AMGRay

I'm looking to tune my recently acquired 2020 GLB 250 4Matic.

Anyone in the US tuning these cars? I'm not looking for anything crazy, extra 50-70hp.

Thanks!

Serhan

I wouldn't do it due to the potential leaking valve seat in cylinder head for 2019-2021 models esp when car is under warranty:
https://mbworld.org/forums/glb-class...ml#post8648095

It is better to get a GLB35 for additional hp...

tbirdvet

If the tuning means increasing the boost I would not do. The engine cylinder head gasket and other parts may not tolerate the increased cylinder pressure.

skullbox15

It's not even worth it. It's like trying to take a lawn mower engine and make it a faster lawn mower.

There are a few threads around here about some complete failures of the GLB 35 engines.

Stay away from tuning this platform.

AMGRay

If I wanted faster, I would have kept my modded GTR R35. I bought the GLB 250 replace my aging WRX. Anyhow, I'm just looking for a little more passing power. Every vehicle that has caught my attention has issues or nearly guaranteed to have issues in the near future, domestic or imports.

skullbox15

Passing power would be nice. I feel you there. I'm still trying to figure out how long I'm going to keep the GLB. As others mentioned, there have been some reports of major failure under 50k miles. Weight your options carefully. I'm not sure how much "safe" room there really is for HP gain on this engine.

AMGRay

I didn't think much about it when I bought the GLB, I just assumed since I've had good luck in the past with Mercedes, it should be a reliable vehicle. So I never looked up reliability issues with it. The vehicles I did look up all had issues including with Porsche and BMW. You know the world is going to hell when you can't can't trust a German automobile

skullbox15

I agree. It makes a buying/keep decision harder. I think part of the issue is how much of the cars rely on electronics/software. God forbid the screens in the dash go out... you can't even drive the car. I miss the old school setup with buttons for the radio and "real" gauges. As these cars get more advanced there are more things to break and less things we can fix ourselves. Seems to be the new normal now. It's just a shame that for the most part, the materials and craftsmanship are less quality for the same price (or more ) and we are beholden to the dealers to fix anything.

E55Greasemonkey

I concur with the above sentiments. The GLB is a cheaply built entry level economy car. You can't make a race car out of an economy car. At the rate they are all burning through cylinder heads I wouldn't go put a tune on it. On top of that, when your cylinder head comes up for replacement, the dealer can and will void your warranty if they find out. All it takes is for them to pull the information from your engine ECU. Are you prepared to spend $5k on a cylinder head for your lawnmower?

AMGRay

Okay, you guys jinxed me!! LOL

The car popped a check engine light a few days ago and I dropped it off at the dealership this morning. Guess what it needs at idk, 23,XXX miles? Yup, it needs a new head...and their on back order.

As for cheaply built, I don't how cheap the build was for my 2018 G63 but get this, at 25,XXX miles, a lost a turbo, a module, and a couple sensors. They literally had to pull the vehicle completely apart...body off chassis and motor off frame! The tech was nice enough to send me some photos lol $150,000 SUV and only 3 yrs old! At what price point can I buy a Mercedes that will last longer than 25,000 miles??

skullbox15

That's insane. Sorry for you luck man. These threads really got me thinking about dumping this thing a year or two from now. I don't want to be stuck with a blown head when this thing is out of warranty. Not sure I'd buy another MB at this point. I just don't like where this brand is going... Making more expensive cars (and I don't even want to get into the whole EV thing...) with cheaper parts, loaded with electronics, and less reliability than the cars they produced a decade ago.

tbirdvet

Not sure why you feel you need more passing power. With the DCT trans and all the torque at 1800 RPM you should have excellent passing power.

