Technical The end is nigh for bumble?

[Popitinpete]

Sounds like you've tried all the obvious things I can think about and, being a mechanically minded person you'll have a good ear for the more common noises anyway. I'd been thinking maybe the pulley bearings in the air con compressor, I've heard some of them making some unusual noises, but you've eliminated that.

These sort of noises can be most frustrating to track down. The first car I bought after I got married was a 105E Anglia (base model) - Heluva come down from my Mk1 Dragoon Red 1500 Cortina GT but marriage makes you broke! I got a good deal on it because it had a very slight knock in the engine which I stupidly, with the arrogance of youth, thought I could easily fix. It was a slightly strange and not very loud noise which was loudest at idle and decreased in volume whenever you stood on the gas. I really didn't know what it was but hoped it was valve gear related. Unfortunately couldn't track it down despite stripping the rockers off and looking for worn bushes, rocker arms and shaft, I'd hoped to find worn rocker arm tips. Then I thought it might be something to do with the mechanical fuel lift pump, but no. Anyway the noise got no louder but didn't go away either. Listening to it every day, and the fact it wasn't getting worse quickly, I began to suspect either piston slap or little ends, so eventually I recommissioned one of my old mopeds to ride to work, took the Anglia engine out and stripped it completely. I was quite surprised to find someone had obviously recently been in there before me. Lots of new gaskets etc. To cut a long story short, it had obviously had a cheap "refresh" done on it. The crank had had it's big ends reground 10 thou down with new shells but the mains hadn't been touched, not even the shells. The bores were quite good with only a small ridge at their tops and the piston skirt to bore clearance was almost to new spec. I noticed it had new rings though. So there I was with a pile of components and, although some showed some wear, I really couldn't fault any of them.

At that time I was fresh out of college so my head was full of all the latest "stuff" and I suddenly remembered reading an article about Cords Rings (Piston rings) where they were advertising their re-ring sets. One feature of which was that the top ring featured a "ridge dodger". This was a small step in the outer diameter of the ring so that the top of the ring didn't go quite, by just a few thou, as far up the bore when the piston was at TDC. These rings were particularly intended for fitting to an engine where a rebore was not considered necessary but a small wear ridge is evident at the top of the bore. Hmm? I wondered. So I bought a set and rebuilt the engine with them taking the place of the almost new standard rings which had been in the engine. No more noise! The new standard rings , or one of them anyway, must have been just kissing the ridge at the top of one, or more, of the bores. That engine then ran faultlessly, including several trips London to Edinburgh and back visiting in laws, (It had actually done that journey at least once with the knock and without it getting any louder) It went on for the next 4 years until the car failed it's MOT when I discovered that someone had stuffed the sills with newspapers over which they had glass fibred and filled and sanded down very carefully until you really couldn't see there was actually no metal there! She went to the happy hunting grounds and I bought a Mk1 1600 Triumph Vitesse. Interesting handling with it's swing rear axle setup! I hope someone got the Anglia engine as I'm sure it had many good miles still in it - but who could have guessed it was the rings that were the problem?

Anyone know if cords are still in business? Those happy days are pretty much over now I suppose. I was looking into recon engines for a friend's Seat the other day and came across the fact that you can't dismantle the bottom end on this model because the block warps as the main bearing cradle is slackened and it's impossible to reassemble it - you have to buy a genuine VAG short block - I believe it's not the only one with this problem either? What a crazy world we live in!

Thanks, its got me stumped a bit, it's the bit when it's silent when cold but tapperty when worm that's puzzling. I'm just off to check the spray bar for blockages, it does seem to be over/at no1 cylinder so maybe one end is blocked, will report back

 

[Popitinpete]

That noise sounds it's at belt speed and as it's worse when the engine is up to temp, what about the waterpump bearing?

I've seen a post somewhere recently with a similar noise that turned out to be just that.

