m40 tappet noise

Wed Dec 14, 2011 9:57 am

as we know the m40 can be a tappy old hector but mines a low miler and isnt tappy.... unless its very cold and its noisy for a very brief second when first started ive had a search but as there are so many m40 and tappet noise threads i cant find what i need, so whats the reason?? oil pressure??? only when very first started on a cold morning and it goes instantly..

cheers chaps

Rotta

Fri Feb 24, 2012 7:46 pm

there's an oil drip bar under the cam cover, if the m4o hasn't been looked after and serviced when it's suppose to have been, the holed that drip the oil onto the cam gradually blocks up, thus making tappety noise, if left it will eventually stop dripping oil and the cam lobes will be worn and scratched as the dry cam rotates against the valves, hope this late answer to your question helps lol

Sun Jun 03, 2012 1:36 pm

Hi,

Also a duly late reply!

I bought my e30 about 4 years ago with only 43000 on it! It's now done 73000.

I tried to hunt down the solution to this problem too, I changed my oil spray bar (referred to above) with an the OEM part (wanted to make absolutely sure!), but it didn't solve my problem. I changed the oil at 12 month periods previously, using 15w40, don't think it was semi synth. Then whilst I was trying to sort this noisy problem out I changed with 15w40, no change, if anything possibly worse! So I took the risk of getting some engine cleaner, which I believe contains a detergent to clean off all sludge (risky as some sludge with older engines, might be sealing damaged gaskets/seals), aparently a similar risk is taken if you use synthetic oil. So after I used the engine cleaner and saw no leaks I used semi synth 10w40, I bought castrol oil to ensure quality wasn't an issue (used halfords own before). It didn't seem to make a great deal of difference.
6 Months later, I changed the oil again using castrol (10w40 semi), but this time I bought an "OEM" oil filter from euro car parts. The car has been quieter since! Not fully quiet mind you, more on off ticking in winter, but when it's quiet, it's lovely. I have noticed that it also has a ticking noise at higher revs...I only notice it if I have the window down, driving next to a wall (so I can hear the sound reflections).
I've read that the oil flow is sooo critical on this engine, I remember reading somewhere that using OEM oil filter is important and something about the oil pump, which I believe isn't a normal replacement part and I've not located it!
If you do replace the oil spray bar, it's worth checking the cams for scratches or wear.

Does your car suffer any other ailments? Mine suffers from a lean misfire...I've investigated extensively, it may be good to chat more if you are having any similar symptoms as I'm wondering if my cam shaft may be slightly worn and therefore not opening the valves enough etc..

Fri Jun 15, 2012 7:44 pm

To be honest, it's normal. When the engine starts, the oil pump can't build up pressure fast enough. I really would't worry. Regular oil and filter (magnatec is good) and a new spray bar is all you can do short of replacing all eight lifters.

Fri Jun 22, 2012 10:48 am

@soul 4t mine does exactly the same thing. It taps like hell. Cold or warm. And it would start misfiring at 5500 revs. So I changed the tappets thinking one had gone soft. One fell apart when I took it out, I thought happy days that was the one! Put the new ones in, put it all back together and its still tapping away, the onlydifference is now the misfire starts at 4500 revs. Im stumped.

Fri Jun 22, 2012 10:49 am

And its burning oil, forgot to add that bit

Fri Jun 22, 2012 1:45 pm

Oh right,

In what way do you know that it's burning oil? Are you having to top up the oil regurarly?

Sat Sep 15, 2012 11:29 pm

My car is rather odd.It starts quietly from cold and after say 30 or so seconds, starts to tap.A minute later, it goes quiet again, a minute after that it taps again and a minute after that it will stay quiet almost constantly until a cold start again where this proccess repeats itself.

Sat Sep 15, 2012 11:49 pm

I think that is the normal warm up for the M40 engine I think it's the self adjusting tappets adjusting to the changes in temp...mine does the same...quiet, then taps heavilly then like a shot it's quiet again....repeating until warm, then it taps fairly lightly....have you had your M40 e30 for long?

