What's this then?

UK forum for general and technical discussion about the Z3 roadster
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Koolflyer
Joined: Fri 05 Jul, 2013 15:51
Posts: 586

  Z3 roadster 2.8

What's this then?

Post by Koolflyer »

All of a sudden a light rattling sound which grew louder, then a bang and a exhaust hissing sound. This bad boy then found under front right of car underneath the exhaust manifold. It now sound like a banger racer! Interestingly, the flat base is covered in soot, indicating exhaust? I'll check underneath tomorrow, but in the mean time do you recognize it? :rtm:
Tks KF

PS And it's not off my lawnmower! :D

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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: What's this then?

Post by colb »

Could it be item 12 on the diagram
http://www.realoem.com/bmw/enUS/showpar ... Id=11_6171

Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: What's this then?

Post by Del »

colb wrote:Could it be item 12 on the diagram
That was a good spot Colb - I wonder why they fitted "blanking plugs" that high up on the exhaust manifold? :shrug
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RockyDave
Joined: Sun 22 Sep, 2013 07:18
Posts: 47

  Z3 roadster 2.2i

Re: What's this then?

Post by RockyDave »

Thinks we better be scouring the drive and the underneath of the car for that "gasket ring" :shock:
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Koolflyer
Joined: Fri 05 Jul, 2013 15:51
Posts: 586

  Z3 roadster 2.8

Re: What's this then?

Post by Koolflyer »

Thanks guys for that, with the sooty bottom it does look like one of the screw plugs from either the front or rear manifold. Hopefully the little gasket might be in position or lying on the driveway.
Cheers :thumb:
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: What's this then?

Post by colb »

Why would they put blanking plugs in that position you ask, they look same size as a lambda sensor further down the exhaust, were they thinking of putting them in the manifold and found it too hot in that position in the design stage for a sensor to survive so fitted it further down the exhaust using one pre cat sensor instead of two in the manifolds?

Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
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Koolflyer
Joined: Fri 05 Jul, 2013 15:51
Posts: 586

  Z3 roadster 2.8

Re: What's this then?

Post by Koolflyer »

To be honest, I don't know either. Perhaps it's something to do with the USA exhaust emissions filter that some of our European cars have, which mine doesn't?? :-?
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: What's this then?

Post by Del »

Koolflyer wrote:To be honest, I don't know either. Perhaps it's something to do with the USA exhaust emissions filter that some of our European cars have, which mine doesn't??
That's a good point - some sort of EGR system perhaps?
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Robert T
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Joined: Mon 12 Jun, 2006 10:35
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  Z3 roadster 1.9
Location: Cheshire

Re: What's this then?

Post by Robert T »

If you look at the uses for the plug, it is used on many different exhaust manifolds and on some models there are alternative parts shown for exhaust temperature and exhaust pressure sensors. These do not seem to have been fitted to any Z3 models (none that I could see anyway), however it may be that BMW routinely casts this feature into all manifolds so that such boffinry can be fitted at a later date should the car be sold in a market that requires it.

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Rafolian
Joined: Wed 27 Feb, 2013 08:41
Posts: 547

  Z3 roadster 2.8

Re: What's this then?

Post by Rafolian »

Looks like lambda sensor blocking plug to me, from the front section. Some had 2 sensors, mine has one. I renewed the system on mine a couple of years ago and there was 2 (one on each pipe from the manifold). I fitted my sensor in one and blanked the other off with a plug similar to that one. The plug in the diagraghm (no 8?) does not have an external hexagon, but a female either square or hex similar to a drain plug.
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Koolflyer
Joined: Fri 05 Jul, 2013 15:51
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  Z3 roadster 2.8

Re: What's this then?

Post by Koolflyer »

Right then. This carboned bolt does look it came from one of the exhaust manifolds and ties up with item No12 on the above realoem as suggested by colb, although its not a hex as the diagram indicates. The only way to get to that area is a set of ramps and going up from underneath. These bolts are situated on the inside of the manifold next to the block. After a bit of fumbling around it soon became obvious where it came from, as you can see by the photos. One of the screw plugs had in fact come undone and dropped out fortunately in my driveway.

Oddly enough the other was completely tight, so why was this one lose? You'll see that there should be a gasket with this bolt, which there is on the tight bolt, however no such gasket has been found on the driveway or stuck to the manifold. If the bolt had been replaced for some reason, it would appear that no gasket ring was never refitted :head: so it gradually came undone, strange that the secure and tight bolt which has a gasket is fine. It now has a gasket and is tightened right up as it should be.

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Tight bolt and gasket

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Look whats missing!
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White
bertiejaffa
Joined: Fri 26 Jul, 2013 09:28
Posts: 1733

  M roadster S50
Location: Manchester

Re: What's this then?

Post by bertiejaffa »

I suspect bmw have them in stock for a few pence but you could probably use a tap washer and some loctite if you cant find the proper part
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Koolflyer
Joined: Fri 05 Jul, 2013 15:51
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  Z3 roadster 2.8

Re: What's this then?

Post by Koolflyer »

Just spoken to Sytner in Nottingham, and they confirmed that there is a gasket which isn't sold separately. You have to buy the screw bolt for £9.36 which then comes with the gasket, which is why the gasket is 'greyed' out in the diagram. Part needs to be ordered from Germany which is the case for a lot of Z3 parts now. As I had the bolt I used an 18mm sump plug washer which tightened up beautifully...job done! Thanks for your input guys.....Pete
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White
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