Z4. 6Cylinder most reliable engine.

[steviesteve]

Hi guys and firstly let me apologise for asking a question that I would imagine has been asked previously. I'm looking at getting back in to Z4 -6 cylinder ownership as foolishly I decided to sell my Z4. I have been looking at the Coupe, but have come across reliability issues with the 'N 52' engine (cylinder head needing up- grades or complete re-newal). Can I have some feed-back regarding just to clarify how bad the problems are, and can somebody suggest the most reliable varient of Z4 engine to go for. Many thanks.

 

[RidgyDidge]

Z4MC comes with a bomb proof engine.


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[Adamski]

I've seen M54B30 (the 3.0) engine variant with 233,000++ miles on them, with no reported problems. Vanos seals tend to go towards 200k, but other than that, they seem pretty indestructible

 

[Taz]

i have the N52 engine, there is the issue with very intermittent knocking when cold, other than that i'm not aware of any other issues

 

[IK.]

Z4MC comes with a bomb proof engine.


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Are they really bombproof? I had thought they would be quite good, since it's an old engine with all the kinks worked out, but wasn't sure...

 

[mmm-five]

Z4MC comes with a bomb proof engine./quote]
Are they really bombproof? I had thought they would be quite good, since it's an old engine with all the kinks worked out, but wasn't sure...

I know of at least 5 Z4MC S54B32 engines that have been replaced (and a few of the same engine in the e46 M3/CSL), through no fault of their owners, so I wouldn't claim they're 100% bomb proof - 99% maybe

 

[IK.]

Is that just people you know, or people you've gone looking for after your engine went pop? If the latter, I'm not too worried!

 

[mmm-five]

Is that just people you know, or people you've gone looking for after your engine went pop? If the latter, I'm not too worried!

Just people that have posted on here & pistonheads. Not sure I want to actively seek out any more failures :?

Cant say the low numbers worry me though, and I'm not driving mine like Miss Daisy with the expectation that it's going to go bang

 

[steviesteve]

If the consensus is that the 'N-54' is the best engine choice, can somebody explain which year of manufacture, and model which is considered the most trouble free.

 

[bcworkz]

That would be the newest engine with the lowest miles. I know that's not the answer you wanted, but it probably matters more than what you were asking.

 

[steviesteve]

Thanks for your input -'bcworkz'.

 

[bmwangler]

Z4MC comes with a bomb proof engine.

RidgyDidge, how do arrive at that - what have you read/heard?

 

[BMWZ4MC]

Z4MC comes with a bomb proof engine.

RidgyDidge, how do arrive at that - what have you read/heard?

There is a recognised problem with premature cam / cam follower wear with the S54 engine in the E46 M3 and CSL, as well as the Z4M. Example here:

http://www.youtube.com/watch?v=2lfjpC4GFJA

Also, pre-2007 Z4Ms can suffer from loosening of the VANOS bolts, ultimately leading to breakage and catastrophic engine failure. Post 2006, the torque rating of these bolts was changed.

 

[Daffy]

The most reliable engine is the M54B30 as fitted to the E46 330s, the prefacelift Z4 3.0se and both the E39 and E6x M5s upto late 2006. The N52s and N53s in later models don't have the self adjustment that allows for near faultless running of the older M54 as there isn't space in the Head.

Again, there are a few failures, and foibles (Vanos, Waterpump etc) but if you watch for these minor things and look after the engine, it's a VERY strong unit.

M.

 

[steviesteve]

Thanks for that top answer 'Daffy' you obviously know your stuff. Used to own a 2.5 SE - 2006. A great car , had a stupid idea to sell it ( May 2010), so I'm atfer a replacement. Constant forum posts with referance to 'Cylinder heads' and 'Ticking noises when cold' are putting me off.

 

[RidgyDidge]

Z4MC comes with a bomb proof engine.

RidgyDidge, how do arrive at that - what have you read/heard?

First up, I'm using a figure of speech ;-) We all know that ultimately there is not much that will survive serious abuse or neglect.

My point is simply that this well proven engine is known to be strong, and with the correct maintenance should easily attain decent mileage before needing any significant overhaul.

As others have already said there will be examples of things going wrong, but planes crash too and we still get on them. Appropriate perspective is always helpful when making judgements about reliability etc


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[IK.]

This was my feeling, personally. The engine has been used for a long time, and most of the major niggles have already been worked out. With an engine like the 'si' range used in the 2.5si and the 3.0si, it's all new technology that may still produce a few niggles.

For what it's worth though, the 'si' engine range is NOT damaged by the very few times you may experience ticking. At least, that's what it says on the SI Bulletin. I had mine done though (revised cylinder head in the end), and it was fine after that.

 

[R26Andy]

I`m with I.K. on this. Si engine will be fine IMO as there are example with over 100k on the clock now. If really worried I would look at an si with an updated cylinder head.

 

[IK.]

I`m with I.K. on this. Si engine will be fine IMO as there are example with over 100k on the clock now. If really worried I would look at an si with an updated cylinder head.

...Which even then, is not what I would deem 'essential', unless you're not using the car very often, where the problem with occur more often. If it's your daily drive, no problem whatsoever.

 

[SimonJ]

If you are really nervous of engine failure why not get a warranty from BMW. I did this when buying my second hand 3.0i and it was £250 for one year for comprehensive with £250 excess am sure power train cover is cheaper. Might be a waste of money but only until something serious goes wrong. You can get it for any BM with >100k miles. Is also good if buying private...

Only downside is need to wait a full month after paying before warranty comes into force (understandable I suppose).

http://www.bmw-warranty.co.uk/Pages/Home.aspx