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Unusual engine noise

W

wahabishtiaq

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Location
Hemel Hempstead, Herts
Car
Honda Accord 2006
Hi everyone hope you had good weekend.

Had recently noted some nose, all sorts of... Rattling, whining, whizzing etc I will try to upload the video evidence of it as well.

Please help...!
 
Is it much quieter when cold? Does it also get quieter when the engine revs are at 1500/2000RPM? If so, then it probably is a chain making the noise, as the tensioners are driven by oil pressure (which drops off when hot and at tick-over).

I'd remove the aux belt to see if the noise is still there, just to be sure it isn't something belt-driven before condemning the chains.
 
As jon says, flip the aux belt off, could be the alternator pulley, if it as then fit the short belt option and get a new alternater, £150'ish on Ebay.. as the old one has very likely got shot bearings.
 
The belt is cheap... it's the replacement of the chains by a garage that'll cost whatever the car's worth, as there is a lot of labour involved! But, if the noise is worse cold, then I'm not sure it's a chain problem... you really need to take the belt off and see if the noise disappears, as the alternator pulley and/or alternator often fail and get noisy (taking the belt off can be a bit tricky, as a strong tensioner has to 'rolled back' to get the belt off, and it's hard to get a large spanner on it without some degree of improvisation, such as some bent pipe over a sawn-off spanner).
 
Tbh, from the video, I don't think I hear anything unusual , mine is basically the same! What is wrong with your car so far?
 
I bought a 7th gen about a month ago - done 140k with some service history.

The car makes a noisy diesely noise, but nothing severe although I can hear a noise from the engine. My fear was that I had not picked up a potential chain noise as I test drove it.

However, noise is only there as I accelerate whether warm or cold so I'm liking the comment about chains getting quieter as the oil warms up! I do tend to get a slight wining noise when cold, so I am hoping that it is something belt driven!!

Thankfully we have a tame mechanic in the village who values his time too cheaply (don't tell him!). Hope I haven't spoken too soon - :ph34r:
 
Good one Paul, you are lucky to have some mechanic who don't cost fortune, and unfortunately its not the case with me.

If its not the chain and its belt driven, this can be alternator, tensioner, and tensioner pulley? How to check which is causing noise?

Jon i didn't get when you say remove the belt and check for noise, if i remove belt than how starter motor will run the initial combustion ( My knowledge of ICTDI engine is not extensive so please ignore if i ask something really obvious).

Sorry for so many questions.... :unsure:

Regards
 
^ some confusion caused by the word "belt".

The "belt" referred to is not inside the engine (the camshaft on your engine is driven by a chain instead of a belt)

It is better known as the "auxiliary drive belt" ....the "auxiliary" devices have pulleys which are driven by this belt.
There are 4 things driven by the aux belt
1. power steering pump
2. alternator
3. water pump
4. aircon compressor

The belt is driven by the pulley on the end of the crankshaft, and under tension it wraps around all the pulleys. The point is that the noise might be coming from any of those 4 things (or their pulleys), or indeed from the belt itself.

The belt can be removed and the engine started and run for a few minutes with the belt off (note that even though the alternator is not running, the starter will still work, your bigger concern is that the water pump is not running, but it will be ok for a few minutes). With the belt off, if the noise is still there, then it's something to do with the chain(s) in the engine.

Note also that on the diesel car there is an "idler" pulley which requires a long belt to go round the other pulleys in a convoluted way, and this is known to cause problems. The "idler" can be removed and a shorter belt fitted which overcomes problems caused by the longer belt.
 
Backto7gen said:
I bought a 7th gen about a month ago - done 140k with some service history.

The car makes a noisy diesely noise, but nothing severe although I can hear a noise from the engine. My fear was that I had not picked up a potential chain noise as I test drove it.

However, noise is only there as I accelerate whether warm or cold so I'm liking the comment about chains getting quieter as the oil warms up! I do tend to get a slight wining noise when cold, so I am hoping that it is something belt driven!!

Thankfully we have a tame mechanic in the village who values his time too cheaply (don't tell him!). Hope I haven't spoken too soon - :ph34r:
Click to expand...
Worn chains definitely get noisier as the engine warms up with the engine at tick-over (because the tensioners rely upon engine oil pressure, which drops markedly when hot AND idling).

Your noise is probably something belt-driven, possibly the alternator pulley?
 
Some very useful info in this thread about removing the aux belt and replacing with the later shorter belt, to convert the belt routing to be the same as the later facelift Accord models (which puts the alternator and alternator pulley under less stress)... http://typeaccord.co.uk/forum/topic/11712-7th-gen-new-aux-belt-alternator-diy/?hl=shorter#entry131057

As Brian has said, do not confuse the aux belt with the timing chains! The external belt is 'fairly' easy to remove, but the internal chains are much harder to access and replace.
 
You know i must say you guys are phenomenal, and i never knew i will learn and get so much knowledge and support from you all.....

