I've read a ton of threads. Looked at multiple forums. What is the answer?

The majority of 2nd Gen owners on forums have turbo versions, so the major concern has been the N14 (2007-2010 for the hardtop turbo) engine, where the timing chain failure is concerned. It seemed as though, so far, there are fewer concerns about the N18 (2011+ turbo) engine. But what about the N12 (2007 - 2010) and N16 (2011+ naturally aspirated engines?

What, exactly, is the difference? It is mentioned in passing that the engines use the same timing chain assemblies. Is it simply that the turbos heat the oil up so much, and may use oil (meaning that the level drops) and the NAs are not as hard on their oil? So the oil will keep the tensioner taut more reliably? Or is there some essential difference between the actual engines (besides the hot turbo environment)?

Why, in hundreds and hundreds of reports of failing timing chains, are there few or no Justas mentioned?

Who knows enough about the actual engine to know the answer?

 

Difference from n12 to n16 is a change in the oil pump. They added a solenoid that comes from inside and comes out of the block to the wiring harness. No trouble with timing chain issues for the naturally aspirated. Any other questions feel free to ask.
Sincerely, trained mini technician and happy justa owner

 

And the n12 to n14 & n16 to n18 engine differences are....there totally different set ups. Justa is intake injected while the s is direct injection. justa has valvetronic solenoid and rod in the head as the s does not. justa has two vanos cam gears as the s has one on the intake cam. Lots more just too much to type on a phone

 

miniSherlock92, that is great information! Thank you very much for it, I really appreciate it! So you have no concerns about the Justas having timing chain issues in either engine then?

See, that's what I wonder about. Let's say, between the N12 and the N14... what is different about the timing chain assembly in those two engines, that the N12 has no problems but the N14 does?

I would LOVE to understand this on a simple level!

Thank you so much!

 

I read that MINI increased the adjustment range on the timing chain tensioner for the latest versions (2011+). The dealers are apparently upgrading the tensioners when they replace the timing chains on the earlier versions. I think the extremely long recommended oil change interval, the difficulty in reading the oil level, and the consuming of oil by some MINI's is a large part of the problem. Most cars do not consume much oil between changes and have much lower change intervals so many people don't check their oil level betweem changes. This causes more of a problem for the S versions since they consume the most oil. Some of the MCS's use over a 1/2 quart of oil in 1000 miles My Justa uses almost no oil between oil changes and from what I have read, this is typical for the Justa. I think the S's are typically driven harder and that would also reduce the life.

Morris, 2011 MC, PW/B

 

All I can say for sure, being I haven't replaced an n12 timing chain, is the top guides are different designs, as the heads are different. Material wise I dont know if they are different I would assume a slight difference since turbo creates more heat.

 

You are correct. New tensioner and o ring

 

anybody knows how much is replacement for tensioner on justa?
mine 07 justa 78k has timing chain or timing chain tensioner issue..

 

good info thanks!! bump for this thread. was just looking into some n12 vs n16 info, since I went from an 08-12

 

Yyj,
I am about to pay $250 to have my N12 engine timing chain tension measured. I'll see if it's loose enough to worry about, and the replace the tensioner bolts while they're in there.
I'll report it back here towards June.

 

Well, it took until July, but having read several of these threads that could be found by searching 'N12 timing chain' I was moved to see how much my N 12 (Justa) timing chain had loosened over 6 years and 65,000 miles. I finally got to the Mini dealer (300 miles!) and for about $300, found that my chain had 69 mm of slack. Spec for this is <64 mm and 68 mm is considered the upper limit. They put in the new tensioner bolt. I hope I'm in better shape now for the long haul to and beyond 100k miles.
My Mini has always had abundant clean oil and a generally easy life, save for one day at the race track in which it got about a years worth of revving and braking :-)
I encourage you N12 owners to get your slack measured.

 

Aren't they supposed to replace the whole timing chain assembly if the chain measurement is beyond the upper limit?

 

Let's look at it from a different angle. On any Valvetronic engine there is no throttle valve. The intake airflow is controlled by the amount of lift of the intake valves. The only time the intake valves are at full lift is when the throttle is wide open. Therefore there is less valve spring pressure being overcome by the intake camshaft during operation less that wide open throttle. Thus less load on the timing chain. This being on the N-16 and N-18 engines. Where on the N-12 and N-14 engines the intake valves are opened to max lift no matter what RPM the engine turns. Thus greater load on the chain. I don't think the turbo has so much to do with engine heat as the thermostats do. In my wife's 2011 Clubman S the water temp runs at 220 to 225 all the time. On my 2013 JCW Hardtop it never goes past 195 F. Same as the 2013 GP2. I don't have a way to measure the oil temp, but I have to believe it's greater too, along with the high water temp.

 

I believe you'll fund that there are throttle valves on the R56 MINIs. I'm not sure if they are used only for warm-up or what, but they are there.

 

TREX is right, if they only changed the tensioner you will have problems down the road! "The chain is already stretched and it will wear to a point where even the new tensioner won't be long enough to provide proper tension." We have seen every case where they only replaced the tensioner that these issues return when you're out of warranty.

 

R56 covers several different engines. N-16 and N-18 do indeed have a throttle valve, used only for startup. Valvetronic regulates the engine RPM from there. It has it's own ECU for that purpose.

 

Excellent info and very interesting, Can these engines (N16) be substituted for the n12.. my n12 ingested something (FOD) and is holding a few valves open. I haven't pulled the head yet and can't tell if it got into the cylinders.

(my best editing comes right after I post)

 

2007 Justa, 46K miles. I think I might be having this dreaded timing chain issue. My engine light came on yesterday (yellow), more than normal loss of power on inclines. I pulled these 5 codes:

inlet camshaft to crankshaft correlation
ignition coil cylinder 1
ignition coil cylinder 3
ignition coil cylinder 4
exhaust actuator movement

Does this seem plausible? I'm 100 miles from the nearest dealer and my car's out of warranty. Safe to drive out there or should I tow? Would appreciate any insight.

Thanks,
Justin

 

I wouldn't drive it, myself. Sounds like the chain jumped timing. :( Driving it 100 miles risks that it jumps even more, and introduces valves to pistons.