After recently purchasing a 2013 Z4 with the 4 cylinder turbo engine, I came across an article about problems with early plastic failure on chain timing belt tensioner. The car has 56,000 miles and has consistent service records performed on schedule at a BMW dealer over the years. The car has a six speed manual and runs great. How common is this problem and how concerned should I be? The cost to remedy the issue is very high.
N20 4 cylinder turbo
- Thread starter Nereidi
- Start date
Sacramento, CA
Don't have any experience with the N20 but was looking into the issue when deciding pre-lci (N20) vs lci (B48) for my f3x and the forums made it seem like it is a legitimate issue for N20s. At 56,000 I don't think its something to do asap but I'd keep an eye on it.
I’ve also got a 2013 4 banger, the timing chain rail was changed late into 2013, around October if memory serves me correctly.. so if you have one of these made after that date, it’s a non issue. Mines from before that date, so I guess it’s an issue.. am I worried about it, nope. I think that if bmw serviced your car, they would have probably done it already, esp as yours is a new car in 2013. If you’ve got an earlier one, and your out of warranty when the notam came up, than it’s possible not been done previously..
Sounds like all these bimmer engines have some kind of Achilles heel … lol.. how about rod bearings? No one talks about that with n54/n20 engines?
Sounds like all these bimmer engines have some kind of Achilles heel … lol.. how about rod bearings? No one talks about that with n54/n20 engines?
I also don’t have any experience of the n20 engine but from what I’ve read the BMW recommended oil change intervals are too long and should ideally be changed every 6000 miles, as yours has only done 53000 in 13 years then the oil change intervals could be relatively low, you can also check if the tensioner guide has been changed by removing the oil filler cap and looking at the colour of the guide, I believe the old guide was orange/brown and the new one is white.
Had a few N20 powered E89's (2012, 2013 & 2015 MY's) and always enjoyed them but I was always concerned the plastic chain guides were going to fail and was constantly checking the chain tension.
The more time I spent on the forums the more concerned I became and it doesn't take long to find examples that have failed once you start looking.
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From what I read only cars produced after March 2015 had the revised guides and stories abound about sudden failures across all levels of mileage. In addition to the point mentioned above regarding oil change intervals I've been told the stop / start functionality also puts undue stress on the engine.
The other thing to note is that there are several iterations of the timing chain bolt - on at least one of the cars I owned I had this changed to the latest iteration as a preventative step.
The more time I spent on the forums the more concerned I became and it doesn't take long to find examples that have failed once you start looking.
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From what I read only cars produced after March 2015 had the revised guides and stories abound about sudden failures across all levels of mileage. In addition to the point mentioned above regarding oil change intervals I've been told the stop / start functionality also puts undue stress on the engine.
The other thing to note is that there are several iterations of the timing chain bolt - on at least one of the cars I owned I had this changed to the latest iteration as a preventative step.
Scottish Borders
As GWest44 stated eloquently…yes it’s a problem that will be increasingly probable..the problem is you just don’t know what the past history and FBMWSH in this case is piss poor…one guy in the US went over 500k miles with no issues but he was changing his oil every 6k with no stop start..
So I’d add £1.5k to put a fresh 2015+ cam subsystem in if I was buying one and it was a keeper..
So I’d add £1.5k to put a fresh 2015+ cam subsystem in if I was buying one and it was a keeper..
North West Surrey
BMW seem to have lost the plot with making reliable cam-chains around 2006.
Mrs Tidy bought an R56 Mini Cooper just in time for Christmas 2006 and a couple of years ago it needed a new cam-chain at less than 75K miles. Last month I had a later Cooper SD Countryman from my Indy that he bought cheap after a cam-chain failure at 93K miles on the N47 engine. That was one of the reasons I unloaded my 2007 123d with the N47 on 81K miles. Still it wasn't all bad as that's when I bought my first Z4!
Sadly I suspect it's more a case of "when" than "if".
Mrs Tidy bought an R56 Mini Cooper just in time for Christmas 2006 and a couple of years ago it needed a new cam-chain at less than 75K miles. Last month I had a later Cooper SD Countryman from my Indy that he bought cheap after a cam-chain failure at 93K miles on the N47 engine. That was one of the reasons I unloaded my 2007 123d with the N47 on 81K miles. Still it wasn't all bad as that's when I bought my first Z4!
