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long time reader, first time poster. Zeroing in on a GLK 250, and one with all the bells and whistles came up in my area for sale, 5K lower than typical asking. One catch engine warning light. he has apparently had it scanned and the result is NOX sensor.
now i know from reading this could be as simple as refilling the adblue or replacing the sensor, and could include adblue injectors etc. If I were to pull the trigger what is the absolute worst case (short of new engine ) i would likely encounter and the cost to do this.
I do my own car maintenance, so i short of major equipment needed i would expect to carry out the work so parts and specialty tools would be my costs - my time is free
Also i have a Blue Driver OBD2 scanner has anyone used this with a GLK and had success?
the niggle i have is as always if it was simple why not fix it himself and sell for more.
any and all advice is much appreciated.
Rusty
Location: Toronto, Canada Car: 2014 GLK 250, 155kms, CEL:NOx issue, buying from original owner, no accidents.
Last edited by RustyBucketBay; 04-25-2021 at 09:24 AM.
Reason: Car & location info
I can’t help on what’s wrong, I don’t know diesels. But on this group I’ve read a lot of people unhappy with the 250 emissions systems that are complicated, expensive to fix, and prone to continued problems. I think if it was a cheap fix he would have done it. Nobody lists a MB with check engine lights on, if it’s an easy fix.
@Mmr1 cheers. I’m having similar thoughts however: it’s got 155km so he won’t get top dollar for it, likely out of warranty hence his repairs are out of pocket, and if not a DIY car guy perhaps the $$ in repair costs out weigh the potential to sell for more to make up for the cost in repair.
As a self DIY mechanic I would always repair before selling.
I added car details to the end of my OP.
One thing I could do is adblue delete as Ontario has removed emissions testing. Not my preferred route but if anyone has ball park costs on it please share. That would be the assumed worst case fix.
Fix NoX sensors are 3K in Canada. If you dont it will have a start countdown and will brick your vehicle. Other option is delete the system + tune. But if Ontario has inspections it wont pass. I would steer clear unless they have it repaired at Mercedes first.
Fix NoX sensors are 3K in Canada. If you dont it will have a start countdown and will brick your vehicle. Other option is delete the system + tune. But if Ontario has inspections it wont pass. I would steer clear unless they have it repaired at Mercedes first.
3k good to know. What’s the Aprox DIY cost. Can’t imagine more than 100-200 for parts, or is there a rabbit hole of issues I could end up chasing. Eg replace nox sensor but still have issue because it’s doing its job and something else is the culprit?
With 3k in mind I can offer him a price if he fixes it and one if he doesn’t.
The other way way of looking at it is I could buy another one and 2months later this could happen anyway having paid ~5k more, plus repair $$ on top of that. The devil you know and all that.
Im not afraid of work, it’s the unknown chase and the reasonable cost.
3k good to know. What’s the Aprox DIY cost. Can’t imagine more than 100-200 for parts, or is there a rabbit hole of issues I could end up chasing. Eg replace nox sensor but still have issue because it’s doing its job and something else is the culprit?
With 3k in mind I can offer him a price if he fixes it and one if he doesn’t.
The other way way of looking at it is I could buy another one and 2months later this could happen anyway having paid ~5k more, plus repair $$ on top of that. The devil you know and all that.
Im not afraid of work, it’s the unknown chase and the reasonable cost.
Unfortunately it cannot be done DIY. I do everything myself and these stupid things are programmed to the car an need the Mercedes Computer to program them. I just went through this and i usually do everything myself. Ended up deleting all of it, but I live in Vancouver with no vehicle checks.
@C300fan2 wow that is awful. Talk about right to repair. It’s a sensor! I saw one trick to disconnect it from the pipe and dangle it into injector cleaner (Lucas fuel additive) overnight then spray it with carb/break cleaner and reconnect and it may work. Idea being soot/carbon has just built up on the sensor. But not being able to replace yourself is BS. Good food for thoughts.
