Hard Start / No Start - Is your intercooler frozen? Check Here!

danham said:

So the question should be how to prevent excessive amounts of water from condensing in the intercooler in the first place. The ice issue is only relevant to the extent that temperature fluctuations are a contributing factor to condensation.

I'd propose "debate" about more relevant questions, such as, what happens when the temperature never drops below freezing? Does water still condense in the IC? If so, how is it dealt with without being sucked into the engine? In other words, our effort should be to find out more about how the system normally deals with moisture as a byproduct of combustion and then hopefully that will lead to why it fails to do so under certain fairly narrow conditions.

My gut feeling remains that short trips are a factor because the system does not reach operating temperature and stay there. VW tried to design for this with all the flaps and sensors and EGR loops and post-injection gimmicks to keep the system operating within a temp range that allows adequate performance and emission control. But that may not prevent excessive condensation as an unintended consequence.

-dan

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44 pages & 600+ responses later people do not understand what was laid out on page 1 of this thread. Under normal above freezing conditions, any water condensed in the IC gets blown through!! Air velocities in the intake are high enough to entrain liquid water!! Under certain conditions, the surfaces of the IC and charge air ducting are cold enough to allow liquid water which would normally be blown through to freeze on the inside surfaces, thus accumulating. despite high air flow velocities in the pipes. Then the car sits and a warm, above freezing area, and ingests the melted puddles on the next startup.

Come on folks... everyone up to speed now?

Up to speed? Yes. Convinced that ice is the key? No. My car saw temp and humidity fluctuations last winter (2010) that make this year look easy. It never had a problem until this winter.

So I'd respectfully suggest that a more useful tactic than sarcasm would be nailing down those "certain conditions."

-dan

danham said:

Up to speed? Yes. Convinced that ice is the key? No. My car saw temp and humidity fluctuations last winter (2010) that make this year look easy. It never had a problem until this winter.

So I'd respectfully suggest that a more useful tactic than sarcasm would be nailing down those "certain conditions."

-dan

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If you are not convinced ice is the problem, you are ignoring a mountain of evidence pointing directly to the issue and the collective experience of users posting here.

Sarcastic maybe - but common sense plus a little basic engineering analysis should tell you that liquid water gets blown through the intake unless it is frozen. Simple airflow calculations, already mentioned in this thread.

Short runs have nothing to do with it I ONLY do long runs and high load, and my problems have been as bad as anyone.

Not trying to be be a jerk danham - but there is a whole lot of "not getting it" going on in this thread lately, and as you mention, it is getting off-track, and in my opinion unfortunately detracts from quality of the discussion. The LP EGR moisture contributing to icing simply fits the system design and symptoms to well to be ignored - and this forum did a nice job arriving at that hypothesis some time ago. No need to make this harder than it is.

Icing is a problem with many systems where air gets drawn/pushed through a restriction, even above ambient freezing, due to the venturi effect. Old people may remember carburators freezing up even when the temperature is 40F.
This may or may not be part of the issue. On some other newer diesel systems with a liquid cooled egr, coolant has leaked into the intake, causing much the same problem.
The only way I know of to get rid of the water is with a bleed hole, but thats an efficiency loss.

I never had a problem with this on my '09. I'll be opening the IC hoses on my '10 this weekend probably.

There are a few differences that I've noticed between the '09 and the '10:

1. The '09 had a significant and frequent "Warmup Hiccup". I could make my '09 do it pretty on every start if I wanted to.

2. The '10 has a significant amout of water vapor in the exhaust during warmup which I never noticed on the '09. Maybe this was because it didn't swirl as much behind the sedan as it does a hatchback, but even backing out of my parking space or when looking in the rearview, it was rarely noticeable on the '09.

My suspicion is that whatever changes VW made to the '10 to lessen the Warmup Hiccup and cause the increased vapor is the major factor in this. The common factor for both of these "issues" is the LP-EGR. Maybe it stayed open longer during warmup on the '09 and that's the key to solving it on the '10s.

