Z3 2.2 - Engine Noise

[davidmkh]

Hi,

I am new to the group and so hello to everyone.

Two weeks ago, I finally bought my dream car. I've been looking at Z3's for a good while now, always convincing myself that it wasn't practical choice as I do a lot of miles, etc. Anyway, out of the 22 cars owned in my lifetime, my Z3 is without a doubt my favourite car of all time, I absolutely love it. I have to say aswell, that it is the most beautiful car that I have owned, so much so my wife is now questioning why I keep going to look at it and I would even say she is becoming a little jealous of the attention my new 'baby' is getting!

Anyway, joking aside, I do have a question for the forum:

I have a Z3 2.2i, 2001 plate. It has just done 70,000 miles and has a FSH (with a recent service) and so I am very happy with the background and also the dealership I bought it from. When I took it for test drive, I did however notice what I thought was possibly some type of belt or fan noise that accompanied the engine noise and was more evident in lower gears but is still there at speed albeit not quite as noticeable. I loved the car that much, it just didn't bother me though I guess as you start to use the car it becomes more of a worry. Overall, the engine sounds beautiful but when I start to drive it is accompanied by this sound. I just don't know if it's normal, whether I should just get used to it and shut up or whether there is something wrong (or about to go wrong!). I am probably not explaining myself very well but I am hoping someone can maybe give me some guidance as to what it may be.

Thanks,


David

[northwestred]

Hi David,
I have the exact same car and from the same year. I recently changed the V grooved alternator drive belt for similar reasons (whirring noise which seemed to get louder). On removing the old belt and bending it, it was obvious there were thousands of little cracks where the rubber had aged. I realised the belt was on its way out so replaced it with one from our local GSF branch......noise gone!!!
Nigel

[g8jka]

I have a whirring noise on mine that gets louder as the rev's increase, thought it was interference at first from the amp through the speakers but its not. It sounds alternator related, did your noise increase with revs also? If changing the belt gets rid of it I'll be doing mine soon, as the noise is very annoying and this seems like a cheap fix and worth a go.

[davidmkh]

Thanks for the feedback Nigel - is the alternator drive belt expensive? I'm hoping as I have just bought the car that the garage may have a look at this for me and I do have a six month warranty. Thanks for coming back so quick, at least I feel like I am not going completely mad and imagining the noise!

[Bonzo]

Hi,

I am new to the group and so hello to everyone.

my Z3 is without a doubt my favourite car of all time, I absolutely love it. I have to say aswell, that it is the most beautiful car that I have owned, so much so my wife is now questioning why I keep going to look at it and I would even say she is becoming a little jealous of the attention my new 'baby' is getting!

Quite agree with you David, the Z3 is a beautiful lady, and my wife like yours, cannot understand how I can love a car and just stand and look at it and drink it in! And as for giving it a name!!!!............. (Walks away shaking her head)

Cheers, Bonzo.

[davidmkh]

With regard to the engine noise, I did have the drive belt checked and it is relatively new and so don't think that this is the problem. The dealership did say that the fan is constantly on and over time can give it a bit of a supplementary background noise. Not sure if having this replaced would make a difference or not?

I do have a second problem now with losing oil. I travel quite long distances and I noticed when I had arrived at my destination a couple of weeks ago that the yellow oil light stayed on for about 10 seconds when I turned the engine off. I didn't think too much of it at the time but when I was heading home again it then came on permanently. I stopped at a garage as soon as I could (about 20 miles from when it came on) and bought some oil and topped it up with about a litre thinking that it would at least be enough to get me home where I could check the car more easily. Incidentally, I am still concerned that the 20 miles may have caused some damage to the engine, though probably just me overly worrying as there is no indication that it has. Anyway, when I got home I checked the oil level and it was virtually empty. I proceeded to put another 5 litres in which then got it to the correct level. The guy who owned the car before me had not used it routinely and it had only done a couple of thousand miles in two years and so I put it down to that.

Two weeks later, i.e. yesterday, the oil light came on again when I turned the engine off last night. So this morning I have checked the level again and unfortunately it is very low again. I have had a couple of BMW's (535's) both of which had oil leaks and both of which were relatively easy to diagnose. This however is a bit puzzling as there is no visible oil leaking and so can only assume I am burning it but again I don't see any white or black smoke. Anyway, I am going to take it back to the dealership but just wondered if anyone had any clues as to what it may be.

Thanks,


David

[Mike Fishwick]

The fan should not be on all the time, but freewheel silently unless the air coming off the radiator is really hot - withthe temperature guage just over the mid position. IF it is making a noise, I would suspect the viscous coupling is on its way out, which after 70,000 miles is about its normal lifespan.

