1988 300ce fan clutch

[hotrodder]

Leaking/weeping is a common way waterpumps go when the bearings and/or seals die of old age. They can also suffer from corroded impellers and various other things either corrosion or impeller related (messing up clearances so the impeller can't pump efficiently). When something like any of the above happens it's fairly common for cooling at idle to be more affected... with a belt driven pump designed to give enough flow for idle speeds they typically flow more than needed at higher rpm most of the time so the drop in efficiency is more noticable when stuck in traffic

Sounds to me like the fan clutch is pretty much dead. The rad may be well past it's best but hotter near the inlet with temps dropping as you go across, then down and back across the core is normal. Coolant path through the rad is like

which is a double pass crossflow layout and gonna have a slightly different heat spread to the single pass type mentioned in that link where coolant inlets and outlets are diagonally opposed whether it's a vertical or crossflow layout

 

[anfieldassasin]

Thanks guys, new nissens rad ordered and fan clutch also ordered. The links really useful as is the diagrams for the rad flow. The rad from that diagram seems to be working fine but it is tatty and the fins are crumbling so might as well replace.

Can someone tell why you need to take of the drive belt to replace the fan clutch? I keep reading that every where. All I was going to do was hang the fan shroud over the fan break the nut in centre of fan loose take fan out with clutch unscrew pop new one in and off you go.

 

[hotrodder]

Don't need to take the poly vee belt off to change the fan clutch, that's backwards to WIS in that you're supposed to remove the fan and it's clutch to change the belt (see 13-1200 & 20-3120 Mercedes Benz Model 124 - M104 Maintenance Manuals)* presumably 'cause feeding the belt around the fan, while possible, is fiddly and can take longer

If you're changing the rad then with the old one out there'll be loads more room to work when changing the fan clutch. Probably teaching you to suck eggs but clean around the ATF unions and tape a bag around the hose ends once split to keep dirt out. You won't lose much ATF but before starting it's worth having a good poke around the atf hard lines and hoses at the bottom of the rad because they can get pretty rotten in that area

* just realised i forgot to go back to the main index and select m103 not that it'll make any difference for fan clutches and belts

 

[anfieldassasin]

Ah that's great mate. I thought from looking at the car it seemed illogical to take the belt off. With it on I should enough traction (I hope) to get the fan nut off as I don't have the pulley tool to slip in behind. Will have a go next Friday and get back to you guys.

 

[anfieldassasin]

Scratch that just found the pulley counter holder for 9 quid online at
Wonderman Tools

Hopefully that should avoid any added frustrations!

 

[anfieldassasin]

Guys the sachs fan clutch arrived, i can't fit till next Friday anyway. Can you please tell me. How I should store it? Vertical or horizontal? There are some mark on the box (see pics) to me it would suggest horizontal with the arrows pointing up but I read vertical also?

 

[grober]

horizontal with the arrows pointing up or vertical [ as it will finally be in the car ] are both fine. horizontal with arrows pointing up is the more stable position for loose storage purposes. That orientation guidance is lost however as soon as its removed from the box unless its repackaged in exactly the same way!

 

[anfieldassasin]

horizontal with the arrows pointing up or vertical [ as it will finally be in the car ] are both fine. horizontal with arrows pointing up is the more stable position for loose storage purposes. That orientation guidance is lost however as soon as its removed from the box unless its repackaged in exactly the same way!

Thank you! Found the following from the sachs PDF instructions for the vfc. Can't upload it for some reason but this is what it says also:

"To ensure proper function of the fan clutch we recommend that these instructions be followed. It is most important that the fan clutch be positioned correctly during transportation and storage. Please note the arrow on the fan clutch package. The fan clutch should be stored either vertically but preferably flat with the arrow pointing up. This is to ensure that silicone oil does not leak past the control pin seal. Should a small amount of oil leak past the control pin seal due to incorrect storage, the fan clutch will still perform correctly."

 

[anfieldassasin]

Hey guys part way through vfc and rad change. All is off and fluid drained. I drive belt is cracking so i thought I would change it also, I undid the big 19mm nut on the tensioner a few turns and then detentioned the belt using the 13mm adjuster nut on top but for some reason when I'm tightening it up it started to tension the belt but part way through it just keeps spinning and the belt won't get any tighter! It's not tight enough at the moment.... Any one have any ideas?

