Smoking when cold!!

[gooddogs]

We have 2 TDI Beetles an 00 and an 01. The O1 is smoking big time when it gets down below 15 degrees. Seems to be burning oil at that time also. Any other time it runs fine and is smoke free. The only other thing that I noticed is the blue coolent light is on but it is full of coolent. (I am guessing a sensor) Not sure how that could be connected or if it is? When it is smoking it seems the smoke is coming from all over not just the exhaust.

Anyone have any ideas why this would be happening only when cold?

[Smileybug]

Does the coolant light go off? It should come on until the engine gets up to temp

[gooddogs]

It either goes on and of a few minutes on a minute or two off then on again or it will stay on for a long time before going back of for a short time. Started doing this a week or so ago but even at 35 degrees but only smokes when real cold out.

[Smileybug]

I'd start with your coolant temp sensor.

[N41EF]

Temp sensor or thermostat? If the coolant bottle is low the blue light flashes. Solid light means the engine is cold. I've never seen one warm up and then cool off again. remember a TDI doesn't generate alot of heat, and has coolant glowplugs to give you heat on a cold start.

Start by checking the engne temp. you can grab the radiator hose to check it, or use a laser thermometer to see how warm it's getting. If the engine is not warming up, and the fans aren't running, I'd replace the thermostat.

[Smileybug]

If the blue light flashes you have a cooling system malfunction (90% of the time its the CTS). Flashing red means low coolant.

[gooddogs]

I have seen one flash before. Usually a none stop thing. This is going on and off more like the thermostat is bad. But I still do not understand how that would make the car smoke in the cold weather.

I have a CTS on order and already have a Thermostat to install.

Anyone else out there ever have an issue like this? It is almost like the PVC Valve is clogging only when cold.

[Smileybug]

What color is the smoke?

[AndyBees]

If it smokes at the time of start-up, something's going on besides a bad T-stat or Coolant Temp Sensor.

The fuel Quantity Adjuster could be too rich. The ECU reacts to the temp per info from the CTC. If the CTC is bad it "may" have defaulted to something like 40 below zero and cause the IP to load more fuel than necessary. So, as suggested, replace the coolant temp switch and go from there! The CTC is not a major task to replace and is relatively cheap.

The T-stat shouldn't have anything to do with smoking from a cold start. Also, the T-stat typically defaults to open when it goes bad. Thus, your engine would have a tendency to take much longer to warm-up to normal operating temp, even on a 30 degree day!

Lastly, if smoke seems to be coming from "everywhere" there may be exhaust leaks in the piping system from the Turbo to the rear of the car .........make an effort to see where it comes from!

[gooddogs]

The issue ended up being the CCV. It apparently freezes closed when cold. Causing excess crank case pressure.