Breaking Down This HUGE L5P MYTH About GLOW PLUGS (Please Don't Do This To Your L5P!) 

Love the truck. But now we need a proper next morning cold start to see if it’s really working.

Great video. One breath you mention that these glow plugs are not good. They should probably be recalled since they keep failing at rapid rate. Next breath, mention how we should always replace with high quality oem parts, and get the same factory glow plugs. Is there not an upgraded higher quality plug available?

I just was a the dealer a hour ago. My number 2 glow plug is bad. There fixing it tomorrow under the power train warranty no questions asked its a 18 with 80000 miles

Awesome content brother love the channel as well nice job Denny

Hey Denny great video! I’m looking to replace glow plug number one. And I was just wondering if there’s a need to “relearn” the glow plug?

Love all the content bro! Def and egr delete is my dream for my l5p. You had any issues with your cameras working on any of the trucks? My camera systems stopped working and I cant figure out a fix for it. If anyone got a fix or the same issue let me know.

Good video man! Glad you did this... I’ve been seeing so much hype of deleting these. Seems so much easier and cheaper to just replace as soon as you throw a code! Keep it up

Was thinking about doing this, but will leave intact. Still need to get my block heater recall done. I wonder if they will sell the parts so I can do myself? I heard the way they bleed the system is run the dog shit out of it in park for several minutes, not sure if that’s true or not? Plus I don’t want them hooking into my ecm trying to do the dpf recall lol nothing there!

Never seems to trigger the glowplug code unless its a cold start where they really heat up. I didn’t realize the l5p had the issue with the glowplugs. My dad has a denali l5p too so now we know lol. That’d be so dumb to delete glow plugs. Lol

How many of these failures were due to not heating the block?

whe is it for sale.. i wanna buy

Do I have to worry about my 18 duramax glow plug if it is stock?

I say just let it nuke the motor. Enough of these happen and GM with have to do something about it

Serious question because I need to do my glows plugs on my 2017 . Are there better aftermarket glow plugs ? I’m not looking to cheap out , I will pay more . If factory AC Delco glow plugs are the plugs that they use stock and they are known to be defective how does replacing them with the same thing do me any good ? They are the same plugs I’m putting back in ? Did they fix the problem with the replacements I will get from AC Delco ? I’m not a mechanic and I don’t want to have to keep replacing them . Any insight to my question would be appreciated. Thx

Great video man, love the L5P content. I literally had 7 glow plugs replaced from the factory over the course of the first year I had mine. 2017 L5P. Dealer gave me an extra 10,000 mile warranty over the standard 100k.

So does the new glow plug need to be programed? From this video it appears thats not true but have seen lots of info online stating it does. I have a 2020 Chevy 2500hd l5p.

As gm parts technician i know those plugs are extremely fragile, if we drop one it goes in the garbage because its no good.

My theory is always buy the best parts you can find when working on stuff because your time is the most expensive part of the job and you don’t want to do it twice!

Hey man, thanks for the info on the firing order ! My #5 is bad and there is no info on the internet about this!

I have a 2017 duramax and have replaced all my glowplugs on it and a month later I already have a code coming up. I replaced all the glowplugs with Acdelco. Any suggestions what else could be going on?

I had 3 glow plugs replaced prior to 22k miles on my 2017. They also did an updated ecm flash in regards to changing the voltage perimeters to the plugs.

Brand new ac Delco broke the tip off on first start

What is the fix for the glow plugs that keeps blowing? Even after replacing with A/C Delco.

Nice video! How do I use the relearn feature after the glo plug replacement?

How do you warm the glow plugs on the new trucks with a push button starts?

I have a 2021 and my father has a 2020 ( 2500 ) Duramax high country Silverado. I have to say haven’t had glow plug problems he 20k & 13k miles on mine. Fingers crossed Haven’t had any issues yet

Could you please explain how the glow plugs actually work on the 2020 Duramax I live in Minnesota my remote starts truck right away no mater how cold

Denny do have the part number to that glow plug on the L5P? Thanks

Just like they did with the injectors with the LB7.

You Getting any random missfires?

Good advice on sticking with ac delco parts but why not just replace all of them at once.

Good video but you forgot to put Anti-seize on the threads Of the glow plug

I just replaced my #6 glow plug on my 07 LMM because of a code. I bought ACDelco but the guy at OReilley said his diesel guys tell him the way to not have problems is to use Bosch (at 2.5 times the cost). I believe my issue was corrosion on the power wire because the nut spun without coming off and was quite rusty. Had to break the stud off to remove it. Used a stainless washer and nut on the new gp

I've got 400,000 Miles on my 2019 durmax.. All original glow plugs, Popped a code last week for number 3 glow plug being out of parameter. Going to buy all 8 today and put them in, Just in case

Lets say Im in the middle of a trip pulling my 5th wheel and a glow plug codes goes off? Will your truck go into limp mode if have not immediately taken care of this?

The local Chevy dealer replaced 2 of my glow plugs under warranty. Cylinders 3 & 7 were reading high resistance so those were the only ones they replaced. I thought I was getting all 8 replaced but the bulletin does not allow that. The letter sent to me says they will cover replacing bad glow plugs on the 2018 model L5P up to 150,000 miles.

