Rattly M30 Engine

[DRIFTBOY]

Hi.
I have rebuilt my M30 engine and fitted it to my E30, as some of you may already know.
It has a Schrick 284 camshaft and a very light head skim (just to make sure it was flat, not specifically for a compression raise).

Apart from a bit of porting the rest of the engine is standard.

I also renewed rocker shafts, rocker arms and adjusters, piston rings, timing chain and crank bearings.

When the engine is cold it sounds great, although I don't drive it hard until it warms up.

When it does warm up though there is a constant rattle, a sort of thrashy top end noise, almost like the valve clearances need doing. I have, of course, been over those a few times and it makes no difference.

I've been told these engines do run the valves VERY close to the pistons after a head skim and with higher lift camshafts!

Anyone got any ideas? Before I rip the b*****d apart again!

Thanks in advance!

[Andy335Touring]

Only guess's..........

Did you bleed the chain tensioner ?

I know it sounds irish but have you tried a bigger valve clearance ?

[DRIFTBOY]

At first I tried tighter valve clearances, no difference.
Then I adjusted them back. The noise changed tone slightly (I think) but is still there.
I know what your'e getting at with the wider clearances, I have thought of trying that, might give it a go at the weekend.

Bleed the tensioner!?
How do you do that? I just shoved it in!

Thanks Andy!

[Andy335Touring]

Assuming it's dry of oil and unbled, you undo the tensioner nut a couple of turns and pour some oil down the inside of the chain cover so it fill's the little oil tray thingy(get your torch out and look down there, you will see what i mean even if i can't describe it very well ) then move the tensioner in and out, you will feel the tensioner starting to get harder to move as the air is expelled/fills with oil.

Oh, and have a rag ready to mop up any oil that gets out of the lose tensioner nut.

It might have self bled by now though ???

[DRIFTBOY]

If they can self bleed then I expect it has by now, it's been over 700 miles since I had it out!

Thanks for the ideas though!

[Andy335Touring]

If they can self bleed then I expect it has by now

Thing is i'm not sure they can, might be worth checking ?

[DRIFTBOY]

Will do - thanks!

[DRIFTBOY]

Oh yeah, I forgot to mention something!

I don't know if it's relevant or not or if it does point to something!

When I switch the engine off you can hear the flap in the air flow meter shutting with a sort of hollow sounding 'plop'!
Is this normal ?
Is it being forced shut by air coming back down the inlet?

Does it on both the afm's that I have so I don't think it's that at fault!

Thanks for any advice in advance!

[Andy335Touring]

Sorry, I can't remember whats normal with the AFM because i haven't had one on mine for about three years now.

[wells696]

being a bit dopy but what do u have if u aint got an afm and why change it

[Andy335Touring]

I've got a mappable ECU that uses throttle angle instead of an AFM, i did it for a slight perfomance gain, better throttle response and future upradeability as with this ECU i can convert to throttle bodies/turbo/super charger which you'd struggle to do with the stock ECU.

[nickso]

Hi.
I have rebuilt my M30 engine and fitted it to my E30, as some of you may already know.
It has a Schrick 284 camshaft and a very light head skim (just to make sure it was flat, not specifically for a compression raise).

Apart from a bit of porting the rest of the engine is standard.

I also renewed rocker shafts, rocker arms and adjusters, piston rings, timing chain and crank bearings.

When the engine is cold it sounds great, although I don't drive it hard until it warms up.

When it does warm up though there is a constant rattle, a sort of thrashy top end noise, almost like the valve clearances need doing. I have, of course, been over those a few times and it makes no difference.

I've been told these engines do run the valves VERY close to the pistons after a head skim and with higher lift camshafts!

Anyone got any ideas? Before I rip the b*****d apart again!

Thanks in advance!

same problem ive got and another bloke round here has exactly the same problem on his 335.

ive done all the clearances 4 times blah blah blah.....

ive given up now although it annoys the hell out of me.

ive decided to just let it blow up if its going to. i can see why you might not like that course of action having just rebuilt your engine though

[gareth]

it's not just noisy injectors is it?

[nickso]

i thought that as well but ive been told my particular ones should be ok.

if i pick up a set in the scrappy im going to try it but im not going out of my way to solve it now

[DRIFTBOY]

I thought it might be injector noise too, especially as I removed all my sound-proofing. I put another set in - no different.
Only does it when the engine is warmed up though.

