Engine rattle on cold start

[poortomsacold]

Morning all

Another day, another problem!

So today I started my 2003 3.0i N54 Z4 (78k on the clock, FSH and last oil change in April 2022, only done about 2,000 miles tops since then) and I heard quite a loud rattle from the front of the engine. Nosie increased a little on acceleration, but disappeared completely after driving for a couple of minutes, and was then fine for the rest of the half hour drive to work.

Aside from the very occasional hesitation, when the car seems to pause and then shoot forward, say in around 2nd or 3rd gear at low revs (again, this is not common) I haven't noticed any other issues performance wise or in terms of fuel consumption.

Is this something I need to get looked at by a mechanic pretty swiftly or monitor it to see how it is over the next week or two? Not sure if this is fairly common, but I can't say I heard it during the last cold spell.

Thanks!

 

[Southwestz4]

If the car has sat for a while and is stone cold its not uncommon as far as I am aware...the valve lifters are hydraulic and it takes a little time for them to pressure up ...short trips and cold oil doesn't help ...check oil level and give it a good run ...my 3.0 does it sometimes if not used for a while ...also maybe worth checking the correct grade oil was put in on last oil change

 

[poortomsacold]

If the car has sat for a while and is stone cold its not uncommon as far as I am aware...the valve lifters are hydraulic and it takes a little time for them to pressure up ...short trips and cold oil doesn't help ...check oil level and give it a good run ...my 3.0 does it sometimes if not used for a while ...also maybe worth checking the correct grade oil was put in on last oil change

Thanks for your reply - has given me some reassurance. I did take her out for a spin last night at around 6pm, so only been sat overnight, but it was very cold when I started her up this morning.

 

[Southwestz4]

No problem...as others here will tell you the M54 engine is a strong unit

 

[patriot66]

Unfortunately it could also be the VANOS telling you that it is not working. A 2003 M54 with 78k miles has almost certainly got partially or wholly inoperative VANOS as the seals will have turned to 'plastic' and possibly the bearings will be well past their best and rattling away at low rpm. The surging in 2nd or 3rd at low revs may be symptomatic. Have you got a code reader ? Any VANOS related codes ?

 

[poortomsacold]

Unfortunately it could also be the VANOS telling you that it is not working. A 2003 M54 with 78k miles has almost certainly got partially or wholly inoperative VANOS as the seals will have turned to 'plastic' and possibly the bearings will be well past their best and rattling away at low rpm. The surging in 2nd or 3rd at low revs may be symptomatic. Have you got a code reader ? Any VANOS related codes ?

Only got an old OBD II code reader but plugged that in and ran Torque app and no fault codes at all...

 

[enuff_zed]

I agree with the vanos theory. Especially if those seals have packed up it’ll let oil drain down more easily. The rattle could be the bearings or even the shuttle valves. Not a massive issue in itself tbh and relatively easy to sort if you are handy with the spanners

 

[Southwestz4]

Unfortunately it could also be the VANOS telling you that it is not working. A 2003 M54 with 78k miles has almost certainly got partially or wholly inoperative VANOS as the seals will have turned to 'plastic' and possibly the bearings will be well past their best and rattling away at low rpm. The surging in 2nd or 3rd at low revs may be symptomatic. Have you got a code reader ? Any VANOS related codes ?

As patriot66 says could be the vanos, my Autophix 7910 reader will let you monitor the vanos operation but not sure if it will show anything other than complete failure of the vanos , ie no movement .

 

[poortomsacold]

Thanks for all the feedback. looks like I will have to research VANOS seals now then! Anyone got any idea what sort of cost I'd be looking at if I got a decent mechanic to sort it for me?

 

[enuff_zed]

Thanks for all the feedback. looks like I will have to research VANOS seals now then! Anyone got any idea what sort of cost I'd be looking at if I got a decent mechanic to sort it for me?

I reckon at least 4 hours labour plus parts.
The X8R kits are just over £100 from memory.
I think you already said you were too far from me, but I'd happily take it on.
Or speak to [ref]bigwinn[/ref], in Lincoln.
I doubt either of us would cost you as much as a mechanic, and we've done few before, which always helps.

 

[bigwinn]

Thanks for all the feedback. looks like I will have to research VANOS seals now then! Anyone got any idea what sort of cost I'd be looking at if I got a decent mechanic to sort it for me?

I reckon at least 4 hours labour plus parts.
The X8R kits are just over £100 from memory.
I think you already said you were too far from me, but I'd happily take it on.
Or speak to [ref]bigwinn[/ref], in Lincoln.
I doubt either of us would cost you as much as a mechanic, and we've done few before, which always helps.

I always enjoy a vanos

 

[enuff_zed]

[ref]poortomsacold[/ref], depending on what your timescales are we could potentially kill a whole flock of birds with one stone here.
If you were prepared to go to Lincoln for Stuart to sort your vanos, then I could meet you there with the LH door and rear bumper we discussed.
Plenty of time to swap out those panels and do the vanos as well if you have a free day?
Only issue then is disposal of the remaining bits.
Worth a thought maybe?

 

[poortomsacold]

poortomsacold, depending on what your timescales are we could potentially kill a whole flock of birds with one stone here.
If you were prepared to go to Lincoln for Stuart to sort your vanos, then I could meet you there with the LH door and rear bumper we discussed.
Plenty of time to swap out those panels and do the vanos as well if you have a free day?
Only issue then is disposal of the remaining bits.
Worth a thought maybe?

