Noisy tappets

[GAZZANATOR]

I know the answer to this one's on here somewhere,but I'll ask the question again anyway.
Anyone know how to fix the very,very annoying noise coming fron my 2L engine,short of stripping it down?
There's no smoke,and it's on 123000 miles.
Was considering an oil additive,or maybe an early service???
Any suggestions welcome.Thanks

[Richieroo]

Hi what sort of noise is it ??

[clipper]

M20 tappety tappets noise seems to have been written about alot, but solved very seldom.

I did a big search recently because mine is also driving me mad. The procedure seems to be the following:

1: Change the oil
2: Adjust valve clearances
3: Adjust valve clearances again
4: Blame the injectors
5: Resign yourself to knowing that "they all do that mate"



I'm at step 4.

[GAZZANATOR]

Have to say that the noise only started after the car was left lying in the cold for a couple of days and seems to get better when the car's warm.Hmmm
Other than that the engine's in good form.

[paddywack]

where abouts i glasgow are you im in glasgow could possibly come by and have a listen for you etc

[Richieroo]

Hi its sounds like it could be lifter lock. Mine was like that to i only use mine 6mths a year and it plays up till i change the oil but ive done the list to on my old touring and i still had the noise is the spray bar ok bmw told me to change that

[bilun777]

Lifter lock WTF......

[clipper]

Lifter lock WTF......

+1

I think he may be talking about those new fangled hydraulic tappets you get in some other engines !!

[GAZZANATOR]

Thanks for the offer paddywack,but I work long hours.It's really a weekend thing for me.Booked in for an oil change next week,will see if that does the trick.
Had a look under the rocker cover and the oil seems to be circulating ok.
Spoke to a friend with a 325i and he gave me the same advice as Clipper,and added "rev its nuts off til it goes away" .Sounds like my kinda solution.
Again,any more thoughts on the subject,I'd be happy to hear them.Thanks all

[Tedswagon]

Your head is stronger in a 320 than a 325 but I would suggest reving the nuts off the engine only after the engine has had a chance to warm up a little!

[johnt0709]

Yip - im at stage 4 as well - contemplating the ultrasound cleaning to help - anyone tried this?

[clipper]

Yip - im at stage 4 as well - contemplating the ultrasound cleaning to help - anyone tried this?

My injectors are in the post !!! when I get them and put them in I'll report back !

TBH I don't expect this to be the cause of most of the tappet sound. It's almost certainly valve train noise (at least in my case) as it gets louder as the engine oil warms up.

I'm putting in refurbed injectors because I know that the engine is in fairly good state, and to try to optimise performance and economy, but if it quietens it down aswell it'll be an added bonus.

[paddywack]

no worries gazzanator, help here if you need it anytime mate

[AG205]

I stripped my '87 M20 325 motor down a few months ago and did a full head strip down and clean along with fitting new valve stem seals and even replacing a couple of valves that were a bit worn. Also took the head to a engine reconditioner to de-coke it and check it over. Spent a fortune on all new hoses and oil seals etc. What I'm saying is, everything was checked and cleaned but from the first time I started it and warmed it up it's been rattling it's tats off ever since. I've tried adjusting the valve clearances 3 or 4 times and nothing has made any difference. Doesn't even really sound like injectors ticking, it's definitely valve train noise and I've no idea how else to fix it short of sticking in some really thick oil (20W50 maybe) to see if that shuts it up.

Now totally fed up with it & resigned myself to binning this engine and sticking in something quieter! Anyone want a good condition, freshly painted high-comp M20 + late management etc?

Andy

[Wocka]

I stripped my '87 M20 325 motor down a few months ago and did a full head strip down and clean along with fitting new valve stem seals and even replacing a couple of valves that were a bit worn. Also took the head to a engine reconditioner to de-coke it and check it over. Spent a fortune on all new hoses and oil seals etc. What I'm saying is, everything was checked and cleaned but from the first time I started it and warmed it up it's been rattling it's tats off ever since. I've tried adjusting the valve clearances 3 or 4 times and nothing has made any difference. Doesn't even really sound like injectors ticking, it's definitely valve train noise and I've no idea how else to fix it short of sticking in some really thick oil (20W50 maybe) to see if that shuts it up.

Now totally fed up with it & resigned myself to binning this engine and sticking in something quieter! Anyone want a good condition, freshly painted high-comp M20 + late management etc?

