W123 Cold start problems? Glow Plug Testing, Reaming and Replacement.

Рет қаралды 4,301

Жыл бұрын

Your OM617, OM616 as well as a multitude of other Mercedes diesels, and honestly diesels in general need a little extra heat to get going in the wintertime.
On these, the glow plug system is responsible for that, and non-functional glow plugs, or weak glow plugs can cause your cold starts to be troublesome, shaky, smoky or potentially no start at all.
When changing the glow plugs, it is wise to ream the holes, which is done by hand, very gently with a 7mm drill bit or reamer that has had the tip coated with grease to catch carbon.
The carbon buildup acts as a thermal conductor that transfers the heat from the glow plug into the cylinder head rather than into the prechamber where the heat is needed.
➡Bosch 80006 "Pencil style" Glow plugs for OM616/OM617 engines: amzn.to/3kqJ8p8
➡Hella Glow plug relay: amzn.to/3iSGfNd
➡7mm Drill bit: amzn.to/3ZKgwas
➡7mm Reamer: amzn.to/3koMxEQ
Links to products on the channel are very likely affiliate links, these earn me a small commission on the products that I already purchase and use, and best of all, it doesn't cost you a penny more while helping me fund making these videos for your entertainment and education!

Пікірлер: 26

@trythistv 10 ай бұрын

Bosch 80006 "Pencil style" Glow plugs for OM616/OM617 engines: amzn.to/3kqJ8p8 Hella Glow plug relay: amzn.to/3iSGfNd 7mm Drill bit: amzn.to/3ZKgwas 7mm Reamer: amzn.to/3koMxEQ Links to products on the channel are very likely affiliate links, these earn me a small commission on the products that I already purchase and use, and best of all, it doesn't cost you a penny more while helping me fund making these videos for your entertainment and education!

@Engineerd3d Жыл бұрын

I would look at the grounding strap on that engine as well.

@ryanking5727 2 ай бұрын

I ran into lots of trouble with my glow plug relay. The circuit board itself some how got some corrosion causing it to act intermittent. I tried to jump the resistors with a wire where the traces were damaged with a little bit of success but then blew the strip fuse and decided it was time to come up with something different. Even on a hot AZ day my car will drain the battery before it starts without glow plugs. I ended up using a starter solenoid off an old Ford. I used the original 12V hot wire that fed the glow relay as the feed for the solenoid. I believe this wire is already fused up by the battery from the factory. I then mounted the solenoid in place of the glow relay and made sure it grounded to the body. The output of the solenoid feeds to a mini 6 slot fuse panel I picked up behind the counter at Napa for about $15. This panel is rated for up to 20A fuses. I then ran a wire from the hot side of the solenoid to a switch I mounted under the dash which then feeds back to the S terminal on the relay. This line is fused, loomed, and ran through a drain plug under the carpet up by the firewall. I then snipped the original connector for the glow plug harness and ran each individual plug wire to its own slot on the fuse panel and gave each slot its own 20A fuse. To take it a step further you can then probe the connectors on the little plug that comes off the original relay, I believe it is a 4 or 5 pin connector. With someone sitting inside the car you can quickly determine which one when probed illuminates the glow plug light on the dash. Conveniently the Ford starter solenoids I terminal provides 12V accessory power when the solenoid is engaged. Cut the illumination wire and run it to the I terminal and you have your indicator light working when the glow plugs are engaged. This does a few things better than the original glow relay in my opinion. I don't know the exact number but from what I have read the original relay can leave the plugs hot for up to 30 seconds after the car has started to help with cold starts. If true this can accelerate carbon build up around the glow plugs and lessen glow plug life. If you have a short in the glow plug harness you risk blowing the strip fuse as I did. When this happens you lose all function of the glow plugs. Using the mini fuse panel you can have each glow plug running off of its own 20A fuse. When one glow plug shorts and pops a fuse you can still make it to work with the rest of them functioning. The only real downside being you have to manually press the button, but I find this to be a good thing. In the morning I only need to press the button for 5 seconds initially and the car starts fine and doesn't need any glow after that. If the engine is warmed up I don't need the glow plugs to start so I don't waste an entire glow cycle as you would with the original relay. The glow plugs put quite a bit of stress on the battery when glowing pre-start so I wouldn't be surprised if this also extends my batteries life. Not to mention on the off chance someone tries to jump start and steal my 300D, unless they know to press the button under the dash they are going to have a very difficult time getting it started.

@zdws19 5 ай бұрын

This is the best video I have found for changing glow plugs. Thank you very much.

@trythistv 5 ай бұрын

Thank you! A good set of glow plugs makes all the difference. I started my car up the other day to pull it inside for some service, it was about 9F outside I believe, it fired right up on the first glow cycle, coughed a couple times but smoothed out within a matter of idling for a minute or so, never stalled! I was quite proud of everything I've done to keep it healthy.

@javierramires2814 5 ай бұрын

Incredible your video just help me big time, you just explain what I was looking to find.

