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Captain Beaky

V8 Tapping Noise

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I've read plenty of threads on noisy V8 engines but none that really fully answer my question so I wanted to put it out there and see what advice comes back.

 

My 2003 535i will now and again give a distinct rattle on start up, sometimes louder,  sometimes subtle, sometimes its a harsh noise and other times more of a knock than a tap??

 

It is completely random I can go a week starting cold with no noise, then a week where it is there more often than not, the only constant is after driving if I leave it for an hour or so sometimes longer it will almost certainly rattle.

 

I have just done an oil change and it seems worst, i used Gulf ULE 5w40 and a K&N oil filter, 

 

Now i've read about air in the oil and  vanos and other stuff 

 

But what is it?  Anyone?

 

   

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Could be the timing chain tensioner starting to fail? They have both a spring and hydraulic function and when the hydraulic function gets weak (perhaps leaks down while off) it takes longer to come up to pressure at start-up. A weak tensioner can cause the chain to slap and break the chain guides.

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Right ok my M60b40 does this very, very occasionally and in my particular situation it's always on start up on cold engine and on mine it's nothing more than a lazy tappet on the o/s bank. To get rid of it quicker I hold the rpms at around 1500 until engine gets up to temp and it soon goes within a few mins. 

I'm not saying this is the same situation for yours, but mine is 100% down to a lazy hydraulic tappet. Also seems to do it if I've manoeuvred the car a few yards and shut the engine down with out letting it get up to temp. 

So to get by this whenever I start the engine I always let it get to temp, drive it a few miles then shut it down which seems to do the trick and lessen the effect of that lazy tappet.

Good luck, hope it helps and like I said this may not be the case with your car, it may well be as previously mentioned, the tensioner starting to get tired.

 

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This rattle lasts only a few seconds, historically with other cars i would put money on the hydraulic tappet being worn or losing oil but I am not familiar with this engine.

 

However today there has been nothing on start up or any time after?

 

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8 hours ago, dan101smith said:

That's the start of your engine dying. Change the tensioner - if that doesn't get rid of it, then you're looking at guides too.

 

Dan how would I check for this?

 

Would it be down to the oil? 

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A different engine I know but my 530i (M54B30 engine) had an intermittent tapping at start up from when I bought it at 100k and still had it 70k+ miles later

 

Generally after changing the oil it was fine, once the oil was perhaps 5k miles old it would intermittently return

 

So if it is a tappet I wouldn't worry too much. Timing chain is a different matter though so I'd definitely try and come to a conclusion as to what the cause is, or at least rule out the chain

 

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I come from Corrado ownership and the VR6's are notorious for timing chain tensioner guides wearing and failing too. The only way to be sure of their condition is a visual inspection. Not sure of how much work is involved in performing such an inspection on an M62 engine but for peace of mind it might be worth finding a specialist capable of doing it and getting it checked out.

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Your symptoms seem too sporadic and the different noises make me think it may not be one thing. Can you stick your head under the bonnet and identify where the noise is coming from? You can use a big screw driver with the handle against you ear and the other end at different points around the engine, block, head, timing cover etc.

 

If it's only present at start up and goes away after a few seconds it's most likely to be the timing chain tensionner, it works via oil pressure but has a spring inside to provide some tension at start up when there is now oil pressure, the spring goes weak with time. If it's never been done it's worth changing anyway. It's a two minute job.

 

Part 20

 

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On 3/15/2018 at 1:51 PM, Oneball said:

Your symptoms seem too sporadic and the different noises make me think it may not be one thing. Can you stick your head under the bonnet and identify where the noise is coming from? You can use a big screw driver with the handle against you ear and the other end at different points around the engine, block, head, timing cover etc.

 

If it's only present at start up and goes away after a few seconds it's most likely to be the timing chain tensionner, it works via oil pressure but has a spring inside to provide some tension at start up when there is now oil pressure, the spring goes weak with time. If it's never been done it's worth changing anyway. It's a two minute job.

 

 

 

 

 

Aye done all that so many times it hard to tell a knock from a rattle and it's only a sound bite before it's gone, I have an automotive stethoscope and it's still  not definite, the ironic thing is that when its idling its so quiet you can't hear it so much so I left it running on the drive for hours once because i forgot about it, even the wife pulled up behind and did not realise.

 

However chain slap!  it is a possibility so I have ordered a chain tensioner from the steelers £84, should be here Tuesday.

