Slight Knocking Noise On Idle?

[Tay]

Hi all,

I have a 1.8 2003 Avensis. It has always made a ticking sound when idling which I believe is normal, but lately I have noticed a faint knocking sound too. Only noticable when engine is warm and the car is idling on about 600 to 700 revs.

I'm pretty sure it wasn't making this sound until recently, any ideas what it could be?

It seems to come from the top of the engine and is just loud enough to hear with the bonnet closed. Car has 78k on it, short motor changed a couple of years ago on about 60k.

Thanks!

[Mistermena]

How's your oil level? Does it soumd like piston slap or deff the cams?

[Tay]

Hi Mistermena,

Oil level is fine, I watch it like a hawk since the short motor was done!

I'm not very technical and don't really know what those would sound like, but the noise is quite faint and dull. More of a slight thud that seems to me to be coming from the top of the engine.

Sorry if that's a bit vague!

[Mistermena]

Try taking a vid of it so we can hear it mate...

[KPARRIS-JONES]

A video will make it easier to distinguish but do it on a decent camera, try and move it around the engine bay slowly so we can hear any changes.

Why did you need to rebuild the bottom end? Did it die of oil starvation? If so then did you replace the oil pump?

We need more detail for questions like this, such as whether or not the frequency of the noise increases as the engine revs rise. Is it metallic? If it sounds off quite quickly then it'd be the bottom end, but if it's slow yet still regular then it may be the cams as they rotate slower than the engine.

[Tay]

Thanks guys, I will take a vid, just haven't had a chance.

The short motor was done under warranty due to oil consumption but the car has never been low enough on oil to be a problem.

The noise isnt particularly metallic and goes completely as soon as revs increase..

I'm inclined to think its nothing to be honest, but wouldnt mind a second opinion so i'll take a video asap.

Cheers

[KPARRIS-JONES]

Should be fine then, chances are it's ancillaries and you're over sensitive to the noises due to having a recent rebuild - you should see me starting up my GTi, it scares the crap out of me every time!

[Tay]

Rattle.mp3

Hi There,

Still havent had a chance to take a vid, but did record the noise on my phone this morning. Y0ou will have to turn up the volumne and its really more of a rattle I suppose which is definately coming from the top rather than the side..

Does this help at all?

Thanks for all your help.

[Mistermena]

Sounds like the cam's (Tappets) to me from what I've just heard... Sounds more like an oil burner than a petrol. If you've had a lower engine rebuild then there could have been a lack of lube to the cams! and this is where more pounds per square inch of oil pressure is on an engine.

[Tay]

Thanks Mistermena,

So would that be a problem then? I mean do I need to get it looked at?

I have read elsewhere that the timing chain can ratlle a little, could that be another explanation or dont you think so? Would the chain have been replaced by Mr T when the short motor was done, i think I read somewhere that they usually do?

Thanks again,

[tobiasdog]

Hi there, i have just had a listen to the noise,it does sound like the tappets.

Sometimes, there is a build up in this area, I have found that doing an engine oil flush, using a product like wynns oil flush, change the oil and the filter, this can quite the problem.

Does any one else have any suggestions?

[Mistermena]

Thanks Mistermena,

So would that be a problem then? I mean do I need to get it looked at?

I have read elsewhere that the timing chain can ratlle a little, could that be another explanation or dont you think so? Would the chain have been replaced by Mr T when the short motor was done, i think I read somewhere that they usually do?

Thanks again,

If its got a timing chain as opposed to a cam belt then the chain tensioner could be an issue! I know on the 1.2 VW Polo's they have a chain that has had problem. My Audi A6 3.2 had a chain snap causing £12,772 pounds of damage! well a new engine tbh. Not suggesting that this is the case with your car. Its very important (With chain driven cams) to renew the oil on a regular basis! thats why with my T-180 I change the oil/filter every 6-8k as the oil lubs the chains!

Weather or not the dealer would have changed the chain is something I wouldn't know! The tech would have checked it for wear and either used the original one or replaced it! unless Toyota have a policy on replacing that with the issues you've had with your motor. Why not give the dealer a ring and ask if that was changed on rebuild.

I would be carful about using an engine flush as on higher milage cars it can cause more harm than good tbh! I've used them in the past and found Forte is the best product! this is only avaliable to the trade, but you can pick a bottle up from eBay. Or if you're close to me I'll give you one for free. You must remember that using a flush can cause the oil ways to get blocked up with all the crap that the flush gets rid of! so its really upto you.

I would 1st try a product called BG44 (Powerenhancers.co.uk) and see if that helps! Or if you are really concerend then take the car to your dealer to have them check it out...