That's what I thought, it was a bew pump when I did the belt but you never know, I'm checking the spray bar first for blocking then I will go back to the w/pump

 

[Popitinpete]

Baring in mind that the noise we are hearing via the video may be a bit different to what you would hear standing next to the vehicle, it sounds a bit "light" to be big ends don't you think? I've found a good way to check for big ends is to apply a large throttle opening from idle and listen to the noise as revs increase. You only need to do this for the briefest of time, probably up to around 2 or 3 thousand rpm. As the load goes on you'll hear a noticeable increase in the volume of the knocking noise. However this doesn't sound like ends to me, it's too "light" a noise. It's not making typical worn bearing noises either. Almost sounds a bit like a worn timing chain, but we have a belt so that's out the window too. Listening to the second clip - the one featuring the top of the engine - there seems to be two noises. A "lighter" clicking sound which is very like something to do with cam followers which is constantly audible, by which I mean it's there all the time and a more "knocky" hammer like noise which seems to come and go somewhat. I think, because it's easy and quick to do, I'd be whipping the cam cover off and having a good look - might even start the engine with it off and see what I could observe.

Have you tried a listening tube? I know you mentioned using a screwdriver as a "listening stick" and I've found this very good for tracking down bearing noises in particular but a listening tube, where you just move the open end around the engine, can bring a whole different perspective. If it's valve gear it might be interesting to take the oil filler cap off and stick the end of the tube in - but not too far of course.

It does to be fair get louder and more pronounced between 1000rpm and about 2000rpm and I've talked myself into thinking I can hear it rumble BUT! it is quiet after 2000rpm!

 

[Popitinpete]

I was ignoring this possibility for now

As the microphone on a phone it quite sensitive to distance and should have been much more noticeable

I did ask earlier if it was worse going up hill which would possibly point in this direction

It’s quite easy to test, remove all the spark plugs, turn the crank so a piston passes top dead centre and starts to fall. Push a wooden dowel on top of the piston and feel for it to drop due to play. You can get technical and measure the fall but it not needed

No difference up hill, not pre ignition or worsens with load no

 

[Popitinpete]

A cracked belt passing the tensioner is what it sounds like. Except the belt was changed 2 months ago

If @Popitinpete took a video from the same location and distance with the timing cover on and off. There should be a noticeable change in loudness. It would still leave the water pump, belt, pulleys or idler. But would at least tell up if we were in the right area

I'm convinced it's inside the engine, just taking the rocker box off now as a start. I don't won't to run it with the cam box off because the CPS won't be above the cam

 

[Popitinpete]

That's an interesting approach to checking for excess clearance in a big end. I never thought of doing that.

If it got to the stage where you could feel the piston and conrod drop it would have imploded before that or at least have the oil light on and it wouldn't be quiet when cold. I'm convinced it's valve train

 

[Popitinpete]

OK no cam spray bar, it uses a system where the oil feed goes into the cam box cavity and is the fed into the 3 cam journal caps via oil galleries and the rest is then 'fountained' for want of another word onto the 2 sections of the camshaft.

Either way plenty of oil up there, no oil holes blocked and all valve clearances in check..

So it's top end back together and reinvestigate around the new cam belt and water pump it is then, please see pics

 

[Goudrons]

So, let me think out loud.

We know the sound is coming from the front end of the engine.
What's there?

There appears to be no driveability issues or loss of power, no smoke, no EML's from any of the sensors.
Doesn't really tie in with serious internal engine trouble.

The sound changes when the engine is warm and perhaps when the rpm rises it quietens.
Again is doesn't sound like serious internal trouble, though you can't write that off yet.
(piston slap sprung to mind at one point)

I'd be more than convinced to check all the low lying fruit like the, damped crank pulley, cam belt, tensioner, water pump and idler pulley and every other item hanging off that end of the engine before I start looking at the engine internals.

 

[Popitinpete]

So, let me think out loud.

We know the sound is coming from the front end of the engine.
What's there?

There appears to be no driveability issues or loss of power, no smoke, no EML's from any of the sensors.
Doesn't really tie in with serious internal engine trouble.

The sound changes when the engine is warm and perhaps when the rpm rises it quietens.
Again is doesn't sound like serious internal trouble, though you can't write that off yet.
(piston slap sprung to mind at one point)

I'd be more than convinced to check all the low lying fruit like the, damped crank pulley, cam belt, tensioner, water pump and idler pulley and every other item hanging off that end of the engine before I start looking at the engine internals.

