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M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 12:41 pm
by E30REDD
The sound is loudest (worst) at 3 000 RPM and I think it's the chain timing tensioner.
Is this a complete timing chain tensioner (is this all I need to buy)?
http://www.ebay.co.uk/itm/Timing-Chain- ... 460cb56c2b
I've heard the chain tensioner from the M44 is better than the chain tensioner from the M42. Does it matter which one I buy?
I'm driving a 318is.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 1:29 pm
by Grrrmachine
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 1:33 pm
by Kedge
Get a new tensioner on there ASAP. While you're at it whip the rocker cover off and check the cam sprockets, if the teeth are getting sharpe it's time to budget for a new chain, sprockets and guides.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 1:55 pm
by E30REDD
Is it okay to drive with the bad tensioner as long as I'm not revving the engine over 2 700 RPM? There are no noises from the engine as long as it's running under 2 700 RPM.
I know that the M44 tensioner fits into the M42 but does it really matter which one I buy?
Is this everything I will need?:
http://www.ebay.co.uk/itm/Timing-Chain- ... 460cb56c2b
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 1:59 pm
by Kedge
It's OK to drive it, but I'd just keep it to a minimum to prevent excess wear.
Yes, it is just the tensioner you've seen there that you need!
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 2:13 pm
by E30REDD
Kedge wrote:It's OK to drive it, but I'd just keep it to a minimum to prevent excess wear.
Yes, it is just the tensioner you've seen there that you need!
Okay, I just ordered it, thank you.
Won't there be comming out a lot of oil from the engine when I unscrew the tensioner?
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Feb 20, 2013 2:23 pm
by Kedge
Some oil will come out but not loads. Just keep an eye on your oil level as usuall.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Thu Mar 07, 2013 1:33 pm
by E30REDD
I changed the tensioner and I think the rattling sound got a little bit lower, but the problem still persist.

Re: M42 - Rattling sound over 2 700 RPM
Posted: Sun Mar 17, 2013 10:45 am
by E30REDD
This rattling sound is completely gone as long as the engine is cold.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Mar 20, 2013 6:44 pm
by E30REDD
Bump
Re: M42 - Rattling sound over 2 700 RPM
Posted: Wed Mar 20, 2013 8:49 pm
by DHFiS
It sounds like the typical signs of a worn timimg chain and sprockets. A new tensioner will not be enough to get rid of the noise. A new chain, sprockets and guides will be about £500 plus fitting.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Thu Mar 21, 2013 6:28 am
by E30REDD
DHFiS wrote:It sounds like the typical signs of a worn timimg chain and sprockets. A new tensioner will not be enough to get rid of the noise. A new chain, sprockets and guides will be about £500 plus fitting.
Yay, for that price I can get about two working M42 engines.
In roughly, about how many km will I be able to drive until it breaks?
Isn't timing belt preferred over timing chain. Sure timing belt has a shorter lifetime than a timing chain but the only thing you have to replace when doing a service on the timing belt is the timing belt itself. You don't have to replace the other expensive parts.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Thu Mar 21, 2013 5:52 pm
by DHFiS
I have never heard of an M42 chain snapping but if the tensioners fail it can fall off the sprockets.
Timing belts are prefered by manufactures because they are cheap. Your engine has lasted over 20 years - how many belts would it have used in that time?
Re: M42 - Rattling sound over 2 700 RPM
Posted: Fri Mar 22, 2013 6:36 am
by E30REDD
DHFiS wrote:I have never heard of an M42 chain snapping but if the tensioners fail it can fall off the sprockets.
Timing belts are prefered by manufactures because they are cheap. Your engine has lasted over 20 years - how many belts would it have used in that time?
Well, it sure wouldn't cost over £500 in total to change the timing belt a few times.
Should I just drive as long as the timing chain doesn't sound too bad?
Re: M42 - Rattling sound over 2 700 RPM
Posted: Fri Mar 22, 2013 9:34 am
by DHFiS
I would buy another M42 if you can find one that sounds good and swap them.
AFAIK there is no way to predict when then engine will fail but it isnt going to get better - only worse.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Fri Mar 22, 2013 10:41 am
by E30REDD
DHFiS wrote:I would buy another M42 if you can find one that sounds good and swap them.
AFAIK there is no way to predict when then engine will fail but it isnt going to get better - only worse.
Then I should just be driving with this engine until it fails. Because it's running very good except from the little chain noise. But for how long will it hold? 3 months, 3 years?
Re: M42 - Rattling sound over 2 700 RPM
Posted: Fri Mar 22, 2013 6:18 pm
by DHFiS
E30REDD wrote: But for how long will it hold? 3 months, 3 years?