@trythistv 4 ай бұрын

Glad it helped you out!

@daveyvane9431 5 ай бұрын

Good. For tghe first time, this wasn't a nightmare!. Tip - you can slip a 3-4" length of fuel line over the 8mm thread end to ease the handling and initial threading into the chamber.

@trythistv 5 ай бұрын

Hey that's a handy tip! It can be miserable to get them started into the head sometimes with the injector lines on. Thanks for sharing!

@estefanofanhani 6 ай бұрын

Boa noite amigo mais um bom video explicativo. Retirei minhas celas do meu om617 para teste. São originais de 1980 . Estavam bem carbonizadas. Esguichei spray descarb no furo da antecâmara . depois dei a partida. A compressao do pistão expulsa toda sujeira. Mais a ideia da broca também é de grande validade

@trythistv 6 ай бұрын

Google translated: (may not be great grammar) Olá! Parece que você tem uma boa técnica aí! Ouvi dizer que os depósitos de carbono podem ficar muito duros e a broca irá raspar qualquer coisa que esteja endurecida, não tenho certeza se o limpador irá quebrar esses depósitos, mas poderia muito bem! Uma vez meu irmão tinha uma vela incandescente que estava presa, ela desaparafusou, mas não saiu da cabeça, então ele a deixou solta, ligou o motor e, depois de esquentar um pouco, ela tirou a vela presa, evitou muitos problemas se tivesse quebrado ou algo assim. Original: Hello! It sounds like you've got a good technique there! I've heard the carbon deposits can get very hard and the drill will scrape off anything that is hardened, I'm not sure if the cleaner will break those deposits up, but it very well could!. One time my brother had a glow plug that was stuck, it unscrewed but then would not come out of the head, so he left it loose, started the engine, and after it warmed up a little bit, it popped the stuck plug out, saved a lot of trouble if it had broken off or something.

@ThatOddLife 2 ай бұрын

Just got a 77 240D from a friend. Odometer stopped at 316k miles, glow plug light on dash comes on, but under 55 degrees or so, it struggles to start. Going to be doing this job soon

@trythistv 2 ай бұрын

A good set of glow plugs goes a long way!

@kermitefrog64 Жыл бұрын

I just had to replace my glow plugs on 2/18/23. It was starting hard and finally on 2/16/23 the glow plug light finally stopped coming on and I had to go through 3 times of trying to start the engine before it kicked over. The glow plugs were all carboned up. I replaced them with Monarch glow plugs from Mercedes Source and did a diesel purge and oh what a difference in the way the engine worked.

@kermitefrog64 Жыл бұрын

This is on a 1981 Mercedes 240d with a 4 speed manual.

@trythistv Жыл бұрын

It is remarkable how much difference it makes, even just knocking the carbon out of the glow plug holes will make the plugs vastly more efficient!

@vintage76vipergreenBeetle Жыл бұрын

👍

@michaelarmellino8334 8 ай бұрын

All my plugs measure 1.5 ohms, I have one plug that I just ordered to change. I’m in Canada would you recommend 9/32 7.144mm or 17/64 6.746mm? To ream.

@trythistv 8 ай бұрын

I would try the 9/32s bit, it should only be pulling carbon out, no metal, and of course as a reminder, do this by hand, no cordless drill or anything lol, and a little grease on the bit that gets cleaned off and replaced between holes to catch the carbon. If it won't go in without grabbing some metal, then go down to the 17/64 bit. I've heard up to 19/64 is ok, but that's the very absolute limit, and we don't need to go that far to accomplish what we need.

@michaelarmellino8334 8 ай бұрын

@@trythistv thanks for the reply will do!

@michalizurej925 Жыл бұрын

Hi . what happen if one have 13.4? is good ? or need to be change ?

@trythistv Жыл бұрын

13.4 ohms is bad in my eyes. You could pull it out and test it by connecting it to a battery (don't burn yourself!) But I would replace it, typically I like to see around 1 ohm or less, and that is what I would expect out of a new plug.

@MrRjnr 3 ай бұрын

how often should glow plugs be replaced?

@trythistv 3 ай бұрын

I'm not sure if there is a replacement interval, They can last for years, or can go bad in months depending on the quality of plug and health of the engine, injectors and stuff. For myself I change them when I notice a rougher idle at cold start, as that often indicates that one has failed, and I typically do an ohm test before it starts getting real cold just so I'm confident I won't have starting issues as soon as the weather gets nasty.

@Altanox 8 ай бұрын

İ'm so confused by these glowplug testing videos. My car does not have tbat box. 1979 in series glowplugs 300D european

@trythistv 7 ай бұрын

The series plugs are a bit rare over here, even my 1980 300SD had the pencil style plugs with the glow relay like in this video. I actually haven't personally seen a 617 or 616 that has the older style plugs. I do know a lot of people tend to upgrade to the pencil plugs and relay like seen in this video, but I'm not sure what is involved.