How to replace the fan clutch on a Mercedes M103

My 1993 Mercedes 300TE 4Matic project gets cooled down with a new fan clutch. This video should apply to all models that used the m103 engine.

[@oglinkgog]

You can lock the fan clutch pulley from behind with a tool- I use a short allen/hex key cable/zip-tied onto the end of an extra-long screwdriver. There are extra holes in the fan pulley mount made for this. You don't have to loosen/take the belt off that way. A stubby 1/4" drive allen/hex socket is worth buying and fits in front of the radiator easily- then you can use a long-handled ratchet as the fan bolt is tightened to 40nm. Also, if you open your bonnet/hood to the service position you'll make your life a lot easier :)

[@JustFixIt99]

+oglinkgog All very good points. I couldn't find the lock hole which is why I chose to use the strap wrench. I didn't show it but I also had the good in the service position. If I was doing a lot of these I would agree that buying a stubby Allen socket would be a good investment, but for a one off the long one plus a box end wrench as I did is fine.

[@davidailles4229]

I make the locking tool from a eavestrough nail. Cut off the point and bend at 60 or so degrees so a 3/4" end can slip in the groove on the left side of the timing cover and into the pulley hole as I rotate the pulley with the hex and a wrench until the groove and the pulley hole line up. I don't take off the fan belt, just the fan shroud. Early cars don't have the two piece shroud, a bit less convenient. Put a piece of cardboard between the rad and fan so you don't dent the fins when you wrestle off the fan and clutch.

[@JustFixIt99]

All very good suggestions.

[@guadalupegomez344]

My head gasket is leaking as well and I have taken off the fan but I need to know where it turns. it’s a M 104 Mercedes engine

[@MrMikolaj550]

Thank you, you helped me a lot.

[@JustFixIt99]

Glad I could help.

[@Tigerfire75]

Aren't you worried that your replacement fan clutch might be possessed and cause you issues

[@c.brooke5490]

There is a way to lock the pulley from behind without doing all the extra removal of [arts. Just and "L" shaped tool that slots into a groove on the back. !

[@pierrepotgieter8076]

Hi Justfixt99. Thanks for a very informative video. One question. I need to replace the serpentine belt on my 103. You took it off without removing the fan but by removing the idler pulley. If I follow your procedure would it be possible to get the new belt on the same way in reverse? Much appreciated and keep up the good work.

[@JustFixIt99]

Once you take the tension off the belt via the tensioner the belt can easily be replaced.

[@pierrepotgieter8076]

@@JustFixIt99 Thanks mate!

[@mjfreshyfresh]

This video shows what it's like to wrench. Problem solving, persistence, patience, pain. LOL! I've got an M102 I need to perform this on, I'm thinking it will be fairly similar. Thanks for putting this info out on the interwebs.

[@nadeemsadeia2999]

Thank you for this video

[@nor4277]

You had two other option ,replace with a fix fan or electric fan ,but yours save a lot of money neat video ,when I had to replace a fan on my truck due to cracking ,it wasn't that easy or cheap .another great job .

[@crystrezerex2life]

Don't you just love those strap wrenches.😁😒😡

[@Wuffenberg]

Haha yeah reminds me of my work. Scratched skin from the tight space between engine and radiator as well as tools falling onto the engine bottom cover :D This M103 is not really Mercedes masterpiece when it comes to service...

[@JustFixIt99]

Not even close..... The V6 engines, as well as the 5 cylinder models are wayyyy easier to work on

[@galeanorodriguez9668]

When loosening the 13mm adjuster bolt which way do you turn it? Some people are telling me counterclockwise some are saying clock wise

[@JustFixIt99]

I did this many years ago and genuinely can't remember. It shouldn't be hard to figure out though. In one direction the belt will loosen and in one direction it wont.

