Smoking question M62tu

[rusteee 52]

Hi Guys

Hoping for a bit of knowledge on the m62tu. Done 171,000kms, recently had the water pump done (no overheating, just a slow leak out on the driveway), Coincidentally, upon getting the car back, every so often, especially when taken for a drive, left sit for 30 mins or so, it will pour out smoke from the exhaust for 2-3 seconds on start up only. Does not smoke when hot sitting at idle, or taking off at lights etc as far as I can see, only start up, and not every time. Now they did over fill it with oil for some reason by just over a litre and I had driven a good 200 odd kms before I noticed. I have since drained out the excess (took 1.2l to get back down to the dipstick full mark). My question is, with those symptoms, is it more likely to be valve stem seals like they suggested, or something along the lines of oil seperator? Just seems strange that its never smoked at all, and never lost oil besides a small valve cover leak, then overnight it turned to this.

Cheers

Edited October 16, 2014 by rusteee

[yng_750 247]

Mine did it similar when the ccv valve went.

Google ccv valve dipstick test

[jeffbebe 1559]

What colour smoke, Russell?

[rusteee 52]

Smoke is white with a very very faint blue tinge to it. I don't know much about the CCV system but did do a bit of google. One of the first things I did was the dip stick/ oil cap test, but it doesn't seem to be abnormal.

[aja540i 1906]

Its probably just from being overfilled, but mine did this when the oil seperator fell apart, if its that it will just keep getting worse until you pull the engine out and fix it. Have you taken the throttle body off and had a look for oil in the inlet manifold? If it was valve stem seals it would do it all the time, not sometimes.

[rusteee 52]

No, havn't had a look in the manifold yet. All I've done is drain the excess oil hoping that was it. Was good for a day, then sat for bit, from cold start yesterday gave a short puff of smoke (not as bad as has been), but still enough to make me cringe.

[Ahmedsinc 414]

Jeez mate, you're really not having much luck with the M62 are you!?!?

[BreakMyWindow 1874]

Could just be some residual oil somewhere where it shouldn't be, and should burn off in time.

With the crankcase being overfilled I'm thinking the excessive oil volume has overwhelmed the separators so you have a nice oily intake manifold.

[jeffbebe 1559]

Could be PCV but, as Andrew says, it would smoke all the time if that had failed. White smoke usually indicates water and blue oil, so if it's mostly white I'd be checking the cooling system. A cracked head would smoke white... Which wouldn't be ideal!

If it's more blue than white I'd guess it's the valve stem seals (although the fact it happens after a 30 minute drive is a bit weird). If they're worn then oil can seep into the combustion chamber when the car is sitting. Once the engine is running and warmed up that's not an issue because it doesn't build up again until the next time you let it sit... Which is the weird thing with your symptoms.

Did they do a full oil change? If so, do you know what oil they used?

[BreakMyWindow 1874]

Could be PCV but, as Andrew says, it would smoke all the time if that had failed. White smoke usually indicates water and blue oil, so if it's mostly white I'd be checking the cooling system. A cracked head would smoke white... Which wouldn't be ideal!

If it's more blue than white I'd guess it's the valve stem seals (although the fact it happens after a 30 minute drive is a bit weird). If they're worn then oil can seep into the combustion chamber when the car is sitting. Once the engine is running and warmed up that's not an issue because it doesn't build up again until the next time you let it sit... Which is the weird thing with your symptoms.

Did they do a full oil change? If so, do you know what oil they used?

Not saying the PCV system has failed, but more has not done it's job which is to separate the oil from blow-by gasses in the crankcase going in to the intake manifold. I think too much oil in the crankcase has been sucked in to the inlet manifold and made it's way to the inlet valves to be burned off.

[jeffbebe 1559]

Actually, I have the same issue with the 8. Pulled the intake temp sensors (at the back of the manifolds in the 8) and both were pretty oily but the car is otherwise running fine... Probably over-filled with oil at some point but will check the breather hoses and valves when I remove the manifolds for cleaning.

Is there an easy way to check on the M62?

