Intermittent over revving

[Rufty]

Our Rav 4 has been displaying occasional over revving in top gear (motorway driving).  The garage couldn't find anything.  But yesterday it did it again and there was maybe 10% loss in power.  Plus the engine management light came on and the traction control light.  Although it then felt normal again (like before) the lights remain on.  What might it be??

[Mike169]

HI Ruth

Is your car a manual or an automatic gearbox?

Mike.

[Rufty]

Hi Mike, it's a manual.

[Mike169]

Hi Ruth.

Do you think the clutch may be slipping?

Mike.

[Rufty]

No, doesn't seem to be

[Mike169]

Hi Ruth.

I personally feel you need some help from a local garage that doesn't charge for a diagnosis to get their opinion as now there are too many options that could be not quite right.

You are welcome to come back on here with their opinion/thoughts.

Mike.

[philip42h]

28 minutes ago, Mike169 said:

Hi Ruth.

I personally feel you need some help from a local garage that doesn't charge for a diagnosis to get their opinion as now there are too many options that could be not quite right.

You are welcome to come back on here with their opinion/thoughts.

Mike.

I'm less sure of the "too many options" bit Mike - but maybe I lack imagination! 🙂

Ruth,

You appear to be saying that when cruising along, presumably in top gear, there is an increase in revs without a corresponding increase in speed. This means that something must be slipping somewhere. With an automatic, that could mean an issue with the torque converter, but with a manual you are pretty much limited to slippage at the clutch or at the wheels - I can't really think where else it could be (others might).

You'd get slippage at the wheels if the car were aquaplaning or otherwise running across a very slippery surface - but I rather suspect that you'd have noticed that ...

You would typically expect to encounter clutch slippage, accompanied by appropriate squealing when you pull away from rest or otherwise change up when torque is at a maximum. So as you say, it doesn't seem to be that.

The only other cause that I can think of off the top of my head is the driver resting a left foot a little too heavily on the clutch pedal ... ?

[Rufty]

Thanks Philip.  Hubby does hold the clutch in at lights, but I don't think he's touching the pedal when driving.  But maybe it is the clutch.  The weather was fine and dry yesterday, we were just pootling along (maybe just a smidge over 70) when it went funny for a few seconds and the 2 lights came on.  They are still on today we we didn't take it anywhere.  We'll take it to the garage a mile down the road tomorrow.  Would a ropey clutch cause those lights?  What might a new clutch cost? 

[IanML]

Have a look at this thread. Apparently the TRC can come on for a variety of reasons not connected with traction control.  I'd advise you read the fault code(s).