T180 Fuel Consumption - Much Too High

[kitlet]

Hi all

I am new to posting on this forum and hope I am in the right place for my problem - also, whilst I love driving, I am not techie and won't always get the technical terms quite right (please bear with me).

Long problems, but only partially resolved to date by Toyota. I have been unlucky enough to have the white smoke emmissions as others have, but now lucky that Toyota eventually (only took c.18 months!!) agreed to replace the engine. However, still have intermittent white smoke puffs and the mpg still appallingly low - c.23-24mpg.

I have owned the car from brand new, mileage c.70k, warranty has been extended (fortunately). Car has been driven c.1000 since engine replaced.

Dealership have just (2 weeks ago) loaded upgraded software for fuel management system. Car then driven c.30 miles in 5 separate journeys - the last being 10 miles on A & B roads - and mpg was at a reassuring 36-37, as it always had been when new 5 years ago. Stopped at a shop for 20 minutes, but when engine started again, mpg dropped immediately to c.23 - it was like someone had simply thrown an internal switch.

Car back to garage but they cannot get any fault readings from the computers. Toyota say that there is nothing wrong and that it is simply the ECU needs to "relearn my driving style" and that "I should drive the car for c.5000 miles" to see if the reading improves!!

Dealership are caught in the middle as Toyota can't/won't authorise any further invesigations - and I am naturally very disbelieving. I do appreciate that the mpg guage will not always be perfect - the other, perhaps more reliable, indicator of my problem is that a full tank only gives me c.280-300 miles max, whilst I used to get c.350-360 every time.

Has anyone come across this before - does anyone have any ideas where I go from here or what my dealership can try next (or even discuss with Toyota what they shold be testing or fixing)??

many thanks in advance.

[wardude]

I get around 350-400 on a full tank. Thats driving till the light comes on. However normally i fill it when its 1/4 full and ive done around 300 by this time. LAst month I bought some Greased Lightning fuel additive. This has improved my mpg no end and the engine runs a lot smoother. A couple of others on here bought some too but I aint sure how they got on with it.

[Lupidog]

I average 43.7 commuting 53 miles each way to work in a late 06 T180 along the country lanes to Aberdeen. I don't exceed 60 on the rare pieces of dual carriageway and not really very light on the accelerator. I find If I intentionally try to drive to conserve fuel I fail badly, but if I just drive normally I tend not to accelerate harshly.

There are a few causes of your symptoms and below are just a few an certainly does not cover all:

Air intake:

Partially wet or blocked Air Filter. (Always check first, 3 clips and less ten 5 minutes. Easiest thing and very common thing to check).

Intake hose and duct before filter partially clogged.

Carbon build up in air manifold ports.

Carbon plugging EGR valve.

Turbo problem.

Incorrect valve timing.

Intake valve or valve seat leaking.

Exhaust:

Turbo problem.

Exhaust system partial obstruction.

Incorrect valve timing.

Exhaust valve or seat leaking.

Fuel:

Contaminated fuel.

Partial blockage in fuel system.

Fuel filter partially blocked.

Fuel Filter defective allowing dirt into injection pump.

Injection Pump defective or miss-calibrated.

Blocked or miss-calibrated injection system.

ECU and Sensors:

Any one of a number of engine management sensor failures.

ECU firmware/hardware malfunction.

A fuse has failed somewhere:

I like this one as my power steering on my Volvo XC 90 failed and the main dealer could not find any fault but came back with my steering rack needed replacing @ £700. I took it for a second opinion at an independent garage and the first thing they check was the fuse to the system which the main dealer and myself never knew about. 68p fuse over £700 steering rack. I never used Volvo again. Sold it and bought the T180 RAV4.

This is by no means an exhaustive list but show some of what may be causing your fault.

[kitlet]

Many thanks to Wardude and Lupidog

The mph you both report is good evidence that my poor car is sick. Incidentally it is also an 06 model.

I think my problem is with the computer fuel management program and this fits with one of Lupidogs possible problems. My reasoning is that the dealership loaded the software upgrade last week and it was running perfectly for the first time in ages...:but only for 30 miles before reverting back to c.23mpg as though a switch had been thrown internally. Toyota are insisting this can't happen (ie they say programs can't fail like that without either dashboard warning light or diagnostic fault codes) and also that the software upgrade can't be reloaded to see if it was just a load failure. Now I am not good with modern cars, but I do understand computers and this sounds like bulls**t to me.

