wheelsloose

Boss,

did you ever change out your plugs yourself?

Bossnova3

No I just change the K&N filters. I've been using the truck with the stock plugs seems to be running fine. I've had a couple of things that I'm waiting some resolutions, but I'll update as soon as I get it resolved.

unix4linux

Just curious at how you guys are holding up with your tunes these last few weeks? Also, what would you guys do if you need to take the car in for service under warranty? Do you send your ecu back for a stick reflash? My only concern would be that if they either see that the ecu is not recognized and reflash it back to stock or if you advise them that you have a tune and not to reflash it that they'll flag you and void any future warranty. Thoughts?

patsy1099

You can instruct the dealer not to update your ECU but if it's a critical update then you really should have them update it......but that is a separate discussion from the warranty. If the ECU needs to be updated by the dealer because of an important software modification from MB, then you just need to make sure whoever you buy the tune from will give you FREE updates. Then when the dealer is done, just take out your ECU and send it back to the tuner. It's EASY to remove, 5 seconds. It's just a pain to ship and you are two days without your vehicle BUT your dealer should only have to update your ecu very seldomly.

Regarding voiding the warranty. This has been discussed many times over both in this thread and in many others. A dealer can't void your warranty for an ecu tune. They MAY down the road TRY to make an argument that an issue is somehow related to the ecu tune and therefore won't be covered but that is a huge stretch (IMO) for a ecu tune only and I haven't heard of it happening before and if it did I think you could fight it. I think the threat of this alone scares many people away.

patsy1099

Still loving the tune by the way. So happy I did it.

unix4linux

Thanks for your input. I sent mine out to RennTech yesterday. It should be here tomorrow. Looking forward to it. It's for my '14 GL450

patsy1099

I'm sure the renntech tune will be awesome as well. Did they suggest new plugs or just to run your oem ones?

unix4linux

They have not mentioned anything about upgrading the plugs. I will ask to make sure.

patsy1099

I would definitely ask. Are you putting the ecu back in yourself? Because then if you did plugs you would need to buy them and have someone else do them for you. Unless you're experienced I don't suggest you undertake that yourself. If you buy the plugs from Renn just know they charge quite the premium for them. I might have posted earlier in the thread but I can tell you what plugs to get and where if you want to have your local guy do it. Def ask Renn if they suggest going one step colder with the plugs. I'm surprised they didn't suggest that.

unix4linux

I'll see what they say and post back. And yep, I am putting the ECU back myself. I have quite the experience with engines so it's not an issue with me. Try changing spark plugs on Subaru's

However, feel free to let me know which plugs you used. It would save me some time researching that. I have a 2014 GL450 (just FYI)

Thanks for your responses

patsy1099

well mine is a 2013 but I can't imagine anything has changed. The engine/tranny is the same. The plugs sit deep down once you remove the coil packs. You will also need a special star socket (snap-on has it) to remove the oem plugs. This is what I went with:

- NGK spark plugs (you will need 8 of them), stock# 93026 (DILKAR8A8) – these plugs are high performance and run “1 step colder” than the current OEM plugs (which for your reference are MB# A0041596403). Best place to purchase the NGK plugs are online at ngk.com (which ironically is NOT NGK’s website but a company called Monarch…..). They are $21 each. One important note. The tech that I spoke to at NGK (the actual plug manufacturer not the website) said that you should NOT gap the plugs since they are pre-gapped and should be left that way. He also said that they should be installed with 10-15 ft/lb torque and not any more, regardless of what the MB tech manual might say. He said if you don't use a torque wrench then it should be hand tight plus another 1/2-2/3 turn. That's it!
- K&N Air Filters – part# 33-2474 - having these installed by my mechanic (the dealer might also do it for you for cost of labor) - you need two filters but they are sold in sets of 2 so you only need to purchase 1 set of these. Cheapest I found was $74.45 on Amazon: Amazon.com: K&N 33-2474 Replacement Air Filter: Automotive Amazon.com: K&N 33-2474 Replacement Air Filter: Automotive
Results:

unix4linux

Thank you very much!

patsy1099

welcome. post back on how you like the Renn tune.

unix4linux

My ECU will be here today but a quick update:

• I asked about the plugs and the air filter and they recommended them for consistent power through the entire range
• The boost levels go from 11.6 to 15.95 psi
• You can gain from 2-3 extra MPG (of course if you cruise)

patsy1099

That's what I thought. I'm surprised they didn't offer that to you when you purchased the upgrade and why you had to go back and ask them the question. Anyway, you can buy from them or the links I gave you above (which will be far less expensive). Either way let me know how you make out. Good luck!

unix4linux

I received my Renntech ECU Friday and got everything completed over the weekend (ECU install, spark plugs, air filters). I am very pleased with the performance of the vehicle. The outcome is phenomenal and happy that I chose Renntech. I know they are more expensive than the other tuners. However, this is an $80k vehicle that I have invested in. If I have any issue with the ECU, I needed a company that has been around for more than just a few years and that is likely to continue to be around for years to come.