Hi there, thanks for your imput. It's not so much the front of the engine it's sort of top of piston one, between head and block area. I didn't notice a damped crank pulley when I did the belt, just the alternator pulley bolted onto the what seemed like just a solid crank pulley. Water pump and idler were new a thousand miles ago along with the new belt but that's not to say they could have failed.. The noise is 'top end' related by the looks of recent developments. I will reply on an update on a stand alone comment in a sec, really appreciate it.

 

[Popitinpete]

OK bit of an update, as per previous post, all cam oil ways clear, cam box oil ways clear etc etc. I had a quick look at the valve clearances and to be honest they are on the limit mostly, some just over, but as you know, bucket and shims don't just get noisy, they wear over time or get vocal if starved of oil. one is definitely a little larger than spec but that's the one I have always heard since we've had it. It ticks away quietly to itself and never changes, it not really noticeable but it is a little louder than it's stablemates. however I checked the smoothness / ovalness (if that's a word) of the buckets, all perfect fit , no sticking ones when I spun them around, no slap, spun them all around and could pull them up a tiny bit until they touched the cam lobes, put it back together and there is a distinct difference to the sound, it's not SO 'knockie', in fact after a run round the block and ten mins of idling and the fan coming on its I would say 95% how it's always been, I can make it a TINY TINY bit 'knockie' if I hold it at certain revs but THE Air cleaner is off and the bonnet open so just could be I'm hearing it in an unusual fashion, inside driving by the way it's silent, can't hear anything. HOWEVER.....

I drove the wife's panda today identical to mine, in fact they could have been next to each other on the production line. Came back to it after an hour, started it up and just for curiositys sake I did the hold the revs at 1200 rpm and guess what? It has the same sort of tapping/clickety sound albeit about 30% of what I've had in volume, it's as if this new ' no spray bar cam oil feed system' has to prime itself first for 30 seconds or so, from cold both cars are silent..... BUT and its a big but, I have a little confession..

I have a couple of 60s British bikes, well I've just sold one actually, and I did a 750cc conversion on one a year back, a morgo big bore kit, and the running in instructions is to use a none detergent, 0-w40 mineral oil to help it 'bed in' after fitment, I did as instructed and the running in process went well but I noticed it rattled its bits off something chronic, it did have a slightly worn tappet block that I didn't replace due to lock down restrictions at the time but as it was running quietly beforehand I just put it back in. After a run when up to temperature it absolutely sounded awful, I'm talking like it had no oil in it. They should run on 20w-50 classic oil but the warranty on the morgo kit specifies 0-w40 mineral or any warranty is invalid...

Fast forward to earlier this month and I needed to top up bumble before a trip to the northeast and back..... Now then, I reached for my normal 5-w40 C3 stuff we use on both cars but it was more or less empty, well a couple of eggcups full at the most, I then reached for another container and wondered why I had put about a litre of oil in a clear container, assuming it was left over from the other pandas oil change.. I topped up with about a mug full, went on holiday, never missed a beat all was fine. Cut a long story short I was idling somewhere waiting for something and I thought bumble sounded a bit tapperty, I revved her and thought that's way louder than normal, [email protected], had I put some of the 'death oil' in that has possibly turned my bike into what sounds like two skeletons bonking on a xylophone? I got back and looked for the old tin of motorcycle oil but it had gone, I really can't remember if I've decantered it into a clear vessel and thrown the can away....

Whilst coming out of tescos last week I revved it just as I was under the tunnel and it sounded very tapperty, did In fact top it up with the 'death oil'? it was due a service anyway so I changed the oil and filter and this made a difference but my conclusion is some of the 'death oil' will still be in the engine, even after a thorough hot drain (in the oil pump, in the crank, cam, block galleries etc and clinging to the inside ) so after spinning the bucket shims around and blowing out to check clearance of the cam box oil ways and it then making a big difference to the sound I'm convinced it's the remnants of the 'death oil' still inside, that would explain the noise was only happening on a warm/hot engine, no oil light on, no smoke and it performing a 1000 miles of motorway work faultlessly in the past month or so.

I will maybe drain what's left in again next week to try and get rid of the remaining incorrect oil.