It is VERY annoying, and a bit worrying!
Especially on my recent 550 mile round trip from Kent to Devon and back, a lot of motorway - I was constantly waiting for the BANG, clatter, rattle and coasting on to the hard shoulder!

It's really ruining my enjoyment of what should be a fine car.

Interesting that others are having the same problem.
Are you also running higher lift than standard camshafts and / or skimmed heads?

Thanks for your replies!

[Ritchie]

Hi.
I have rebuilt my M30 engine and fitted it to my E30, as some of you may already know.
It has a Schrick 284 camshaft and a very light head skim (just to make sure it was flat, not specifically for a compression raise).

Apart from a bit of porting the rest of the engine is standard.

I also renewed rocker shafts, rocker arms and adjusters, piston rings, timing chain and crank bearings.

When the engine is cold it sounds great, although I don't drive it hard until it warms up.

When it does warm up though there is a constant rattle, a sort of thrashy top end noise, almost like the valve clearances need doing. I have, of course, been over those a few times and it makes no difference.

I've been told these engines do run the valves VERY close to the pistons after a head skim and with higher lift camshafts!

Anyone got any ideas? Before I rip the b*****d apart again!

Thanks in advance!

same problem ive got and another bloke round here has exactly the same problem on his 335.

ive done all the clearances 4 times blah blah blah.....

ive given up now although it annoys the hell out of me.

ive decided to just let it blow up if its going to. i can see why you might not like that course of action having just rebuilt your engine though

That would be me! Hows it going Nick? As said, mine does it too. Sound great when cold but as soon as the temp gets up it sounds like a pneumatic drill. Im at a loss aswell, if it still does it after a rebuild i dont know where the noise could be coming from.

[Brianmoooore]

it's not just noisy injectors is it?

Injector noise will stop the instant you kill the ignition.

[gareth]

an obvious and easy test might check mine just in case, though it's not really noisy or anything...

[nickso]

Hi.
I have rebuilt my M30 engine and fitted it to my E30, as some of you may already know.
It has a Schrick 284 camshaft and a very light head skim (just to make sure it was flat, not specifically for a compression raise).

Apart from a bit of porting the rest of the engine is standard.

I also renewed rocker shafts, rocker arms and adjusters, piston rings, timing chain and crank bearings.

When the engine is cold it sounds great, although I don't drive it hard until it warms up.

When it does warm up though there is a constant rattle, a sort of thrashy top end noise, almost like the valve clearances need doing. I have, of course, been over those a few times and it makes no difference.

I've been told these engines do run the valves VERY close to the pistons after a head skim and with higher lift camshafts!

Anyone got any ideas? Before I rip the b*****d apart again!

Thanks in advance!

same problem ive got and another bloke round here has exactly the same problem on his 335.

ive done all the clearances 4 times blah blah blah.....

ive given up now although it annoys the hell out of me.

ive decided to just let it blow up if its going to. i can see why you might not like that course of action having just rebuilt your engine though

That would be me! Hows it going Nick? As said, mine does it too. Sound great when cold but as soon as the temp gets up it sounds like a pneumatic drill. Im at a loss aswell, if it still does it after a rebuild i dont know where the noise could be coming from.

nae bad min

mine is the same.....nice and quiet when cold but very noisy when hot....like i say ive stopped worrying now and will just wait for the bang and clatter if it happens.

if it does its the perfect time to rebuild for a turbo or something

[nickso]

it's not just noisy injectors is it?

Injector noise will stop the instant you kill the ignition.

think ill give that a go tomorrow though

[gooner1]

I know this is an old thread but i was wondering if any of you had solved the noise issue with the M30 engine.
Have been told by the seller that the 535i engine ive brought is a bit noisy in the top.
Plan to change camshaft anyway along with anything else i can manage. Think a noisy engine would really detract from enjoying the conversion though, half my mind would be waiting for the worst to happen.
Have also noticed a couple of posts where the oil pump failed, was this a coincidence or are they a weak point on the M30 like the water pump seems to be.

[DRIFTBOY]

Hi, I am still keen to get to the bottom of this too!
And yes, the noise does detract from my enjoyment of the car!
Haven't heard of oil pumps failing myself, that'll just make me more paranoid!

