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

[MayorDJQ]

Is there still pressure from the turbo when idling and when going downhill?

While there is a throttle, it's not there to create vacuum like in a gas engine. There should still be possitive pressure in the IC, turbo, and rest of the intake tract when idling and going downhill.

Just talked to a shop mechanic foreman that takes care of 30 diesel trucks. Pressure on the charge side. Suction on the cold side. Also thought there was no way a cup or two water could condense in the intercooler.
dweisel

I don't buy that for a minute. How is there vacuum between the I/C and intake manifold? What happened to all the boost? How many of us installed a boost gauge in the upper pipe on an ALH? We still have boost there, no vacuum.

 

[dweisel]

Being a "truck mechanic", I'm guessing that this guy isn't overly familiar with the operating characteristics of the Low Pressure EGR on our CR engine and that it dumps EG in upstream of the compressor side. After researching this quite a bit, I have no doubt that LP-EGR is the primary source of the water, we'll see, but I'll gladly take a friendly wager on it (loser makes a $20 donation to TDIclub)

Yea, 25 years of diesel mechanic experience means nothing. How many times did you say you read the Study Guide?

I'll take that bet to keep things interesting. So, I guess we wait for VW to come out with their fix. If its a revised intercooler hose or intake I win. If its a change to the Low Pressure EGR you win.

dweisel

 

[Conan]

Does anyone know if any other 'clean diesels' use the lp/hp EGR scheme? It would be interesting to see if they condense water out in the intercoolers too.

 

[MonsterTDI09]

The condensation is not the problem.The problem is keeping the I/C temperature high enough to evaporate the condensation.

 

[MayorDJQ]

The condensation is not the problem.The problem is keeping the I/C temperature high enough to evaporate the condensation.

Which pretty much defeats the purpose of having an intercooler.

 

[VeeDubTDI]

Yea, 25 years of diesel mechanic experience means nothing. How many times did you say you read the Study Guide?

I'll take that bet to keep things interesting. So, I guess we wait for VW to come out with their fix. If its a revised intercooler hose or intake I win. If its a change to the Low Pressure EGR you win.

dweisel

Please explain how there is a vacuum in the charge air system on the TDI. What about the intercooler creates a vacuum on one side of it?

 

[dweisel]

While there is a throttle, it's not there to create vacuum like in a gas engine. There should still be possitive pressure in the IC, turbo, and rest of the intake tract when idling and going downhill.


I don't buy that for a minute. How is there vacuum between the I/C and intake manifold? What happened to all the boost? How many of us installed a boost gauge in the upper pipe on an ALH? We still have boost there, no vacuum.

Here is some info from myturbodiesel.com about:"What is a boost leak and how to find it."

Its called a boost leak instead of a vacuum leak because it appears when the engine is under boost from the turbo. The turbo pressurizes the air in the intake path when the engine is boosting so if there's a leak it will flow out instead of in. When the engine is NOT boosting the leak can become a vacuum leak.

I'll stand by my diagnosis for water in the intercooler hoses as a less than adequate seal.

dweisel

 

[VeeDubTDI]

Is this your diagnosis for ALL intercooler water? Or just for your car?

 

[VeeDubTDI]

Also, are you standing by your 25-year mechanic's assertion that it is impossible for water vapor to condense inside the intercooler?

 

[dweisel]

Is this your diagnosis for ALL intercooler water? Or just for your car?

Nope. Just cars with similar conditions as mine. I can't say it will fix ALL problems. My wife's 09 Sedan has remained free of water other than a teaspoon. The Sedan's seals are evidently okay.

dweisel

 

[dweisel]

Also, are you standing by your 25-year mechanic's assertion that it is impossible for water vapor to condense inside the intercooler?

Yep,until proven otherwise.

dweisel

 

[tcp_ip_dude]

Yea, 25 years of diesel mechanic experience means nothing. How many times did you say you read the Study Guide?

