GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV
VW GTI MKVI Forum / VW Golf R Forum / VW Golf MKVI Forum / VW GTI Forum - Golfmk6.com



Go Back   VW GTI MKVI Forum / VW Golf R Forum / VW Golf MKVI Forum / VW GTI Forum - Golfmk6.com > Technical Topics > GTI 2.0T Engine / Drivetrain / Exhaust / Tunes


Reply
 
Thread Tools Search this Thread Display Modes
Old 03-05-2018, 06:21 PM   #1
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
Help Troubleshooting After Decarb

Hey folks,

First of all let me say this is my first post here, I've read all the way through everything I can find in the forums and don't see anything remotely approaching my situation, but if I've missed something useful please let me know.

In July of last year I bought a 2012 GTI with 72k on it. Started noticing some misfires, mostly cold start, around 75k. Replaced plugs and then coil packs. Got a little better, then worse again. Misfiring all the time, no power, bad fuel economy...started researching and realized it probably needed a carbon cleansing. My friend is an engineer and a race car driver, and I'm an engineering student and love working on my car, so we bought a walnut blasting kit and said to each other, "how hard could it be?"

Nine hours later...we managed to blast the ports clean, get everything back together, and get the car started. It feels SO MUCH BETTER to drive. Yay, sort of. I'm still throwing a couple of codes and having a problem, and I'm wondering if anybody else has ideas/input on things I should check/try.

1) The car does NOT want to start without intervention. Initially I thought it was because we drained the fuel from the rail. But it kept happening after the first start. It appears something is going on with the "flappers" inside the manifold and they are staying closed when I try to start the car, which is sort of choking it. If I actuate the thing by hand and open it, the car will start.

2) I have a check engine light and two fault codes. One is for the manifold (P2014 I believe). One is a camshaft position sensor code. I have a crappy, $10 OBDII Sensor (a Vag-Com is on the way but won't be here for a bit) so I can't even view the code unless it's plugged in and of course I've already forgotten the number, but I have no idea why it would be throwing that and if it is even accurate.

3) The EPC light is on and I can't clear it with my crappy OBDII. I assume this is because I took the negative lead off the battery and it needs to be cleared with a better tool than what I have on hand?

Did anybody have these issues after removing your intake manifold (for a decarb or otherwise)? Called the dealership today and the guy told me there is, in fact, a warranty extension on that manifold. The thing was super gunked up and we didn't really bother cleaning it up, just replaced the seal. Seems far too coincident for it to be a random failure, and I don't know what we could have done to break the thing, but...it's not working. Have done a ton of work on my car and never had this kind of a problem so this is pretty embarrassing. I'm taking it in Thursday but wondering if there's something obvious here that I'm missing to check up on...or maybe I should just take a step back and let the "professionals" handle it.
SarahO12 is offline   Reply With Quote
Old 03-05-2018, 06:32 PM   #2
Boscogn
FIA GT Champion
 
Boscogn's Avatar
 
Drives: CSG 2013 GTI DSG 4DR
Join Date: Jun 2015
Location: San Luis Obispo, CA
Posts: 1,165
Just to confirm when u cleaned it you turned the camshaft to close the intake valves before you blasted? Also on manifold did you clean injectors?

I want to say the manifold has an extended warranty to 120k I would tell the dealership ur getting a code and play dumb. There is a revised intake manifold with better design. Generally I always recommend people carbon cleaning to replace the intake manifold with updated part as it's only $150 and another $40 for injector seals.

Edit: I've been waiting for my intake to duce so I could get it replaced under warranty and get a cheap carbon clean. Although at least under warranty you don't have to worry about taking off ur manifold again.

Sent from my Pixel using Tapatalk
__________________
Wish List: Golf R InterCooler | Unitronic or IE CAI | P3 Air Vent Boost Gauge | 034 Motorsports RSB
NOTE: Please PM me if you are selling anything in my wishlist! Also check out my Build Thread!