Also, can anyone tell me if Toyota claim that the ECU needs to 'learn my driving style' in order to determine how best to inject the fuel upon demand is true or just more bulls**t??

All help much appreciated.

K.

[Lupidog]

I am led to believe that the ECU can adjust to different drivers through their usage of the accelerator, I can't go into technical details, but this is stated across a range of cars by various manufacturers. So I guess there is some basis to it.

However. all of your stated symptoms suggest very strongly that this is not the case with your car.

As I said before I like fuses (I don't think it's a fuse in your case but I as using this to demonstrate how modern diagnostics work). I have an XC90 that the power steering failed on (yes we read that). Volvos computer diagnostics failed to recognise that the fuse had blown. I had a Renault 19 16v which the ABS system failed twice whislt driving. The ABS fault was to lock the brakes in the off position so that they wouldn't function. Renaults computer diagnostics failed to even see a problem and only months of hounding Renault made them finally take the car and the ABS failed while one of their reps was using it. If this hadn't happened Renault would not have believed me or done anything about it.

So you know see that I hold absolutely no faith in computer diagnostic systems. Sure they pick up all the faults they have been programmed to pick up, but it stops there.

As you said it happened suddenly on both occasions and once after an ECU upgrade, I would strongly suggest that there is a fault with the ECU. It could be something as simple as a dry soldered joint, or there could be component failure or a weakness. It is unlikely to be the firmware as it work after the Toyota upgrade albeit for a short time.

Probably the only way to find out is to change the ECU. Sorry thats going to be expensive whichever way you source the ECU and fit it.

Alternatively push your point with Toyota. Make them very aware that the issue has gone "public", if your local dealer cant or wont assist you go to the main Toyota Franchise UK. If they won't help you got to Toyota Japan. Don't give up the T180 is a fantastic car. But every know and then a faulty component can slip past QA.

[kitlet]

Thank you Lupidog.....back to the dealership for me with your comments and let's see what they can do. Will let you know what happens.

K.

[anchorman]

Some ECUs definitely learn but couldn't confirm if this is so with the T180 in your case. Don't read too much into that trip computer. You have to do your calcs by neck to neck fill ups. If you left your engine idling for even a couple of minutes before switching off it will estimate what effect that will have on your average consumption - using fuel and no mileage = big reduction in mpg. Leave it idling a few minutes and watch it. Even a few minutes in traffic will make a big difference. You need to keep zeroing that trip meter every couple of weeks or fill up and then only use it as a guide.

Don't look too hard as a result of that readout - it's just a toy. It is highly unlikely that it changed or that anything has suddenly broken!

[igormus]

Hi all

I am new to posting on this forum and hope I am in the right place for my problem - also, whilst I love driving, I am not techie and won't always get the technical terms quite right (please bear with me).

Long problems, but only partially resolved to date by Toyota. I have been unlucky enough to have the white smoke emmissions as others have, but now lucky that Toyota eventually (only took c.18 months!!) agreed to replace the engine. However, still have intermittent white smoke puffs and the mpg still appallingly low - c.23-24mpg.

I have owned the car from brand new, mileage c.70k, warranty has been extended (fortunately). Car has been driven c.1000 since engine replaced.

Dealership have just (2 weeks ago) loaded upgraded software for fuel management system. Car then driven c.30 miles in 5 separate journeys - the last being 10 miles on A & B roads - and mpg was at a reassuring 36-37, as it always had been when new 5 years ago. Stopped at a shop for 20 minutes, but when engine started again, mpg dropped immediately to c.23 - it was like someone had simply thrown an internal switch.

Car back to garage but they cannot get any fault readings from the computers. Toyota say that there is nothing wrong and that it is simply the ECU needs to "relearn my driving style" and that "I should drive the car for c.5000 miles" to see if the reading improves!!

Dealership are caught in the middle as Toyota can't/won't authorise any further invesigations - and I am naturally very disbelieving. I do appreciate that the mpg guage will not always be perfect - the other, perhaps more reliable, indicator of my problem is that a full tank only gives me c.280-300 miles max, whilst I used to get c.350-360 every time.

