Avensis Verso D4d-pre-ignition?

[Whitecrane]

Hi,

I'm new to the group and am finding the forums very interesting.

I have an Avensis Verso D4D, which we bought new 3 years ago. I have had no problems with this car until recently when I noticed that, when I put the engine under load in 5th ger (and sometimes 4th) around 1500-2000 revs I can hear what sounds like a 'pinking' noise. It dissapears when the revs get over 2000 and the turbo comes on boost. The engine is running perfectly and is not losing power and fuel consumption etc is all ok. In fact apart from the noise ther car is fine.

My dealer has looked for the problem and changed the air and fuel filters. They stated that the air filter was damp. I don't know how! This has not however cured the noise. I have also tried using different diesel ie from a mainline supplier and not the usual supermarket fuel. I'm not sure that this helped. I can avoid the noise by revving more between gear changes but would appreciate any advice/opinions re this.

Thanks for your comments in advance

All the best

[Airbag]

I had a Rav4 with a D4D turbo engine, and I seem to remember that changing up at 1500-2000 rpm is really way to low. and results in engine lugging (in the Rav) Long term lugging can cause excessive wear on the lower half of the engine. Now, of course, this may not be the case with your Avensis, but really, I'd try and drive the thing with the rev counter above 2000 rpm where possible. While Toyota diesels will pull away at 1500 rpm, it's not the best way to drive 'em!

My partner recently got a V**xhall *stra 1.8 diesel. She was grumbling that the thing was sluggish and noisy, but, was driving it at extremely low revs, below 2000 rpm in fact. (Her previous diesel was a 3 tonne van) . Same thing applied there. She now keeps the revs above 2000 rpm and it's a whole lot better. One other pointer, I come from a marine diesel background, (yeah, I know - different animal) but we saw endless problems with turbo diesel engines that had been run long-term at low-revs. Gummed up piston rings, glazed cylinders, and excessive oil consumption, not to mention carboned up turbo waste-gates, exhausts - and overheating problems. My own personal ethos (and your mileage may vary) is to change up with the rev counter somewhere at between 'ten-to' and 12'0' clock positions on the tach on most things I drive, unless it's a motorcycle. That keeps the engine in its most responsive rpm band, and one where, generally speaking, the engine is producing plenty of torque. Modern engines, including diesels are designed to be revved, running them outside of the torque band (in either direction) can cause excessive wear and expensive maintenance bills.

The rattle that you now experience could be lower engine wear ( big ends, crankshaft bearings) or it could be almost anything else. Only an engine tear-down will tell you. Keep your revs up, change the oil every 5000 miles, and you'll minimise further wear.

Finally, fifth gear is an 'overdrive' for straight road cruising, at say, over 40 mph, or more........... Don't go there if it puts the rpm below, say 2200.

Of course, none of this may apply to your problem... :-), but 2000 rpm is only just above idle revs on most modern diesels, unless you're driving a truck or a 30ft fishing boat.

[Whitecrane]

Airbag,

Thanks for the reply.

I don't think we are talking about the same thing. I normally do drive the car over 2000 revs and only change up when the turbo has kicked in. I only normally use 5th for cruising above 45-50. I only actually noticed the noise when I absentmindedly shifted up into 5th gear at low revs. It's the usual story, once you notice something, you go looking for it again. I would say that I only ever do notice it when I actually look for it to make sure that it is still happening.

As I said in my post the car is running as normal and I am not using much if any oil, there is no noticeable smoke from the engine, in fact no signs of engine wear. I would say at a guess that the noise seems to come from the top left (from the drivers seat) of the engine bay near the air filter/inlet manifold and the best way to describe it is that it sounds exactly like 'pinking' that you would experience from a petrol engine. The mechanic who road tested it with me informed me that diesels can experience a similar thing due to fuel not burning completely. This was the reason that I tried main brand diesel. I'm not particularly worried about it to be honest and was just wondering if anyone else had noticed the same thing. I've just renewed my Toyota warranty so there is a degree of peace of mind there.

Take care and all the best