[BennnChen]

.

[D041987]

This may not be the full case as we are missing exactly what happened etc etc. but Piggybacks do not alter fuel trim, they just raise boost and let the ECU decide what is best. Sometimes this fails and other small things as well and fuel trims go out of spec which causes an even more lean condition and kaboom goes the motor! Although this is not fully proven as most say the boost levels that are provided by the piggy backs should be in the ECU range of correction but we all know that this is the typical case.

Our cars run lean from factory so it has been covered a lot to not push the N20 on a piggy back. Have you tried to get a full confirmation as to what exactly happened to the motor (what was the part that failed) other then them saying it ran lean? Do you have the warranty from Dinan and what do they have to say about this? Since BMW just pointed and said inadvertently Your Piggy back caused the engine to run lean and blow it up.

Did you have any logs prior on your car to see if the tune was good for the car? What gas did you run when this happened?

[CalCarNut]

Makes me want to fatten up my AFR..

[D041987]

Back end flash stacked onto the JB4 is safe option when running piggy back on our N20's. Or get a full custom ECU flash and call it good.

[LaCross]

Dinan_Engineering

[BennnChen]

.

[LaCross]

I would contact Dinan if I were you. The whole premise of their expensive products is that they're safe

[BennnChen]

Originally Posted by LaCross

I would contact Dinan if I were you. The whole premise of their expensive products is that they're safe

The new car warranty is already over, it's 4 year 50k miles and I'm at about 56k miles now

[mike@x-ph.com]

There a ton of N20/N26 engine issues ... It is even happening with stock cars.
This engine has defects.

Im sorry to hear about your issue OP

[BennnChen]

Originally Posted by mike@x-ph.com

There a ton of N20/N26 engine issues ... It is even happening with stock cars.
This engine has defects.

Im sorry to hear about your issue OP

Have you heard of anyone getting the engine replaced through warranty, something almost like my situation?

[F30MmmSport]

Sorry about the engine, and not trying to be a dick, but your posting history shows all sorts of engine issues in the past. You've also had more mods than just the Dinan S1 and intake.

http://f30.bimmerpost.com/forums/sho....php?t=1314994
http://f30.bimmerpost.com/forums/sho....php?t=1295164
http://f30.bimmerpost.com/forums/sho....php?t=1310507

I don't think it's fair to act like your car was operating perfectly and pointing the finger at Dinan and their tune. It sounds like you had a bad engine from the start.

[BennnChen]

.

[Polo08816]

Originally Posted by BennnChen

I have a N26 with the Dinan S1 and an Injen intake. I blew my engine and BMW is saying my car was running lean so I'm not covered under warranty. I never had a CEL saying I was running lean or anything. My car seemed to be running perfectly but I guess not since my engine blew. Has anyone heard of something like this?

You should have just bought a 335i and kept it stock. At least you would have been able to extend the warranty to 100k miles.

[mike@x-ph.com]

Originally Posted by BennnChen

Have you heard of anyone getting the engine replaced through warranty, something almost like my situation?

I have seen people getting it replaced under warranty. Not sure it applies in your case since your warranty expired.

[D041987]

Try working with the dealerhsip. Give them all the facts etc. 6K outside of warranty is not much and they can maybe do a good faith program with you if you are nice. Just reason with Service Advisor. Ask them what exactly failed. If they installed the tune etc have Dinan confirm it was there tune that blew it up etc. Worst case if nothing happens. Threaten to go to court and they will work with you. But I would not buy a engine from dealership. Best bet would be to either get a used engine and install it probably around 5k or have it rebuilt with forged internals and than throw a big turbo and spank on modded 335i's etc.

[madmortar]

Seems like something went wrong with the engine outside of the tune. Which sucks.
Also out of warranty so im not surprised they didnt cover anything. Thats the main point...engine out of warranty.

But for sure fight tooth and nail and figure out what exactly went wrong.

[BennnChen]

I still have the CPO warranty though

[Polo08816]

Originally Posted by D041987

Try working with the dealerhsip. Give them all the facts etc. 6K outside of warranty is not much and they can maybe do a good faith program with you if you are nice. Just reason with Service Advisor. Ask them what exactly failed. If they installed the tune etc have Dinan confirm it was there tune that blew it up etc. Worst case if nothing happens. Threaten to go to court and they will work with you. But I would not buy a engine from dealership. Best bet would be to either get a used engine and install it probably around 5k or have it rebuilt with forged internals and than throw a big turbo and spank on modded 335i's etc.

Who races in a straight line these days? That requires almost no skill at all.

[madmortar]

Originally Posted by BennnChen

I still have the CPO warranty though

Then how are they refusing your warranty?
They installed your tune.

In your other threads you said you were running rich, now engine is blown and you were running lean. Sounds like your dealership is a POS

[madmortar]

Also, with 17K on the line, I would have camped out until they gave in or at least gave you hard facts why the we're denying your CPO warranty.
Are they blaming DINAN? The intake? The charge pipe?

I wouldn't be surprised if they blamed the intake before they did the DINAN tune.

I would call DINAN ASAP too. As well as BMW North America.

[bradsm87]

Another piggyback "tuned" N20 bites the dust. Luckily, Dinan claim to offer a warranty for that kinda stuff.

[bradsm87]

Originally Posted by mike@x-ph.com

There a ton of N20/N26 engine issues ... It is even happening with stock cars.
This engine has defects.

Im sorry to hear about your issue OP

I disagree. Every single engine ever offered in a road car has a very tiny percentage that fail in stock form. The N20 is no different to most other engines in that regard. All of the N20 failures I've heard of were running the stock DME tune with a piggyback.

Piggyback tunes absolutely run an increased risk compared to flash tunes. They rely on reactive (sensed knock) rather than proactive (reduced timing target) knock control. They rely on fuel trims to get the fuel right, rather than higher DME load target and fuel scalars. They can't change the AFR target to something much safer in the midrange. The fuel trim safety margin is severely reduced. There are also many, many other safety-related DME tables that scale with DME load.