www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW MKVI-A6 Golf family including Jetta SportWagen (~ 2010-2014)

VW MKVI-A6 Golf family including Jetta SportWagen (~ 2010-2014) Discussions area for A6/MkVI (2010-2014) Golf and Golf Wagons (Jetta Sportwagon in the USA).

Reply
 
Thread Tools
Old November 15th, 2014, 06:52   #1
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default P026A code this morning

My car threw a CEL this morning, but absolutely no difference in drive-ability. It was about 27 degrees F out, and I have the winter covers from IDParts installed. My car is also Stage II with the delete. After doing some searching on here I can't find anything definitive pointing to what it could be. Anyone have any ideas? On my simple OBDII reader it read as "Fuel Air Metering", but from what I have read on here it has something to do with the charge air cooler and the flow. Any guidance is greatly appreciated guys!
__________________
YukonLT is offline   Reply With Quote
Old November 15th, 2014, 06:59   #2
yatzee
Veteran Member
 
yatzee's Avatar
 
Join Date: Jan 2004
Location: Montreal, Qc
TDI(s): see sig
Default

likely intercooler freezing

http://forums.tdiclub.com/showthread.php?t=302863
__________________
2015 Passat TDi 6 spd, 2005 C230 6 spd, 1994 E280 5 spd, 1991 405 mi16, 1986 190e 2.3-16

Please use the search function
yatzee is offline   Reply With Quote
Old November 15th, 2014, 07:08   #3
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default

Quote:
Originally Posted by yatzee View Post
I've read all about that, and my car has that kit already. But, with the deletes I haven't ever heard of anyone having that issue.
__________________
YukonLT is offline   Reply With Quote
Old November 15th, 2014, 17:12   #4
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default

No ideas from anyone? I checked everything out on the car and all seems fine. It is running normal too...I'm at a loss
__________________
YukonLT is offline   Reply With Quote
Old November 15th, 2014, 18:07   #5
da.hs
Member
 
Join Date: Jul 2012
Location: SK, Canada
Default

Do you by any chance have the air intake piece removed so as to get air from the "warm" engine bay area rather than straight from the front grille? Dealers do that sometimes on VW instructions as a way of reducing IC icing. In conjunction with the winter front it can cause the issue you describe - due reduced air pressure in the engine bay (happened to me in second winter, before revised intercooler "cold weather kit").

Or are the winter front peices blocking the cold air intake a bit?
da.hs is online now   Reply With Quote
Old November 16th, 2014, 11:59   #6
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default

I'm starting to think its something to do with the front covers I put on. Gonna take them off and see what happens. Will this code clear itself after a couple drive cycles?
__________________
YukonLT is offline   Reply With Quote
Old November 16th, 2014, 12:15   #7
VeeDubTDI
Good Ol' Boy
TDIClub Enthusiast
 
VeeDubTDI's Avatar
 
Join Date: Jul 2000
Location: Springfield, VA
Default

P026A = charge air cooler efficiency below threshold.

This is likely due to your winter front blocking air flow over the intercooler. The ECU isn't satisfied with the temperature drop and is throwing a code for it.
__________________
TDIClub Chat: irc.freenode.net ##tdiclub
VeeDubTDI is offline   Reply With Quote
Old November 16th, 2014, 23:32   #8
TDI_Coast2Coast
Veteran Member
 
Join Date: Sep 2009
Location: Lehighton, PA
Fuel Economy: TBA
Default P026A code this morning

Quote:
Originally Posted by VeeDubTDI View Post
P026A = charge air cooler efficiency below threshold.

This is likely due to your winter front blocking air flow over the intercooler. The ECU isn't satisfied with the temperature drop and is throwing a code for it.

What he said....

Good news- you're not going to ice up your IC with that code.
Bad news- you're closer to detonation. You don't want to drop that efficiency too far.
Probably too cold to be an issue, but the code is telling you your IC is relatively hot.

And I can tell you why you are getting that code I think...

