Rav 4 Sluggish Between Gear Changes

[Graeme Ross]

Hello,

Forgive me, I'm new and I'm looking for a bit of advice regarding my beloved Rav 4.

It is a Y Reg (yes, that old) Rav 4 with 88,000 miles that was serviced 6 months ago and has just had the front brake pads replaced (probably not relevant but thought I should add). It is an automatic transmission.

Today, out of nowhere, I felt the car was losing power between gear changes. It starts off fine in first gear, but then I found I was having to accelerate harder, hearing more revs, before the car moved up a gear. I also felt it was losing power slightly when decelerating and then struggling to get back up to full power again.

This has never happened before. I appreciate the car is getting on, but before I take it to get looked at I was wondering if anyone had come across this before and may have any ideas as to what may be wrong??

I'm not well versed with cars so small words would be appreciated!

Thank you in advance for your time in looking at my post, and even more so if you can find the time to reply.

Graeme

[firemac]

Welcome Graeme. Given your reg/model year, I suspect that it could be a late 4.1 or an early 4.2. It would help if you would go into your profile & fill in your car's details. MMeanwhile, does your car look like this?

If so, it's a 4.2.

Does the engine rev cleanly & as you would normally expect when it is in N or P? If so and the fault only occurs when D is ehgaged then it would point to the gearbox or the ECU. There is a known fault with the ECU on early 4.2s and it can be repaired relatively cheaply by a company called ECU Teasting in Derbyshire. they operate a very good mail order service which several of the forum members, me included, have used successfully.

First of all though pls confirm some more details and which model you have.

[Graeme Ross]

Hello and thank you for replying!

I've updated my details as you requested and I can confirm it is a 4.2 as in the picture.

I was due to put it into the garage on Monday. What you have described is an accurate reflection of what is happening to the car. I'm a bit nervous as I'm due to travel abroad in May and the last thing I need is the car breaking down abroad! If I get the car part can I take it to a garage to have it fitted? - I wouldn't really know what to do to be honest.

Thank you again for taking the time to repsond to me and for talking this through.

Graeme

[firemac]

Hi Graeme,

It would be best if you check the automatic trans fluid (ATF) first just in case it is a matter of low fluid. You'll find this under the bonnet on the N/S of the engine bay, i.e. on your right as you look at the engine bay. It is a round cap on top of a long dipstick tube and it is held on with spring clips. If you allow the engine to warm up to normal op temp, switch off then unhook the clips and withdraw the cap & its dipstick. Wipe any fluid off with a rag, re-insert it and withdraw again. You can now see if the ATF level is within the marks on the dipstick. If its low then you will need to top it up to the correct level. You should check with your local Toyota dealer for the correct fluid as this g/box must use the correct spec of ATF. Also smell the fluid on the dipstick - if it smells burnt as opposed to "oily" the it may need replacing.

However if the ATF is OK then it is possible that the problem is with the ECU. This is a known issue on early 4.2s and the unit can be removed and effectively re-programmed by ECU Testing - www.ecutesting.com. They will check it and if it's faulty, they will "reflash" it and return. The cost is about £200 but check the website and they will only make a nominal charge if it is OK. They usually turn these around within 5 days.

You will need to remove the ECU - it lives behind the glovebox and you will need a special tool to remove the security bolts - and send it off to them along with the completed documentation that can be downloaded from their website. If you are unable to remove it yourself then get your usual garage to do it for you; it takes no more than an hour to remove or replace it.

Without knowing exactly what the symptoms you are experiencing are, I can only surmise that it's the ECU problem given that there are seldom any other problems with this gearbox. It may be something completely different however but if you have the ECU checked and it is OK then at least you will know that the problem lies elsewhere. For the £25 or so that ECUT charge if the unit is in fact working OK, plus the postage, that is not, in my view, expensive given what garages charge for labour these days.

If the ECU checks out OK then you can take the next step which would be to have the box looked at by an autobox specialist.

Good luck and keep us posted on progress.

[Graeme Ross]

Thank you very much for your incredibly helpful response. I will follow your advice and see what results.

Hopefully it is one of the issues you have highlighted and I will give you an update as soon as I know anything.

Thank you again for taking the time to write back to me and for providing such comprehensive advice.

Graeme