Jack Frost said:

My interpretation is much like yours in that the throttle is not there to create a vacume or affect air/fuel ratio. I think it might just be there to help the motor shut down quickly.

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It's there to pull in and regulate HP-EGR flow. It might also serve as an Anti-Shudder shutdown valve too.

nicklockard said:

It's there to pull in and regulate HP-EGR flow. It might also serve as an Anti-Shudder shutdown valve too.

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I don't think it does. The CRs have more shut-down "rumble" than ealier ASV-equipped cars, IMO.

Ryephile said:

Wow, the sky is falling again.

If you want to be proactive, every 10k oil change, loosen the IC hose and dump out whatever is in there. It'll add a whole 2 minutes to your oil change procedure, and ease your mind.

A catch can would be another good idea, though AFAIK nobody has developed one for the CR TDI yet.

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IFRCFI said:

You can guarantee it will be as inexpensive a solution as possible, and be kept as quiet as possible. TSBs generally doesn't equal Recall or even re-engineered or additional parts/components. So, draining it will probably be the quiet solution.

OK resident TDI engineers, time to develop a solution to put a petcock drain at the low point on the intercooler hoses.

Small airplane engines use this to separate air from the oil/moisture that normally would drip out the breather.

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IFRCFI said:

Perhaps like this:

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53 willys said:

The sky is not falling.....but it's total BS to have that kinda sludge in a brand new car...and it don't matter if you drain it or not..when the turbo pressurizes the cooler that sludge is getting sucked/pushed in your $10k+ engine..


a drain is a waste of cash..and time.
Good luck getting that kinda sludge to drain through a petcock..lol

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IndigoBlueWagon said:

It's interesting to me that owners of these cars are the ones systematically denying issues, including HPFP problems. Making a generalized statement like "this is an isolated case" is no more accurate or useful than saying "this is a universal design flaw." What's important at this point is to not ignore what seems to be going on.

Good news about this issue, unlike the HPFP one, is that an owner can take preventive steps. Get the car in a warm place and drain the intercooler piping. If I owned an '09 or later I'd certainly be crawling under the car. Why not? Doesn't cost anything, gives you peace of mind.

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frugality said:

It's an intriguing idea, though. Maybe put a petcock/valve there, and once in a while open it and, while stationary, rev the engine up and maintain boost for a minute or so to blow the gook out.

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53 willys said:

I dont think think the oil/water mix would drain out of a petcock either?? I dont have a boost gauge so I'm not sure you can free rev our cars and buid any boost?? most likly would have to take it for a drive and get some load on the engine to build enough boost for it to drain/push the mix out..?

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I got about to post 250 and got tired. If I missed someone already covered both the following ideas, I appologise.

If you add an automatic feature to your draining process, you really have some good ideas of using boost to blow the goo out.

A simple solenoid, when thawed, would open the drain with a switch during boost. It could be orifice regulated and activated with a pressure switch and temp sensor.

A radiator cap of chosen poundage would drain at a certain boost. With an orifice it would not lose too much boost doing the job.

A catch can could catch either of these automated purges.

Ya'll will get it done.

eddif

MayorDJQ said:

I never had a problem with this on my '09. I'll be opening the IC hoses on my '10 this weekend probably.

There are a few differences that I've noticed between the '09 and the '10:

1. The '09 had a significant and frequent "Warmup Hiccup". I could make my '09 do it pretty on every start if I wanted to.

2. The '10 has a significant amout of water vapor in the exhaust during warmup which I never noticed on the '09. Maybe this was because it didn't swirl as much behind the sedan as it does a hatchback, but even backing out of my parking space or when looking in the rearview, it was rarely noticeable on the '09.

My suspicion is that whatever changes VW made to the '10 to lessen the Warmup Hiccup and cause the increased vapor is the major factor in this. The common factor for both of these "issues" is the LP-EGR. Maybe it stayed open longer during warmup on the '09 and that's the key to solving it on the '10s.

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I agree the 10 has less of a warm up hiccop than the 09.On both I never saw water vapor out of the exhust during warm up.On the 09 I did pull off the I/C hose,and very little water came there was more oil than water.