I will keep you posted

 

[koalar]

sound, it's not SO 'knockie', in fact after a run round the block and ten mins of idling and the fan coming on its I would say 95% how it's always been, I can make it a TINY TINY bit 'knockie' if I hold it at certain revs but THE Air cleaner is off and the bonnet open so just could be I'm hearing it in an unusual fashion, inside driving by the way it's silent, can't hear anything. HOWEVER.....

Oil isn’t too important on pre VVT engines. Good quality around the correct grade is fine. I always use whatever cheapest at home and bargains

One engine 1.1 on a 06 did over 200,000 miles

1.2 did over on a 05 did over 170,000

Both you could hardly hear from inside at idle

Are the rubber dampers present on the airbox and ok

My 06 1.1 active would rattle badly if the front spring from the airbox is missing. I forgot to fit it once after doing some work

Not all airbox use a front spring and they are often missing but it’s easy to test as the sound changes if you put your hands on the airbox.

Look at your latest photos looks nice and clean.

 

[Popitinpete]

Oil isn’t too important on pre VVT engines. Good quality around the correct grade is fine. I always use whatever cheapest at home and bargains

One engine 1.1 on a 06 did over 200,000 miles

1.2 did over on a 05 did over 170,000

Both you could hardly hear from inside at idle

Are the rubber dampers present on the airbox and ok

My 06 1.1 active would rattle badly if the front spring from the airbox is missing. I forgot to fit it once after doing some work

Not all airbox use a front spring and they are often missing but it’s easy to test as the sound changes if you put your hands on the airbox.

Look at your latest photos looks nice and clean.

That's what I was thinking about the oil, it looks like I have topped it up before my big trip by mistake with the 0-w40 mineral oil, about a mug full and it really shouldn't be a problem with a relatively small amount but the way it made my bike sound after I used it when I changed its oil was nothing short of disastrous.

The air filter housing has good rubber bushings and the front spring clip is on, the noise is definitely valve train related. As I mentioned this afternoon, after I had spun the shim buckets around and blew out the oil galleries in the cam cover it was immediately quieter, so much so even after getting it hot and letting it idle until the fan came on I couldn't replicate the tapping noise again, it was 99% sounding as it has always sounded so I'm putting it down to adding rather foolishly what I now refer to it as ' the death oil'. I may have inadvertently moved a bit of crud at the same time when I blew the oil channels out who knows.

I couldn't get any better audio quality videos of what I've already posted either.

Don't forget its got nearly 100k miles on it and a few tolerances in the valve train will be let's say of a different tolerance to when it was new and the 'death oil', which was more or less 'running in oil' I guess has had a bit more of an audible effect on things than I would give credit for.

I will run it for another 1000 miles and do another oil change and by that stage most of the incorrect oil should have been drained out. Its the silent when started from cold, no blue smoke, no oil consumption etc etc that has convinced me now that it's not terminal, especially after my inspection of the top end today.

Thanks for your imput everyone and I will report back in due course

 

[jackwhoo]

Hi,

I have hesitated to join in .

Sometimes exhaust manifold gasket leaks sound exactly like tapping/knocking.

Was it @Baglady1990 that had a similar noise on her 500 that turned out to be exhaust manifold gasket failure?

 

[Baglady1990]

Hi,

I have hesitated to join in .

Sometimes exhaust manifold gasket leaks sound exactly like tapping/knocking.

Was it @Baglady1990 that had a similar noise on her 500 that turned out to be exhaust manifold gasket failure?

I did indeed however my noise disappeared as soon as the manifold got hot! Obviously the gasket expanded and blocked the leak! But yeah that tapping noise is horrible and I don’t miss it

 

[Popitinpete]

Hi,

I have hesitated to join in .

Sometimes exhaust manifold gasket leaks sound exactly like tapping/knocking.

Was it @Baglady1990 that had a similar noise on her 500 that turned out to be exhaust manifold gasket failure?

Hi, yes it did cross my mind too but its definitely a mechanical noise and I've traced it back to me putting in what I now refer to as the 'death oil'. It was the same oil that made my bike sound like it had no oil in it. After the inspection yesterday and doing a few things it's made a difference to the noise so it's definitely internal and definitely valve train, thanks for the heads up