Has anyone come across this before - does anyone have any ideas where I go from here or what my dealership can try next (or even discuss with Toyota what they shold be testing or fixing)??

many thanks in advance.

hello mate

as you are the first owner and thanks to your initial driving experience - you can easy calculate difference.

as far as I ve caught this difference is around 60 miles (97 kms)-- it is really not big amount and logycally you have to investigate what might go wrong: as from my side I 'd check with tyres pressure; all filters condition; WHITE smoke -- it is a signal of bad working of either SCV or injectors or late injection timing. ANd never believe to your MPG on the screen -- it is really toy. A real consumption can only be measured by flow meter installed on the suction line. All other methods are toys only !!!

Cheers/Igor

[Lupidog]

White smoke can also be a sign that water is entering the combustion cycle.

You would have to be very unlucky for it to be the head gasket as you have already had a new engine fitted.

May be worth taking a look at the Oil Cooler (if fitted) and the Turbo intercooler (if fitted) as it is unlikely that these would have been changed along with your engine.

Also check you fuel tank for water. Sometimes it is as easy as putting some water finding paste on the rounded tip of a blunt plum-bob and just dipping to the bottom of the fuel tank from the filler.

If you had a very slight cylinder head gasket leak. You would probably only see short, small puffs of white smoke when the engine is cold and also when moving off from junctions, traffic lights, accelerating from idle, etc. when the engine is warm.

Just somthing else to look at

[kitlet]

Hi all

Thank you for your replies. I do understand that the mpg gauge is an indication only. My tank fills are confirming the gauge however...a typical tank when the car was new (06 plate) was 350-370, whereas now it is 250 if I am lucky.

Also, I did have white smoke issues...the dealership since have replaced entire engine (on Toyota instruction as head warped), and subsequently loaded a software upgrade to the fuel management system. After the latter, the car was running perfectly (by which I mean it felt perfect in response, power and general feel - with the mpg gauge showing 36 and still climbing) unfortunately it was only this way for 30 miles before very suddenly reverting to its former sluggish feel and a reading that plummeted bank to 23-24 and simply won't rise. At the precise moment the engine changed, the cabin had a sudden strong exhaust smell. I cannot tell you if there is still white smoke as my 30 miles were driven at night and in fog....and the garage has had the car ever since.

Lupidog has suggested water in the fuel...is this likely to have such a sudden effect but with no fault codes? The dealership have just advised me that no codes are showing even as pending on the ecu diagnostics.

Thoughts please...I really need help as Toyota are still sticking to their advice to drive 5000+ miles to let the ecu learn my driving....this cannot be right and really does sound like an attempt to force me to go away. Even the dealer thinks it is odd, but they cannot do any warranty works without approval.

K.

[Lupidog]

What's the engine temp doing? If you've blown the head gasket again (loss of power and exhaust in engine bay) your either very unlucky and no one should join your lottery syndicate or there is a fault causing the head to blow that is not on the engine.

I ask about the engine temp as your cooling may have a blockage either in the radiator or pipework, or your radiator may be packed out and your not getting enough airflow and coolong effect, did you drive through anything that may have blocked of some of the radiator fins before all this started? Does you Fan actually work on the radiator? Your temp gauge or sender may be faulty and not indicating overheating.

Your exhaust may be partially blocked. Unlikely but possible.

Was the Turbo changed with the engine? Perhaps your Turbo Dump Valve isn't dumping.

Water in the fuel inside the combustion chamber can either:

If atomised will turn to steam which has a far greater expansion rate that air and unless the engine is designed for a water injection system and the extra sudden pressure... "pooof"

I not atomised it will not vapourise until after ignition, by which time as you can't compress water you loose compression area inside the cylinder at TBC and overpressure the cylinder... "pooof".

Author's technical note: Yes, I know you can actually compress water, if given enough pressure. But the ammount of compression is so small that this sentence isn't worth reading.