The Low Oil Level warning light should operate at about 1 litre below the 'Full' mark - after about 1 litre.

Are you sure that you put 5 litres into the engine? It only holds about 6 litres, and after already putting 1 litre in, it would have been a miracle to avoid it siezing.

Your engine either burns oil for a pastime (very unusual) or has a cracked sump.

Silly questions maybe, but have you looked underneath? Did you fully insert the dipstick when checking the level?

[davidmkh]

Thanks for coming back so quickly Mike.

I'm sorry, I got it wrong with how much I added. I was thinking that the small oil top-up containers were 2.5L but they are actually only 1L and so in total I topped up 2L to get it to the correct level. I have added another half a litre today and it is almost back to the correct level again.

I have looked underneath and I can't see any visible signs of leaking, certainly nothing on the garage floor either. Yes, I did fiddle a bit with the dipstick to make sure I had it fully inserted and neither are silly questions incidentally when it comes to me and cars!

Going back to the fan noise, the temperature gauge is consistently half way. However as I do more Miles, the car does seem to get a bit more "boomier" on the exhaust (I don't know if that's normal) and possibly a little more sluggish - does not feel like it quite has the power from when you first start. I fan noise starts from the engine being cold - you can't hear it when idling but the moment you put your foot down it's just a bit of an irritating accompanying noise. I only have three months warranty on the car and so if it something that can be done now then all the better.

I must point out that these issues aside, I have never loved a car like my Z3!

Thanks,


David

[Bench]

After losing tha tmuch oil you deifnetely need to investigate this further, a sMike said there would be pools of oil under the car if the loss is that bad?

[Mike Fishwick]

Check the consumption acurately - note the mileage, fill tothe Full mark, and check it every day of two. Run it down tothe Low mark, and then carefully note how much oil is used to reach the Full mark again, and the number of miles covered since Full.

Do not keep adding oil - the upper portion is always burnt at a higher rate - it will do no harm to run the oil level down tothe Low mark.

Check that the viscous fan can be easily turned by hand when the engine is cold, and as it is warming up.

[TitanTim]

Regarding the whining noise these types of noises can be hard to detect and usually through a process of elimination, I'm not sure the belts actually whine with age but tend to either squeal or chirp when cold as mine did then the noise goes when warmed up. Once changed noise went. If its not the fan worth checking belt pulleys as a worn bearing can whine. Check also for any split hoses.

If the car is not leaking oil it has to be burning it, whats the inside of the filler cap like? and does it have an acrid burn smell?. It might be worth getting someone to follow you and really rev engine hard and see if it smokes, does it smoke on startup? or have a compression test done?

Tim.

[davidmkh]

Thanks for coming back to me Tim.

The engine noise is not so much a whining, more a 'whirring' hence more like a fan noise. You can't hear when idling even after driving 200 miles, it's just when you start moving and is very noticeable in the lower gear range. I am not too sure what to do really as the dealership where I still have the warranty seem rather disinterested to say the least and are certainly not pulling all the stops out to try and get to the root cause. Not to sound to sceptical, but I am sure they will suddenly be more interested once the car is out of warranty.

I assume I must be burning oil as you say as there is certainly no evidence of it leaking. So since acquiring the car I have added about 2.5L in total (not the 5L that I previously stated). Anyway, I am going to take it to them tomorrow and hope that they can diagnose the problem. I'll let you know what they say.

David

[TitanTim]

Thanks for coming back to me Tim.

The engine noise is not so much a whining, more a 'whirring' hence more like a fan noise. You can't hear when idling even after driving 200 miles, it's just when you start moving and is very noticeable in the lower gear range. I am not too sure what to do really as the dealership where I still have the warranty seem rather disinterested to say the least and are certainly not pulling all the stops out to try and get to the root cause. Not to sound to sceptical, but I am sure they will suddenly be more interested once the car is out of warranty.

I assume I must be burning oil as you say as there is certainly no evidence of it leaking. So since acquiring the car I have added about 2.5L in total (not the 5L that I previously stated). Anyway, I am going to take it to them tomorrow and hope that they can diagnose the problem. I'll let you know what they say.

David

Hi David,

Yepp if it has a warranty take it back, its the garages responsibility. It does hack me off when garages sell cars with a warranty which as much as anything are given to entice and are meaningless. They need to honour the warranty and fix the problems. Its times like this and in hindsight when buying a car to ask exactly what any warranty covers. Good luck.

Tim.