I been lucky with my 09 LMM, this winter I had 3 stopped working,so I just plugged the heater in, so soon as it warms up here in northern Ohio Im replacing all of them with GM OEM from Amazon

Just got a check engine on my 17 l5p. The codes were P06C5 and P0671. Im guessing its the cylinder 1 glowplug. How long can i drive with a bad glowplug or should i replace it and not drive the truck at all. New to diesels lol.

what is your view on pcv hose deleting?? venting to atmosphere?

I was under the impression that modern diesel glow plugs aren’t just for cold starts but can effect the warm running of these new engine designs vs the old school stuff.

I saw no mention of using Never Seize or similar on the GP threads. Also, having a comparison of new vs old GP's .. It looked from video like the tips of the old plug wore off/down

What was the code that your truck through when you replace the glow plug? Mine keeps throwing a glow plug offset and all they do is update and remove code.

I replaced all 8 of mine on my lml when one went bad at 60K. No point in just replacing one when another will go soon after. I’ve read on Facebook duramax forums about the plugs snapping off, but 1/2 the time the truck were in the salt regions & the engine areas where completely shitted up with rust & corrosion. Also put anti-seize on the threads, it’ll help you when removing the plug.

I recently purchased a 2021GMC 2500 Denali and the L5P is my first diesel. Any suggestions for someone brand new to diesels? Nonetheless, appreciate the videos. Please keep them coming.

I probably am going to delete my glow plugs. I’m in California always

Honestly if it's factory it has to come out not being bias of anything but whenever is on it when it rolls off the line is only going to be as good as the price tag so it would be a good idea to get that stuff out of it

Yes I completely get your point on this, the guys that are actually deleting these glow plugs for the fact of making more horsepower, they are seeing these plugs drop into the cylinder, I deleted mine already due to the fact that I am shooting for high horse power. I just installed the s400 kit, I’m here in wi and the truck starts perfectly fine at 0 degrees

Thanks for the great information and let us know the cylinder numbers so we know wish glow plug to replace and you just got a new subscriber.

I'm having this issue with my 3.0 Duramax. I've reset it twice!!

So the factory L5P glow plugs are a peace of sh-t, and you want everyone then go out and buy the same glow plugs that you are now calling the best glow plugs??????? I have a 1996 GMC truck with the 4.3l V6 engine, no telling how many OEM injectors I had replaced the first 4 years of its life. I would not sell it because I did not want to stick someone else with the problem. I even went so far as buying tow insurance to make sure it would be brought home. I would not drive it more than 55 miles from home. I think it has only 134,000 miles on it today. What solved my problem was buying a after market complete injector spider with 6 aftermarket injectors. Have not had to change a injector for the past 80,000 miles. GM knew they had injector problems with that year truck engine and just kepted replacing them with the same injectors. The complete aftermarket spider and 6 injectors cost less than 2 OEM injectors. How many times does the aftermarket companies have to slove the manufacture's screw up's??????????? Time and time again.

Is there a brand which is superior to GM glow plugs?

How do you tell witch one is the one that is bad we’re can I look up the code meaning

I have a 17' Duramax Denali just got the P0671

I have 2019 GMC, GM sent a letter about the glow plugs, "an unresolvable issue with glow plugs in the L5P generation of diesel engines", and did something like a 14 year warranty on the glow plugs. I've only had one replaced so far at 32,000 miles (coincidentally the turbocharger died at the same time).

Nice video. A little common sense goes a long way.

Wonder if NGK makes an upgrade glowplug?

do you need to go to the dealer to get the glow plug learned once installed? @denny Diesel

You're one heck of a guy! Thanks for the knowledge on the ol' L5P!!

That video helped me a lot man thanks what tune and exhaust do you have on your truck

Good content, thanks for taking the time to do these.

Did I miss the code? What is the code? Is it P133E?

What has been done to that truck? Suspension tires etc?

Might be. A dumb question but I need my #6 cylinder replaced on my 17 the dealership already did it once and I took it apart now to do it myself when I reinstall the new one does it need to be relearned to the gpcm? I saw online someone said it did? I was just gonna delete the code after installing and hope that fixed it my code is p133d

How many of these failures were due to not heating the block?

What is the codes for a glow plug ?

This video go help lot l5p owners

Do you need to re-flash or re-learn the glow plug after replacing?

i go through plugs like crazy

“Stock” 700 or 800hp yeah okay lol

Is that WCfab red under the hood?

I’ve owned many diesels and switched to a gasser.. missing the towing power with a diesel. Would you recommend an L5P as a daily driver/tow vehicle? I’ve had another diesel shop owner suggest the L5P is actually a pretty stout build in regards to GM. He went as far to say as reliable as an LBZ. 😳

Great videos. I appreciate every one of your videos that I’ve seen so far. Based on your experiences with the L5P platform do you have any regrets on purchasing one and would you buy another one over any of the big “3” heavy duty trucks?

I've heard L5Ps are garbage. Stop messing with duramax and get a 6.7 powerstroke that are better admit it !