Many Thanks once again.. I will give it a go myself needs to buy tool kit and a nice sunny outdoor day; won't hesitate to get my hand dirty :)
 
Let us know how you get on with taking the aux belt off and listening to the noise... hopefully it'll go away, proving it to be one of the items mentioned by freddofrog. It is common for the alternator to become noisy (and/or its pulley), but simply fitting the revised (shorter) belt would probably NOT provide a cure in itself (it will make it less likely that the alternator will have future problems though).

If the noise remains with the belt off, then it is almost certainly the timing chains (there are two, a camshaft chain plus a balancer/oil pump drive chain)... which are a lot more expensive to have fixed (my best 'all inclusive' quote was £1100). But I covered about 20k miles from when the engine first became noisy, until I replaced both chains back in the summer, so a bit of chain noise doesn't mean the engine is about to self-destruct! I was told by a friendly Honda technician that these engines often have some degree of chain noise at higher mileage, and they continue to run OK when noisy, it's only if the noise suddenly changes or gets louder that you need to become properly concerned. Chains are known to break, and the engine can be wrecked when this happens, but this is fairly rare...
 
I'm not saying anyone is wrong here before I'm accused of that. Oil pressure shouldn't and,does drop as engines warm up, well, not by any real margin, this is because of multi viscosity oil. Modern oil which we use now has different weight numbers, ie 0w 40w. Modern oils get thicker with heat, so technically, it's the colder the engine oil the reduction (albeit small) in pressure.

I can't comment on the noise. People here may have heard it more than I. However, I totally agree to taking the aux belt off to see if the noise continues.

If run chain engines for years with Lucas oil stabilizer in to great results. Its only my opinion, but my accord is running it and,is running well and has got quieter.
 
Engine oil (even modern/synthetic multi-grade types) does get less viscous ('thinner') when warm, which definitely leads to engine oil pressure dropping off at tick-over. Hence worn engine chains becoming noisy in those conditions.

This Wikipedia page explains how multi-grade oils offset this change with viscosity index improvers, but nevertheless the viscosity does still drop off (logarithmically, apparently) with increasing temperature... http://en.wikipedia.org/wiki/Motor_oil#Multi-grade

Most of us are familiar with the advice to 'warm up' an engine prior to draining the sump during an oil change. This is make the oil thinner and therefore flow more easily.

Don't let the numbers (e.g. 0w-30) cause confusion... the 0w (cold viscosity) and the 30 (operating/hot viscosity) do not share the same scale.
 
Ok, we'll have to agree to disagree on that one buddy.


Anyway, regarding the noise, if you can try and get a mechanics stethoscope, we use them in my garage almost daily. Will help locate the noise.
 
Just a fleeting visit ...

Jon, I think that what Richard implied in #21 does read the same way as you and that Opie oils page.

Richard said "Modern oils get thicker with heat, so technically, it's the colder the engine oil the reduction (albeit small) in pressure"
Stand that on its head and he's saying that you need a lower A [in Aw-B] to keep the oil pressure up when first starting in cold weather but at operating temperature, if you have a high B [in Aw-B] then the oil is thicker.


cheers, I'm outta here.
 
Yeah I didn't come for an argument or make anything personal. Yes I'm a mechanic and panel beater, was just offering some advice from what I've been taught in the last 20 years. My' agree to disagree' was not a fasicious it was exactly that, to avoid argument or personal jibes.

Surely it's more important to come together to help people...after all, I came to seek advise from people who may have more experience with this make and model of car than I. Just trying to return the favour, not have personal conflict. You think one thing, I've been taught differently, ergo "agree to disagree ".
 
Disagreements are perfectly welcome Richard, but do become pointless and confusing to others unless both sides can provide some level of evidence so others can then judge things for themselves, especially with an important issue like oil viscosity.

I don't believe that simply saying that you're a mechanic who was taught this information in the last 20 years is a strong argument against both Wikipedia (freely edited worldwide to help ensure accuracy) or Opie Oils (a well-respected TypeAccord approved trader) so - to get this thread back on track - I currently stand by my ***ertion that oil viscosity falls when the engine becomes hot, resulting in lower oil pressure at idle, resulting in our hydraulic chain tensioners being unable to apply sufficient force to a stretched chain, resulting in noise. And this noise is what convinced me last year that my timing chain has become stretched, which indeed it had (see 8th picture down)... http://typeaccord.co.uk/forum/topic/16473-replacement-of-engine-chains/page-2?hl=febi
 
Derailing this thread with unsubstantiated arguments was a little unhelpful. If you find some links to back-up your oil viscosity claims then why not start a separate thread so anyone interested can debate the matter there... I would genuinely be interested in seeing conflicting evidence and I honestly promise to keep an open mind while we do this.

The only intended jibe I've seen here is you describing your car as a 's**** accord'!
 
I get that hissing background noise on very cold days. Also that extra tick tick load noise to. In the freezing cold i drive about 300miles a week. I would probably do another start mid day. I am no mechanic or any one that knows there cars inside out but i am guessing the cold temps and the car warming up gives that water pump broken noise :/. I drive a 2.4 exec man petrol
 
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