DHFiS wrote:
AFAIK there is no way to predict when then engine will fail
Re: M42 - Rattling sound over 2 700 RPM
Posted: Sun Mar 24, 2013 3:05 pm
by mwggriffiths
Mines been rattling for 18 months and is still going strong, I gave it a new tensioner soon after I bought it and run it on quality oil and change it often and its been fine.
Then again my PAS pump lasted a year too, and when I asked I was told it was weeks away from exploding! Maybe I just have more mechanical sympathy than most?!
Just bought a whole M42'd 318Ti for £300 which runs better than mine, so I might swap the engines at some point.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Sun Mar 24, 2013 5:31 pm
by E30REDD
mwggriffiths wrote:Mines been rattling for 18 months and is still going strong, I gave it a new tensioner soon after I bought it and run it on quality oil and change it often and its been fine.
Then again my PAS pump lasted a year too, and when I asked I was told it was weeks away from exploding! Maybe I just have more mechanical sympathy than most?!
Just bought a whole M42'd 318Ti for £300 which runs better than mine, so I might swap the engines at some point.
Sounds good!
Do you hear a low rattling noise when driving in normal speed, for example about 90 km/h? If I listen carefully I do hear it, but it's almost so low that it's unhearable.
Do you also have the problem that the chain rattles a lot when revving the engine to 3 000 RPM? Over and under 3 000 RPM is quite fine, but right at 3 000 it rattles a lot.
Re: M42 - Rattling sound over 2 700 RPM
Posted: Sun Mar 24, 2013 5:33 pm
by mwggriffiths
E30REDD wrote:mwggriffiths wrote:Mines been rattling for 18 months and is still going strong, I gave it a new tensioner soon after I bought it and run it on quality oil and change it often and its been fine.
Then again my PAS pump lasted a year too, and when I asked I was told it was weeks away from exploding! Maybe I just have more mechanical sympathy than most?!
Just bought a whole M42'd 318Ti for £300 which runs better than mine, so I might swap the engines at some point.
Sounds good!
Do you hear a low rattling noise when driving in normal speed, for example about 90 km/h? If I listen carefully I do hear it, but it's almost so low that it's unhearable.
Do you also have the problem that the chain rattles a lot when revving the engine to 3 000 RPM? Over and under 3 000 RPM is quite fine, but right at 3 000 it rattles a lot.
I'll have to drive the Ti a bit more, my iS has rattled since I bought it so its all "normal" to me!
Re: M42 - Rattling sound over 2 700 RPM
Posted: Sun Mar 24, 2013 5:39 pm
by E30REDD
mwggriffiths wrote:E30REDD wrote:mwggriffiths wrote:Mines been rattling for 18 months and is still going strong, I gave it a new tensioner soon after I bought it and run it on quality oil and change it often and its been fine.
Then again my PAS pump lasted a year too, and when I asked I was told it was weeks away from exploding! Maybe I just have more mechanical sympathy than most?!
Just bought a whole M42'd 318Ti for £300 which runs better than mine, so I might swap the engines at some point.
Sounds good!
Do you hear a low rattling noise when driving in normal speed, for example about 90 km/h? If I listen carefully I do hear it, but it's almost so low that it's unhearable.
Do you also have the problem that the chain rattles a lot when revving the engine to 3 000 RPM? Over and under 3 000 RPM is quite fine, but right at 3 000 it rattles a lot.
I'll have to drive the Ti a bit more, my iS has rattled since I bought it so its all "normal" to me!
All my questions above was regarding your is.
What does Ti mean,
Touring and something more?
Re: M42 - Rattling sound over 2 700 RPM
Posted: Sun Mar 24, 2013 6:09 pm
by mwggriffiths
E30REDD wrote:mwggriffiths wrote:E30REDD wrote:
Sounds good!
Do you hear a low rattling noise when driving in normal speed, for example about 90 km/h? If I listen carefully I do hear it, but it's almost so low that it's unhearable.
Do you also have the problem that the chain rattles a lot when revving the engine to 3 000 RPM? Over and under 3 000 RPM is quite fine, but right at 3 000 it rattles a lot.
I'll have to drive the Ti a bit more, my iS has rattled since I bought it so its all "normal" to me!
All my questions above was regarding your is.
What does Ti mean,
Touring and something more?
A 318Ti is an E36 Compact with a 1.8 or 1.9 engine. No idea what T stands for!
As I said, because my iS has rattled since I bought it I don't know what it should sound like when its running properly! Mine seems to rattle between 3 & 4k RPM and is particularly bad on the over run. It seems sensitive to how you warm the engine up, it seems worse if you're very gentle with the engine until it reaches operating temperature

It's also worse just after an oil change.
When I first bought it I assumed it was the manifold blowing, because thats kind of what it sounds like, but I've welded that up and the problem has persisted, and I can't see any black soot that would indicate another crack / leak path
