I recently noticed in my 07 mcs, when I start the car it lets out a bit of blue tinted smoke that lingers and does it when I take off from a start. It is very recent, only in the past week or two. I just changed the oil 2 weeks ago and it seems to have started from there. I know I put everything back together and put the right amount of oil in, but maybe it is just a fluke. Any comments or suggestions? it doesn't appear to be burning oil but I am going to monitor it every day.

 

I must admit it does sound odd. How many miles on your MINI and what oil did you use(exact weight, brand, etc.)?

 

93000 miles and I use castrol Syntec Full synthetic 5w-30.

 

This happened to me before I upgraded to the Borla Exhaust System, but not after the installation of the Borla. I clearly remember my brother telling me that when I pulled out of his garage he saw blue smoke, I told him it's not a problem and he said, "fine then" with attitude. I explained to him that N14's are known for burning lots of oil (oil burn off) and not to worry about it, my stock exhaust after 50,000 miles probably had all the oil coating the inside of my entire exhaust system from all those years of burning oil.

However my new exhaust is clean inside, I suspect that in 50,000 miles it will get coated with oil which is perfectly understandable for our unique situation. It could be more than just an exhaust coated with oil gue, you my friend need to have a leak down test performed and find out where the oil is slipping by. It will either be the valves, valve stems and or the piston rings, but if it's just the valves and valve stems the repair bill will be a lot cheaper than a new or rebuilt bottom end.

Regards,
Systemlord

 

Well what is weird is it only does it sometimes. I drove an hour yesterday and when I got into city areas it was fine for 15-20 mins which makes me think that there is a drip somewhere. I took the divertor valve apart that is just in front of the turbo inlet and found some oil on the tip that may have been getting misted and burned when I take off from a start.

 

I originally bought an AEM CAI last summer and when I installed the inlet charge pipe I noticed oil dripping towards the turbos inlet via PCV hose, after a few months goes by I needed to buy a new valve cover, some time later I decided that the AEM CAI wasn't for me. When I took the inlet charge pipe off I noticed it was very dry and no trace of oil residue whatsoever in the PCV hose leading to the turbo. There has to be oil in my intercooler, I plan on upgrading to a Helix intercooler this year.

 

It is weird that it comes an goes. I do notice oil dripping from the pcv inlet hose just before the turbo. Maybe my inter cooler is full of oil as well as it seems to do it more when it is warm outside and if i don't have a smooth start. it just seems weird it started after I changed my oil. I called the dealer and got a hold of the service manager and he says he has only seem a few cars at around the 90k mark that needed rings or valve seats replaced. He was thinking more along the lines of carbon buildup related issues but wouldn't know until he took a look. the smoke appears to have a bluish tint but I could be wrong. I know it has some carbon buildup just looking at the exhaust tips but I may take things apart in the next week or so and see if something external to the engine is causing the problem.

 

You need to have a compression or a leak down test to pinpoint where the oil is going, there's three ways, blowby passed rings, valve stems and or sucking up oil vapor through the intake system. This is the only way to truly know what's going on. I suspect the rings and valve cover, if the PCV system built into the valve cover is not functioning properly.

 

But... if you have not had a carbon blasting/cleaning of the valves at 93K, do that. It will need to be done in any case.

 

I agree, there was a lot of soft oil goo coating my valves and intake runners at just 49k, if OP hasn't had it done it's going to be messy!

 

In a week and a half, I am going to take the intercooler off, check for lots of oil in it. Take off the intake manifold, check for excessive carbon, oil, gunk. If time permits, I will check the pcv system which seems a little elusive on this car and if someone could explain the routing and number of ports would be a big help. I don't understand other than for buildup reasons why the PCV system doesn’t rout into the exhaust behind the cats. Because it comes and goes and appears to be blue smoke (It may be me wanting to see it blue) I don't think it is a relation to carbon buildup on the valves but dealing with the intake side of the motor will help determine where the oil is coming from.

I am hoping it is not a turbo seal issue, but I would rather have that than a valve guide or piston ring failure as I do not have the time to do it myself and would prefer not to spend the money at the dealers rates unless I have to. If all else fails, to the dealer it goes for them to do their tests. Just ruling things out myself will make sure the dealer doesn't screw me over for unnecessary work that I know it doesn't need.

I read some stuff on turbo seal failures, and that seems to sound alot like what I have as far as symptoms go, any thoughts?

