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Mini Cooper - Blue Smoke from exhaust - Michael Collison

Hi

My son has just spent £3000 on an 09 plate mini cooper (1.6). It has done around 60k miles. He has noticed that there is a bit of blue smoke coming out of his exhaust when he accelerates. I believe that it is likely to be piston rings or something similar, which ive been told is an expensive fix!

My question is this... Is it worth keeping the car and regularly topping up with oil? Ive spoken to a friend (car salesman) who has said it may be difficult taking it back (only bought last week) as the car is running smoothly and isnt 'faulty'. Its a 13 year old car so we should expect some smoke etc, but with it being blue its obvious what the fault is.

For £3k, the car is immaculate and finding something similar is difficult. It passed an MOT last week, so is good for 12 months! Is it a risk worth taking, or should we be banging on the dealers door for our money back???

Any help much appreciated...

Mini Cooper - Blue Smoke from exhaust - Andrew-T

On the basis of what you have said, IMHO there is no point complaining to the seller of a 13-year-old car if its only fault is an occasionally-blue exhaust. If you have paid a fair price for a car in better than average condition, your cheapest option is topping up the oil regularly (don't overdo it) provided the car continues to pass its MoT emission test. If it fails to do that it may be time to rethink.

Mini Cooper - Blue Smoke from exhaust - elekie&a/c doctor
The Prince engine fitted to these and numerous Peugeot and Citroen models are notorious for bad oil consumption. As already suggested, best just to keep the oil level topped up . Fixing the issue is not financially viable on a car that cost £3k .
Mini Cooper - Blue Smoke from exhaust - Michael Collison
Thanks for your input. Hopefully will get a couple of years at least out of it but who knows!
Mini Cooper - Blue Smoke from exhaust - craig-pd130

As others have said, impress on your son the importance of checking the oil level at least once per week, and before any long journeys, and topping up as needed.

Buy a 4-litre pack of the cheapest oil that meets the specification for the car from Halfords or a reputable eBay vendor like Opie Oils, it works out much cheaper that way (as it's burning oil, there's no need for mega-expensive stuff, just whatever meets the appropriate BMW, API and viscosity specs).

Mini Cooper - Blue Smoke from exhaust - Andrew-T

... as it's burning oil, there's no need for mega-expensive stuff, just whatever meets the appropriate BMW, API and viscosity specs.

Even if it 'burns oil' when you accelerate, the oil may not disappear at a great rate. The important thing is to check it often so that you learn how often, and how much, to top up.

If the EGR system is working properly it should stop the cat getting too contaminated.

Mini Cooper - Blue Smoke from exhaust - bathtub tom

I'd suggest checking all the breathers, particularly the PCV (Positive Crankcase Ventilation valve).

Mini Cooper - Blue Smoke from exhaust - edlithgow

I'd suggest checking all the breathers, particularly the PCV (Positive Crankcase Ventilation valve).

Yeh, I had a Renault 5 Campus fail its MOT for "visible smoke" and cleaning out the crankcase breather (not actually a PCV on that. AFAIK I've never had a PCV) may have fixed it.

But I also changed the oil, added Wynn's Viscosity Improver, and, possibly most importantly changed the MOT tester, so I can't be sure what, if anything, fixed it.

Mini Cooper - Blue Smoke from exhaust - edlithgow

IF the oil is being burnt due to worn rings (or bore), thicker oil (either the thickest approved, or thicker than that if you arent too bothered about being disapproved of by BMW, which I probably wouldn't be) may help reduce consumption.

Of course the only way to cure worn rings (or bore) is a partial rebuild, which, as has been said, is a lot of work, and too expensive to get someone else to do.

IF, OTOH, the oil is being burnt due to stuck rings, you MAY be able to unstick them. One "home remedy" for this is to dribble some brake fluid down the plug holes and leave it overnight. Best done shortly before an oil change since the brake fluid may find its way into the oil.

