Timing chain guides

DanTman13

DanTman13

Regular Member
British Zeds
Joined
Jul 3, 2023
Points
24
Location
Barnsley
Model of Z
Z4
Hi all, firstly great day had at zedfest yesterday met some great people and beautiful cars!
soooo the question is do I need to worry about-or replace my timing chain guides? I have a 2012 20i z4 with 77k. After a service it drives and performs as it should, just done neatly 300 miles over the weekend and never missed a beat! Looking at remapping the car and spoke with a few who said only do it if the guides have been changed? Car is not showing any symptoms of a bad belt and after checking the belt-is super solid on the guides! Is there a way to check the guide and belts to see if need changing??Loads about saying you have to change but mainly if any symptoms which I havent! Be great to get peoples thoughts And advice on this thanks in advance! Dan 👍🏽
 
You seem to be confusing timing belts and chains Dan.
You can't see the timing chain from outside the engine. A (rubberised) timing belt runs outside of the engine inside a (generally) plastic casing.
The 4 cylinder BMW engines do have a potential for the timing chain guides to fail which allows the chain to "jump" meaning pistons and valves collide. There are many videos on YouTube showing the results of such occurrences.

Tony.
 
This is something causing me some concern too.
Have seen somewhere that the dark brown chain guides on the earlier engines is the one to worry about. White ones ( which go more coffee colour after use) are more robust if I recall correctly. But, the link below indicates that colour is entirely down to age.
You can see a small bit of the timing chain and the guide under the oil filler cap.

I mentioned this concern to a BMW Indy and they said it isn't something they see and suggest there isn't anything to worry about. They had never seen a failed one. I remain to be convinced.

This link may help --> https://f30.bimmerpost.com/forums/showthread.php?t=1415105 although it isn't without ambiguity.
That said, it also indicates that 2012 onwards are better but that the failure rate isn't dramatic.

After all that, I feel none-the-wiser!
 
Thanks for the replies (redline &tony) Tony I did do a bit of a typo with the belt lol, it’s deffo chain I’m talking about and yes redline I have looked inside the oil cap and that’s where I tested the tension of the chain! My guide deffo the brown one!!!Maybe worth phoning a few dealers/ indies to get further advice. Just really want to know if I have to change anything now or wait for the symptoms of a Bad one, but would that be too late??? Oh the mine field 😫
 
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The new cam chain sub assembly and associated oil pump drive sub assembly were fitted from beginning of 2015..so prior cars had the brown guides, the later were white..

A pronounced whining sound when revved is the most obvious tell tale..

Some develop slack and jump timing teeth without that warning sign.

I preemptively swapped mine out on my 2012 20i..it was about a £1,200 bill using and Indy…
 
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The last 2.0 4 pot BMW I had was a 2010 3 series. It went without warning at 50k miles. Result, new engine! This is why I would never buy a 4 pot E85. However, as said, newer cars are supposed to be better.
 
Z Victor 1 said:
The last 2.0 4 pot BMW I had was a 2010 3 series. It went without warning at 50k miles. Result, new engine! This is why I would never buy a 4 pot E85. However, as said, newer cars are supposed to be better.
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If I still had the black 2013 20i I'd be changing my pants after reading that before phoning my mechanic to get it booked in for a guide replacement =))

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Z Victor 1 said:
The last 2.0 4 pot BMW I had was a 2010 3 series. It went without warning at 50k miles. Result, new engine! This is why I would never buy a 4 pot E85. However, as said, newer cars are supposed to be better.
Click to expand...

I think that was the normally aspirated N43 engine..the N20 IMHO was a much better engine..mine was great..it does appear that its Russian Roulette on the camchain…there is an example of a Z4 with that engine that has done 500k miles..but I do know a few that have had that problem..poor servicing and extended use of stop / start seem causal factors..
 
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The N43 was used on the E model 1 and 3 Series (and 520i E60) from late 2007 and it's absolute garbage. The E85 Z4 2.0i retained the older N46 but they're not exactly brilliant.
The N20 is turning out to be pretty grim for reliability as they get old - crankshaft thrust washers and the timing chain are the main things. The chain guides break up and bits block the oil pick up, just like the N43 leading to oil starvation and seizure. The oil pump chain is crap on earlier ones as well so I'd advise a proper sump-off chain replacement.

It'll cost £1000 to have it done (use genuine BMW or febi boxed parts only) but once done it'll be fine.
 
gookah said:
11 x 2 litre 4 pot E89 cars on auto trader with over 90,000 miles, one with 160,000
20 odd with over 60,000, seem to be plenty about that can do big mileages, didn't see any reference to timing chain replacements on most of them.
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It’s like many of these designs..a percentage will be affected…bad news travels…my guess is it’s under 5% of the cars..maybe not even 1%..🤔

Certainly way way cheaper to manage and more reliable than the N54 in the E89 35i/35is…😳

Multiple events there that cost anywhere between £1k and £5k🙈
 
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