Page 1 of 1

Noisy engine

Posted: Mon Jul 11, 2022 8:34 am
by Grumpy21
I was at a car show yesterday in my other toy when the local MM club drove by in convoy. It struck me how quiet their engines seemed compared to mine.

Mine sounds like the tappers are way out and the timing chain is about to jump a tooth.

But… the tappets are well adjusted with a new rocker shaft and no discernible pay in any of the rockers or pillars. And I fitted a new duplex chain when I got the car last year. Both done in an attempt to quieten the engine. It burns no oil and doesn’t smoke, runs nice and smoothly and pulls well for a tiddly engine.

I’m thinking I have play in the valve stems but lack of smoke would suggest not

Not a big problem and certainly not something I’m unduly worried about but it would be nice to have a engine that’s a quiet as the ones I heard yesterday.

Cheers

Re: Noisy engine

Posted: Mon Jul 11, 2022 9:15 am
by kevin s
I would suggest the first thing is are you comparing like for like, yours might sound quite different when standing a few feet away and being driven past at a slow speed.

Other things that can affect the timing chain noise are flywheel mass (there are I believe 2 thickneses of flywheel) and ignition timing (also cylinder to cylinder variation from a worn distrbutor).

My experience would suggest properly adjusted tappets are still a bit noisy, an alloy cover helps a bit.

Re: Noisy engine

Posted: Mon Jul 11, 2022 12:37 pm
by PhilipW1039
Not sure how helpful this is, but the one piece of very simple wisdom that I’m learning from owning a Moggy, is that you have to learn what your individual car likes or doesn’t like. Sometimes, adjusting for noise or what runs better is a far better benchmark than all the official settings. Those can just be a starting point.

Re: Noisy engine

Posted: Mon Jul 11, 2022 4:01 pm
by Monty-4
Perhaps the others had the under-bonnet sound proofing pads fit? ;)

Re: Noisy engine

Posted: Mon Jul 11, 2022 4:40 pm
by simmitc
If it's a rattling noise, check that the crank pulley is in good condition - the riveted ones do sometimes come apart.

Re: Noisy engine

Posted: Mon Jul 11, 2022 6:25 pm
by mowogg
A damped pulley as fitted to minis can make quite a difference to the general engine smoothness. Having changed from a riveted version I would never go back

Re: Noisy engine

Posted: Mon Jul 11, 2022 11:19 pm
by Grumpy21
simmitc wrote: Mon Jul 11, 2022 4:40 pm If it's a rattling noise, check that the crank pulley is in good condition - the riveted ones do sometimes come apart.
Interesting, thanks for the tip, I’ll have a look at mine.

Re: Noisy engine

Posted: Tue Jul 12, 2022 4:51 am
by NETTIE
Just a thought were these cars driving on grass it has massive sound deadening properties..

Re: Noisy engine

Posted: Tue Jul 12, 2022 7:54 am
by Grumpy21
NETTIE wrote: Tue Jul 12, 2022 4:51 am Just a thought were these cars driving on grass it has massive sound deadening properties..

Yes they were, but my engine is noisier, had a short drive yesterday and now I notice it more than ever.

Interestingly it lessens as the revs rise and isn’t in synch with the engine noises. So it isn’t a tick tick tick of the rocker or anything bottom end. Does sound like something loose rattling about but I can’t see anything and everything seems well fixed.

I’ll have more of a fiddle when the weather breaks and I get it back in the garage

Thanks for the pointers chaps

:tu1:

Re: Noisy engine

Posted: Tue Jul 12, 2022 8:24 am
by philthehill
Loose baffles in the silencer??

Re: Noisy engine

Posted: Tue Jul 12, 2022 8:25 am
by Grumpy21
No it’s definitely coming from engine bay and not underneath

Re: Noisy engine

Posted: Tue Jul 12, 2022 8:37 am
by philthehill
Dynamo or alternator bearings??
Disconnect either and run the engine & see if the noise is gone.

Cam followers pitted and worn out??

Re: Noisy engine

Posted: Tue Jul 12, 2022 8:56 am
by Grumpy21
Not regular enough to be linked directly to rotating components slough a loose pulley or fan could well be the case.

Trouble is it’s got me thinking (always a bad thing).

Noisy engine, take it apart and find out why. May as well do a bit of work while it’s apart, skim head, rings and shells , why not bore it out and fit better cam. More power, maybe 1275 or even 1380, 5 speed and disc brakes.. or just live with it and enjoy…

Oh hum..

Re: Noisy engine

Posted: Tue Jul 12, 2022 9:20 am
by philthehill
Live with it and enjoy. 8)

Re: Noisy engine

Posted: Tue Jul 12, 2022 9:02 pm
by James k
As mentioned above, perhaps you could get someone else to drive the car and have a listen from a similar distance to where you were standing from the ones you saw. I've had the same thoughts as you about my car compared to other Moggies I've seen around. It can be pretty deafening inside but when I've watched someone else drive it, it's sounded perfectly fine.

Re: Noisy engine

Posted: Wed Jul 13, 2022 10:22 am
by nutsandbolts
You will find it eventually, in the mean time you could turn the radio up...... Only joking

Re: Noisy engine

Posted: Wed Jul 13, 2022 10:58 am
by Monty-4
Grumpy21 wrote: Tue Jul 12, 2022 8:56 am Not regular enough to be linked directly to rotating components slough a loose pulley or fan could well be the case.

Trouble is it’s got me thinking (always a bad thing).

Noisy engine, take it apart and find out why. May as well do a bit of work while it’s apart, skim head, rings and shells , why not bore it out and fit better cam. More power, maybe 1275 or even 1380, 5 speed and disc brakes.. or just live with it and enjoy…

Oh hum..
I went down this path and the car has been off the road two years. Don't do it!

Re: Noisy engine

Posted: Wed Jul 13, 2022 11:47 am
by philthehill
Turning up the radio reminds me when I went to see Fleetwood Mac (supported by Blodwyn Pig https://en.wikipedia.org/wiki/Blodwyn_Pig) many years ago in Haverfordwest. I was driving the Minor I still own. The diff back was then very noisy - came to go home and the diff was silent. The benefits of listening to noisy music still astound me. :wink: 8)

Re: Noisy engine

Posted: Wed Jul 13, 2022 12:56 pm
by Bowie69
Small exhaust leak?

They sound like a horrid rattle, and can change with temperatue.

Re: Noisy engine

Posted: Thu Aug 11, 2022 8:34 am
by Grumpy21
Thread revival

Still getting the odd but regular rattle and did notice something new the other day. Slight puff of blue smoke after idling for some time.

Now I’m wondering if I’ve got a worn valve guide causing the valve to rattle as it moves up and down. Decent compression (145-150 all round) so nothing serious in that respect. No oil usage to speak of, maybe a cup full every 4-5 tanks (1000 miles)