It just seems weird that the problem has made itself apparent after an oil change as my driving habbits haven't changed. I did notice a little gritty feeling in the oil when I drained it, but it wasn't too dirty and I didn't notice any metal filings or anything.

 

Typically if you're overfilling during your oil change the excess will be burned off, that's what members have seen when checking their OCC (oil catch can), the amount of oil overfilled seems to be equal to what they find in their OCC. Members who use OCC seem to find lots of oil in the intake tract, mainly the intercooler on up to the intake manifold. It is this reason why I decided against using any OCC's!

How the PCV system works from my understanding is if you're at a stop the throttle body PCV port (passenger side rear port) allows oil vapor into the engine to be burned, once you begin to accelerate under boost the throttle body PCV port closes and the other port (PCV port turbo inlet) opens. I find more oil in my throttle body PCV port than with my PCV port turbo inlet, then again we are probably not under boost 85 percent of the time we are driving.

The PCV system (Cyclone Separator) is built into the valve cover, they last anywhere from 50k-75k then fail typically, they put up with a lot of heat!

 

I have been driving the car more and it no longer smokes at startup, it only smokes a little when I go over some bumpy railroad tracks on my way to work and stop at the following light. Since it isn't a consistent error I'm not going to worry as much about it , but I am going to take the intake manifold off for sure to see any buildup, oil or carbon and adress it if need be.

 

What are your oil change intervals? N14 owners that followed the 15k miles intervals have seen turbo failure as low as 43,xxx miles.

Turbo's don't use a seal persay, because there is no seal capable of withstanding the heat and speed, not to mention the need for thermal expansion, so the bearings that are on the turbine shaft and the oil between them create a dynamic seal. If you baby the car you're going to see excessive oil weeping past the seals, same as if you run the car low on oil, or oil that has broken down and lost its lubristic properties, which leads to bearing wear and a lessening tolerance held between the bearings and the charger cartridge. Proper maintenance will cut down on wear of the bearings, and lessen the amount of oil consumed.

Not saying that this is your problem, but it has been more than a problem for some, when the car is cold, take the intake off the turbo and feel if there is evident shaft play, there will be some but you'll be able to tell if it's excessive, also look in the compressor inlet to check for evidence of compressor wheel contact on the housing. If so, then you'll want to start thinking about a turbo replacement.

The amount of oil that would be required to actually cause a haze of blue through the PCV would be quite large. You will however always have some oil residue in the intake tract due to the PCV system, a catch can will help it, but it doesn't stop all the oil vapor.

Nick
Detroit Tuned

 

 

A quarter of a quart every 1500 miles is better than most N14's, my N14 is about the same on oil consumption. Driving it on the freeway seems to reduce oil consumption while lots of city driving I notice a tad more oil consumption.

Glad to hear you issues have subsided.

 

Well I thought they subsided, but I added oil yesterday afternoon and the commute back and fourth to work had some puffs of bluish smoke when pulling away from a couple lights. I'm thinking turbo or PCV system. What is funny is that they will both end up costing the same whether I send my turbo out for a rebuild or I buy a valve cover seeing as I can't replace the valves inside of them. I will be taking off the intake this weekend to look for carbon and oily buildups.

 

I wouldn't do anything until you get a leakdown test to see if it's the rings and or valves, don't waste your money until that is done! You wouldn't want to buy a new turbo and valve cover only to find out it's the piston rings. Buy and install the valve cover yourself, it's pretty easy to do. I don't like buying rebuilt turbochargers (one exception, JMTC) I'd buy a new one provided it's the problem you're having.

 

If you do need the N14 engine valve cover, systemlord linked it. Thanks

If you need the stickers and emblem for the valve cover or valve cover there here:

https://www.northamericanmotoring.co...ment-help.html



Thanks

 

I pulled things apart today. I found that there is some carbon buildup on the intake valves, but it isn't as bad as some that I have seen. I am going to arrange a service for the dealer to do a leak down test to find where the oil is coming from. I am 80% sure it is PCV related as the symptoms are only under initial take off. I felt the turbine wheel and shaft for slop and inspected for any signs of impeller contact with the housing, but things seemed good. I will wait to hear results from the dealer however and probably get a de-carbon job as they quoted me $415 and I would rather them screw up than me.

On a side note, are both PCV valves built in the valve cover? Because if they tell me that is the problem, I am not paying someone $100 to put a $300 part on my car when I am perfectly capable of doing that. Things buried further inside the motor I don't have the time or the specialized tools required to do.