 

[grober]

Have you got the correct length of belt? The one for aircon equiped cars is longer. Always wise to compare old and new belts side to side before fitting.

 

[anfieldassasin]

Have you got the correct length of belt? The one for aircon equiped cars is longer. Always wise to compare old and new belts side to side before fitting.

Hi yes correct belt when compared together. Belt came from merc directly (was cheaper than Ecp dyco belt!) I suspect maybe the threads on the adjusting rod are stripped as the collar nut just spins?it was quite rusty and looks like the original tensioner.

It was so cold out I gave up and came in for lunch and to warm up. Will go out in a bit an pull out tensioner and check. Was hoping for a quick diy but there's always something with these W124's

 

[hotrodder]

Belt tensioners, at least the earlier type, are fairly infamous. Discovered mine was fubared the first time i had to remove or replace the belt

 

[anfieldassasin]

Belt tensioners, at least the earlier type, are fairly infamous. Discovered mine was fubared the first time i had to remove or replace the belt

I take it you would advocate replacing the tensioner anyway whilst there? I was planning to only replace the adjusting rod.

 

[hotrodder]

Personally i'd only replace it if the spring feels weak, the rubber bits are perished etc as while the adjusting rod is cheap and the belt damper pretty cheap the tensioner itself isn't, IIRC cheapnese tat are over £50, better/trustworthy brands in the £100 - £150 ballpark & genuine MB a chunk more than that?

Mine had knackered bushes, a partly stripped tensioner rod and a dead damper

 

[anfieldassasin]

Personally i'd only replace it if the spring feels weak, the rubber bits are perished etc as while the adjusting rod is cheap and the belt damper pretty cheap the tensioner itself isn't, IIRC cheapnese tat are over £50, better/trustworthy brands in the £100 - £150 ballpark & genuine MB a chunk more than that?

Mine had knackered bushes, a partly stripped tensioner rod and a dead damper

Got. Called out to. Work so couldn't R&R it today. It's not squeeking or has any play or torn rubber from what I can see the tensioner rod has a lot of rust on it though.

Have ordered a rod anyway so will go from there. Discovered the transmission is leaking whilst under the car and also there is an oil leak on front drivers side don't know if it's either headgasket or timing cover but will post on that once I close this thread

 

[anfieldassasin]

Right so cut belt off, pulleys out with exception of water pump pulley which I can't budge (I can slide it back forward on the shaft but it looks like there's a flange of some sort on the outside of the pulley around the shaft which won't budge and I didn't want to force it) but tensioner came out easily anyway. Tensioner looks good but the threads on adjuster rod are stripped I can slide the rod nut up and down the shaft lol

New rod ordered but will need new deflection pulley (it's the black little one far left of pic as bearing sounds noisy when spinning but no noise when car was running tbough) anyone know it's official name?

Also did some scrubbing whilst there, there was caked on oil every where!!

 

[anfieldassasin]

More pics

For some reason I have to delete old pics from previous post to upload more pics

 

[anfieldassasin]

Hi guys so quick update.

All parts in today new deflection pulley, new tensioner pulley, new belt, new tensioner rod, new radiator (nissens), new fan clutch (sachs) Put everything back together and topped up coolant.

Quick tip: do not leave the fan pulley tool engage when you start the car! Guess what I did quick squeeking and burning smell later from belt slipping I realised and turned car immediately off and took it out.

Haven't Road tested it yet but will updated again Re temps once I have done so tomorrow.

Also the fan clutch was so obviously dead when you compare it to the new one on the car. Pushing much more air at start up till it settles down again.

Thanks for the help guys!

 

[anfieldassasin]

Further update. Went out for test drive, 30mph and below car still runs at close to 100oC on guage, 40mph and above runs around 90. With heater set to max runs at 85.

I noticed when I floor it with kickdown and revs go to 4k ish within 1-2 sec temp drops to 80-85 with or without heater on. I don't think I would have travelled far enough to consider the increased air across radiator to account for the drop.

Which leaves me with a circulation issue? Only bit of cooling system not new is water pump which is not leaking. Can't find any leaks anywhere else.

Any ideas would be helpful, don't want to replace water pump unless there is a real necessity to do so. I any case it's summer time I'm concerned about rather then the current winter temps

 

[anfieldassasin]

Guys just bumping this thread to see if anyone has any ideas or am I resigned to having to do the water pump as well based on the abovr