I am the owner of a 2010 Mini Eng: 1.6L, In-Line4 (98CI) VIN(C). It is really my daughter's car and she loves/ed it. It Has about 92K miles on it. We bought it used a couple years ago as her college car.Earlier this year my daughter's mini 2010 mini was up for license renewal and had to go to the DEQ to get emission tested. It failed as the exhaust was too Smokey after being revved, after idling in line. I took it to a local shop with a good reputation and was told that it was most likely a valve seal issue and that it needed work. They also found plastic pieces of the timing in the oil pan and told me that this was not an uncommon issue with these models. I decided to have it fixed, the cost of which was similar to what the car is worth. I was hoping that this would get my daughter through the rest of her college without too many other issues. We had the head/valves and timing work all done. We drove the car a bit and then took it on one long trip. Because of covid, it was only driven about every two weeks for a half hour after that. The car seemed great, lots of zip and we were very happy.

One morning my daughter started the car up and got an engine light. She took it to the local auto parts store to get it read, and it said she had misfires in several cylinders. She was out of town at college so I had her take it to the local mini dealer. They confirmed that the reading and performed a leak-down test at the request of our local shop. They did not seem to really know how to do this test or come up with any conclusions other than it had issues. We had it towed to the local shop and they also did a leak down test, which it failed. They think that the issue is a bottom-end issue with ring wear due to leakage into the bottom end, They seem to be up-front type of guys, however, I find it very improbable that two cylinders (3 and 4) would show leak-down issues within 1.5K miles of getting the top end work done. I admit having worked on a lot of equipment in my youth, I am a "last thing fixed, first thing too look at when an issue arises" type person. I am also told that bottom-end issues are not common in this mileage. For two cylinders to have issues at the same time just seems improbable. Engine codes shoed misfire issues in at least three cylinders. The shop does not see any signs of some sort of head issue like moisture in the oil, sparkplugs looking too clean etc., but that was the last thing done, and with not a lot of mileage from the repair to the issue.

My questions are:

1) Has anyone run into a similar issue where it has not been a bottom end issue?
2) Is there any other diagnostic that could be used without tearing the car apart again.
3) Other advice?

At this point, since I have already spent as much as the car is worth, any future work on it, I will most likely do myself due to labor costs. Any advice would be greatly appreciated. I have the ability to work on the car myself.

Thanks for any input you can give me.

Kevin

 

Did they do a leak down test before they did the head work? Also whens the last time it was filled with gas? You said you had timing work done. Did they reuse any of the old timing chain components? Like the chain tensioner? Or any of the old bolts? They are stretch bolts, so they are one time use only, including the crank bolt.

 

You can get a leakidown test gauge pretty cheap, so you could repeat it yourself. Do it warm, as that is when it counts.

If you have anywhere close to normal compression, I would just change coils & plugs, then see how far you get before spending big money on it.

 

With it being 2 adjacent cylinders at the same time you'd also want to consider it could be the head gasket.

 

Hi,

Initial money already spent. This was a large expensive $6K repair meant to set the car up for at least another 30K or so miles if not more.

1) They used all new parts for the timing. Timing guide, tensioner, chain, bolts all new all replaced. Coils and plugs are all new also.
2) They used all new bolts, including crank shaft bolts etc.
2) I do not believe that they did a leak-down test on the engine before the work or after. I do not have a detailed list of their diagnostic work beforehand or afterwards though.
3) Gas was within a month, not old
4) Head was sent to a machine shop, and rebuilt with new seals etc.

Yes, I think it is may be a head issue or head gasket issue, but leak-down shows leakage into the bottom end. I know some leak to the bottom end is normal, but the test seems to indicate a large leakage. The shop says that if it were through the head, that there would be signs like fluid in the oil or "very clean" spark plugs etc. They seem to know what they are doing, I just doubt the cause as it is statistically not likely for two cylinders to have issue like this after less than 1.5k miles ...

Is there any other way to figure out if it is the head or the rings causing the issue. At this point the shop is saying it is not their issue. They are a good shop, but the timing and severity of the issue has me questioning the source of it, especially two cylinders.

Is it common to to have ring to bottom end issue in this engine in the 90K miles range?

 

There hasn't been many posts on here with ring issues that I've seen at that mileage. Most of those who do post about ring issues are modified. Long shot here but with it sitting for longish periods of time the rings might have seized. But I would still do a compression test and see what the numbers are.

 

Another idea to figure it out, put the bad cylinder on TDC. Apply compressed air to spark plug hole. Listen for where the hiss is coming from. If you can hear it from oil fill hole, it's rings. If air is escaping from intake or exhaust, it's valves.

Be careful as engine can turn from the air pressure.

My bet is on a head problem. Just because it was rebuilt doesn't mean it is OK.

 

I would first move plugs around to see if the misfire moves with them. Second move coils around. This is cheap and easy.