Mini Cooper S R56 - fix stem valve seals myself or not?

[mrrossi]

Hi guys, after a bit of advice please. I have a Mini Cooper R56 turbo. N14 engine. Yes, terrible, I know NOW... anyway. Pretty certain the turbo was shot (lots of play, smoking etc) and I managed to replace the core. This is the most "advanced" work I've done on a car myself and it took weeks as I didn't have the right tools, experience etc. Read up a lot and used YouTube videos etc but still a hard job for me. Anyway, still have smoke and pretty sure it's the stem valve seals, rather than the piston rings (not certain*, but I don't have some of the symptoms of the latter, such as power loss or misfires - she runs really well, just a ton of smoke!). There's plenty of guides and videos about replacing the N14 stem valve seals but I've got to buy lots of special kit (and all the links are US based, so I've got to find/research/check I can find suitable UK ones) and I'm thinking it could be beyond my skillset / patience levels - for example, I've got to lift up and get under the car for one part, which I hate doing, plus don't have something suitable / safe currently to lift it, so that's something else to purchase...

Alternate is to chop it in cheap when I buy my next car. I bought it "cheap" (issues aside!) for 3200 and then next car will be somewhere between 12-14K, so I'm assuming I'll get a 1.5-2k type part exchange and nothing off the price of the new car. Whereas if I fixed and solved privately, I may get 3.5k and will be buying cash so can negotiate on buying price so will be better off by 2-3K - in theory!?!

Problem with chopping in now is I'm not really ready financially. I could do it but it'd be TIGHT for the next 6 months... but can I risk continuing to drive it for 6 months without fixing? Sounds like I could knacker it, screw up the cat for example etc etc.

Else I can pay a garage to fix, and a quick google suggests £500-£1000. Which actually sounds like the most viable option, given the "bargaining power" aspect of selling privately before buying the replacement and the fact I'm not ready to buy another for 6 months really. The missus won't be happy me spending that, but she also won't be happy me being exhausted with my hands and arms bleeding and back aching for weeks like what happened when I changed the turbo :')

Thoughts?!?

• As I've wrote this I remembered reading that I can do a compression test to prove whether its the piston rings or not. The test kits don't seem too expensive so will look to get one & carry this out first.

[SystemOfAFrown]

Have you already checked out the PCV system? They are notorious for this failing and causing smoke.

[K50 DEL]

Just as an aside to this, are you certain that you'd get £3500 for the car if fixed? that sounds a lot to me for an N14 - I bought an N18 Cooper S last year, in decent condition for £2500 and wouldn't expect to get that for it now.

[mrrossi]

Thanks guys. I should have mentioned that this is an auto, they seem to be much higher priced - I only bought it earlier this year and they were all priced around 3.5 to 4k.

I did look into the PCV system, it doesn't seem to have most of the symptoms of that (such as rough idle) and the error codes I've had also don't suggest an issue there. Any easy way to check / rule out?

I did have the oil pressure checked as believe that can be an issue, that checked out all ok.

[finlo]

Have you checked that the intercooler and exhaust aren't full of oil?

[paul_c123]

Chop it in.

I've heard stories of being able to do valve stem seals by feeding some rope down the spark plug hole then turning the engine, but I'd not fancy having to use one of them lever-type spring compressors, leaning over the engine and placing the tiny collets. If you're not confident about lifting the car, doing valve stem seals is a bigger job.

[GeniusOfLove]

Punt it off to WBAC and never buy another, they're miserable things. If it is the stem seals you'll do that and 6 months later it'll be burning oil past the rings or it'll st it's chain or something else will go.

Great to drive but they really are absolute crap.

Valve stem seals could be interesting on that valvetronic motor with all that "stuff" in the valvetrain but I wouldn't suggest it as a good job for someone new to spannering.

Edited by GeniusOfLove on Tuesday 3rd June 21:44

[ATM]

Whoah there Cowboy

I had a smokey BMW V8 which was probably the valve stem oil seals but I managed to make this a lot better by adding some snake oil - pic below

Before anyone tells you this won't fix it let me be clear, I'm not guaranteeing it will .... I'm suggesting it might help and it will cost you very little to try

This stuff or similar is what you need

[E-bmw]

Just a few pointers from my opinion/experience.

Auto's don't "go for much more" so you need to temper that jet.

A smoky N14 could be a VERY expensive money pit when sent to a garage to fix.

Why do you think it is valve seals rather than something MUCH more expensive?

You 100% NEED to to a compression test as a minimum before spending any more.

If it were me I would be getting rid immediately.

