Blue Smoke upon startup

[JRW]

Hi, I 've got a MY03 'S' which has covered 32k miles and have noticed that it has begun to emit blue smoke from the exhaust (which I assume is oil) each time I start from cold. Its not just a small puff of smoke but tends to be a cloud that swirls around! I'm a bit concerned and wondered if anyone has any comments as to the cause, and whether this is an indication of bigger problems ahead? I'm not hard on the car (always ensure it is well up to temperature - especially the oil - before opening it up) and have had it fully maintained by my OPC. Thanks.

 

[akwaugh]

Hi,
My 2000 2.7 with 36k miles does the same thing and has done over the 2 or so years I have had it. It does this whether it is in constant use or has been lying about for a while. As there are no other noises or drips or anything I'm ok with it. Oil consumption over a year (7k miles) is minimal - 1 bar on the dash gauge - and only gets more when it has it's annual oil change.

I don't know if this is typical of the breed but hope it helps.

Andrew

 

[Black80XSA]

Absolutely typical - its due to oil seepage past the piston rings when the car is stationary, a feature of flat engine designs

 

[Rob Edwards]

Hi
Is your car parked on a slope? I have heard that due to the 'boxer' configuration of the engine that on occasion when parked on a slope that oil seepage can cause a puff of smoke on start-up. If it is this, I don't think you have much to worry about.
If not, I'd get it checked by a good independent.
Hope all works out OK.

BlackBoxsa - you beat me to it![]

 

[JRW]

Thanks for your comments. Sounds like its nothing out of the ordinary, so I'll worry not! Cheers.

 

[Glyn]

The Boxer engine is horizontally opposed in that three cylinders point to the left and three to the right, If the car is parked on a slope - Left to right or vice versa as oil drips back to the sump when switched off some oil returning will drip onto the bores below the pistons due to the angle of the car.
When hot the pistons are round and completely seal the bores, however once cold the pistons return to their oval shape which allows oil to seep past the oil control scavenge ring and the piston rings, hence when you start again the oil burns off , this is completely normal and nothing to worry about.

To explain the ovalness of pistons, Pistons are made of alloy and like all metals expand when heat is applied, manufactures have to calculate the expansion and allow for this, The piston has a "Small end" this is where the connecting rod between the pistons and the crankshaft fit. There is a significant amount of alloy that makes up the little end and therefore more metal means more expansion - hence ovalness when cold

 

[JCB..]

It also explains why it does it when my car is parked on a level surface and is only moved a short distance without the engine getting warm. The next start will inevitably result in a cloud.

 

[Robin M]

You are not alone there John. Mine has always done it and I assumed it was something to do with Oil getting past the Piston rings and convinced myself not to worry. Now I definately won't