I found a 2014 GL350 out of state that was exactly what I was looking for. Tow package, 65k miles, southern car. I had it inspected by lemonsquad. No issues reported. Clean car fax. Just normal wear. I don’t like independent dealers but this place sold only high end cars, even some lambos. I figured I wouldn’t get nickeled and dimed. I negotiated with the dealer, made a deal, and it was delivered yesterday. I took it out for a drive. Within 5 miles the check engine light was on.

I text the salesperson. He is shocked. 🙄 “It’s probably just a sensor, no big deal” he says, “take it to Autozone and get the code.” The dealer was closed so I went to Autozone and got the code. P229F NOx sensor Circuit Range/Performance (B1S2)

I have an appointment at my local MB dealer on Monday.

I think they deleted the code before the inspection but I could be wrong. My only recourse if they don’t pay for the repair is a negative review. How pissed would you be?

@BenjaminPQ Diesel or gas?

Diesel

Not pissed as you should have had it checked before hand and they should have then checked if a proper driving cycle has been complete and any codes stored...

USED car...

I had it inspected.

Also, do you think it’s appropriate to erase a code right before an inspection instead of fixing the actual problem? I wouldn’t do that.

Did you not research the nightmare known as the adblue system, or the tendency of that diesel engine to sludge and seize? I'm sorry to be the bearer of bad news, but I would never recommend to buy any Mercedes diesel built after 2006. This unfortunately is just the beginning of the complete failure of the adblue system, which generally begins failing around the 70k mile mark. The repairs often meet or exceed the value of the vehicle. The MB dealership you're taking it to Monday will hopefully be upfront with you about the many failure modes of the adblue system, if nothing else to cover themselves. Even if it's just a bad Nox sensor, or both of them, you will be returning to see them when the next component fails.

Yes, I researched it. I live in a county with no emissions checks and will delete the the def, egr, swirl, and dpf as soon as it gives me an issue. I may even do deletes proactively. As far as the sludge goes, the egr delete will help but I will
also do oil changes a every 5k miles.

Thank you for your concern.

Don't forget to use only the MB specificied oil, and oem filter as well. I'm guessing you'll be doing the deletes after your estimate on Monday. At least you know what you're getting into. 👍

I’ll use the best stuff I can find!

I had a Toyota Sienna that supposedly was a sludge engine. I maintain my stuff for the long haul so I never had a problem.

@BenjaminPQ Sorry to say, but it was a mistake to buy a Bluetec. There are endless posts from multiple users on this site, over a period of time that say, “do not buy the diesel”.

Your options are this point are to sell it, or dive in and transform it (delete everything + tune) into something somewhat useable. Both paths have potentially significant costs.

As I said above, I bought it with the intention to delete.

IF they deleted codes...
you would know since it would show the car did not complete a driving cycle....

If it completed a driving cycle (certain amount of miles speeds temps gear etc.) then the check engine light might have come on if they deleted it.

So your inspectors were weak and probably only looked and did not really inspect.

Could have had car brought to any MB dealership and they could have inspected.. for small fee

I figured I wouldn’t get nickeled and dimed.

This is a flag for me.........trusting someone that works at a dealership or used car lot? That was the first mistake!

@BenjaminPQ OK, in that case, you shouldn't be angry. You knew you were buying a basket full of problems, and you intended on addressing those problems by deleting equipment and tuning the ECU. So far, you are on track to achieve your goal. Do you agree with this?

Trust? No. It was just part of the calculation.

So I should be mad at both the dealer and inspection company?

It looks like the nox sensor might still be under warranty. I’m taking it to the local MB dealer on Monday to find out.

Under the federal 8/80 emissions warranty? Hmm...that'd be nice!

Yes? No?

I know you said you owned a 1MZ-FE engine that was prone to sludge, but that is a terrible comparison relative to what you've gotten yourself into now.

Best of luck to you - I hope it is covered by the 8/80 warranty!

The OM642 can be an incredibly reliable engine under the right conditions. Get on a Sprinter forum. I will strip all the emissions stuff off, change the oil every 3 to 5 thousand miles and drive this thing until the road salt eats it.

If you have the owners manual pouch there should be an additional booklet explaining the federal emission warranties and what is covered.

If you have this figured out, why are you asking us who to be angry at? The OM642 might be a reliable engine with a tune and a bunch of modifications. My point was it is not at all comparable to a Toyota MZ engine.

This post was about buying a car and having check engine light come on within 5 miles. It was quickly hijacked by the diesel police.