[motco]

If the oil is being burned it is either top end wear - valve guides - or piston wear. A compression test will help, as would a leak-down test. The simple way of diagnosing which part is the culprit is to warm it thoroughly and let it idle for five minutes and then blip the throttle while you watch for exhaust smoke. If the valve guides are worn then smoke will be seen in significant amounts after idling or running to a stop on a trailing throttle. Bore wear will not cause this to the same extent as valve guides, but oil passing pistons (bore wear) will cause smoke under power. This is harder to see for obvious reasons - get someone to follow you and observe. A compression test shows bore wear more easily and can be done at home. A well-worn engine will have multiple symptoms of course. My 2.2 uses a little oil (31,000 miles) and I also find the low oil warning is a bit premature; it shows the orange light on switch-off when the oil is only a little down from full.

[davidmkh]

Thank you to all for your responses for this - it has been really helpful.

The dealership has suggested that I monitor the oil level for a couple of weeks. They have suggested that with the age of the car (2001) and the fact that it is a BMW V6 that it will potentially use a litre of oil over a couple of thousand miles. I had a BMW V8 previously (535i 175,000 miles, 2000) and never had to top up.

Still need to tackle them on the fan noise but feel this is the priority at the moment.

Best regards,


David

[motco]

Thank you to all for your responses for this - it has been really helpful.

The dealership has suggested that I monitor the oil level for a couple of weeks. They have suggested that with the age of the car (2001) and the fact that it is a BMW V6 that it will potentially use a litre of oil over a couple of thousand miles. I had a BMW V8 previously (535i 175,000 miles, 2000) and never had to top up.

Still need to tackle them on the fan noise but feel this is the priority at the moment.

Best regards,


David

If the dealer told you it's a V6 then go to another dealer - fast!

[gookah]

They have suggested that with the age of the car (2001) and the fact that it is a BMW V6 that it will potentially use a litre of oil over a couple of thousand miles.

Straight six for starters, but the other bit is a typical 'fob you off' answer.
If that was the case, the service indicator would be allowing you to cycle completely, an oil change between services.....

[TitanTim]

Oh dear

Tim.

[Vic-Z3]

Try spraying all the belts with silicon spray, see if that cures the whirring noise, it does on mine.
Try getting someone to hold the throttle open at around 3500rpm a have a listen under the hood.
You can stop the viscous fan spinning up by stoping it by hand on tickover first.
My own Z3 2.2i 6 cylinder (straight/inline not V6) 65000 miles, uses a bit of oil, this does not worry
me as I like to see some oil usage in a sports car.

[davidmkh]

Again, thank you to you all for your comments, I really appreciate your help.

Oil-wise, I have done a further 2,000 miles and added about half a litre and so I am not too concerned, guess I just need to keep an eye on it.

Engine noise-wise, you have all been kind enough to offer lot's of advice on this and I appreciate that you are basing responses on my description of the issue (which probably isn't very good) and so it is difficult to pin it down completely.

I think the best I can do is just book it in and suggest some of the possible causes that have been suggested, thanks again for everyone's help.

David

[g8jka]

As described earlier in the thread, I too had a whirring noise that increased with revving the car which sounded a bit like if you get interference through the speakers or from a faulty alternator. I knew it was not the stereo, so after the recommendation of changing the drive belt which cured someone else's problem this was the first step we took. The belt was changed and whilst it was off the alternator and water pump were tested as the noise was still present and after changing the belt for a new one it was still there.

I also had another problem with a whirring noise when the clutch was fully down, which was definitely coming from the clutch release bearing. It has made this noise since I brought the car 2 years ago but had gradually got worse. Anyway Gookah changed the clutch release bearing in my zed at the weekend, curing the noise when the clutch pedal was fully pressed and the other whirring noise disappeared also.

The car now sounds as it should, a proper straight 6 sound and with the nice burble coming from the exhaust on slow down, no more whirring up and down when accelerating and de-accelerating

So it maybe worth checking your clutch release bearing, it will alter in tone when the clutch is pressed. May be a completely different problem altogether but just sharing my experience of what I think was a similar noise to what you describe

[gookah]

The release bearing still turns when the clutch is out, the slave cylinder puts just enough pressure on it so it is still in contact with the driven plate springs (fingers) and it still rotates,whining away merrily, just not under load.

The noise got worse when pressing in the clutch pedal, as more pressure was applied through the bearing, making it 'complain' even louder,

New bearing and no noise whether pedal in or out.....

[geordie90]

is replacing the clutch release bearing a big job??

My z seems to chirp and squeak , I changed alternator belt thinking it may have been that but it hasnt cured problem.

Craig

[BladeRunner919]

Yes. You are basically changing the clutch, so you need to take the gearbox out. See here:

http://webspace.ringling.edu/~dplassma/cj/cj.html