Engine Clatter

jonathan49bat · May 3, 2016

When the engine is cold there is no noise but once warm and at 3500 rpm a clatter can be heard, it does not sound to be from the block but from the head and I wonder whether it is an oil pressure issue in that warm engine thin oil and insufficient oil getting to the camshaft via the spray bar.

Before I start pulling things down and for example a loose banjo found (on the spray bar) and the banjo nut cannot be sufficiently tightened due to perhaps a poor thread - is this a head off job to fit a helicoil?

deQuincey · May 3, 2016

jonathan49bat said:
When the engine is cold there is no noise but once warm and at 3500 rpm a clatter can be heard, it does not sound to be from the block but from the head and I wonder whether it is an oil pressure issue in that warm engine thin oil and insufficient oil getting to the camshaft via the spray bar.

Before I start pulling things down and for example a loose banjo found (on the spray bar) and the banjo nut cannot be sufficiently tightened due to perhaps a poor thread - is this a head off job to fit a helicoil?

in my experience that is a normal behaviour (up to some extent, cos unless you upload a video is difficult to tell the difference from a clatter to an earthquake, and you know things are fairly subjective

)

my car when cold no clatter in the head
warm iddle a Little clatter like a sewing machine
if you push the accel pedal clatter noise is reduced or dissappears

if the thread for banjo bolt on the head is poor helicoil will make the job but you can not put the helicoil in a head that is mounted on the engine, cos you can not eliminate the debris safely :-(

Simufly · May 3, 2016

Clatter

Timing chain tensioner?

sfdon · May 3, 2016

Getting a little ahead of your self
Look under the valve cover first for the banjo bolts and wear on the cam.
Make sure the oiler bar isn't in backwards.
Is the noise from the front of the head?
Is your crank nut tight?

jonathan49bat · May 3, 2016

Gents

Thanks for responses.

The engine is smooth and as quiet as most that I've heard there is no clatter below 3500, so for example I can drive the car hard in all gears but as soon as I near the 3500 rpm in any gear the chatter is such that my mechanical sympathy takes over and I back off - when I say chatter it is a cold mechanical noise.

I was alerted to the 'loose banjo' syndrome and removed the cam cover to find the rear most (i.e. bulkhead end) banjo was loose-ish, in trying to nip this up it felt as though the integrity of the thread might be at risk - so withdrew and applied some loctite in the hope that if indeed it was this problem I might get some short term gain and this would give me a pretty clear indication the issue was indeed the banjo.

Unfortunately it didn't make the difference I'd hoped for but then the oil pressure at 3500rpm might be quite strong and have no respect for loctite and a possibly weak thread!

My intention is to now remove the cam cover again and check the condition of the cam lobes (wish I'd done this before but had not developed my thinking at the time). Because if there is oil starvation I would expect to see greater wear.

My sense is that the 'loose banjo scenario' fits with what might happen but of course this could simply be wishful thinking…

I have not considered the timing chain tension as 'I sense' the noise is coming from the rear and not the front but will check.

Will report back!

jonathan49bat · May 3, 2016

Have just removed the cam cover the lobes on the camshaft are not perfect but actually any lip or wear is hardly detectable with the nail at least.

On checking the two banjo bolts I've measured the existing tension with a torque wrench, (the spray bar is in the correct position) rear most is at a torque setting of 7nm and turning the front at 10nm and turning (manual states 11 to 13nm) when I say turning neither will tighten up.

The question is whether due to this insufficient oil pressure is reaching the spray positions?

HB Chris · May 3, 2016

I would highly doubt it, the tension spec is to keep them from loosening.

jonathan49bat · May 4, 2016

After a nights sleep it does feel unlikely that although the banjo bolts are not too spec they are not the cause. More that I was pinning my hopes after a few years of this issue it would have been a relatively easy fix and a great relief...

The tappets were cold adjusted last year and were pretty close to spec, the oil changed every 3k miles with 20/50 multigrade. The head is original and covered approx 80k miles from new, the block was replaced under warranty by BMW (back in the day) and the replacement has covered approx 60k.

A few years ago I did remove the head to essentially replace the hardened oil seals and all seemed in pretty good shape, the cylinder bores likewise 'appeared well' so discounted little end bearings.

The only reason I have not stripped the entire engine down is because there are no pistons available from BMW for the 3153cc and didn't want to have a parted out engine laying around waiting to have some made.

