anything relating to DPF. I want to determine when exactly does regen start and end, so I can see if it coincides with fuel consumption increase/decrease. This would also show it the car is stuck on regen cycle all the time.

Additional question, is it possible to temporarily disable DPF regen altogether? I don't want to clog it on purpose, I just want to see if disabling it makes a difference if fuel consumption. If yes - then it means it is definitely stuck on regen all the time.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share





×
×
  • Create New...




Forums


News


Membership