I'll take that bet to keep things interesting. So, I guess we wait for VW to come out with their fix. If its a revised intercooler hose or intake I win. If its a change to the Low Pressure EGR you win.

dweisel

I have my doubts about how much they can reduce the use of LPEGR without blowing out their NOx budget, we'll see... I believe it'll be a combination of ECM tune and modification to the IC/ducting, but not for the reasons you stated (i.e."sucking in water"), but rather to better cope with accumulated condensate and perhaps a draining mechanism.

My wager was simply that the LPEGR was the primary source of water being introduced into the intake air system (not what the solution might be), so let's let VW's description of the problem settle the bet. i.e. if they say water is being "sucked" into the IC ducting from a bad seal then you win, if they say it's related to excessive LPEGR then I win.

 

[bsalbrig]

Here is some info from myturbodiesel.com about:"What is a boost leak and how to find it."

Its called a boost leak instead of a vacuum leak because it appears when the engine is under boost from the turbo. The turbo pressurizes the air in the intake path when the engine is boosting so if there's a leak it will flow out instead of in. When the engine is NOT boosting the leak can become a vacuum leak.

I'll stand by my diagnosis for water in the intercooler hoses as a less than adequate seal.

dweisel

I think you need to step back and think about what you are posting here. There is a reason Diesel motors have a vacuum pump....cause they don't make vacuum. The only reason you see oil leaking from these connections is because there is 22psi forcing it out. With 22psi you only get slight residue, how much vacuum do you think it would take to pull an equal amount of water into the pipes?

 

[devilyellow]

Wow, still no fix.

I'm getting close to the next service appointment on both the JSW and 'egg. I was hoping there would be a fix by now

 

[dweisel]

I think you need to step back and think about what you are posting here. There is a reason Diesel motors have a vacuum pump....cause they don't make vacuum. The only reason you see oil leaking from these connections is because there is 22psi forcing it out. With 22psi you only get slight residue, how much vacuum do you think it would take to pull an equal amount of water into the pipes?

Yes, I know diesel motors have vacuum pumps. That slight oil residue leakage is slight because there's not much oil being produced. Its not on that side of the intercooler that I'm saying the water is being sucked in. Its on the cold side.

I'll start my JSW today and try and check to see if under certain conditions a vacuum does or doesn't exist. I say there is and the excerpt from myurbodiesel backs that up.

The only reason that style clamp/seal is on the intercooler hoses is to allow some movement so the hose isn't flexed when the engine torques,which could cause cracking or pull it loose from the intercooler fitting. I did away with those clamps on my hoses. Will it work? Maybe,maybe not,but I can't afford to take the chance of my engine gulping water.

dweisel
Oh, almost forgot...........LUBRICITY,LUBRICITY,LUBRICITY!

 

[jchall]

Hello all this is my first post since I am new to the TDI family. I purchased my 2010 Jetta TDI in Nov 2010. Prior to this I had a '93 Jetta - 188k, a '87 Jetta - 135k, and a '78 Sirocco - forgot the milage.

After reading through all of this topic and several others I'm keeping my fingers crossed. On two occasions after my car sat for a couple of days due to snowstorms (I drive my red F-250 4x4 rather than my white gold TDI Jetta during snowstorms, the truck is much more visible in the snow) I had rough starts. The first time I popped the hood to see where the noise was coming from, and to me it sounded like it was coming from the alternator, I suspected it was the alternator because the cumulative values for the elapsed time and average fuel consumption reset. Thew second time it just idled rough for about half a minute. On both occasions the car sat for 2 days because of snow, I don't remember exactly what the weather conditions were before I parked it, but it was snowing and cold during the time it was parked.

I mentioned this to the service manager 2 weeks ago when I had my car in for the 6000 mile/90 day courtesy check and he had never heard of such a problem. I think his words were " That's a new one for me." In the post service survey I also mentioned this and VW of Old Saybrook's response was as follows:

I have reviewed your last repair order and your comments on this survey and can only tell you that yes we are aware of the 2 concerns that you spoke of and VW is working on a fix. With the mileage so low on your car I am certain that there is no water in your inter cooler.

