A Teaser/challenge For You Experts!

[baldzone]

Evening all!

I'm hoping some of you experts can shed a bit of light onto a strange problem I'm having with my 2007 Rav 4 2.2 D4D.

When the outside air temperature is above about 8 C, the engine runs fine. No lag, no hesitation, no problems.

The past few weeks, when the temperature is cooler (below 5 C), the engine starts fine, runs perfectly up until the engine is up to temperature. Then the fun begins.....

It is hesistant, it won't accelerate above approx 1500 rpm willingly. It's like it's missing (comapring to a petrol). It takes about a minute to get up to 50 mph and on the flat can stretch to 70 if gentle with the throttle in 6th.

The more I push the throttle, the more severe the symtons of jerking. Hard to describe but the power comes and goes quickly. Can hear a whine when the power comes which sounds like the turbo spinning up and down.

So far I have tried cleaning the MAF, EGR valve, put REDEX in the tank, checked for fuel cap causing a vacuum, resetting ECU on motorway (switch off ignition for a few seconds and back on again), sat in a jam with heater on full blast with windows open to get a slight coolant temperature drop, which made no difference to performance.

The most puzzling thing to me is there are no fault lights on!

I'm sure it will be fine in the morning for the first few miles, then when up to temperate it will reappear like the past few weeks.

I'm keen to get this fixed quickly as it's not exactly safe to drive and I'm a little concerned about the impact on the drive train too. Why did I buy a diesel? ;)

Any thoughts or suggestions before I have to take the plunge and spend lots of money....?

[Devon Aygo]

Have you changed the fuel filter? As the colder weather thickens the diesel causing a greater then normal restriction in the fuel filter causing a lack of power when the engine requires fuel as you accelerate.

There is also a technical bulletin regarding lack of power, worse when the temperatures are low which requires a new modified filter cap and modified filter and new ECU software to improve fuel heating and flow in colder weather.

[baldzone]

The fuel filter was replaced about 20,000 miles ago. And it's only causing problems when the engine is up to temperature. Is the fuel filter still a likely cause? If so I'll grab a new one tomorrow.

Please excuse my ignorance, I'm pretty new to Toyota problems (probably due to good reliability of the them!) How would I go about finding that technical bulletin?

[Devon Aygo]

During colder weather we see quite a few Rav's with hesitation/lack of power and most of the time a new filter or the modification is the cure.

Access to bulletins for customers is either by paying your dealer to diagnose and fix or via www.toyota-tech.eu ( access is payable by the hour, day, etc )

The bulletin ref is EG-0104T-1111

Modified Filter cap part # 23380-26112

Modified fuel filter part # 23390-33030

ECU update has to be done at dealer.

Toyota allow 1.6 hours to complete all of the above.

[baldzone]

Thank you very much for the info!

I'll try the filter tomorrow and let you know how I get on.

Someone also suggested (petrol head-not diesel) at work to disconnect MAF when the fault returns to see if it improves or at leats goes into limp mode (which should hopefully be better than this!)

I've also been using Sainsburys fuel. Is this likely to be a contributing factor?

[firemac]

Thank you very much for the info!

I'll try the filter tomorrow and let you know how I get on.

Someone also suggested (petrol head-not diesel) at work to disconnect MAF when the fault returns to see if it improves or at leats goes into limp mode (which should hopefully be better than this!)

I've also been using Sainsburys fuel. Is this likely to be a contributing factor?

Supermarket diesel is a big NO-NO!! I had an XT-R 4.3 auto before our current LC4 and I wouldn't use anything other than Shell or Esso's best in them and have never had fuelling problems.

Bearing your fuel usage in mind, you should change the fuel filter then run the car on Shell Nitro for a few tanksful to clean up the system and the combustion chambers in the engine. Nitro is a bit more expensive but worth every penny IMVHO; you can switch back to the regular Shell/Esso/BP diesel after that (although I'd stick with the Nitro personally).

There are many threads on this and other forums highlighting the problems caused by using supermarket rubbish!

[baldzone]

I made matters worse this morning!

After the fault returned, I pulled over and unplugged the MAF. The revs increased slightly and the warning lights came on as suspected. Once driving away, it quickly became apparent the fault was still present.

So I pulled over again, switched off, reconnected the sensor, started up and pulled away. The warning lights were still there!

It's currently sitting outside with the Battery disconnected in the hope of resetting the ECU.

When I get a minute I'm out to grab a new fuel filter.

Thanks for advice ref Diesel. Will be avoiding supermarkets in future! Noting an approx 20-30% increase in fuel consumption with this fault too!

Currently looking into OBD software for my laptop and an adapter. Any recommendations?

[baldzone]

Evening all,

Quick update!

I changed the fuel filter, cleaned the plugs with switch lubricant on the MAF, EGR valve and the 2 ECU connectors. Took it for a long drive and all seemed well. Although the lowest temperature was showing 5 C and the defect usually occurs when it's colder. Keeping fingers crossed!

When I changed the filter, there was a thin brown film of something around the water sensor. Is that normal or is it likely to be a sign of contaminated fuel?

[baldzone]

Afternoon all,

Had a long drive today. No recurrence of fault!

Many thanks for the suggestion of the fuel filter. I would never have put ti down to that.

I popped into Toyota branch to pick up filter and mentioned the symptoms and they immediately suggested EGR valve. £30 for filter, £300 for EGR valve. I'll try the filter first, thanks, and it worked!

Thanks very much for advice!

[firemac]

Afternoon all,

Had a long drive today. No recurrence of fault!

Many thanks for the suggestion of the fuel filter. I would never have put ti down to that.

I popped into Toyota branch to pick up filter and mentioned the symptoms and they immediately suggested EGR valve. £30 for filter, £300 for EGR valve. I'll try the filter first, thanks, and it worked!

Thanks very much for advice!

Now keep your nice new filter happy by avoiding the supermarket fuel!!

[baldzone]

Lesson learnt! No more Sainsbury's fuel, even if I do have to drive several miles out of way to get a decent fuel station ;)