The problem with a drain you can dump oil and water on the ground.The ice up problems happen to more people who drive on the high way.I think what happens is the real cold air 10* to 20* range hits the I/C when the car is moving at 60mph the cold air is taking most of the heat out of air stream.

MonsterTDI09 said:

I think what happens is the real cold air 10* to 20* range hits the I/C when the car is moving at 60mph the cold air is taking most of the heat out of air stream.

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BINGO. Exactly Right. My car froze and threw low MAP code on the highway at 14degrees and falling.

nicklockard said:

It's there to pull in and regulate HP-EGR flow. It might also serve as an Anti-Shudder shutdown valve too.

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According to VW's Self Study 2.0 Liter TDI Common Rail Service Manual pf 54, the intake throttle serves to:

1. create a differential between the manifold and exhaust pressure,
2. regulate intake air volume during active DPF regeneration, and
3. allow smooth shut down of engine

This document mentions at least another ; the exhaust throttle so we should be careful to qualify which one we are talking about when mentioning "throttles". It calls the device that regulates high pressure gases to the intake systems as a "valve" and not a throttle. Don't know why, but there it is.

Jack Frost said:

This document mentions at least another ; the exhaust throttle so we should be careful to qualify which one we are talking about when mentioning "throttles". It calls the device that regulates high pressure gases to the intake systems as a "valve" and not a throttle. Don't know why, but there it is.

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I think you're splitting hairs.

In its basic form, a throttle valve controls the flow of air/liquid. According to the diagrams in the self-study guide, there are 4 valves that would technically be throttles:

1. Throttle Valve between the IC and intake manifold.
2. HP EGR valve under the hood.
3. EGR cooler valve.
4. LP EGR exhaust flap between the NOx cat and H2S cat.

But each of these has specific name/function, so when one mentions the "throttle valve" it really shouldn't be confused with the HP-EGR valve.

LOL @ dweisel. That's some funny $#!7 right there. Time to pay up and go away, buddy.

VeeDubTDI said:

LOL @ dweisel. That's some funny $#!7 right there. Time to pay up and go away, buddy.

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I think he already has gone. I figured he would just disappear if he was found wrong...

I want to know where our $80 is.

I don't see a solution to this problem that doesn't involve one of the following

a.) a catch-tank that needs to be drained periodically,
b.) your car periodically draining water and goop onto your driveway or while you're traveling down the road, or
c.) significantly reducing LP EGR
d.) dehumidifying the LP EGR stream

This might be a stupid question, but: Couldn't you either reduce coolant flow to the intercooler or put a winter cover over the radiator? As long as you could keep the cold side above the dew point, I imagine little water would collect.

MayorDJQ said:

I think you're splitting hairs.

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I don't think so. These terms are assigned by engineers and peer reviewed by many others including technical writers, there must be a reason why they either named each part a valve or a throttle.

However, they all look the same in the system diagram. The hint is that the parts name throttles are either where the air enters the system (intake throttle) or leaves it (exhaust throttle). Everything else is a valve.

To me that whole system is not as complex as it first looks. Each throttle or valve is like a variable resisters in an electrical circuit. The mathematics behind that is well understood so I'm sure the engine's computer can understand what is happening and make the appropriate adjustements.

VeeDubTDI said:

I don't see a solution to this problem that doesn't involve one of the following

a.) a catch-tank that needs to be drained periodically,
b.) your car periodically draining water and goop onto your driveway or while you're traveling down the road, or
c.) significantly reducing LP EGR
d.) dehumidifying the LP EGR stream

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RzTen1 said:

This might be a stupid question, but: Couldn't you either reduce coolant flow to the intercooler or put a winter cover over the radiator? As long as you could keep the cold side above the dew point, I imagine little water would collect.

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I think the word radiator should read intercooler.

Jack Frost said:

I don't think so. These terms are assigned by engineers and peer reviewed by many others including technical writers, there must be a reason why they either named each part a valve or a throttle.

However, they all look the same in the system diagram. The hint is that the parts name throttles are either where the air enters the system (intake throttle) or leaves it (exhaust throttle). Everything else is a valve.