Normally that cover wouldn't throw a code. But you already have a cover on your intercooler. Kind of. It's called your TSB IC. Or cold weather intercooler...Whatever you want to call it.

That intercooler TSB, in short, reduces the efficiency of your IC below a set ambient temperature. I don't know the exact temperature, but I guarantee your IC is running in bypass at 27F, meaning it is less efficient already. That's what your TSB does. It reduces the surface area of the IC coil via a bypass controlled by a t-stat.

So now you put another blanket on it...So your IC efficiency dropped even further.

If you had the stock IC, you would be less likely to get the code. And you would have more power.
__________________

- 2010 Jetta SW 6 speed manual / DG SS kit -- Escort 9500ci - Vag-Com(hex+can) -
Snow Methanol Injection - Malone Stage 2
TDI_Coast2Coast is offline   Reply With Quote
Old November 17th, 2014, 04:11   #9
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default

Thanks for the help guys, much appreciated. I took the covers off this morning for the ride to work and have decided to just keep them off.
__________________
YukonLT is offline   Reply With Quote
Old November 17th, 2014, 05:22   #10
TDI_Coast2Coast
Veteran Member
 
Join Date: Sep 2009
Location: Lehighton, PA
Fuel Economy: TBA
Default P026A code this morning

I think that code pretty much says if you have the TSB IC, you probably shouldn't block off. Probably not going to damage anything, but in actuality, you may be negating any gains.

See if I can explain a little better.

With stock IC, if you block off, you save some heat from the radiator(and the IC), so the engine can warm up faster AND stay as close to the state where the coolant t-stat wants to open as possible, but not open. 190F say. If your t-stat does not get to that state, you need to cover more. Once the t-stat opens, you covered too much and are negating any gains, the more you cover past this point, the more you negate. In a perfect world, you would have variable veins. that would sense when the t-stat opened and would block off the radiator...a Cold weather grille kit. Hmmm maybe a new product?

Let me explain the problem with the TSB IC that I just realized.

As you found out, you can't run a winter cover without a code, which is telling you that you aren't cooling your compressed intake air very well basically. This is just bad for your turbo. Not as bad when it's cold, but compared to an IC that is working more efficiently, it is definitely adding stress to it. The colder it is, the less stress, but IMO, any added stress will shorten it's life. It's life. Stress kills.

Here is where I thought at first the TSB would act like a winter grille. It kind of does. BUT the TSB has a bypass that just goes around the internals of the IC, so that IC on the outside is not blocked, therefore the radiator will flow freely and cool the same. IC will be hotter, but since it's still colder than the radiator, that is not going to help you radiator keep warm. It is going to add HOTTER intake air. That in itself is going to help warm you up, but not as well as blocking off.

Here is the problem. You're IC is already blocked off INTERNALLY. Now if you block off, you reduce airflow over the IC, which already is bypassed internally. So I can actually see that IC getting pretty hot. You will warm up faster, but you are generating such high IAT's, that you are actually probably losing power/economy, plus cooking your turbo...call it slow cooking.

I'm pretty sure if you have the TSB, a winter cover will HURT your mileage once the car is warmed up initially. Will help it warm up super fast(high IAT's). But the second you reach temp and the coolant stat opens, you are risking possible(highly unlikely) detonation if those IAT's get high enough. Which gets me thinking...

Ahh, you may have figure out, by accident, why people detonate their motors...What happens if the bypass sticks open on the TSB IC, past the set temp? Or the the TSB IC bypass t-stat doesn't read correctly?
__________________

- 2010 Jetta SW 6 speed manual / DG SS kit -- Escort 9500ci - Vag-Com(hex+can) -
Snow Methanol Injection - Malone Stage 2
TDI_Coast2Coast is offline   Reply With Quote
Old November 17th, 2014, 06:33   #11
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default

Hmmm, I wonder how hard it would be to remove the TSB IC kit. Since my EGR is deleted out, there is no use for it now it seems. I wonder if Malone does anything different with the tune if the car has the TSB IC kit? Can they even tell is they are just shipped the ECU? Many questions...
__________________
YukonLT is offline   Reply With Quote
Old November 17th, 2014, 07:20   #12
TDI_Coast2Coast
Veteran Member
 
Join Date: Sep 2009
Location: Lehighton, PA
Fuel Economy: TBA
Default P026A code this morning

If you have had an IC event, and your intake manifold is still plugged in, you still kind of "need" it. EGR is only part of the issue. The most important part is that you assure you have no intake restrictions. It's the intake restriction that is the main cause for the IC "icing", IMO. No intake restriction, no need for TSB.