[dervdave]

Rattle.mp3 Hi There, Still havent had a chance to take a vid, but did record the noise on my phone this morning. Y0ou will have to turn up the volumne and its really more of a rattle I suppose which is definately coming from the top rather than the side.. Does this help at all? Thanks for all your help.

I have to say that apart from sounding a bit `tapperty` the motor sounded quite sweet to me but I don`t know what they`re supposed to sound like.

Have you compared yours with others ?

[Tay]

Hi all,

To be honest, I’m just going by how it sounded before I noticed this new noise!

It’s not the clackity clack sound that I’m on about though, it’s always done that before and after the rebuild.

It’s the background intermittent kind of rattle/knock that I haven’t noticed before. It is quite faint, not loud enough to hear without listening for it if that makes sense, but its definitely there.

Could (fingers crossed) be nothing, I think the best thing is to drop by a dealer and ask for an opinion of it. Hopefully, bearing in mind the thing was rebuilt 14 months ago, they will be accommodating

[dervdave]

Hi all, To be honest, I’m just going by how it sounded before I noticed this new noise! It’s not the clackity clack sound that I’m on about though, it’s always done that before and after the rebuild. It’s the background intermittent kind of rattle/knock that I haven’t noticed before. It is quite faint, not loud enough to hear without listening for it if that makes sense, but its definitely there.

Yeah I`ve got the noise, its a bit like diesel knock and personally don`t think its anything to worry about but you obviously are so get it back to the dealer. :)

[Tay]

Hi Dave,

Yes thats the one! It is very much like diesel knock actually just quieter..

Just seems odd thats its suddenly started.

Thanks for your response..

[dervdave]

Hi Dave, Yes thats the one! It is very much like diesel knock actually just quieter.. Just seems odd thats its suddenly started.

Or has it been there all the time and you`ve only recently noticed it ?

[Tay]

The car is garaged so the engine noise is very noticable when I park up if you see what I mean, it echoes around.

I have only recently noticed it and I THINK I would have noticed it before...

Could be wrong though, it has occured to me!

[dervdave]

The car is garaged so the engine noise is very noticable when I park up if you see what I mean, it echoes around. I have only recently noticed it and I THINK I would have noticed it before... Could be wrong though, it has occured to me!

You do seem to hear a lot when its in the garage :D

Do you normally have the radio on and put the car away with it switched off and were listening for noises ?

[Tay]

No i don't normally listen to it particularly.

I just happened to have the engine running with the door open recently and noticed it then, now of course, I can't stop noticing it!

[dervdave]

No i don't normally listen to it particularly.

I just happened to have the engine running with the door open recently and noticed it then, now of course, I can't stop noticing it!

Haha that happens :D

[jedi134]

Could be your crankshaft telling you it needed proper oil :D

[acetip]

Sounds like the cam's (Tappets) to me from what I've just heard... Sounds more like an oil burner than a petrol. If you've had a lower engine rebuild then there could have been a lack of lube to the cams! and this is where more pounds per square inch of oil pressure is on an engine.

Hi Taff,your correct about the high loading on the valve gear that many are not aware of.

A typical engine loadings are

Crankshaft 20000 psi

Gudgeon pin 40000 psi

Conrod 60000 psi

Valve gear 80000 psi

Thats why it is inportent to use an oil of the correct spec for each engine.

Plane bearings surfaces in an engine are kept apart whilst running by the hydronamic effect (not by oil pressure) this does not happen with cams or other valve gear.

The correct oil is cheaper than engine parts.

[Mistermena]

Sounds like the cam's (Tappets) to me from what I've just heard... Sounds more like an oil burner than a petrol. If you've had a lower engine rebuild then there could have been a lack of lube to the cams! and this is where more pounds per square inch of oil pressure is on an engine.

Hi Taff,your correct about the high loading on the valve gear that many are not aware of.

A typical engine loadings are

Crankshaft 20000 psi

Gudgeon pin 40000 psi

Conrod 60000 psi

Valve gear 80000 psi

Thats why it is inportent to use an oil of the correct spec for each engine.

Plane bearings surfaces in an engine are kept apart whilst running by the hydronamic effect (not by oil pressure) this does not happen with cams or other valve gear.

The correct oil is cheaper than engine parts.

Eh up my mate... Yer the psi on the valve gear is really high! The only reason wht I remember this as you told me it! Lol... :D

[Tay]

Thanks for the replies everyone..

The car had been dealer serviced up until the last one which I had done at a local garage.

Looking at the invoice (its not very clear) they COULD have used 10-40 instead of 5-30 so I've booked it in for an oil change next week.

It's done 6k since that service, would that be the cause then do you think?