'15 Jetta TDI after phase 2 mod

[devmike]

'15 Jetta TDI

Looking for direction(to the right pages) to regain the lost power and ~8-10MPG.

Bought the car in '15 at 0 miles, now in '19 with 65k.

After phase 2 completed in '18, the car runs roughly, with slower acceleration and has markedly lower MPG previously ~52-57, now ~38-47 MPG, same driving.

I personally noticed that if I turn on the AC the MPG drops real low, like a direct effect of lower MPG, turning it off MFA rises slowly to around the ~47 range, where did the power go?

What did they do to my car? And how do I fix it?

Also, there is an insane rattle inside the car around 60-65 MPH on the driver's side(maybe a loose nut plate or misplaced bolt), its the type of rattle that is bothersome because it wasn't there before the VW Mechanics paid me to ruin my car.

 

[devmike]

The car horn - inop

Oh, yea, The car horn, doesn't work now either - any good replacements available? I had it replaced by VW once, but it broke again.

 

[Zawurah]

Haul the car back to VW dealer, tell them your woes. Some users had ECU reflashed. Most have been ignored. But whatever they do, have them put down your complaints in writing (even if they do nothing), so then you have record of notifying them.

 

[Radek]

Don't have high hopes for getting your power and mpg back unless you tune it, my car is the same and was told they don't have any different tuns and no reflesh is available

Sent from my SM-G935U using Tapatalk

 

[Uberhare]

Buy a spare ECU from a wrecked car that never had the update. Chip tune that version and enjoy

 

[turbobrick240]

Buy a spare ECU from a wrecked car that never had the update. Chip tune that version and enjoy

It's not so easy to swap ecu's back and forth on the '15's. You'd end up paying a tuner a whole lot, if you could even find one willing to do it.

 

[HPsenicka]

Bought a 2015 Passat TDI in December... didn't notice any particular issues, but applied a Malone Stage 2 tune last week, and am very happy with the improved performance and driveability so far.

 

[ritsco]

Had mine done (they did do a reflash) and didn't notice any loss of power or drop in MPG. It does sound as though you may have some other issues going on. I would check under the hood and make sure the mice haven't gotten to the wiring harness.

 

[Lightflyer1]

Oh, yea, The car horn, doesn't work now either - any good replacements available? I had it replaced by VW once, but it broke again.

I personally would try and get your car to one of our trusted mechanics for a going over. Tens of thousands of other cars have had the same info loaded into them with little to no change for them. I would predict you have something else going on that maybe got screwed up when the tune was done. You have at least 4 or 5 close to choose from.

 

[740GLE]

Buy a spare ECU from a wrecked car that never had the update. Chip tune that version and enjoy

With "component protection" i think hot swapping ecus died quite a while ago, every module in the car is looking for the same vin/ecu to play nicely otherwise no go.

Think of it as VW's version of DRM.

 

[MGCJM]

you say you just completed the phase 2 mod - and now wonder "What did they do to your car? ". Did you save your invoice with the list of repairs itemized ? I am about to take my 2015 passat in for my phase 2 mod - and want to know what to ask or be prepared for. Can someone please share their document here on the forum?

 

[Steve140]

Get a tune and delete. I took my VW money after the fix and spent it getting my car really fixed. No regrets. More power, more reliable and better fuel economy.

 

[Lightflyer1]

Once again don't just jump in and suggest tune and delete when you know nothing yet about what is going on or what his state requirements are or anything. Also there could be something else wrong with the car that has absolutely nothing to do with the tune at all. The first rule of getting a tune is get the car running perfect first. This isn't the case here. A review by a knowledgeable mechanic is called for, not a tune and delete.

I am surprised when someone has a flat you don't recommend a tune and delete to fix it.

 

[740GLE]

not sure what you're getting at, a tune and delete fixed my flat tire and burnt out headlight, LOL.


Did they do an alignment after the fix? I heard the jetta is a bit more invasive than other platforms for getting parts in and out. What's your tire pressure? check the belly pan, they may not have replaced all hardware and it's flapping around.

 

[Lightflyer1]

Seems like every time there is an issue someone just jumps in and says "get a tune and delete and fix it" when it may be something else entirely. First identify the issue then fix that. Then if you want a tune and delete get one. But the OP is driving a 15 Jetta which has tens of thousands of cars with the "fix" done with little to no trouble. I would suspect something else happened at the "fix" that is causing the issue other than the "fix".

 

[devmike]

So I should tune it and delete, seems to be promising.

I'll check out the belly pan and see what they did under there.

