Blue smoke on start up

**Peter_HMR** · 02-08-2010,04:44 PM

Hi I have a 130pd TDI passat and its kicking out a decent amount of blue smoke on startup. It only occurs from cold and goes away once the engine has warmed up. Theres no modifications to the car but there was a tuning box fitted before I had the car. Anyone any ideas?

**Peter_HMR** · 04-08-2010,10:15 AM

Anyone have any ideas?

**Hex69** · 04-08-2010,10:22 AM

Originally Posted by Peter_HMR

Anyone have any ideas?

The only answer I can give is, "They all do that, Sir"

It's a diesel, Any unburnt fuel pushed through before ignition will come out of the exhaust. I drive a number of diesel vehicles, from a 1968 MF135, to a VW Passat 115, to a Mitsubishi L200, to a DAF LF55 (2010), and they all smoke on starting (the MF135 smokes so much you can't see for a minute around you

)

So unless it's burning oil or using water or excess fuel, I'd not worry about it.

**Peter_HMR** · 04-08-2010,11:54 AM

No worries its just pumping out a fair bit of blue smoke constantly for a bit and anyone in the proximity gets a whack of fumes it embarrassing more than anything.

**Clinterous** · 04-08-2010,12:06 PM

Shouldn't really be much in the way of smoke on start up from a PD. I only occasionally get a puff of black smoke on start up. Wonder if you have some excessive oil seeping in somewhere. How many miles on the car?

**yaman** · 04-08-2010,12:12 PM

If its blue/grey smoke, then its oil getting burned in the
combustion process, could be valve stem seals or (more likely)
piston rings which then expand with heat and reduce the gap.

An over-fueling problem would produce blacksmoke.

Regards
Jim

**Peter_HMR** · 04-08-2010,12:21 PM

Its definately blue with grey theres 124k on the clock. If its the piston rings i guess its due to engine wear and not something thats easily fixed.

**yaman** · 04-08-2010,01:07 PM

I got surprisingly good results from "piston sealer"
on Peugeot TD engines. It was a easy fix and lasted
well, 20k+ miles.

Haven't had to use it on VAG engines........yet! But its
always an option.

Regards
Jim

**Peter_HMR** · 04-08-2010,02:41 PM

If its piston wear is there a way of diagnosing this further.

Has anyone any experience with piston sealer??

**PeteK** · 04-08-2010,04:47 PM

How much oil does your car use? Mine smokes a little bit on start up but has never once needed topping up between 10k services. I thought it was just normal to be honest, however mine does appear to be black rather than blue smoke.

For what it's worth, I certainly wouldn't consider using piston ring sealer on a PD engine!