I havn't actually done this, but I have used brake fluid to decoke horribly plugged EGR plumbing on a Honda Accord. Smoked a lot but cleared eventually.

Possibly leave it until the problem gets worse and its necessary to do something

The other classic cause would be worn valve guides. These two are classically distinguished by the effect of adding a little oil to the cylinders on compression readings. If the oil restores compression, bore/rings. If not valves. A leak-down test might also be informative but thats a more difficult DIY proposition..

I suppose worn turbo oil seals might be another possibility, but have no experience of turbos.

Edited by edlithgow on 09/03/2022 at 06:46

Mini Cooper - Blue Smoke from exhaust - Bolt

IF the oil is being burnt due to worn rings (or bore), thicker oil (either the thickest approved, or thicker than that if you arent too bothered about being disapproved of by BMW, which I probably wouldn't be) may help reduce consumption.

Of course the only way to cure worn rings (or bore) is a partial rebuild, which, as has been said, is a lot of work, and too expensive to get someone else to do.

IF, OTOH, the oil is being burnt due to stuck rings, you MAY be able to unstick them. One "home remedy" for this is to dribble some brake fluid down the plug holes and leave it overnight. Best done shortly before an oil change since the brake fluid may find its way into the oil.

I havn't actually done this, but I have used brake fluid to decoke horribly plugged EGR plumbing on a Honda Accord. Smoked a lot but cleared eventually.

Possibly leave it until the problem gets worse and its necessary to do something

The other classic cause would be worn valve guides. These two are classically distinguished by the effect of adding a little oil to the cylinders on compression readings. If the oil restores compression, bore/rings. If not valves. A leak-down test might also be informative but thats a more difficult DIY proposition..

I suppose worn turbo oil seals might be another possibility, but have no experience of turbos.

From the nephews I have that have owned several of these, they all have suffered from scored bores, so can only assume from mileage around 60k or less they are not run in properly and thrashed from new, but could be wrong? and possibly caused by poor engineering or metal used, but imo would say poor running in was more likely

some buy them thinking the engine is already run in but they are not, so I was told, and manual states as I think most do, engine, needs running in over time, though not many do?

Mini Cooper - Blue Smoke from exhaust - Andrew-T

<< Some buy them thinking the engine is already run in but they are not, so I was told, and manual states as I think most do, engine, needs running in over time, though not many do? >>

Historically a new car was meant to be 'run in' carefully, with revs kept below recommended levels for 1000 miles or so. But a lot has been said on here for many years that that is no longer needed, and it may be better to give the engine a bit of welly from the word go.

I guess it may depend on the degree of finish the bores and rings are given to start with, and what metals are used, whether there are liners, etc ? Also the lubrication makes a contribution.

Mini Cooper - Blue Smoke from exhaust - Gibbo_Wirral

Doesn't the Mini (especially of this age) have that horrible oil-drinking Peugeot engine in it?

Mini Cooper - Blue Smoke from exhaust - badbusdriver

Doesn't the Mini (especially of this age) have that horrible oil-drinking Peugeot engine in it?

It does (as was stated earlier in the thread), though it was a joint development between PSA and BMW, not just a Peugeot engine BMW decided to use.

Mini Cooper - Blue Smoke from exhaust - John F

The clever manufacturing of this engine is done in France and the bits and pieces hammered together in Warwickshire. A quick google of 'prince engine problems' throws up yards of entertaining threads quoting a variety of problems including the wrong type of oil scraper rings, failing valve seals...etc. As long as it passes the MoT I would just keep pouring cheap oil into it till it breaks. Try keeping an accurate record of how much per 1000 miles it uses.

Edited by John F on 09/03/2022 at 15:08

Mini Cooper - Blue Smoke from exhaust - edlithgow

Saw some talk of adding catch cans to the crankcase ventilation path.

Shouldn't hurt, though if its got EGR as well it'll only stop some of the muck.