 

[Lightflyer1]

So I should tune it and delete, seems to be promising.

I'll check out the belly pan and see what they did under there.

About a $1k bill at least to do and against the law (Federal at least) and should easily void most of your warranty and you may have trouble even getting anyone to even work on the car as they become liable as well for the delete if they do anything with it. It still may not fix the issue if the current "fix" tune isn't the real problem. Expect VW to wash their hands of you as well. They will probably refuse to touch the car again blaming everything on the tune and will enter it into their system so other dealers won't be able to touch it either. Your choice, but why not have it looked over first by a knowledgeable tdi mechanic.

 

[yahmon]

Buy a spare ECU from a wrecked car that never had the update. Chip tune that version and enjoy

Why not tune the one that's in it, just did one 2 days ago

 

[Lightflyer1]

Because some people want to cheat and change out the ecu and then claim nothing has been done to the car, when actually it has. Same as tune swapping using one of the boxes for that purpose. But they can now tell that now as well. If you do it then claim it and live with the benefits and consequences that go with it.

 

[yahmon]

About a $1k bill at least to do and against the law (Federal at least) and should easily void most of your warranty and you may have trouble even getting anyone to even work on the car as they become liable as well for the delete if they do anything with it. It still may not fix the issue if the current "fix" tune isn't the real problem. Expect VW to wash their hands of you as well. They will probably refuse to touch the car again blaming everything on the tune and will enter it into their system so other dealers won't be able to touch it either. Your choice, but why not have it looked over first by a knowledgeable tdi mechanic.

1K?????!!!!!!! Not sure how you ad that one up

 

[devmike]

The Delete is like $600 and the tune another $400, plus Malone needs to prep the clutch for the increased power with a $350 kit ~$1k

 

[devmike]

I get what your saying Lightflyer1, I do regularly take my ship to VW to have the maintenance done and they'd likely notice the headers off the engine with smoke stacker exhausts out the sides..

 

[yahmon]

did tune delete for 300 the other day, the guy doing his own exhaust work. you can also do a tune without delete making it drive-able again

 

[Lightflyer1]

You can also probably work up something with paperclips and duct tape for pretty cheap too.

The Malone stage 2 with no delete is $549. Flashzilla another $180. I would imagine an "off road" deleted tune would,be more. Plus new hardware for the delete. Labor to do all the work. I would say at least $1k US. Tried to go to AA Rodriguez site but got a Norton virus warning so no prices for hardware.

https://safeweb.norton.com/report/show?url=http://www.aarodriguezcorp.com/&ulang=en

 

[yahmon]

Up to you to pay that much, if a guy gets a bit crafty he can gut the DPF and remove the cat himself and save tons of money. However some people prefer wasting it.

 

[devmike]

From what I understand the EGR is the major fault zone in the environmental fix by directly recirculating the soot from the combustion cycle right back through the EGR to the engine resulting in hotter engine and collection of all that lobster mash collecting and substandard diesel engine performance.

 

[devmike]

So blanking plates halting the EGR recirculation might work by sending that "90x the legally EPA allotted soot" back into the environment, though, I never saw black smoke coming out my pipes before the fixes, only the lower engine performance after.

 

[yahmon]

So blanking plates halting the EGR recirculation might work by sending that "90x the legally EPA allotted soot" back into the environment, though, I never saw black smoke coming out my pipes before the fixes, only the lower engine performance after.

A tune can take care of your egr by just turning it off.
no blocking plates needed unless the tube is removed

 

[ZippyNH]

NEVER put a tune on a car that isn't running right....will just be harder to fix.
fix the problem...then tune.
MANY FIXED cars run PERFECT. Read the threads. Something is going on with your car.

 

[dodgeit]

There's nothing wrong with the OPs car. Mine (2015 jetta) lost 6-8 MPG measured at every fill up after phase 1 and did not improve after phase 2.

It is also low on power, have to manually downshift to merge into interstate.\

Observations since phase 1.

Fuel quality seems to have went down, which would account for the occasional better tank mileage seen (3-4 low).

After phase 1, best mileage was at 70 mph or lower (low,low 40s)

After phase 2 best mileage is 78 mph or higher (mid 40's).

been to two different dealers both checked out car and said nothing wrong. However they have seen intakes clogging up with soot from EGR, causing problems.

Lastly DEF regens take 30-40 miles out of a tank full. Mine regens at least 3 times per tank. That is 90-120 miles of range lost, which accounts for the 6-8 mpg loss in MPG.

Before fix there was maybe one regen per 600+ miles.