Sun Sep 16, 2012 10:57 am

i have the question which oil is the best for e30 m40 engine

Sun Sep 16, 2012 11:51 am

I'm having a read of some oily threads on here, lots of info!

I use a semi-synth 10w-40, normally magnetec.

As far as I can glean:
5w-40 fully synth is I think the most recommended, but may not be quite as quiet...depending on the condition of your engine...but it won't do any damage...despite the noise! I haven't tried 5w-40 as it's a bit more expensive and I'm happy to change every 6months...ish.

If you want full info, check out oilman's threads on oil!

Mon Sep 24, 2012 1:01 pm

Andyboy wrote:To be honest, it's normal. When the engine starts, the oil pump can't build up pressure fast enough. I really would't worry. Regular oil and filter (magnatec is good) and a new spray bar is all you can do short of replacing all eight lifters.

Pardon me for I am new to the E30's but I found a set on EBAY Germany for Cam shaft and lifters for about 200 Euros they are aftermarket . Would this be another fix to the tapping noise?

thank you

Mon Sep 24, 2012 4:47 pm

I've heard of people changing quite a few parts and the tapping returning after a month or two...If I can remember, someone thought it would be best to change the followers as well...basically everything short of taking the head off. I was contemplating doing it and thought I'd probably replace everything except for the valves, but then after looking at the cam I thought it's probably not worth doing it yet. As the cam itself didn't look bad.

Mon Sep 24, 2012 7:48 pm

try some thinner oil 5w-40 semi , ive got a 49,000 mile m40 donk in my touring and its as quiet as a mouse even on startup, I use 5w-40 semi in mine. might need a good run out, has it been stood long ?

Run some diesel oil in it for a few thousand miles will help clean crap out of hydrolic lifters etc

Mon Sep 24, 2012 7:55 pm

Interesting...well worth a shot! I think I'm gonna try the 5w-40...haven't yet! It is the recommended best oil by castrol.

Mon Sep 24, 2012 7:59 pm

its a worn cam mate. there is a kit for a cam set for them. think they cost under 300 you get the lifters too

http://www.c3bmw.co.uk/StockItem.asp?ca ... m=unassign

Wed Sep 26, 2012 7:46 pm

rich318i wrote:its a worn cam mate. there is a kit for a cam set for them. think they cost under 300 you get the lifters too

http://www.c3bmw.co.uk/StockItem.asp?ca ... m=unassign

thank you i just might try it

Wed Nov 07, 2012 10:03 pm

soul4t wrote:

Does your car suffer any other ailments? Mine suffers from a lean misfire...I've investigated extensively, it may be good to chat more if you are having any similar symptoms as I'm wondering if my cam shaft may be slightly worn and therefore not opening the valves enough etc..

mine does exactly the same and sometimes stalls on the mis-fire, and now that its getting colder it sounds like its running on 3 cylinders from cold, but once engine has warmed up the tapping goes, I've changed the hydraulic lifters approx a year ago which healed it for a about 5 months but now sounds worse than ever

are there any fixes for this issue?

Wed Nov 07, 2012 10:21 pm

Hmm, Well I've been able to calm the misfire a bit by richening up the idle CO mix, using the screw on the AFM. But this is a temporary fix for a problem thats not sorted.

Did changing the lifters cure the misfire and cold running issue? I've not heard about the tapping really contributing to any other running issues...only in really extreme circumstances...

To see if your symptoms are the same as mine, check out my thread about the cold start and misfire...I've got videos up there just below half way down the 3rd page: http://www.e30zone.net/modules.php?name ... c&start=50

It would be interesting to know if someone else has the same prob! What exact car do you have, year and cat?

Mon Nov 26, 2012 12:32 am

Just an update,

I'm pretty sure that my tapping/misfire problem is not due to a worn cam...

This is what mine looks like at the mo:

And I've just redlined it in 3rd to 6200rpm...70 or so mph...