[xr650]

Hi just watching this post with interest.lots of good advice re dash display mpg readings being no more than a toy cause they are just that.my rav endures 450 mile journeys to the north western parts of scotland in 1 hit, only stopping for fuel & returns 340 to the tank every time. if it is worse its usually due to poor driving conditions.having said that the smoke may be a clue,you said that the head was warped, if so its been reel hot. if the engine did not come with new injectors then maybe the nozzle tips have been damaged by the overheating causing fuel to inject in a pattern causing either poor mpg through over fueling or a lack of power through incomplete burn making you apply more pressure on the accel pedal than what is required,need to fill up the tank, run to empty & refill checking fuel used for the milage covered.

[kitlet]

Hi Lupidog

In answer...

1. Not sure about temperature as never looked before latest problems. Did notice however that after the latest drop in mpg, the gauge was not rising off cold in my short drive to work which is only 1.5 miles. Only reason I have noticed this now is because I was constantly looking at mpg and also because with rav being off-road for so long I have been driving my other car a MAZDA RX8 which is critical to ensure engine hot before turning ignition off (very common for people to flood Rx8 engines by not checking!!!). In your opinion would rav temp rise in this short distance which does include a steep hill?

2. This prob has been there so long I couldn't say if I drove through anything that may have blocked the fan. However, I didn't mention before that 12 months prior to engine replacement, a different dealership looked at the intermittent white smoke problem and did replace the head gasket. I was not happy they had resolved the smoke problem as it still smoked occasionally but.no fault codes were showing up so I had to wait until problem so bad that the current dealer managed to persuade Toyota engine replacement needed. Do you think this may support your blocked fan theory. Would such a blockage throw up fault codes or not? If not, is there any test or check that dealer can do to see if this is the culprit?

3. Exhaust...who knows. I do know egr cleaned when engine replaced.

4. Turbo was not replaced.

5. Water still seems a possibility from what you say...perhaps worth asking them to perform your suggested dip test?

What do you think?

K.

[kitlet]

Hi zr650

Many thanks for joining in.

Since engine replaced, car did a 1000 mile holiday to cornwall, so it was given a reasonable chance to check tank fills not just mpg gauge. Low tank measured mpg and smoke and lack of power ( although it is not lack of power exactly, more an extreme reluctance to make the effort like a child saying do I have too!!) made me take it back to be checked. The smoke convinced dealer & Toyota to load software upgrade although I think this may have been an overdue normal upgrade.

I would hope that nozzles were checked when engine replaced for the reason you state, but I will check with the garage and report back.

You may be right that I need to get the car back to run 1 or 2 full tanks again as a check, but I am really reluctant to do this with toyotas stance that I should drive 5000+ before complaining again.

What do you think?

K.

[Davrav]

Hi zr650

Many thanks for joining in.

Since engine replaced, car did a 1000 mile holiday to cornwall, so it was given a reasonable chance to check tank fills not just mpg gauge. Low tank measured mpg and smoke and lack of power ( although it is not lack of power exactly, more an extreme reluctance to make the effort like a child saying do I have too!!) made me take it back to be checked. The smoke convinced dealer & Toyota to load software upgrade although I think this may have been an overdue normal upgrade.

I would hope that nozzles were checked when engine replaced for the reason you state, but I will check with the garage and report back.

You may be right that I need to get the car back to run 1 or 2 full tanks again as a check, but I am really reluctant to do this with toyotas stance that I should drive 5000+ before complaining again.

What do you think?

K.

How many of these 1.5 mile journeys are you doing in a week? Very few engines would reach optimum temperature in that short distance and certainly not a diesel, especially in winter. Your mpg would be very poor if you are doing these short journeys regularly. I doubt it would have a beneficial effect on the CAT either.

[kitlet]

Hi davrav

My rav has done c.72k since new...06 plate...all me.

My office is 1.5 miles from home but I don't always go in...most journeys are considerably longer. As I said to Lupidog, I have never had any reason before to look at temp gauge on the rav, I only asked the question of whether it is significant because of the inherent problems with my Rx8 making me curious (Rx8 is an entirely different engine so this question may have no significance at all).

Main point is mileage pattern has not changed during ownership, but mpg has in last 18 months. It is costing me a fortune in fuel and, much as I adore my rav, what's the point in having one that now only gets the same mpg as my sports car? And I can't afford to trade in for a new one just to solve mpg...a bit drastic!!!

Do you have any more ideas....I am really appreciating the time everyone is putting in on this.