That's such a generous offer - and one I will certainly think seriously about. It's around a three hour drive each way, but for some much needed work! I also need to fit some new (to me, but used) rear wings but that might be pushing it!

Thanks again for all of your help and support.

Is there any way of definitely confirming it's a VANOS issue?

 

[enuff_zed]

poortomsacold, depending on what your timescales are we could potentially kill a whole flock of birds with one stone here.
If you were prepared to go to Lincoln for Stuart to sort your vanos, then I could meet you there with the LH door and rear bumper we discussed.
Plenty of time to swap out those panels and do the vanos as well if you have a free day?
Only issue then is disposal of the remaining bits.
Worth a thought maybe?

That's such a generous offer - and one I will certainly think seriously about. It's around a three hour drive each way, but for some much needed work! I also need to fit some new (to me, but used) rear wings but that might be pushing it!

Thanks again for all of your help and support.

Is there any way of definitely confirming it's a VANOS issue?

Aye that is a long day for you then! Have to think long and hard about the logistics of it.
Unless you could come up the night before and stop somewhere?
If we're talking rear wings as well it's pushing it all in one day, though [ref]bigwinn[/ref]'s done more panel changes than me so may say otherwise?
I would suggest though that the whole process, including a night in a hotel, would still be cheaper than a garage.
Without hearing it of course I cannot guarantee the vanos is causing your rattle but at the mileage of your car it will definitely benefit from being changed regardless.

 

[poortomsacold]

poortomsacold, depending on what your timescales are we could potentially kill a whole flock of birds with one stone here.
If you were prepared to go to Lincoln for Stuart to sort your vanos, then I could meet you there with the LH door and rear bumper we discussed.
Plenty of time to swap out those panels and do the vanos as well if you have a free day?
Only issue then is disposal of the remaining bits.
Worth a thought maybe?

That's such a generous offer - and one I will certainly think seriously about. It's around a three hour drive each way, but for some much needed work! I also need to fit some new (to me, but used) rear wings but that might be pushing it!

Thanks again for all of your help and support.

Is there any way of definitely confirming it's a VANOS issue?

Aye that is a long day for you then! Have to think long and hard about the logistics of it.
Unless you could come up the night before and stop somewhere?
If we're talking rear wings as well it's pushing it all in one day, though [ref]bigwinn[/ref]'s done more panel changes than me so may say otherwise?
I would suggest though that the whole process, including a night in a hotel, would still be cheaper than a garage.
Without hearing it of course I cannot guarantee the vanos is causing your rattle but at the mileage of your car it will definitely benefit from being changed regardless.

Yes, I think if it's manageable it'll be an overnight stay beforehand. I've not worked on cars before so would be good to gain some experience in that respect - it's very different from my day job!

Ig bigwinn is able to let us know his thoughts on how long it all may take that would be a real help too.

Thanks again!

 

[enuff_zed]

That's such a generous offer - and one I will certainly think seriously about. It's around a three hour drive each way, but for some much needed work! I also need to fit some new (to me, but used) rear wings but that might be pushing it!

Thanks again for all of your help and support.

Is there any way of definitely confirming it's a VANOS issue?

Aye that is a long day for you then! Have to think long and hard about the logistics of it.
Unless you could come up the night before and stop somewhere?
If we're talking rear wings as well it's pushing it all in one day, though [ref]bigwinn[/ref]'s done more panel changes than me so may say otherwise?
I would suggest though that the whole process, including a night in a hotel, would still be cheaper than a garage.
Without hearing it of course I cannot guarantee the vanos is causing your rattle but at the mileage of your car it will definitely benefit from being changed regardless.

Yes, I think if it's manageable it'll be an overnight stay beforehand. I've not worked on cars before so would be good to gain some experience in that respect - it's very different from my day job!

Ig bigwinn is able to let us know his thoughts on how long it all may take that would be a real help too.

Thanks again!

The rear bumper off is a step towards taking the rear wings off anyway.
If we can wait for slightly longer days (with a better weather guarantee)I reckon we'll be fine.
What's the travel time to me in Attleborough, Norfolk? There's a hotel less than a mile from my house and providing Stuart is happy to travel that may be another option. If that were the case you could travel up the day before and we could make a start, then I could drop you at the hotel and collect you the next morning?
Loads of options. Have a think and I'm sure we can sort something out.

 

[patriot66]

Poortomsacold, when Enuff_Zed says change the VANOS regardless he is absolutely right. If you enjoy driving your Z4 now then you will enjoy it MUCH more with a rebuilt VANOS and your M54 realising its full potential. Bang for buck one of the best jobs you can do...Worth every penny !

 

[poortomsacold]

Poortomsacold, when Enuff_Zed says change the VANOS regardless he is absolutely right. If you enjoy driving your Z4 now then you will enjoy it MUCH more with a rebuilt VANOS and your M54 realising its full potential. Bang for buck one of the best jobs you can do...Worth every penny !

Yes from what I’ve read it sounds as though it’d be something well worth doing.

As is typical, when I started her up to drive home - no rattle. But it was a little warmer than when I set off this morning. Will try again tomorrow.

 

[enuff_zed]

I assume the oil is the correct level too?

 

[poortomsacold]

I assume the oil is the correct level too?

Morning. Am going to check that this weekend. If it needs topping up, what’s the recommended oil to use on these ones?

Thanks.