I was lucky enough to go in person and check out the place and the work they do there is awesome. The fact that most of their R&D among other things are all in-house proves invaluable when looking for reputation. That is just my thought and happy with the overall process and assistance I received there.

patsy1099

unix that's awesome. Thanks for the update. Glad you like the tune. Good luck with it and keep us posted.

TOURIN

I am looking forward to my tune in 2 weeks and after reading your thread I am even more excited about it! Are the plugs that necessary? I live in Alaska with a lot colder climate, but I'll bring this up with my dealer. Renntech sells the air filters for this also, but more cost than the K&Ns that I am familiar with. Thanks!

jasonjeross

You need to rethink that statement. Not only CAN it void your warranty it DID void your warranty.

Let's see:

You are "over boosting" your engine (ignore the fact it may be able to handle it, you are now running with more boost than was offered by the factory calibration).

You are likely running a leaner air fuel ratio now. Oh wait, I'm sure Tuner X,Y,Z all spent countless hours on the dyno with wideband air fuel meters. Just like you installed a wideband in your truck and monitor it right? Of course not.

Oh, the car runs "good/great" now right? What happens when your transmission's torque converter starts slipping? How's that differential? Oh it's OK because the tune didn't cause that right? Actually it's quite easy to prove it did.

I'm sure you fell for the "we can just flash it back to stock" if you have to take it in for dealer work right? Guess what, that will be painfully obvious in multiple ways to detect. It also is a massive PITA to wait for some mail order tuner to reflash, send it back, then drive your truck to the dealer (if it even drives after whatever damage you incurred).

I can't disagree enough with your posting (or lack of general mechanical knowledge).

FYI: K&N filters? Really?! Spend 10 minutes googling.

jasonjeross

And when you pop a piston or burn up the transmission you will hear nothing other than the multi-thousand cash register ring up at your dealership.

Ask them for dyno sheets, air/fuel readouts, what type of dyno was used, how many miles were their calibrations tested, etc. I'll be shocked if they offer any of that.

jasonjeross

You are asking questions about spark plug heat ranges to guys that don't even know how to change their own spark plugs.

Honestly, without a data logger and a wideband air/fuel meter no one on this board will have that answer.

You guys are playing with fire on seriously expensive vehicles. I can't advise enough to abort.

Dalema

Wow. I was going to ask if you got up on the wrong side of the bed this morning given all these posts on this thread, but then I saw you only just joined the forum and with your recently activity -it's flame city. Anyway, each to their own style I guess.

Is there a reason for your strong opinion - have you been burnt by this before? I figured it must be something.

So - you have an objection to tuning the 450 engine to 550 specs? I thought they were the same engine and that's all a lot of tuners are doing - pulling the 550 mapping.

TOURIN

Well to clarify, I did talk to my dealer today and specifically asked about warranty issues. Service and sales both told me there are no issues at all. They stand behind Renntech(that's why they chose to be the dealer) and the tune fully. I do know a bit about supercharging engines being an old drag racer. But yes, you can have all the power in the world but if you can't get it to the ground it does you no good. Transmission, and the entire drive train are all covered, and safe.

BlownV8

The dealer or manufacturer can't void your warranty unless they can prove that your modifications directly caused the damage or failure. The onus is on them. See
Magnuson–Moss Warranty Act

jasonjeross

Good luck with that. I'll bet money you will hear crickets from whatever "tuner" shop you use and MBUSA will be happy to deny your warranty claims. IF nothing happens, great! However, something of this magnitude should be left for people outside of their warranty OR have deep pockets for the inevitable.

I'm not "trying to flame", I'm trying to inform. I used to own a firm that recalibrated pcms for another manufacturer. I speak from experience.

What's the old racer's saying? Fast, cheap, reliable. You can only pick two.