[polley 916]

Common for intakes to be coated in oil on engines where crank case gases are recirculated.

[BreakMyWindow 1874]

A dry oil vapour is common, but if it's fresh looking oil then that is not normal. Easiest way is to whip the TB off and have a looksy.

[rusteee 52]

Cheers for the replies, Yea not much luck at all hahaha, all in the fun of it though I suppose. Still have to get the gearbox issues sorted, but really want this issue sorted first. They did not do a full oil change, I don't even know why they touched the oil as it only went in for water pump etc, and because it was already at max level (which I usually check once every 2 weeks or so) i questioned when he said they added a litre because it was down?... My first thought was that it had been cooked without me realizing? headgasket/head cracked, but then its not showing the typical signs, not losing any coolant, no mirky oil, no moisture residue on cap, and it doesn't smell like burning coolant. Doesn't affect the performance in anyway it seems, still smooth power/idle etc.

[jeffbebe 1559]

I'd follow Martin's advice initially then, Russell. Check the manifold for excess oil... Hopefully, it's something simple like that.

[rusteee 52]

Yea, gonna go out and have a quick look at it now see what I can find.

[aja540i 1906]

Yea, gonna go out and have a quick look at it now see what I can find.

Be carefull removing the small vacuum hose from the side of the plate behind the throttle body, i snapped mine off when doing this and had to find a replacement!!

[EuroSurgeon 2]

Would almost guarantee its pcv valve, put your finger over breather of pcv, if engine squeals then its faulty

[rusteee 52]

Just an update, no oil in intake. Ended up taking it back in to be checked out. They had a good look over and could not fault anything, PCV was good, valve stem seals etc good and they couldn't get it to smoke. They were very good about it, dropped the oil and re-filled to correct level with new oil, left it over night an re-checked. Picked it up today and took it home, sure enough an hour later smoke out the exhaust. Not too sure what to do from here.

[aja540i 1906]

Sounds like the oil seperator, just whip the engine out, pull off all the timing gear, and put a new one in! The part is only about $60 from BMW.

[rusteee 52]

Yea I know whats involved in chaging it, I'd rather cut my losses and call it a write off in that case. They said they tested the the PCV/crank case ventilation system and found no problem? Would it not smoke everytime as well as when driving if it has failed? or have some sort of tell tale sign that its failed? The smoke is no where near the amount it had been. Hasn't smoked once today done about 500kms, it seems erratic

Edited October 25, 2014 by rusteee

[aja540i 1906]

Mine only did it on start up, only when it had been driven then left to get cold. I think it is something to do with hot, oily air from the crankcase getting into the manifold, then cooling, condensing, and making its way down to the valves.

Im not sure if there is any way to test the oil seperator, its basically a plastic venturi that spins the fume and seperates out the oil, when it falls to bits the oil gets sucked into the inlet with the air.

It can probably be done in the car, but i did everything at the same time so it was easier to pull the motor out!

[rusteee 52]

Hmm yea its a bugger of a thing, was usually doing it when hot, not really on cold start. Surely they would have been able to pickup that it is faulty if thats the case? And over filling with oil wouldn't have contributed to this?

[Allanw 1071]

Yea I know whats involved in chaging it, I'd rather cut my losses and call it a write off in that case.

I'll give you $100 for the car

At least drive it until it gets shocking :-)

If you think it's residual in the manifold, you could get some intake cleaner (I like Wurth Sytem Cleaner) and flush it out a bit. Sounds like it's something a bit more though.

[rusteee 52]

HA ha, yea na, even as parts this car is immaculate and worth a good couple k, but hopefully wont need to go down that track. Im not convinced the seperator is buggered. Done another few 100 kms again today and didn't smoke once, not even after sitting hot, or cold start... so maybe it was residual? When it smoked the last time on Friday, it was pretty minimal but enough to see. Will keep an eye on it. Has to go into panel beaters on tuesday as someone hit the back corner of it. Torque converter is getting pretty noisey too, trying to organise the repairs on this thing it is a goddam mission, still fantastic cars to drive none the less =)