Metallic Tapping Sound.......what Is It?

[philbuck]

Hi

I have a '51 1.8 VVTi petrol avensis. Has about 70k on the clock.

When driving along in virtually any gear, once you get to about 3000 rpm, you can hear a very pronounced tapping sound (almost like tappets). As you increase the revs, so the sound frequency increases. If you just gently ease off the throttle with your foot, (trying not to loose much speed), then the sound dies almost to nothing very quickly. If you squeeze back down on the throttle, it appears again. Hope this description makes sense.

Anyone any ideas?

It's driving me mad.

I suspect that the source of the sound is there below 3000 rpm, I just can't detect it.

Oil level is good, albeit it drinks oil, but then that's a different issue

Help !!

[mwilson]

Can't promise it is the same thing but an old car of mine (not Toyota) exhibited similar behaviour and it turned out to be the head gasket failing. Hope it isn't that but worth keeping an eye on the oil and coolant.

[philbuck]

Can't promise it is the same thing but an old car of mine (not Toyota) exhibited similar behaviour and it turned out to be the head gasket failing. Hope it isn't that but worth keeping an eye on the oil and coolant.

Will do. Just one more thing. I can't hear anything on tickover. If it were tappets (which someone told me were hydraulic and not alterable), surely I'd hear it then, either hot or cold !

[rockerbox]

Hi

I have a '51 1.8 VVTi petrol avensis. Has about 70k on the clock.

When driving along in virtually any gear, once you get to about 3000 rpm, you can hear a very pronounced tapping sound (almost like tappets). As you increase the revs, so the sound frequency increases. If you just gently ease off the throttle with your foot, (trying not to loose much speed), then the sound dies almost to nothing very quickly. If you squeeze back down on the throttle, it appears again. Hope this description makes sense.

Anyone any ideas?

It's driving me mad.

I suspect that the source of the sound is there below 3000 rpm, I just can't detect it.

Oil level is good, albeit it drinks oil, but then that's a different issue

Help !!

As the noise only appears to be there on load - maybe it's the exhaust gasket or a cracked exhaust manifold or downpipe connection. Get someone to rev it at night while you take a look under the bonnet - the exhaust flames should be visible if there are any leaks - you may have to remove the heat shield to get a better view - but just try it as is first. Otherwise perhaps it's pre-ignition (pinking) another load related sound.

Good luck!

[philbuck]

As the noise only appears to be there on load - maybe it's the exhaust gasket or a cracked exhaust manifold or downpipe connection. Get someone to rev it at night while you take a look under the bonnet - the exhaust flames should be visible if there are any leaks - you may have to remove the heat shield to get a better view - but just try it as is first. Otherwise perhaps it's pre-ignition (pinking) another load related sound.

Good luck!

Thanks for that. Will do that asap

[alan333]

Will do. Just one more thing. I can't hear anything on tickover. If it were tappets (which someone told me were hydraulic and not alterable), surely I'd hear it then, either hot or cold !

If it's the same 1.8vvti as fitted to an 05 plate then the tappets are old fashioned shims and to adjust them you need to fit a new shim of the appropriate thickness.

I had the same noise on my 05 plate a while ago but it went away when the engine warmed up or, bizzarely, during summer. I was convinced it was tappets but I traded the car before I got round to fixing it. The tappets are supposed to be checked/adjusted at 5 years or 60k so if yours have never been done then it's worth getting them checked.

[philbuck]

Will do. Just one more thing. I can't hear anything on tickover. If it were tappets (which someone told me were hydraulic and not alterable), surely I'd hear it then, either hot or cold !

If it's the same 1.8vvti as fitted to an 05 plate then the tappets are old fashioned shims and to adjust them you need to fit a new shim of the appropriate thickness.

I had the same noise on my 05 plate a while ago but it went away when the engine warmed up or, bizzarely, during summer. I was convinced it was tappets but I traded the car before I got round to fixing it. The tappets are supposed to be checked/adjusted at 5 years or 60k so if yours have never been done then it's worth getting them checked.

Thanks for that info. I was told that they're hydraulic tappets, and don't need adjusting, yet in my own mind, it's a tappet noise. Will look into this as well.

[philbuck]

If it's the same 1.8vvti as fitted to an 05 plate then the tappets are old fashioned shims and to adjust them you need to fit a new shim of the appropriate thickness.

I had the same noise on my 05 plate a while ago but it went away when the engine warmed up or, bizzarely, during summer. I was convinced it was tappets but I traded the car before I got round to fixing it. The tappets are supposed to be checked/adjusted at 5 years or 60k so if yours have never been done then it's worth getting them checked.

Thanks for that info. I was told that they're hydraulic tappets, and don't need adjusting, yet in my own mind, it's a tappet noise. Will look into this as well.

[terryirwin]

I have EXACTLY the same problem and have been thinking of posting for months! More than a year ago I foolishly neglected oil level checking and virtually ran it dry. By the way I have the same 1.8 petrol VVTi ( 01 Reg ). After just saving the engine by stopping and filling up with oil then not long afterwards the tapping started. It has carried on since then and is possibly louder now than some time ago. However engine runs fine in spite of it. I have asked my local mechanic who looks after the car for his opinion because I too thought it sounded like tappets. His view was that it was more like little ends which would make sense with oil starvation. Am just carrying on regardless with the rattle as it does not seem to cause any particular problem with the normal running of the car. If it is little ends then I cant see that it will suddenly break up. More likely it will just become slowly more noisey.

Hope this helps.

Terry

Have just noticed my member description is wrong. Mine is a 2001 VVTi. My wife has a 2007.

[philbuck]

I have asked my local mechanic who looks after the car for his opinion because I too thought it sounded like tappets. Am just carrying on regardless with the rattle as it does not seem to cause any particular problem with the normal running of the car. If it is little ends then I cant see that it will suddenly break up. More likely it will just become slowly more noisey.

Ta for that. It's just so embarassing though, driving this car down the road making this noise !!