I've recently done a compression test on mine:

178 Cylinder 1
188 Cylinder 2
180 Cylinders 3 & 4

I've been told not to worry about these it would be interesting if any of you guys could do a test on yours to see if that bears any correlation?...You never know!

Mon Dec 03, 2012 12:14 pm

Hi Guys
Interesting topic, and one I am sure has every M40 owner wanting to put a gun in his ear and pull the trigger at some stage.

About two years ago I decided to tackle the noisy valve train in my M40, as I had a spray bar that was all gummed up and not spraying onto the cam and the cam had chewed itself up pretty badly.

I had to replace the cam and rockers, so I decided to do the lifters as well, to make sure the entire valve train was new, no chances.

I also took a drill and opened up the holes in the spray bar a little bit, to give some extra oiling to the cam, and also to prevent the holes from clogging up as easily.

Bottom line...........................even with a complete new valve train, it still taps away, making a noise, however mine is not always there, it is intermittent, some times it taps away, other times it is as quite as can be.
I am thinking in a totally different direction here, and wondering if it is not a case of excessive lifter to bore clearance?
If, with age, the bores that house the lifters wear and the clearance opens up, would it not affect the pump up of the lifter and the amount of pressure it could sustain before bleeding oil off into the now, enlarged area between the lifter and bore, with the result of the lifter collapsing slightly and leaving a tiny air gap between it and the rocker?
You would not need much, a few thou would do it.
If this is indeed the case, it would seem like high mileage motors are doomed to tappet noise, as I don't see any way of resleeving the bore and renewing the tolerances back to factory new spec.
However, that said, I have not studied it in depth.

For those who have not seen the carnage created by a blocked spray bar.
Rockers, new and old...

Camshaft

Complete replacement Kit

Mon Dec 03, 2012 11:03 pm

Thanks for posting these thoughts and Photos up mate, should prove usefull I rekon!

Interesting you say that the noise is sometimes not there...what oil are you using?...just out of interest really, don't think I'm going anywhere with that one!

Mon Dec 03, 2012 11:08 pm

SkyKnight wrote:Hi Guys
Interesting topic, and one I am sure has every M40 owner wanting to put a gun in his ear and pull the trigger at some stage.

About two years ago I decided to tackle the noisy valve train in my M40, as I had a spray bar that was all gummed up and not spraying onto the cam and the cam had chewed itself up pretty badly.

I had to replace the cam and rockers, so I decided to do the lifters as well, to make sure the entire valve train was new, no chances.

I also took a drill and opened up the holes in the spray bar a little bit, to give some extra oiling to the cam, and also to prevent the holes from clogging up as easily.

Bottom line...........................even with a complete new valve train, it still taps away, making a noise, however mine is not always there, it is intermittent, some times it taps away, other times it is as quite as can be.
I am thinking in a totally different direction here, and wondering if it is not a case of excessive lifter to bore clearance?
If, with age, the bores that house the lifters wear and the clearance opens up, would it not affect the pump up of the lifter and the amount of pressure it could sustain before bleeding oil off into the now, enlarged area between the lifter and bore, with the result of the lifter collapsing slightly and leaving a tiny air gap between it and the rocker?
You would not need much, a few thou would do it.
If this is indeed the case, it would seem like high mileage motors are doomed to tappet noise, as I don't see any way of resleeving the bore and renewing the tolerances back to factory new spec.
However, that said, I have not studied it in depth.

For those who have not seen the carnage created by a blocked spray bar.
Rockers, new and old...

Camshaft

Complete replacement Kit

not seen a worn M40 cam that bad b4

Mon Dec 03, 2012 11:54 pm

soul4t, been on Castrol multigrade, 15W40, nothing special, in fact I am not a big fan of Castrol and normally avoid it.
I do like Duckhams or Agip, when yo0u can get it, but that is like drinking Chivas every day, too rich for my blood right now.
Rich, down here we ride 'em and make sure we get our monies worth out of them.