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Timing chain tensioner sounds the issue .... The trouble normally starts after leaving the faulty tensioner for months.

 You should be fine :D 

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A rattle like that at startup, will be most likely down to the vanos units not being full of oil due to them  leaking down because of worn seals and check valves.

I engineered open both of my vanos units and resealed them with new seals i had a threaded cap made for the vanos and had the vanos body threaded so it closes back up again.

Drop your oil pan and check to see if you have any debris from your guides if so you really do need to strip it down and change them out.

It's not a ridiculous job but there is lots to come off and go back on again.

 

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Just done an oil change which has now increased the frequency  of times it rattles on start up. When I drained the oil I used  a clear plastic bag to line the bowl and after draining it out used a torch to shine through the plastic, there was nothing of interest, in addition I poured the oil through muslin as a strainer and nothing there either!

 

 

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If any bits of chain guides are in there they are not likely to come out with the oil.

Edited by kenny

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Tend to agree with above statements. Drop sump and see what's inside. Not a difficult job at all and shouldn't take too long to complete. Just make sure you order up new gasket in advance etc

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I've bought a tensioner and will change it soon, however if there was the possibility of any debris in the sump I would have seen some evidence in the oil with the thorough examination it was given, I checked the  plastic and muslin with a illuminated bench mounted magnifying viewer, the filter was washed out with petrol and both checked. If there was anything, even fine bearing material in there, this method would find it and is a proven method previous to this.

 

I am convinced now it's the Vanos, ive changed the oil and the result is the rattle is more frequent, it's a definite step change which has caused a reaction. Opie Oils recommended 5W40 so I opted for the Gulf ULE, I don't know what oil was used previously this is the first change i've done on this car but it seems to have worsened the issue. The only other change was the oil filter, Opie supplied me with a K&N filter, has anyone used one of these before?

 

The plan now is to drop the oil and try something else.

 

  

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Both the tensioner and the Vanos work by oil pressure in a piston so changing the grade of oil could have a similar effect on each. 

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5 minutes ago, Oneball said:

Both the tensioner and the Vanos work by oil pressure in a piston so changing the grade of oil could have a similar effect on each. 

 

Yes you are right but the tensioner also has spring assistance and if the spring weakens it will will allow a degree of slackness in the chain, which is why I am replacing it as a matter of course.

 

 However this rattle has increased in intensity and frequency which points to the vanos and not the chain tensioner because of the wrong or thinner oil, so i am going to try 10w50 or 20w50

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10w40 perhaps. Plenty of choice in that. You may get a slight improvement, but it will only be partially masking the underlying problem.

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This is why I don't buy from steelers!

Because they f**k you when you order and F'**k at the counter and by the time your home it's too late you're f**ked

After paying £84 for a tensioner I would expect to seem the copper washer/ crush washer whatever you want to call it. This is pennies to them and is a vital component to fitting the tensioner, BUT oh no! there isn't one there!

 

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Anyway the tensioner has been swapped out but i can see no real wear in the other, from previous posts a failed or weak unit should be shorter.

 

So its in! Lets see what happens?   I'm not convinced that this £84 was well spent but it does give reassurance I suppose.  

 

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When I swapped mine out the new tensioner was significantly longer. 

 

Has as it made any difference to the noise?

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Too early to say, there was the obvious noise from the tensioner not doing its job on start up because the oil had not hydraulically charged it, i did think about priming it first? however i have not read about anyone else doing this.

Interestingly the noise on start up while the tensioner was charging was a completely different noise, it was a duller noise definitely chain on plastic, so i still think it's Vanos

 

If this works though I will be eating Beanie Hat for tea not Hot Dogs :D

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Hot Dogs for Tea Boys  :P

Changing the timing chain tensioner made absolutely no difference whatsoever, so i will be dumping the oil and going to 10w50

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 Read this article from Beisan which show you how to change the seals in the vanos. But I think it's a much better idea to machine open the vanos as i did. It's so much easier changing the seals and you can do it without any fear of damaging them but it will cost some machining money in my case around £80

Depending on what you find you may need to replace the oil distribution piece and the sealing rings on the end of the cam.

The delight of starting up the car after doing the above and not hearing all those rattles and generally getting your engine back to fighting fitness will feel great. 

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I have skimmed through the article, it's a lot of work! too much for me, I don't have the time or desire to go through all that shit.

what's this other method you mentioned?

 

 

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