Diesel engine glow plug replacement - Mercedes Benz OM642 Glow plug replacement C, E, G, R, S Klass

Showing my approach on how to change safely the glow plugs on the OM642 3.0 V6 Mercedes Benz Diesel engine

[@4xAbuse]

This engine (OM642) calls for the engine to be brought to operating temperature before removing any plugs. At least in the '08 Factory Service Manual for Jeeps.

[@winstonbrown1516]

EVERYONE..., watching this holds their breath when you start to turn that wrench!

[@FrenchConnectie]

Thanks Alex.... Changing my injectors on my Viano V6... Might as well do the Spark plugs as well!

[@James-um8pq]

Thank you Alex for the Brake fluid tip, good video

[@isakisak7310]

Very thorough explanation and very helpful video. It seems you have to be very careful when changing these plugs. If they break off it would be a nightmare. I don’t think I’m confident to do it myself but I’m worried that a garage will not be as careful with the replacement as you.

[@AlexAndreiZAR]

Thanks for the appreciation. You just have to bite the bullet and do it like I've done it. Thanks for taking your time to watch my KZbin video.

[@isakisak7310]

@@AlexAndreiZAR Thank you for the encouragement. Much appreciated. I might have a go!. Thanks again for sharing the video. Best wishes.

[@Jeff-tr2vp]

Use an impact wrench and the night before soak the glow plugs in penetrating oil.

[@em4703]

I always used a torque wrench set to 20-25nm max to remove them, so that I dont go too hard and break them. Luckily they all came out, but if they didnt, i would not go over 25nm. (From tests they sheer off at 35nm). If they’re still stuck, this is when this method of 50%brake fluid-50%acetone mix would come into use. Thanks for the video, this is not something to force out. Patience is everything

[@akoshutoczki3284]

Thank you for the video. Can the brake fluid cause any damage in the combustion chamber? I have never heard of this trick but my plugs are tight as anything so have to think of a solution...

[@AlexAndreiZAR]

That is why you need to blow out the brake fluid with compressed air. The brake fluid that creeps on the threads is not much. As a matter of fact, it is in negligible quantity. Once the glow plugs are out, crank the engine for a couple of seconds. It will spit out any excess out of the combustion chamber, if there is any excess present. Also, disconnect the sensor on the left high pressure fuel ramp so that the system doesn't inject any fuel.

[@bmouthboyo]

Hi Alex, was you getting any EML light for the glow plugs? My E350 is failing DPF regen but with no error codes or EML, so wondering if could be this and how best to test. Thanks

[@AlexAndreiZAR]

I had Engine Check Light on. Dpf regeneration is stopped if regeneration prerequisites are not met. Faulty glow plugs don't allow for the DPF to be regenerated.

[@ianduckworth8595]

Thanks

[@AlexAndreiZAR]

Thank you sir!

[@fixingproblems3183]

I am getting glow plug number # 3 open circuit error with check engine light ON. I replaced the battery and cleared the code. Do you think it’s my battery causing the issue or glow/controller ?

[@AlexAndreiZAR]

Hi. I can't say for sure. You need to check the glow plug it's self. Check it with a multimeter for resistance or continuity. Do a scan with Xentry or DAS (depending on your vehicle). For good measure, if I were you, I would replace all the glow plugs and put in a new glow plug controler if the error is still in place after changing all the glow plugs.

[@alexandrutache3515]

Salut Alex! Cele mai top videoclipuri de mentenanta pt 3.0 cdi de pe youtube!! Am facut revizia completa uitandu ma la clipurile tale si totul a mers ceas, ba chiar nu a fost asa de complex pe cat am crezut prima oara. Acum m-am trezit si eu cu un check engine si eroarea - Cylinder 3 glow plug circuit malfunction, asa ca se pare ca urmeaza sa fac si eu ce arati aici. O intrebare: am gasit dupa codul de mercedes atat bujii Bosch cat si Beru, la 55 ron bucata. Merita sa dau 156 ron bucata pentru originale mercedes sau cele originale sunt facute de unul din cei 2 producatori? Si apropo, poti recomanda un site unde pot comanda scule, sau un brand de calitate?

[@AlexAndreiZAR]

Salut. Cumpara bujiile pe original. Eu asa am făcut, altfel dacă vrei o varianta mai ieftina alege BERU... cele originale Mercedes sunt făcute de BERU. Suspectez sa fie ceva diferenta de calitate. Cat despre scule, mergi pe Yato, Gebo... sunt scule mai de clasa medie, având un raport calitate preț decent. Nu vreau sa fac reclama, dar eu majoritatea sculelor le cumpăr de la magazinulcuscule.ro, gebotools.ro, selectauto.ro, blacktools.ro și cricul îl am de la BJC Tools București (undeva pe strada Lanternei, dai un search pe google și dai de ei). Bafta și mulțumesc frumos pentru vizionare și comment.