Last edited by Boscogn; 03-05-2018 at 06:38 PM.
Boscogn is offline   Reply With Quote
Old 03-05-2018, 06:40 PM   #3
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
Yes, we taped off three ports and only worked one at a time, turning the crank until they were sealed. We did the walnut blasting method so everything else was also taped up as well. Then we used compressed air/vacuum to make sure everything was clear before moving to the next.
None of the injectors came out with the manifold so I didn't replace seals, but I did clean the tips of the injectors. That was mostly laziness, knowing we both had to come to work today and we were so exhausted we just couldn't deal with it. We replaced the main (orange) seal where the manifold meets the head.

It does go to 120k. I was not smart when I called the dealership and I admitted to being the one who did the cleaning, but not sure if he caught that. I didn't know about the warranty issue until last night or I would have just dumped the money into a new manifold and done it all at the same time. If the dealership won't replace it I'll likely go that route.
SarahO12 is offline   Reply With Quote
Old 03-05-2018, 07:29 PM   #4
Boscogn
FIA GT Champion
 
Boscogn's Avatar
 
Drives: CSG 2013 GTI DSG 4DR
Join Date: Jun 2015
Location: San Luis Obispo, CA
Posts: 1,165
Ok cool. Just trying to rule out any error on ur part but it sounds like you did it right. Also u only need to replace injector seals if ur installing your old injectors into a new manifold.

Yeah I would keep mum about the cleaning and just see if they won't replace the manifold under warranty. If they mention anything just say you had it carbon cleaned to fix the rough idle and cold start misfires.

Sent from my Pixel using Tapatalk
__________________
Wish List: Golf R InterCooler | Unitronic or IE CAI | P3 Air Vent Boost Gauge | 034 Motorsports RSB
NOTE: Please PM me if you are selling anything in my wishlist! Also check out my Build Thread!
Boscogn is offline   Reply With Quote
Old 03-05-2018, 07:55 PM   #5
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
My thoughts too. Was hoping it would be something super obvious that we got tired and didn’t think of. I’ll just hope the dealership takes care of it for me on Thursday...!
SarahO12 is offline   Reply With Quote
Old 03-05-2018, 09:23 PM   #6
GroceryGTIer
Rally Car Newbie
 
Drives: 2013 black Wolfsburg
Join Date: Dec 2017
Location: Tri-state
Posts: 316
Is the manifold flapper popped out? If you've researched this, you've likely seen that, but I'm just wondering.
GroceryGTIer is offline   Reply With Quote
Old 03-05-2018, 11:06 PM   #7
BudgetPhoenix
FIA World Rally Car Champion
 
Drives: 09 GLI
Join Date: Jul 2016
Location: Bay Area
Posts: 641
Whats the cam sensor code? That could be playing a big part.
BudgetPhoenix is offline   Reply With Quote
Old 03-05-2018, 11:58 PM   #8
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
Quote:
Originally Posted by GroceryGTIer View Post
Is the manifold flapper popped out? If you've researched this, you've likely seen that, but I'm just wondering.
It's not "popped off" per se (we watched a Humble Mechanic video on youtube and it doesn't look like that), but it's not actuating when throttle is applied. That's being done in neutral, so perhaps it would in gear...I don't know. But it just gives a little twitch at high rev and that's it.
SarahO12 is offline   Reply With Quote
Old 03-06-2018, 12:05 AM   #9
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
Quote:
Originally Posted by BudgetPhoenix View Post
Whats the cam sensor code? That could be playing a big part.
I went back out and hooked the thing up so I could screenshot the codes. Again, totally crappy sensor, but it's the one I've got.

P2014 Intake Manifold Running Position Sensor/Switch Circuit

P0343 Camshaft Position Sensor "A" Circuit High

The first one makes sense given that we were just effing with the intake manifold, but I don't get the second one. I am a pretty huge car noob so I have to do a lot of googling before things click. I know that's one we messed with to get the manifold off so perhaps we damaged the thing or got dirt in the connector?
Edited to add: I found the sensor and blew it out with some compressed air as that's all I've got. Put it back in, cleared the code...comes right back when I restart the engine. As I understand it could be a wiring issue but I don't think I have the ability to test that...

