TDI Frozen Intercooler

So this morning I go to start my car after sitting overnight in my garage. It was about 50 deg in there (really cold outside). Go to start the car and it shudders and doesn't start. Try again, same thing. Looks like I have the problem where the intercooler freezes in cold temps, then melts overnight and leaves water in there. VW has a "cold weather kit" which from what I've read doesn't work. Does anyone know of a way to resolve this issue? This is going to be very annoying if I have to deal with this all winter. I plan on putting a plastic board in front of the intercooler for now to keep it warmer and hopefully not let it freeze up.

Frozen IC TSB

I'm inclined to say that if you get a large air flow rate through the IC before shutting it off, you will probably blow out enough of the water to keep it from freezing to the point of complete blockage. When this has happened in the past, was the car idling or at low load for an extended period before shutting it off?

This was a big issue with H2 fuel cells when I worked on them and they would 'purge' the systems by blowing a bunch of air through the components (not terribly dissimilar to IC channels) before shutdown.

In reply to bludroptop:

That's the VW solution that people have said does not work. Plus my car is out of warranty and it costs $$$.

I guess if the ice is building up while you're driving around, that won't work though...

TSB or cardboard sound like good options. Or boosting it enough to heat up the IC and melt the ice before shutting it off.

In reply to JohnyHachi6:

This is the first time it has happened to me. I suppose I can give it some boost before I pull into the garage for the night.

Try that, but be warned......you might be dangerously close to hydrolocking it.

If you get the IC hot enough to start melting the ice while the engine is running (through a little spirited driving, or otherwise), I don't think you'll stand much chance of hydrolocking. The ice will melt gradually and the engine can ingest it and spit it out the exhaust easily. I imagine that the problem is when it all melts overnight and you try to start it with a ton of liquid water in the IC.

Well, if you're bored, there's a 305 page thread about this on TDIClub:

http://forums.tdiclub.com/showthread.php?t=302863

page 305 has some serious geekery going on...

block it with cardboard or start driving it harder.

Well, I opened up the lower intercooler piping after work. Several tablespoons of water came out. I'm letting it thaw and drain in my garage currently. I made a plastic board to go behind the lower grill and ziptied it in. I also blocked off half of the upper grill. Hopefully this will keep temps high enough to prevent water from condensing in the intercooler. I will monitor temperatures using torque to see what effects it has.

I thought the TDI was the one VW that didn't have odd problems. I guess at least it's physical and not electrical.

We have the odd gas Volvo show up in cold weather with blocked intercoolers. It seems to happen most in snowy conditions, and my theory is that some snow makes it into the airbox, creating a high humidity area, which then freezes in the tubes of the intercooler. It can be reduced, but not eliminated, by removing the snorkel between the air filter and the front end of the car, forcing it to draw underhood air. A layer of cardboard in front of the intercooler could help a bit, too.

I stared at an 850 one day for a while, trying to figure out the plumbing needed to bypass the intercooler completely in cold weather, since I don't think your average driver would benefit from an intercooler at -25 in a blizzard. It could be done, but would have involved some cutting and welding.

Streetwiseguy wrote: It can be reduced, but not eliminated, by removing the snorkel between the air filter and the front end of the car, forcing it to draw underhood air.

This is a solid idea, shouldn't matter much to a diesel but its a common gas engine hypermiler trick to reroute the airbox inlet to draw over a radiator hose or near the exhaust manifold.

Any chance you could install a drain on one end or the other? Could be as easy as one of the oil pan repair plugs with the drain plug inside it or even an auto trans drain plug kit. Through a small enough drain tube you wouldn't loose much boost and you could close it up for trips and when the weather warms up.

Wally wrote: I thought the TDI was the one VW that didn't have odd problems. I guess at least it's physical and not electrical.

It's a fairly basic physics problem, not easy to fix, and very not unique to the VW, or diesel.

The more boosted engines we get, and the higher compression, which requires cooler and cooler charges, the more condensation and many problems due to that we will see.

oldopelguy wrote: Any chance you could install a drain on one end or the other? Could be as easy as one of the oil pan repair plugs with the drain plug inside it or even an auto trans drain plug kit. Through a small enough drain tube you wouldn't loose much boost and you could close it up for trips and when the weather warms up.

My experience has been that its not a large block of ice, its a buildup of frost on the inside of the tubes in the core. Volvo intercoolers have small drain holes in the bottom to drain off condensation, I'd bet most others do as well.

oldopelguy wrote: Any chance you could install a drain on one end or the other? Could be as easy as one of the oil pan repair plugs with the drain plug inside it or even an auto trans drain plug kit. Through a small enough drain tube you wouldn't loose much boost and you could close it up for trips and when the weather warms up.

The problem is that it's not really about being cold- it's more about being humid and cool enough. Or humid enough and cold.

I think the latest TDIs went to air-to-water intercoolers.

I'm thinking of some kind of drain I can make. Maybe a ball valve with a push-pull cable. Park the car and open the valve to drain overnight. Close valve and start car in the a.m. I could also figure out a way to make it automatic. Hmm...to the drawing boards!