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2007 GTI won’t rev over 3k *Fixed*

BbbyBld

New member
Location
USA
Car(s)
2007 GTI
Reversing the rear hatch security override did nothing.

I had some time to mess around with the car again. I thought I was on to something because others with my P0321 fault had the same symptom and it went away after replacing the g28 sensor. I pulled g28 and the end was covered in bits of metal. I cleaned it off and reinstalled. I really thought that would fix it.

The main problem is still there, but I wasn’t getting that fault code anymore after several driving attempts. I thought it was possibly a problem, but not the problem. I decided to pull g40 for inspection and it was also covered in bits of metal. Cleaning g40 also did nothing for the main problem.

I finally forced the P0321 fault to come back by holding the accelerator down at the point where it the engine stutters.

I know it’s possible that g28 needs to be replaced, but it seems unlikely to me. It seems like if that sensor failed I would have other problems. I’m thinking about replacing g28, but I’m afraid it’s just a waste of more money.

I’m not sure about what to check next.
 

BbbyBld

New member
Location
USA
Car(s)
2007 GTI
I decided to Seafoam the fuel and intake and then replace AFM coils and plugs with OEM. I didn’t have a lot of hope for this, but was planning to do it anyway. This did not fix the issue.

I‘m trying to keep this updated in case someone else has this problem in the future.
 

BbbyBld

New member
Location
USA
Car(s)
2007 GTI
I may be getting somewhere now. I replaced the fuel filter. I was holding off because it looked like it was replaced recently and the fuel pressure didn’t seem low, but I was wrong. That filter was oem. It seemed like the issue was getting better after driving a bit to the point of becoming intermittent. I can actually hear the turbo spool now and the ECU is allowing some boost. I think I will start doing some logging again later today.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Do the logging...MB 231 if you do. I wold like to see the low pressure through a rev range. I think it may be the LPFP...but not sure you've changed it before or not. Been inattentive recently.
 

BbbyBld

New member
Location
USA
Car(s)
2007 GTI
Do the logging...MB 231 if you do. I wold like to see the low pressure through a rev range. I think it may be the LPFP...but not sure you've changed it before or not. Been inattentive recently.
I tried to do some logging today, but I keep getting the G28 fault, the car goes into limp mode, and it breaks the VCDS connection and stops the log. That fault keeps coming back. I posted a while back about inspecting/cleaning it. I ordered a new one today.

The LPFP is on the list, but I need to rule out G28 first.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Generally, when the G28 has been replaced and it doesn't fix the code...you need to check power to the sensor. I wouldn't decide the G28, by the oil cooler, is OK. The G28 volt check...you can check and confirm it is correct. I believe VW spec is 5v.

But, ....it can be something else. This damage was found to be the problem with another that would start and run. But it wouldn't rev very high and would then limp. Removed the oil pan and found this;
ono.png


...not sure if you find yours to be damaged that that portion can be purchased separately from the crank. It does appear to be removable:
p0321a.png

https://www.ecstuning.com/b-genuine...XuS1HMFPoMrQBUYjRnrhWhDlzHktLvtRoCxgwQAvD_BwE
 
Last edited:

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
I'm not...trust me.
It would kill me as well if I was having this code and were stuck trying to resolve it.
I'm just making you aware of the only other resemblance I know of when one was stumped...so you are aware should you find no other resolution. I'm wishing for you better than this. ;)
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
So it was the G28? Better than a damaged "whatever that is in the pic I posted."

Did you check its volts or just replace it?
 

BbbyBld

New member
Location
USA
Car(s)
2007 GTI
I just replaced it, but I would have checked voltage if it didn’t work. Obviously the old one wasn’t dead because it idled and ran perfectly. I guess it can just wear out. Maybe the output logic level was on the edge and was out of range at higher RPM’s or something like that.

I went on an extended test drive today. It was my first chance to enjoy the car since I got it back in April.

I still have a lot of plans...LPFP, timing belt, diverter valve, etc...then on to mods.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Sounds right. Every sensor or coil I have replaced on my mk5 was due to it fading from existence.
 

Pudding

Passed Driver's Ed
Location
UK
The engine will still start and run just fine with a dead crank sensor, because it substitutes G28 with G40 (cam sensor) to 'guesstimate' crank position. That can only work up to a certain speed though as the cam sensor has a very low resolution tone wheel, hence the forced 3000rpm limit.

That damaged crank tone wheel in the pic above looks bad! The gap on the right is normal though. It's a standard VAG 60-1 missing tooth tone wheel.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
The engine will still start and run just fine with a dead crank sensor, because it substitutes G28 with G40 (cam sensor) to 'guesstimate' crank position. That can only work up to a certain speed though as the cam sensor has a very low resolution tone wheel, hence the forced 3000rpm limit.

That damaged crank tone wheel in the pic above looks bad! The gap on the right is normal though. It's a standard VAG 60-1 missing tooth tone wheel.
I didn't know it was one tooth shy, but that gap must be so the sensor can read the engine speed, yes?
They never posted what caused the damage, but apparently it was damaged enough to cause the same code.
 

Pudding

Passed Driver's Ed
Location
UK
The missing tooth is the 'synchronisation gap' sir. The ECU uses that gap as a zero point (or 0 degrees) and then counts the teeth from there to figure out crank angle, if that makes sense?

It looks like some struck that part of the tone wheel? But that is hidden under a windage tray normally, so maybe it's tool damage removing it? Anything hard enough floating around in the engine to cause that much damage, would cause other damage, surely?
 
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