To me that whole system is not as complex as it first looks. Each throttle or valve is like a variable resisters in an electrical circuit. The mathematics behind that is well understood so I'm sure the engine's computer can understand what is happening and make the appropriate adjustements.

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Take the last three posts and address all three of the issues the owner has control over.

1.. It is possible to install a drain and put in a catch-tank. Although it may not be a long term solution, it will save possibly engine damage. If a sensor can tell when engine coolant is low, a sensor can tell when the water containing goo tank needs draining and give a light warning.
2..A winter cover will solve a lot of problems for some areas. High humidity areas need a drain and a cover.
3..An electronic tune and parts are probably going to have to come from VW. The system is so complicated that somehow about a liter of water can get in the tubes. If you slosh the water in a curve, hit a bump under boost and high flow and send enough of that water into the intake there can be huge problems.

Realize that #3 is needed, but do #1 & #2 till the problem is solved.

Club members have come up with the simple solutions that will work, till a true solution is found. If the winter cover over the intercooler bothers you, get a temp guage that will let you know when the boost is too warm and move the winter cover.

Seeing the amount of water some are getting out of their cars, denial will not work. If your stock car hits the magic combination of humidity, temp, valve operation and driving conditions and injests water into the intake; two will be guilty: VW and the individual owner.

It appears to me as a shade- tree redneck from Mississippi, that you have come up with enough information to help the cars. With a few sensors you can monitor what is going on. The goop will be a challenge for a sensor to tell if it is goo or almost all water, but there are some that can handle even that.

It does not just have to be a solution by a person. It appears that at least two solutions together will help. Join forces. Please.

eddif

As I stated before, Malone Tuning has been able to tune the CRs for about a year or so. He has also been able to reduce/kill EGR after coolant temps have gotten up to NOT on pervious generations (ALH).

Maybe we can intice him to investigate this for the CR. It might be a $575 fix plus a tune. Yeah warm up times are when most of the humidity happens, but I've also noticed that longer I run, at one time, in "the magic weather", the more likly I'll notice the issue after temps rise in the afternoon.

RzTen1 said:

This might be a stupid question, but: Couldn't you either reduce coolant flow to the intercooler or put a winter cover over the radiator? As long as you could keep the cold side above the dew point, I imagine little water would collect.

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The Intercooler in our cars is an air-to-air heat exchanger, not a liquid-to-air heat exchanger

eddif said:

I think the word radiator should read intercooler.

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Sorry eddif and tcp_ip_dude, I wasn't sure what type of intercooler was in the car. I'm not sure how much of the water present would normally come from the simple compression of air, but in my mind the sudden cooling of moisture loaded air would be the the primary issue.

RzTen1 said:

Sorry eddif and tcp_ip_dude, I wasn't sure what type of intercooler was in the car. I'm not sure how much of the water present would normally come from the simple compression of air, but in my mind the sudden cooling of moisture loaded air would be the the primary issue.

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Coolant temps are well above ambient temps (195F-210F) which if used in a liquid based heat exchanger (intercooler) would raise the temp of intake air charge to highly undesirable level (therefore lowering density), so you'll never see an intercooler/heat exchanger using engine coolant as the exchange medium. The goal of an intercooler is to increase the density of the IAC by cooling it (i.e. not heating it up).

195-210F is higher than the pre intercooler temps? Also what's the IAT of cars without IC? Also what about EGR?

I'm not arguing with you about how well an water to air intercooler works vs air to air.

Also why didn't they as another air to air IC for the EGR? I imagine if your tossing direct exhaust gasses back into the intake, at who knows what temps, why go with an water to air?

Space and ducting? warm up times? How well does the EGR cooler work at bringing down the EGR temps, pre/post cooler?

740GLE said:

Also why didn't they as another air to air IC for the EGR? I imagine if your tossing direct exhaust gasses back into the intake, at who knows what temps, why go with an water to air?

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They did. It's called an EGR cooler. I'm not that familiar with the CR, but my ALH has one.