You may be able to eliminate the bypass, but I'm not sure what the ECU would think when the IAT's numbers don't jive. I assume the t-stat function for the TSB IC is added to the ECU via software update. So if you were to bypass(block off) the bypass somehow(allow flow through entire IC) and a tuner could tune out the t-stat(basically undo software from TSB), I would think it would be eliminated. And car would act as if it had stock IC. I could be missing something, but that should work.

As long as the TSB IC(when bypass is closed) has the same efficiency as the stock IC, you should be fine. And below set temp, better.
__________________

- 2010 Jetta SW 6 speed manual / DG SS kit -- Escort 9500ci - Vag-Com(hex+can) -
Snow Methanol Injection - Malone Stage 2
TDI_Coast2Coast is offline   Reply With Quote
Old November 17th, 2014, 09:35   #13
VeeDubTDI
Good Ol' Boy
TDIClub Enthusiast
 
VeeDubTDI's Avatar
 
Join Date: Jul 2000
Location: Springfield, VA
Default

Coast2Coast, the IC kit is a thermostatically controlled flap that bypasses 80% (approximately) of the intercooler when the ambient temperature is below 40 degrees (approximately). This all mechanical - there is no software or sensors controlling its operation.

You're saying that the grill covers are making it doubly hot, which isn't really accurate, because with the grill blocked, the kit should not be in bypass mode.

As for high intake air temps, they will not cause "detonation." These aren't gasoline engines. The engine will not be harmed with these high intake air temperatures, it will just be less powerful.

I would recommend opening a portion of the winter front for the bottom grill. Open just enough to pass enough air over the intercooler to prevent the code from triggering. This will allow you to retain the fast warm-up characteristics as well as keep your fuel economy up as much as possible.
__________________
TDIClub Chat: irc.freenode.net ##tdiclub
VeeDubTDI is offline   Reply With Quote
Old November 17th, 2014, 10:50   #14
TDI_Coast2Coast
Veteran Member
 
Join Date: Sep 2009
Location: Lehighton, PA
Fuel Economy: TBA
Default

Sorry, I should have worded it better. I'm on the phone/taptalk...hard to type lol. I didn't mean to give percentage of heat gain from the grille to be blocked. I just meant that if you block your grille, you are in essence blocking some airflow(external) away from the IC radiator. If you do that, you Decrease the efficiency of the IC. So the IAT's go up. That I don't think we can argue. Forget the bypass, if you have stock IC.

So we agree stock IC with blocked grille will be just a wee bit hotter. Not much, never gonna notice. But higher IAT's offer less power at same boost. Can we agree on that? Now how much, just higher or lower.

Now add the TSB. It isn't bypassing the outside, if I understand correctly. It is just bypassing the coil(internally...important). So the size of your IC coil is smaller and you said it bypasses 80%??? If so that's crazy if it that thing ever sticks open when it's 100degF you are at full boost and your intake has malfunctioned.

100F air pressurized to 25psi....That has to get pretty hot right. I need to get my charts one of these days. Anyway, my point is. At 25psi, it's going to be HOT! If that bypass stuck, 80% of IC is not helping get rid of it. If your intake manifold is failed (which is why the IC kit is in there to begin with...just pretend Intake flaps are stuck shut.), then you have NO airflow. No air = no air out. I hope you are on the train already, cause this heat train just went down a hill with no brakes.