It was my hope that I could nail this issue and take the car to Munich (from the UK) in September for the 100 yr celebrations but without stripping this down, inspecting and measuring I fear this may have to wait until time constraints allow for I can see nothing obvious that is causing a problem.

The only thing I can say is that it must be oil related for sometimes on start up it takes a second or two for oil to make its way around the tappets. Perhaps I should take some oil pressure readings to see if the pump is doing its job...

deQuincey · May 4, 2016

jonathan49bat said:
After a nights sleep it does feel unlikely that although the banjo bolts are not too spec they are not the cause. More that I was pinning my hopes after a few years of this issue it would have been a relatively easy fix and a great relief...

The tappets were cold adjusted last year and were pretty close to spec, the oil changed every 3k miles with 20/50 multigrade. The head is original and covered approx 80k miles from new, the block was replaced under warranty by BMW (back in the day) and the replacement has covered approx 60k.

A few years ago I did remove the head to essentially replace the hardened oil seals and all seemed in pretty good shape, the cylinder bores likewise 'appeared well' so discounted little end bearings.

The only reason I have not stripped the entire engine down is because there are no pistons available from BMW for the 3153cc and didn't want to have a parted out engine laying around waiting to have some made.

It was my hope that I could nail this issue and take the car to Munich (from the UK) in September for the 100 yr celebrations but without stripping this down, inspecting and measuring I fear this may have to wait until time constraints allow for I can see nothing obvious that is causing a problem.

The only thing I can say is that it must be oil related for sometimes on start up it takes a second or two for oil to make its way around the tappets. Perhaps I should take some oil pressure readings to see if the pump is doing its job...

i have oil pressure readings while normal driving, i do have a gauge permanently fitted

BTW, i would recommend to change oil to 15w40 semisynth

jonathan49bat · May 4, 2016

deQuincey said:
i have oil pressure readings while normal driving, i do have a gauge permanently fitted

BTW, i would recommend to change oil to 15w40 semisynth

Would be very interested to know what your oil pressure readings are at what revs as this will be my next check…

15w40 semisynth - is worth a fill and might cling a little better to the surfaces…

Many thanks

Ohmess · May 4, 2016

VDO makes a sender that can send a signal to both the oil pressure warning light and to a gauge. This dual output sender installs in the location of the stock gauge.

http://www.jegs.com/i/VDO/918/360-028/10002/-1?parentProductId=

You could use one of these to wire an oil pressure gauge to get the necessary readings.

deQuincey · May 4, 2016

it is a very good idea to put a set of gauges to control parameters,

http://www.e9coupe.com/forum/showthread.php?t=9513&highlight=gauges

you can make it look cool too

http://www.e9coupe.com/forum/showthread.php?t=18777&highlight=gauges

some figures,

for semisynth 15w40 castrol gtx

warm engine, water at 87 deg, oil temp at 90 deg

at 3500 rpms oil pressure is 3,6 bar

at iddle 900 rpms oil pressure is 1,8 bar

hope it helps

Stevehose · May 5, 2016

my oil pressure on a hot engine is 28psi at 975rpm and 60psi at 3500 rpm.

deQuincey · May 6, 2016

Stevehose said:
my oil pressure on a hot engine is 28psi at 975rpm and 60psi at 3500 rpm.

steve that is

1,9 bar at iddle
and
4,13 bar at 3500

which oil grade do you use ?
i guess 20w50 ?

Stevehose · May 6, 2016

Yes 20w50

deQuincey said:
steve that is

1,9 bar at iddle
and
4,13 bar at 3500

which oil grade do you use ?
i guess 20w50 ?

sfdon · May 6, 2016

Manual or automatic?
Did check your crank nut?
Can you rev your engine and look at it closely with a flashlight?

jonathan49bat · May 6, 2016

Sfdon

The car is a manual (CSiL 3.2) - no I have not checked the crank nut but believe it is tabbed up with a locking plate, I could rev it and look with a flashlight - what is your thinking in this regard?

Engine Clatter

jonathan49bat

Active Member

deQuincey

Quousque tandem...?

Simufly

Well-Known Member

sfdon

Well-Known Member

jonathan49bat

Active Member

jonathan49bat

Active Member

HB Chris

Well-Known Member

jonathan49bat

Active Member

deQuincey

Quousque tandem...?

jonathan49bat

Active Member

Ohmess

I wanna DRIVE!

deQuincey

Quousque tandem...?

Stevehose

Well-Known Member

deQuincey

Quousque tandem...?

Stevehose

Well-Known Member

sfdon

Well-Known Member

jonathan49bat

Active Member