Sadly I suspect it's more a case of "when" than "if".
The cam chain can be pulled by a pick ..through the oil filler cap...if it lifts at all its toast..
Usually some whine / rattle is a precursor
Miscowjones
Member
Interesting thread ‐ visual check of mine through the oil filler hole and it looks pristine. Even the orange plastic appears to be free of any discolouration.
Gave the chain a push/pull and no movement whatsoever.
Sadly I can't unread this thread, so it will always be a slight niggle.
Gave the chain a push/pull and no movement whatsoever.
Sadly I can't unread this thread, so it will always be a slight niggle.
Deepseaskateboard
Senior member
If it’s tight there is nothing to worry about.
Just test it every 1000 to 2000 miles.
Obviously if you hear anything like a whine, then check it too.
Cost to fix is roughly £1500 so it’s not world ending, especially with a 24 month interest free card. If you like the car - check it, and if it’s loose then book it in. (Don’t drive it anymore if you notice it loose tho - trailer it to garage)
The N20 was why I wished I'd gone for 6cyl when I bought my Zed. Was never happy with it from the off, always tappety accompanied by a loud whine when cold which BMW never found the cause, they changed a few solenoids but it never went away fully. It was a shame as I would have kept the car for alot longer. I think the engine was voted engine of the year when it first appeared. No idea why really.
Tim.
Tim.
Because nobody knew about the cam-chain problems then!
Much like the 123d I bought less than a year after the launch of the N47 diesel that also became known for cam-chain, and sometimes crank, issues. So I sold it before it happened to mine and bought my first Z4 which was a positive outcome.
I guess so, it was back in 2012, the positive thing back then when I bought the Zed was BMW were doing crazy deposit contributions on their PCPs for the Z4, think I got 8k contribution at £299 a month, which was pretty decent, you wouldn't get that now. I remember I test drove a 2,3 6cyl and ordered the 2.0lBecause nobody knew about the cam-chain problems then!
Much like the 123d I bought less than a year after the launch of the N47 diesel that also became known for cam-chain, and sometimes crank, issues. So I sold it before it happened to mine and bought my first Z4 which was a positive outcome.
I had two 1 Series in 2009 and then 2010 which were second hand and I did know about the cam chain issues, I think the issue would start with a chugging sound that would give it away. My second 1 Series just started to make the dreaded sound so traded it in for the Z4.
Tim.
I was so obsessed that the guides were going to fail on a previous 20i I owned that I checked the chain tension multiple times a week. I had my suspicions about the validity of the test because one day it wouldn't budge and the next day there was a fair amount of slack. I mentioned this to my me panic and he just laughed and told me I was wasting my time.
Google seems to agree with my him:
1. The Oil Cap "Pick" Test
While lifting the chain off the guide while the engine is off isn't a definitive test of stretch, many BMW specialists use it as a preliminary check. If you remove the oil filler cap and the chain is extremely loose—or if the plastic guide rail is visibly broken, chipped, or can be moved easily—the timing assembly has likely failed and requires immediate attention. [1, 2]
2. The Chain Stretch Test (Professional Method)
The only official, accurate way to check for physical chain stretch without pulling the entire front timing cover off is to have a mechanic perform an official BMW Timing Chain Stretch Test. This requires special dealer-level tools where the hydraulic tensioner is removed and a specific measuring tool is threaded in place to determine how much the chain has elongated. [1, 2]
Google seems to agree with my him:
1. The Oil Cap "Pick" Test
While lifting the chain off the guide while the engine is off isn't a definitive test of stretch, many BMW specialists use it as a preliminary check. If you remove the oil filler cap and the chain is extremely loose—or if the plastic guide rail is visibly broken, chipped, or can be moved easily—the timing assembly has likely failed and requires immediate attention. [1, 2]
2. The Chain Stretch Test (Professional Method)
The only official, accurate way to check for physical chain stretch without pulling the entire front timing cover off is to have a mechanic perform an official BMW Timing Chain Stretch Test. This requires special dealer-level tools where the hydraulic tensioner is removed and a specific measuring tool is threaded in place to determine how much the chain has elongated. [1, 2]