[@rahulsoni6652]

Hi Alex which is cylinder 3 and 6?

[@AlexAndreiZAR]

Hi. Standing in front of the car and facing the engine you count the cylinders as 123 on your left (right of car) and 456 on your right (left of the car). 1 and 4 ar towards car front. 3 and 6 are towards the cabin. Cheers

[@bpy4073]

Ive been tol my number 5 plug needs replacing but which one is number 5 cheers from the uk

[@AlexAndreiZAR]

The middle cylinder on the driver side. Replace them all. It's best for you and your engine

[@em4703]

@@AlexAndreiZARnumber 5 is on passenger side in the uk, they got their driving side on opposite compared to rest of europe

[@jeffreystork6530]

i wonder where the pvc tube is going????? not by the inlet turbo! but were do you put=it

[@AlexAndreiZAR]

Watch my other videos. You will see. It is routed before the airfilters so that it gets prefiltered. Having it in this manner the intake system doesn't get oil vapours like it used to have, therefor less issues with clogging up by exhaust soot and oil vapors. Oil vapors and exhaust soot clog up the intake system.

[@jeffreystork6530]

That’s a great idea 😊

[@duncanpoundcake]

Where is the pcv valve tube routes to. It doesn't seem to be in the Y-Plenum 🤔

[@AlexAndreiZAR]

@damehyndman5526 watch my other videos on this topic. It has been rerouted to an oil catch can and after that into the airboxes before the airfilters. This reduces hugely the oil vapours in the intake system, no oil will gather in the intercooler and no oil will mix with EGR soot particles in the intake manifolds. This means the intake manifolds will be clean, exhaust gases will be cleaner, the dpf will live longer. Only downside is that airfilters need to be changed every 7000km and oil catch can needs to be checked and emptied regularly (once every 1000km).

[@duncanpoundcake]

@@AlexAndreiZAR Interesting. Shall have a look 👍

[@seankellogg6154]

Hi Alex, what issue(s) we’re you having to cause replacement?

[@AlexAndreiZAR]

Hi Sean. If you take a close look at the video you can see a bad glow plug coming out of cylinder #5. I traveled 960km with a bad glow plug causing the dpf to get filled up to 47.7%. After changing the glow plugs I went for a drive outside of town and now my dpf is 0.0% full according to readings from Xentry. Cheers

[@em4703]

@@AlexAndreiZAR Was the DPF filled because the active regeneration uses active glowplug during that process correct? This wouldn't be an issue with a W211 for example, without active dpf regen? Mersi!

[@AlexAndreiZAR]

@@em4703 hi. Haven't got a clue if the w211 is different. I know many modern diesels (talking about cars with minimum euro 4 and dpf filter) need glow plugs to do proper regeneration. It ain't worth leaving a bad glow plug in the engine cause it has to do with much more than just regeneration of the dpf.

[@em4703]

@@AlexAndreiZAR Yea today I had the "issue". Issue was that after the glow light went off, started the engine normally, all was good and the start was quick, then the light turned on a few seconds after the engine started for another 20-30 seconds, before finally turning off completely. I'll just have to call my mechanic and check it with a mercedes tester for more details on the issue. If it's one of the plugs, I'll just replace them all and avoid any future hassle. I do know that my model has no active regeneration, so no function that increases the diesel injection amount to burn the nox in the dpf. The regeneration is passive by just driving at higher rpm.

[@AlexAndreiZAR]

@@em4703 perfect way of thinking. They are great cars if maintained properly! Thanks for visiting my KZbin channel

[@fixingproblems3183]

Do glow plug thread all the way in ?

[@AlexAndreiZAR]

they need to be screwed in until the torque ratchet releases at 10NM

[@AlexAndreiZAR]

If you screw them in with a 1/4 ratchet then you will feel resistance at some point - careful not to overtighten them cause you can snap them in the engine heads.... torque wrench is recommended and they should be torqued at max 10NM

[@James-um8pq]

if you were close I would have you do mine

[@AlexAndreiZAR]

Where are you from?

[@James-um8pq]

@@AlexAndreiZAR UK

[@AlexAndreiZAR]

@James-um8pq just follow my video... get some courage in you and start doing them yourself. Be mindful and have common sense when trying to unscrew them. First you try to tighten them for a lil bit and then unscrew them. Go like this back and forth.

[@sadder9531]

the controller it self is extremely bad designed i can repair it for 3 USD but it will be broken again and again as the problem is in the design of the controller it self by mercedes engineers