MayorDJQ said:

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From this diagram, it looks to me as if there is only one EGR cooler - and it's on the low pressure side.

740GLE said:

195-210F is higher than the pre intercooler temps? Also what's the IAT of cars without IC? Also what about EGR?

I'm not arguing with you about how well an water to air intercooler works vs air to air.

Also why didn't they as another air to air IC for the EGR? I imagine if your tossing direct exhaust gasses back into the intake, at who knows what temps, why go with an water to air?

Space and ducting? warm up times? How well does the EGR cooler work at bringing down the EGR temps, pre/post cooler?

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Sorry to stray off topic, just wanted to clarify my point. I was just trying to let RZten know the reasons why you wouldn't see an engine coolant based heat exchanger to cool intake charge air.

The charge air temp leaving the compressor side will vary depending on pressure, but without doing the calculations I would guess you are seeing no more than 10-15 degree increase over ambient temps (without any LP-EGR), but well below the coolant temps of an engine at operating temps.

My point was not about the effectiveness of liquid-to-air heat exchangers vs air-to-air exchangers, there are plenty of examples of those, in fact, we have one in the car, it is the EGR Cooler, what is relevant is the temperature differential between the two sides of the heat exchanger, that is what determines what gets cooled and what gets heated (i.e. 2nd law of thermodynamics, energy moves from greater to lesser concentrations. Heat ==> Cold)

The point I was making was about using "Engine Coolant" as the heat exchange medium for a charge air intercooler would have the effect of heating the intake air. As stated above, there is an EGR cooler and it is cooled by engine coolant, but exhaust temps (500F+)are well above the temperature of the engine coolant, therefore it will have a 'cooling' effect on the exhaust gasses.

Again, sorry to sidetrack the thread, back to your regularly scheduled programming.

I started reading the commonrail Self Study about an hour ago. Figured I'd toss out some info that I haven't seen in this thread yet...

High pressure EGR takes place at low engine speeds and low engine loads. That is shifted to the low pressure EGR system as engine speeds and loads increase.

commonrail self study p. 28/90 said:

The air mass regulation of the High-Pressure EGR
is regulated by the EGR Vacuum Regulator Solenoid
Valve N18 and servo and by the turbocharger vane
direction. The short path of the High-Pressure EGR
is used in order to reach the desired EGR rate while
driving at lower engine speeds and loads.

The combined EGR operation is continuously
adjusted depending on engine operating conditions
and revolutions-per-minute (RPM). Thus, no-load
engine operation results in high amounts of High
Pressure EGR application.

With rising engine load and engine RPM, the
recirculation of exhaust gases is shifted to the Low
Pressure EGR system to increase the recirculation
rate. This happens in order to obtain optimal
NOx reduction at middle and high engine loads.
Particularly in the high engine loads, the cooled Low
Pressure EGR is a very large advantage over the High
Pressure EGR system.

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So what does this mean? Some people are suggesting that higher engine loads will reduce condensation and freezing in the intercooler due to increased IATs from the production of boost by the turbocharger. While the higher IAT part is true, the higher loads also result in more LP EGR, which results in more humid air being introduced into the intake system. Under certain cold weather conditions, this could exacerbate the condensation/freezing problem.

VeeDubTDI said:

I started reading the commonrail Self Study about an hour ago. Figured I'd toss out some info that I haven't seen in this thread yet...

High pressure EGR takes place at low engine speeds and low engine loads. That is shifted to the low pressure EGR system as engine speeds and loads increase.



So what does this mean? Some people are suggesting that higher engine loads will reduce condensation and freezing in the intercooler due to increased IATs from the production of boost by the turbocharger. While the higher IAT part is true, the higher loads also result in more LP EGR, which results in more humid air being introduced into the intake system. Under certain cold weather conditions, this could exacerbate the condensation/freezing problem.

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I guess people who jump on the highway with a cold engine on very cold day will have the most problems with icing.

VeeDubTDI said:

Figured I'd toss out some info that I haven't seen in this thread yet...

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Oh, it's been said all right. Good luck finding it though