M30 top end rattle is common, I believe it's camshaft wear or simply valve clearances usually.

I have tried different valve clearances with mine but it still only ever rattles when it is hot, sounds sweet when it's cold.
I feel I might have to take the head back off to find out what is happening.
A local engineering company told me that they always pocket the pistons for valve clearance when they fit a higher lift camshaft to M30 engines, and that I might be getting valve-piston contact!

[Jhonno]

whip the head off and you'll soon find out..

[DRIFTBOY]

I would do it now but it's my only car!

I'll have to wait untill I have some time off work as it might take a while to fix it, depending on what horrors I find in there!

[SPADGE]

I know this is an old thread but i was wondering if any of you had solved the noise issue with the M30 engine.
Have been told by the seller that the 535i engine ive brought is a bit noisy in the top.
Plan to change camshaft anyway along with anything else i can manage. Think a noisy engine would really detract from enjoying the conversion though, half my mind would be waiting for the worst to happen.
Have also noticed a couple of posts where the oil pump failed, was this a coincidence or are they a weak point on the M30 like the water pump seems to be.

Hi mate
The noise from the top end of that engine was very slight in comparison to what is being described here!
Cheers Spadge...

[Dan318-is]

If the valves were contacting the pistons though, after this amount of time surely there would be an adverse effect e.g. no more m30?

Did you change the oil pump when you rebuilt it?

[gareth]

i've had valve hitting pistons before and it's very obvious! if it was like this for more than a short while, i suspect the cam lobes and followers would be showing signs of the impact on each revolution.

M30 cams wear like M20 cams do. it's usually down to a progressive blocking of the oil spraybar over a few hundered thousand miles!

[evodan]

Mines is noisy only when hot too, nice and quite when cold, could this be oil pressure dropping when oil heats up?
What oil grade you guys using.
Did think in the past that the engine must be humped but hasn't got any worse and still pulls like a train over 8 thou miles later engine must have aprox 150k under it's belt.
Sounds like an M30 trate, Or anyone got a quite one?

[gooner1]

I know this is an old thread but i was wondering if any of you had solved the noise issue with the M30 engine.
Have been told by the seller that the 535i engine ive brought is a bit noisy in the top.
Plan to change camshaft anyway along with anything else i can manage. Think a noisy engine would really detract from enjoying the conversion though, half my mind would be waiting for the worst to happen.
Have also noticed a couple of posts where the oil pump failed, was this a coincidence or are they a weak point on the M30 like the water pump seems to be.

Hi mate
The noise from the top end of that engine was very slight in comparison to what is being described here!
Cheers Spadge...

Cheers mate, was really trying to pin down the noise described in a few other posts, noisy engine/noisy woman both do your feckin head in and detract from there enjoyment/Only joking ladies.

[DRIFTBOY]

I didn't replace my oil pump but did strip, inspect and measure it and it was very healthy. Even turning the engine by hand has oil sqirting through the spray bar.
I'm using 10/40 semi synthetic oil at the moment.

I also would have thought valve-piston contact would have done something spectacular in 3000 miles of driving, and I do rev it hard (when it's up to temperature).

It's not a very loud rattle but when it's hot it's always there, if I drive fast with the window open and the radio on quietly I can't hear it!

[Dan318-is]

"M30 engines can suffer from oil starvation on the camshaft resulting in damage. This is preventable with a new design of hollow bolt for the oil feed bar."

Taken of the unix nerds BMW site?

[gareth]

interesting...

[SPADGE]

"M30 engines can suffer from oil starvation on the camshaft resulting in damage. This is preventable with a new design of hollow bolt for the oil feed bar."

Taken of the unix nerds BMW site?

These bolts often losen themselves which causes problems!

[Dan318-is]

Worth a check driftboy?

[nickso]

the spraybar and bolt on mine are fine....the head looks like brand new inside so its obviously had good and regular oil changes. i assume mine has the old style bolt...ill just check it regularly.

im not in the slightest bit worried about mine now......ive tanned the arse off it on several occasions so i doubt its the pistons and valves touching. if it is the cam wearing or the engine slowly disentegrating ill just put a different engine/cam in.....a pain in the arse maybe but not very expensive these days.

the only thing i havent tried yet is brians suggestion of turning off the ignition while moving in gear to see if it is the injectors....ill get round to it if i remember one day