Andy

Same for me. Only there was some play in the valve guides, not noticed any smoke mind you. So it's either that or a worn cam?

[clipper]

I didn't add it to my list, because that was a bit tongue in cheek, but I did read somewhere that if our motors go a long time without having the gaps adjusted and generally at high mileage, the eccentric adjusters can get a flat spot worn onto them where they make contact with the valve stem.

This can mean that after having adjusted the gap, the tendancy is for the adjuster to rotate itself back to the original position because of the flat spot.

I suppose it could be true. If the adjustment is slight and the small nut is not extremely tight I can see how the repeated impact on the valve stem would rotate the eccentric back to its original position....

It seems that the best way to check for this is to remove the eccentrics and roll them on a glass table to feel for the flat spot.

I too had my head looked at when it was skimmed and was told that I didn't need to replace any parts, (180,000km motor) but how many engineers would check the curvature of the eccentric adjusters

I haven't done this but it should really be step 5 of the list I suppose.

[Brianmoooore]

Checking the condition of the contact points of the whole of the valve gear, including the eccentrics, should certainly be on the list for any compentant engineer!
A M20 engine in good condition should not produce any intrusive valve train noise.

[clipper]

Checking the condition of the contact points of the whole of the valve gear, including the eccentrics, should certainly be on the list for any compentant engineer!

I absolutely agree, but my doubt remains. I'm sure you see what I'm getting at...

[HairyScreech]

get a stethoscope and determine where its coming from, on mine you can clearly hear the injector actuation through the injector bodies. and they do sound like tappets.

[Martinaston]

When i can be bothered i'm going to wrap the injectors in self amalgamating tape and see if it improves things.

Tappets always seems to be a bit hit or miss, when you do notice it you think has that just started or have i been tuning it out because its so bloody annoying

[GAZZANATOR]

Wow !!!! Appear to have opened a real can of worms here. .I know quick fixes and so called miracle additives rarely work,but has anyone tried any of them to see if they make a difference ??

[clipper]

Thread revival !!!

Today I put new eccentric adjusters in my head and set the clearances at the cam end of the rocker (to take into account the slight, but visible wear on the top of the valve stems).

I set the gap at 0.17mm basing this on a leverage ratio of 1:1.5 (1.5*0.17 = 0.255) The ratio was found on internet, not this site, so I hope it was accurate......

Result = near silent top end and pulls like a train.

If anyone knows of any problem with what I've done please let me know because I've got a 1,000km round trip this weekend !

PS, I know that the best would have been to replace the valves but that'll have to wait.

[Charlie3000]

I'm sure someone will correct me if I'm wrong, but I thought that the valve clearances should be set at 0.25mm?

[Simon13]

yup 0.17 is way too tight hence why it goes well! a loose tappet is a happy tappet. 0.25mm cold is BMW recommendation

[cecotto479]

That'll certainly quieten them down. And you'll get to replace all your valves much sooner than you planned - at least at that point you can reset the tappets to the slightly noisier, but safer 0.010.

[Brianmoooore]

Today I put new eccentric adjusters in my head and set the clearances at the cam end of the rocker (to take into account the slight, but visible wear on the top of the valve stems).

I set the gap at 0.17mm basing this on a leverage ratio of 1:1.5 (1.5*0.17 = 0.255) The ratio was found on internet, not this site, so I hope it was accurate......

[clipper]

Thanks for that Brian.

As a secondary check I measured the clearance at the valve stems after doing this on a few of the valves, and I was getting a clearance of about 0.23 - 0.24mm, which seems to indicate that the slight mushrooming of the stem heads is causing an indentation of approx 0.015 - 0.02mm which I think is reasonably acceptable.

I have read that the leverage ratio is 1:1.5 or 1:1.56. Can anyone confirm the real spec ?

[cecotto479]

My apologies.

[anton89]

I got my more door a month ago and the valve train was horrible, some gaps were massive, I adjusted all of them to the correct tollerance when I started it up there was less noise but still a definate tick. Anyway I found the source of the problem, Rocker No2 on the exhaust had been inserted slighty uncenterd with the valve stem. This has caused the ecsentric to only make contact with half the valve, all the other eccentrics make a dull knock on the valves when moved by hand however the uncentered rocker made a much tinier tick.

You can find out which rocker/eccentric / valve is causing the noise by using a screw driver, wherever has the highest pitch tick is the source of the problem.

Anyway realigning the rocker reduced the noise to a dull clatter barely audible with the bonnet down

hope it helps