[@galeanorodriguez9668]

@@JustFixIt99 Yea I think my issue was I needed to replace the tensioner cause it wasnt loosening nor tightening either way haha

[@JustFixIt99]

@Galeano Rodriguez I could be mistaken, again it been a while since I did this, but I seem to remember there was a locking bolt you had to loosen first?

[@hazemabuali1905]

Thanks for the info that was great 👍

[@jerryz1846]

can you show tighenting and losening the fan belt alot slower...Which bolts are you talking about on the m103 engine ? I can not find it

[@JustFixIt99]

There is a big 19mm bolt just under and to the right of the water pump pully, its the only 19mm bolt there, a mirror may help you if you can't see it. Once you have loosened the 19mm bolt, loosen the adjuster that I show in the video.

[@crystrezerex2life]

Low low price of free!!🤦😂

[@jerryz1846]

just wondering if you ever did the water pump too ? I am thinking of doing mine myself...they wanted 800.00 US $ and they said 6 hours of the same engine M103...thanks

[@JustFixIt99]

Check your other comment for a reply.

[@aldoruiz6815]

I’ve done a water pump, I can tell you you need to remove the power steering but not the hoses, the tensioner and disconnect any electrical plugs in the way. It’s a fairly simple job just very time consuming because of having to remove unnecessary things to have access to the four Allen bolts that hold the water pump

[@aldoruiz6815]

They said the same thing to me about getting it worked on but the bill was going to be 1000 so I got a pump for 70 and spent half a day replacing it

[@paulsheets4048]

This is foliah

[@anyanelekelechi2149]

Mr, your procedure is too cumbersome! Remove the radiator to creat enough space for the whole process.

[@dikranberg7600]

Ok😊

[@guadalupegomez344]

I have a question where does the fan turn when the engine starts?

[@JustFixIt99]

I’m afraid I don’t understand your question. What do you mean “where does it turn”?

[@guadalupegomez344]

JustFixIt99 where does the fan turn when you start the engine?

[@JustFixIt99]

I think we might be having a miscommunication here, can you phrase your question differently for me?

[@_lexus-gx470_l.s4]

may fred

[@prtattoos993]

That was 4 matic, am i right?

[@JustFixIt99]

As it says in the description, yes, it is a 4matic

[@prtattoos993]

JustFixIt99 sorry, i didn't read it. Tell me, is it true that americans like european head lights more than US version?

[@JustFixIt99]

Absolutely, the US spec headlights are absolutely useless for lighting the road. The optics in the european ones are infinity better. Most of us agree they look better too

[@prtattoos993]

JustFixIt99 that is funny, becouse everybody goes crazy about US lights down here in Europe

[@JustFixIt99]

Until they have to drive at night.... They really are useless...

[@williamjohnson2225]

Where did you find the pulley holder

[@JustFixIt99]

I just used a standard rubber strap wrench. They are available at any hardware store

[@williamjohnson2225]

JustFixIt99 awesome bro i found it just was using wrong name much appreciated

[@JustFixIt99]

Glad to help

[@daghanam]

Hi Folks I have mercedes 250c , 1970 coupe Thinking to upgrade the original fan since its is running constantly , making roaring noise while im on the hwy , also having extra load on the engine while the temperature is low and doesn’t need to work Any advice ? Should i use electrical fan or clutched fan ? Appreciate your help in advance 🤙

[@JustFixIt99]

Tough call. If a good quality (known brand) fan clutch is available, I would probably choose that route, just because it’s relatively straight forward and known to last a long time with relatively little issue. Electric fan would be my second choice just because of the complexity involved, it may also require an alternator upgrade depending on the size of the fan you install.

[@daghanam]

JustFixIt99 Thanks for reply There is few brands available like Meyle , Uro parts I was thinking thinking the same way so i dont need to instal temperature switch on thermostat and worry about harness Thanks for your help 🤙🤙🤙

[@JustFixIt99]

If at all possible, avoid uro, their quality is garbage.

[@daghanam]

JustFixIt99 sure i will Thanks for your help 🙏🏼🙏🏼