Ontario did away with E tests in 2018/2019. Used to have to get my Mini Cooper done every 2 years. Apparently the tests were not solving any emissions issues etc. Think big artic trucks still have them but not general public. So id happily delete if the options are can’t repair yourself or engine won’t start count down.
If your set on buying it , it looks like you are, offer 4000-5000$ less and see what happens
im set on a glk 250. But only on this one if it’s a good price - to offset repairs. He’s asking 15k, i offered 12 he rejected that said he had a bunch of 12k offers.
Hes considering my updated 13.5 offer. I need to confirm a few things and see it in person if it’s been well looked after aside from this error. For 2014 155kms on the clock no CEL he could get 17/18k.
Im trying to confirm safety checks in Ontario. Believe can pass with CEL so long as it’s not ABS/SRS related. But also discovered a line about exhaust mods and adblue delete would likely red flag. So once I pass safety I can do a delete but not before.
Quick question. Is it safe (to the car) to drive with NOx issue?
C300fan said you will get a countdown timer and a bricked glk. Look it up. The countdown and problems are well documented as are 250 problems with emissions. You need to figure out if it could be a bigger problem than 3000$
If it was just NOX sensors and could be fixed cheaply then the owner would have done it. It's more likely that it has habitual problems with the diesel emissions system and the owner is wanting to unload it so it is someone else's problem.
It may look cheap now but in a few years you may look back on it as an expensive mistake.
Agreed with the above posters. If the CEL was easy to fix, it would've been done already. The last thing you want to worry about is buying a car that's going to be in "limp mode" until properly fixed, or worse, it will give you the "10 starts remaining" and then you're stuck somewhere.
My advice is keep looking. I would rather take a higher mileage vehicle that's running great, with good service records, than a lower mileage one with all kinds of problems.
all sound advice. I’m going to look at it anyway no harm in looking. And he said he is fine with me plugging in my own obd2 scanner to see if it confirms codes or sees anything else. Hopefully my bluedriver obd2 does a decent job scanning.
WRT passing the buck, he could very well be, at the same time as you’ve all said you need specialty software to adapt new sensors hence it’s 2-3k job at MB to fix. So Perhaps he is thinking someone’s else’s problem at good price is less headache for him to pay for and sell at no extra profit, so why bother.
As as a buyer being aware i have to weigh the possibility of fixing myself (software obd2 nox overide module, buying Mercedes diagnostic software to adapt new sensors, adblue delete, and perhaps literally clean the current sensor - something a mechanic might not try vs up selling 3k repair) against it going to Mercedes. If I’m 3k on the hook I think there is a happy medium if everything else is good.
I will say be biggest realisation from this discussion is the lack of being able to just replace a sensor and reset the system without specialty software. Like this could happen to any glk 250 I buy.
Get it looked over before you buy it. take it to mb or a real good mb mechanic. Look through archives here about emissions issues and contact someone that seems to know this stuff. At mb or even the mechanic in your area ask if they worked on it and it’s history. I think your going blind into something that might be a lemon and not worth it. At 100,000 there are a lot of different things that go wrong besides the open code
@Mmr1 appreciate the advice. I think you’ve convinced me otherwise. I’ve found another 2015 fully loaded inc tow hitch which saves me a job, only 75kms asking 23+tax. But it’s a dealer so I can finance/trade in if I wish.
I might let let the guy know if he gets it fixed I’d buy for 17k. It’s got double the mileage of this other one so I’d expect a better price plus private sale vs dealer.
Anyway I do appreciate all the info. I’ll eventually have one of these myself and if/nox goes I have a starting point.
Last edited by RustyBucketBay; 04-27-2021 at 10:17 PM.
Just wanted to wrap up this post. GLK was delivered today. Previous owner looked after it well and must have ticked every option down to the genuine leather and factory tow package. Absolutely delighted. As is herself, it’s her car after all, I am super jealous! Thanks for the advice steered me towards this beaut:
04-24-2021, 10:04 PM
) i would likely encounter and the cost to do this.