Last edited by SarahO12; 03-06-2018 at 12:16 AM.
SarahO12 is offline   Reply With Quote
Old 03-06-2018, 12:40 AM   #10
BudgetPhoenix
FIA World Rally Car Champion
 
Drives: 09 GLI
Join Date: Jul 2016
Location: Bay Area
Posts: 641
In my experience, Signal high sensor sensor codes is wiring issue or a faulty sensor, and a bad cam sensor could def cause running issues or cause a car not to run at all. Not sure about the p2014 tbh, usually p2015 is most common intake manifold fault, but manifold can fail in multiple ways and cause running issues as well. Myabe double check all the wiring connections and harnesses to the intake mani, and make sure vacuum lines are hooked up correctly.

Last edited by BudgetPhoenix; 03-06-2018 at 12:46 AM.
BudgetPhoenix is offline   Reply With Quote
Old 03-06-2018, 07:24 AM   #11
GroceryGTIer
Rally Car Newbie
 
Drives: 2013 black Wolfsburg
Join Date: Dec 2017
Location: Tri-state
Posts: 316
Quote:
Originally Posted by SarahO12 View Post
It's not "popped off" per se (we watched a Humble Mechanic video on youtube and it doesn't look like that), but it's not actuating when throttle is applied. That's being done in neutral, so perhaps it would in gear...I don't know. But it just gives a little twitch at high rev and that's it.
It will sound stupid, but are you sure you plugged in everything back after decarb? There's a lot of little plugs that you can miss. Like the little plug on the opposite site of the flapper control, to the right of the oil filter?
GroceryGTIer is offline   Reply With Quote
Old 03-06-2018, 12:40 PM   #12
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
Quote:
Originally Posted by GroceryGTIer View Post
It will sound stupid, but are you sure you plugged in everything back after decarb? There's a lot of little plugs that you can miss. Like the little plug on the opposite site of the flapper control, to the right of the oil filter?
Not stupid, I actually pulled the oil filter yesterday, unplugged and blew out that plug, and plugged back in. We put some dialectric grease on the plugs because they were so hard to get off during disassembly. I wonder if I should try to repeat on all plugs.

We noticed as we were taking it apart that someone has been in there before us and it appears they were somewhat heavy-handed. So I would not be surprised if a wire/harness was damaged.
SarahO12 is offline   Reply With Quote
Old 03-06-2018, 03:06 PM   #13
RAT TAT TAT
Passed Driver's Ed
 
Drives: 2012 GTI DSG 2 door APR S1+ v2.4
Join Date: Jan 2012
Location: NYC
Posts: 10
got a 0343 code on start ups. Cold starts didnt sound great, and when starting the car warm, it would crank and not catch and the check engine light would come on along with the EPC light.

without testing the two outer leads (of the 3 leads in the harness) on the wiring harness of the camshaft sensor for 5V power (which is how to tell if the issue is power or ecu related) I changed the Camshaft Sensor with a $22 auto zone one (dealer wanted like $60 after tax) and voila!

I had been doing troubleshooting with APR for some time with my v2.4 file and they had sent out an APR mobile dongle to do some logging, but after changing that cheap little sensor, the car feels like it never did.
The stage 1+ v2.4 file is pulling as it should, and shifting (dsg) and drivability issues seem to have been cleared up.

Furthermore, the car starts right up and sounds great, cold or warm.

For $22, you cant go wrong as a first step at troubleshooting.

Autozone part # SU12964
RAT TAT TAT is offline   Reply With Quote
Old 03-06-2018, 04:08 PM   #14
SarahO12
Passed Driver's Ed
 
Drives: MkVI GTI
Join Date: Mar 2018
Location: Seattle, WA, USA
Posts: 8
Shoot! I’ll grab one of those on my way home. What you’re describing is EXACTLY what is going on now. It will crank and not catch several times before it finally starts.
SarahO12 is offline   Reply With Quote
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


All times are GMT -4. The time now is 01:39 AM.


Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.