I have not responded to his comment that due to the mileage on my car there should be no water in my inter-cooler, however my feeling is that the water accumulation IS due to environmental conditions and LP EGR, NOT the age and mileage of the vehicle. Moisture IS a byproduct of combustion and it IS getting introduced into the intake by definition, EGR=Exhaust Gas Recirculation.

My big concern is what will today bring, here in CT we are supposed to get ~1-1/2" of rain, then it's going to get cold. From what I have read it sounds like good conditions for IC icing. I am supposed to drive about 60 miles this evening and I'm wondering if I should drive my truck that gets 1/3 the fuel economy.

Sorry about the long post, but I wanted to get this out there so more of the members on this forum know of another case of rough starting and to see what happens with anticipated weather conditions similar to those that have caused problems with others.

 

[danham]

Has anyone been able to correlate short trips and water buildup? This fits my one incident, but I don't know if it applies to others.

Seems to me that condensation effects from the LP EGR would be worse when the engine is run for a short time and then shut down. Witness the water streaming out of a gasser's tailpipe during the morning commute, for example.

-dan

 

[740GLE]

I had a rough idle after start up last Tuesday afternoon, this was after driving the car 150 miles from NH to CT. Temps durring the trip were 12-18F, when starting it back up temps climbed to the 40s. It never stalled, just idled/skipped for 10 seconds then cleared up.

I don't think anyone can peg it down to short or long trips. It's how the miles are put on and the condidions that'd lead to ice build up in the IC. Biggest thing would be keeping heat out of the IC so icing can happen, if you can keep the heat out while putting around town or say on a 50 miles highway run then you shouldn't have a problem.

 

[Dieselfitter]

Since burning a gallon of diesel produces a gallon of water, it is absolutely possible for condensation of EGR gasses in the IC to produce the amounts of water we're seeing. The question is under what conditions the condensation takes place in such a manner that it collects in the IC.

Lets start with High Relative Humidity. Lets add the Moisture from the LP EGR. We can also add the moisture from the PCV system also.

When you compress air, the ability of the air to hold moisture is diminished. This is why shop compressors have drain valves in the bottom of the tank.

At 100KPH, my scangauge is reading 21-22 MAP (manifold absolute pressure). So I would imagine that if I was driving in high humidity conditions, that I would get WATER forming in the Intercooler.

VW absolutely has to come up with a FIX FOR THIS !

 

[bmble b]

Hello all this is my first post since ....caused problems with others.

Welcome Jchall. I live in CT too and take my car to VW of Old Saybrook. I know a couple of people who work there. Do you remember when you took it for the 6K/90 day check?

Our car when there Dec 17th with the intercooler icing problem. They told me it was the first one they had but had heard of the problem. They told me they documented the case and sent it to headquarters who were aware of the problem then and were working on a solution. We had 10K then and we're close to 14k now.

Hopefully they come out with a fix ASAP.

 

[Goldwing]

Absolutely correct. On the large diesel engines I have worked on for 20 plus years, many of them incorporate a condensate drain on the aftercoolers (intercoolers) which are small orrifices that are always open to atmosphere. You can see water vapor exiting these small orifices when the engine is under load. Keep in mind, these engines don't have an EGR. An EGR system would make the moisture accumulation increase substantially at low engine loads and speeds. These engines develop enough moisture while just chilling the compressed intake charge to warrant a continuous drain.

VW has to come up with a fix which would not include the above mentioned drain because this would not be practical or safe in a car. But they have to do something to combat this accumulation as it is a huge problem.

 

[MonsterTDI09]

Lets start with High Relative Humidity. Lets add the Moisture from the LP EGR. We can also add the moisture from the PCV system also.