K.

[Lupidog]

Would such a blockage throw up fault codes or not? If not, is there any test or check that dealer can do to see if this is the culprit?

There is no sensor to tell you if the vanes on the outside of you radiator are blocked. It is highly unlikely that there is one to say that the fan is not working or that the thermostat is not opening.

1.5 mile from cold, does get warm air comming from the air vents insive my Rav4 T180, so the car does have time to start heating up over 1.5 miles but it shouldn't overheat if you are just going that distance.

Take the car for a 20 minute drive and see if your temp. gauge moves at all.

Your probably won't get an oil pressure warning light as modern synthetic oils cope very well with high temps. In older cars with plain mineral oils in the engine you would sometimes see an oil pressure warning if the engine was over heating due to the oil losing viscocity at high temps.

[bothwell_buyer]

ma wee brains hurting trying to yake all this in....

If yer car isn't getting up to temp now and again, I'd suggest from experience that the breather pipes might need cleaned out.

Also checking the hoses etc tomake sure no leaks as the ecu will compensate for a lean mixture or wrong ignition timing by adding more fuel. This just happened on my number 2 RAV which I discovered when the mpg fell to 16 mpg (using tank to tank fillups). Even my racing RAV is hitting 22mpg just now! When I take number 1 out for a run, I try to make sure it gets up to temp then give it a bit of a thrash and yes I get a puff of smoke as the turbo really kicks in. Then all is well !

I use a Jap car tuning specialist who know much more than any dealers (they actually train mechanics from dealerships !!!).

[Davrav]

1.5 mile from cold, does get warm air comming from the air vents insive my Rav4 T180, so the car does have time to start heating up over 1.5 miles but it shouldn't overheat if you are just going that distance.

Don't forget that the inital warm cabin air is generated by a subsidary electric booster heater - watch the temp gauge on a cold morning, after the air vents blow warm air it will take a few more miles to register significant temp in the engine.

[anchorman]

Yes I feel the same too and I certainly wouldn't be ready to write a second engine off.

Kitlet, the instructions for cleaning that EGR are pinned and if you are using supermarket diesel it could well want doing again. It makes quite a difference to the way the thing runs so for what it takes, just give it a try.

[kitlet]

hi all

I am at a slight disadvantage here as I am not doing the tests/checks/works that everyone is suggesting myself but am having to rely on the dealership. On the plus side, if I can ever get them to find what is wrong (which is only likely to happen after I have badgered them sufficiently to check all the things everyone here is suggesting), my car has the benefit of an extended warranty so the 'cure' will be free.

re fuel, I use whatever is available, but as the car only had 4 fills after the engine replacement and prior to going back to the garage yet again, it seems unlikely the egr could be blocked again so quickly...also, my problem was temporarily fixed by the software upgrade and yet reverted back to its current sluggishness so suddenly. Anchorman - do you think a blocked egr is still possible, does it become more prone to accummulating dirt as it ages??

otherwise, I am waiting for the dealership to open tomorrow so that I can persuade them to check a list of items that have arisen as possible areas of concern from people on this forum.

I can only wait until then and will post the response/answers that I get....I hope, but am not holding my breathe, that something may show up!!

K.

[kitlet]

Hi everyone.

Just wanted to let you all know what happened next.....the delay has been because I was away for a couple of weeks.

The garage refused to check any of the ideas you all made and insisted that either it couldn't be that or it had already been checked.

I insisted however that as the car was running at a consistent 23-24mpg (per the gauge accepting not fully reliable) they should simply give the car to the technician to drive while I was away to test toyotas theory that it needed to relearn how to drive itself (i am being deliberately facetious here).

On my return, I was given a car that now drives perfectly, has a gauge reading of 30-35mpg depending on all the usual stuff....but the big difference is I am again getting 400+ miles to a tank....yippee.

Now perhaps Toyota were right....but I am very cynical and can only suspect the technician found a mistake in his earlier work which he simply did not admit too. Whatever, i have my car back and am overjoyed.

Thank you everyone.

K

[anchorman]

It is not unknown for them to not admit doing something especially if you have mentioned this forum. I believe they prefer to keep a check of the "floodgates"!!!

Anyway as long as you are happy that is all that matters.