AMGRay

The DCT is super nice that is for sure. Other than that, the tuning on the car is blah. The throttle pedal response in economy and comfort is slow. Response on the auto stop/start is lacking as well. It literally has to think about starting when you give it gas when its temporally turned off at lights. That DCT is amazing when the car actually decides to move. The delay on take off is painfully slow, you don't have to worry about hitting people running opposite red lights because it takes forever to move. The GLB placed my WRX w/6spd for daily/winter car. So I'm not used to a lot of bs drive by wire nonsense or delays on auto starts. Yes, my G63 has drive by wire and auto start/stop but its a lot more responsive. I should have bought the GLB 35 but I didn't want to spend the extra money on something that was going to be cover in snow and muck 6 months out of the year. That is why the tuning, I had hoped I could buy the more affordable GLB 250 with higher ground clearance and put a GLB 35 equivalent tune on it. The way things look, I should have kept my WRX, 90k, it was more reliable and responsive. I would have bought a new WRX but I hate the CVT trans their using. Its hard to find one vehicle that fits all and is reliable these days.

tbirdvet

There must have been a calibration change from early models to 2023. My 2023 has a very quick off idlle throttle response. It feels like my race car that I use to drive. i went back to the dealer to complain about acceleration vs pedal angle as being too quick. i was told that is the way it is now. I drive in C mode and it is this way. My auto/start function compared to my Lincoln is very quick and smooth.

Odd Piggy

I haven’t dug into the GLB250, but the throttle response on the MBs from early 2000s on was programmable. The accelerator pedal dead space and the throttle response curve could be set by someone who knew what they were doing. I would expect the GLB to be similar.

If they have, in fact, listened to buyer complaints, that’s great! Especially the start/stop. The start/stop on our ‘15 GLK350 was imperceptible. The start/stop on the ‘21 GLB250 was as bad as the BMWs from the early teens, a big step backwards.

lowwolf

Wow! I thought I was the only person ever to go from a WRX (2009) to a GLB250! I also want more power.

At the same time, though, I’ve also had the cylinder head fail at 20k, so I’m not sure about the robustness of these engines.

Please keep us informed of your progress. DM me if you find a solution.

ILoveNY

is the engine fail common on glb250?

what about the glb35?

Odd Piggy

Don’t know the percentage of engines that fail. Certainly not all of them but it’s enough to be notable. There is a known head problem in the manufacture of the head on the M260 used on the GLB250 & GLA250. New heads became available in about September of last year, so, hopefully, the problem is solved.

I haven’t heard about the GLB35 failing. It also has the M260, but head, valve train, and turbo boost must be different. The 221HP GLB250 has 10.5:1 compression while the 302HP GLB35 has 10.0:1 according to MBUSA.

Serhan

It is common enough to MB Canada to extend warranty for 15 years on GLB, but not common enough in US for MBUSA to extend the warranty on GLB...

It happens on GLB35 also. My MB service guy said they had one GLB35 fixed with the same issue. When I bought mine, there were only 15-20 GLB35's for sale in 500 miles radius in comparison to 500+ GLB250's. So GLB were rare till 2023. This year I see 95 2023 GLB35's for sale in comparison to 500+ GLB's in 500 miles...

Also most of the information that I posted came from A35 forum, so it happens on all MB M260/M264 V4's incl GLC300/GLE350 V4 turbo engines. That is why 2023 GLC300 has an updated V4 engine.

Vladimir Livson

Sounds like they did not fixed the issue on 2023 and 2024 models, except for C class?

ILoveNY

so should I import a GLB from canada? what do you think?

Vladimir Livson

Not sure that Canadian warranty would work in US. Wouldn't be easier to get an extended warranty, or getting a brand new car?

Odd Piggy

It won’t be covered by a Canadian warranty if you import it. Warranties don’t cross international boundaries because MBCA & MBUSA, etc, are different companies. And the M260 engine is the same regardless of where the car was originally sold because all North American GLBs are built by COMPAS in Aguascaliente Mexico.

Also, importing a car less than 25 years old from Canada is a real PITA. Canadian safety requirements are just enough different that modifications will have to be made to register it in the US.

M254 recently replaced the M264 in all the models using longitudinal engines. There is no comparable replacement for the M260 transverse engines in the A, CLA, GLA, GLB.

ILoveNY

even brand new glb didn't fix the issue?

Odd Piggy

New heads for the M260 became available in about September of 2022. I’m told that fixes the issue. Others say no. But the A & B cars and SUVs with transverse engines did not get a completely new engine. I guess only time will tell.