No air out is important. x volume of intake=x volume of exhaust. Can we agree? That is a valid equation? We have the variable of fuel, but just to make it easier in discussion, let's say coasting down a hill in gear...so fuel is removed from equation for now.

If we agree that equation is correct, let's play with it.

100cfm in = 100cfm out. Check mark, smiley face
50cfm in = 50cfm out. Check mark, smiley face

Ok, now let's complicate it just a bit.

Let's give some value of heat to the cfm, tells us useful info for volume, we don't know if it's 100F or 1000000000F.

Let's just say 1:1 cfm to joules. Keep everything constant in the environment.

So 50 cfm has 50 joules, 100 has 100, etc. I'm just trying to show the heat flow, heat in = heat out minus losses.

So if we flow more air we can carry more heat. Bigger exhaust, it gets out faster. But we have a problem? If what I said was correct, then my exhaust should be 100 joules. Let's just call it 100F, the intake air temp. It's definitely way hotter. Oh that's right the fuel!

We took that intake air, boosted it at 100F to 25psi. We took 80% away from IC if bypass sticks. So what we can't remove stays on the heat train.

So god only knows how hot that intake air is. Now add fuel, with very little air because of a bad intake manifold. You have a rich mix, afterburn, high egts. Bad stuff yo! Unless you went to a tuner and had something taken out. Once that is gone, you can get rid of all that heat, with it, it's got nowhere to go (of course some loss but mostly inside exhaust piping) for a while...Low pressure egr stuck open, with a malfunctioning egr cooler....Rut row. That's some hot stuff going straight into an IC that we already agreed is much less efficient with bypass open. Exhaust flap stuck closed....it's like driving over the GW bridge trying to get out. If everything goes right, it's ok, but too many cars(heat), especially when you keep adding them, can't go anywhere if you keep closing lanes and exits. You get a pile up of heat. Watch a rush hour traffic jam....It builds and go backwards. Always more heat towards the end of the restriction. But if you don't clear the traffic ahead, and keep adding cars, eventually you get gridlock. No movement of HEAT.

So let's think about detonation. I only brought it up, because I swore in the IC thread I read someone say they detonated, but I, like you, said no way....But the code you diagnosed got me thinking. And you saying 80% only strengthened my suspicion.

Covering up a car with TSB can REDUCE efficiency enough to trigger a CEL. What happens when it's hot? Now this is where I would think ECU would step in at some point with IAT sensor, but I am ignorant of when ECU steps in. I would think it would be able to avoid it.

It sounds simple to undo TSB then. Just shut the bypass and have a good day!
__________________

- 2010 Jetta SW 6 speed manual / DG SS kit -- Escort 9500ci - Vag-Com(hex+can) -
Snow Methanol Injection - Malone Stage 2
TDI_Coast2Coast is offline   Reply With Quote
Old November 18th, 2014, 04:57   #15
YukonLT
Veteran Member - TDIClub Enthusiast
 
YukonLT's Avatar
 
Join Date: Nov 2012
Location: N/A
Fuel Economy: Good
Default

I wonder if just blocking the upper grill for the radiator would help at all...
__________________
YukonLT is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Code P00AF this morning mkvme VW MKV-A5 Golf/Jettas 5 February 1st, 2013 12:55
This morning..... VOLKSWAGEN_JETTA_TDI VW MKIV-A4 TDIs (VE and PD) 4 November 12th, 2010 19:42
Code P0673 and P0674 every morning vk_bigTDI TDI 101 6 April 1st, 2010 10:42
vegi oil on Good morning America tomarow morning mainer Alternative Diesel Fuels (Biodiesel, WVO, SVO, BTL, GTL etc) 6 May 26th, 2004 16:49
4'F this Morning! master cylinder VW MKIV-A4 TDIs (VE and PD) 20 December 4th, 2002 13:34


All times are GMT -7. The time now is 12:43.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.18477 seconds with 11 queries
[Output: 137.46 Kb. compressed to 115.85 Kb. by saving 21.61 Kb. (15.72%)]