[GeniusOfLove]

ATM said:

Whoah there Cowboy

I had a smokey BMW V8 which was probably the valve stem oil seals but I managed to make this a lot better by adding some snake oil - pic below

Before anyone tells you this won't fix it let me be clear, I'm not guaranteeing it will .... I'm suggesting it might help and it will cost you very little to try

This stuff or similar is what you need

The snake oil is to get it good enough for long enough to trade it or get an old heap through an MOT really. I use it regularly

[ATM]

GeniusOfLove said:

ATM said:

Whoah there Cowboy

I had a smokey BMW V8 which was probably the valve stem oil seals but I managed to make this a lot better by adding some snake oil - pic below

Before anyone tells you this won't fix it let me be clear, I'm not guaranteeing it will .... I'm suggesting it might help and it will cost you very little to try

This stuff or similar is what you need

The snake oil is to get it good enough for long enough to trade it or get an old heap through an MOT really. I use it regularly

I'm going to disagree with you. I think it's perfectly reasonable to put in an older engine. Because things like gaskets and seals do need help. This stuff doesn't thicken the oil like some of the old fashioned stuff people used to stop engines smoking - that was deffo to get it through an auction or MOT. Instead it has chemicals in which treat seals. Have you heard of that stuff people put on window seals - is it called gummy fledge. Well this is similar. I've seen some bad looking window seals with cracks rejuvenated with chemicals. So if window seals need help why not seals inside the engine too. Don't wanna go on too much because I still think for the cost it's worth trying. But I believe some motor oil companies like Mobil are now producing oils for older engines which again contain chemicals to help treat seals and gaskets. Anyway that will do. I'm done defending the snake oil industry now.

[mrrossi]

Thanks again everyone. On the subject of "snake oil", I have similar "quick fixes" before - or rather for coolant leaks (would that then be "snake water"?!). Although not had much success.

Hadn't thought of it here. Certainly worth a go; have read up & seems some people have had success. Liquid Moly oil saver is only a tenner on Amazon and can be with be by tomorrow, so have ordered a bottle. Else STP High Mileage Oil Treatment + Stop Leak may be better and worth a go.

Regarding the intercooler and exhaust being full of oil, I haven't checked, but looks like even if they were it could be a symptom of many things, including dodgy turbo (which I had), PCV system, stem seals or possible even piston ring issues so I'm not sure how that would help me diagnose / confirm one thing or another? I've ordered a compression test kit now so will look to get that done soon and hopefully rule out the latter condition.

I've also emailed a couple of Mini indies near me to ask how much they'd charge for a valve stem seal replacement so at least I know. The more I look into doing myself the more solid a "nope" pops into my head!

May as well check WBAC too to have any idea but pretty sure it'll be pennies.

[mrrossi]

JFI - valuation comes back as £1,690. Not great, and I'd hope to be able to fix & sell for a lot more, but nowhere near as bad as I was expecting - something to bear in mind at least.

[paul_c123]

Is it smoking badly or do you think it will pass the superficial check WBAC and the like would do when you take it there? (Or is the valuation, with the fault declared)?

In any case, your OP estimated a trade in price of £1500-2000, so I'd not be too disappointed.

I would bet that if you asked a garage or mobile mechanic to do the fix, then you sold it, the two would pretty much cancel out no matter how good of a price you got for the job. Only if you competently did it yourself, and had most of the tools already, you'd be up - but then you'd have put time into it.

[mrrossi]

paul_c123 said:

Is it smoking badly or do you think it will pass the superficial check WBAC and the like would do when you take it there? (Or is the valuation, with the fault declared)?

In any case, your OP estimated a trade in price of £1500-2000, so I'd not be too disappointed.

I would bet that if you asked a garage or mobile mechanic to do the fix, then you sold it, the two would pretty much cancel out no matter how good of a price you got for the job. Only if you competently did it yourself, and had most of the tools already, you'd be up - but then you'd have put time into it.

It's a bit intermittent; you can see on start up occasionally, but it's bad after 15 mins or so. I.e. not sure if I'd get away with it... but "snake oil" may reduce it enough?!

The valuation didn't ask for anything like that. The original one was £100 more and I corrected a few assumptions and it came back with that slightly lower number.

Just got a quote back from one garage, seems they want to do the full head out method and replace everything, so it's a whopping £2733 quote!!! Erm... HARD PASS, thanks!

[GeniusOfLove]

Trade hates these things (for obvious reasons) so valuations are low.

I really think the best thing you can do is cut your losses now.

[E-bmw]

If it "gets worse after 15 mins or so" it is unlikely to be valve guide seals.

[mrrossi]

E-bmw said:

If it "gets worse after 15 mins or so" it is unlikely to be valve guide seals.

I'm getting conflicting information on symptoms of valve vs pistons vs PVC vs other possible causes, and it's not helped by some intermittent behaviour / not always noticing smoke due to having to concentrate on the driving element..!

My next step is compression test (probably Friday) to hopefully rule out piston rings. If that looks ok, the "most likely candidate" is still the valves but there's no real way to "prove it 100%" without actually having them replaced!

I'll try a couple of "snake oils" too over the next week or so and see if they help.

I'm also going to "raid the piggy bank" and see if perhaps I can justify getting "the next car" (which would be a keeper, well, for at least 2-3 years, whereas the Mini was only a stop gap - admittedly a poor one!).

Thanks again all for your input / advice!