When you compress air, the ability of the air to hold moisture is diminished. This is why shop compressors have drain valves in the bottom of the tank.

At 100KPH, my scangauge is reading 21-22 MAP (manifold absolute pressure). So I would imagine that if I was driving in high humidity conditions, that I would get WATER forming in the Intercooler.

VW absolutely has to come up with a FIX FOR THIS !

Is it true the higher the pressure the higher the temperature?Would the hot air evaporate the condensation? Then I guess what is happening as soon the air hits,the I/C then it loose all most its heat then starts to freeze.I am no expert if this way out in left field I am sorry.

 

[gpshumway]

You're not out in left field. Compressing air heats it, that's just a thermodynamic property of air (and other gasses). The intercooler's purpose in life is to remove the heat added to the intake air by compressing it in the turbo.

The exact mechanics of how the condensation forms and in what amounts requires a deeper understanding of the system's operation than we have at the moment. Indeed VW doesn't seem to have this level of understanding either or we wouldn't have the problem in the first place.

 

[MayorDJQ]

You're not out in left field. Compressing air heats it, that's just a thermodynamic property of air (and other gasses). The intercooler's purpose in life is to remove the heat added to the intake air by compressing it in the turbo.

The exact mechanics of how the condensation forms and in what amounts requires a deeper understanding of the system's operation than we have at the moment. Indeed VW doesn't seem to have this level of understanding either or we wouldn't have the problem in the first place.

The prevailing theory of too much moisture from the LP-EGR seems to be the best explanation. If humid atmospheric/intake air were the problem, then the problem would exist on earlier generation TDIs, as they all have I/Cs.

If the hose connector on cool/outlet side of the I/C is loose enough to allow water to be drawn in under a very, very light vacuum--not that I agree a vacuum is created--then 22PSI of boost should be more than enough to blow out the water from said loose fitting. Plus, any moisture pulled in by this vacuum should wind up getting pulled downwind into the combustion chamber, since that's where the vacuum is coming from. It wouldn't go upwind into the I/C.

 

[dweisel]

It sucks!

Well for all you positive pressure in the cold side intercooler hose guys, I'm taking bets. I got a $20 dollar donation for the tdiclub in your name IF the cold side doesn't suck. Any takers? If I'm wrong I'll send in $20 donation for each member that signs up in this thread.

dweisel

 

[MayorDJQ]

If there's enough vacuum to suck in water from OUTSIDE the I/C, then why won't 22psi blow it back out the same hole it got in through?

How are you planning to measure vacuum? Will you be installing a boost/vac gauge? There's no vac sensor in any TDI that I know of. Will the MAP sensor measure vacuum? I'll play around with VCDS tomorrow.

 

[dweisel]

If there's enough vacuum to suck in water from OUTSIDE the I/C, then why won't 22psi blow it back out the same hole it got in through?

How are you planning to measure vacuum? Will you be installing a boost/vac gauge? There's no vac sensor in any TDI that I know of. Will the MAP sensor measure vacuum? I'll play around with VCDS tomorrow.

No need to measure the vacuum. I'm done............ both my 09's will be fixed on Monday when some parts come in at the dealership. There will be no more water in my intercoolers.

dweisel

 

[MayorDJQ]

So what's the fix?

 

[UberVW_TDI]

Yes, if anyone has any details of the VW "fix" please share.
I've talked to VW CustomerCare about this and they claimed to not have knowledge of what specific parts will be added/removed/changed.
I'd like to know the details of what VW came up with before I let the mechanics wrench on my car.

 

[UberVW_TDI]

It still seems weird to me that VW didn't catch this issue in product development?

Not to be too cynical but, for all the respect and hype given to the term "German Engineered." Shouldnt one expect to not have such design issues? (poor LP-EGR design & such a sensitive HPFP).

I really love my TDI, but I'm rightfully getting a lot of ribbing at work due to the fact that my new VW has issues in the cold weather.