1988 300ce fan clutch

[anfieldassasin]

Sounds like you are almost there. Hot & Pop idle can be running too lean, get your mixture checked...

My gas analyser is mildly bipolar at the moment so don't know if I can trust it but it last read co2 at 0.26 although my nose was telling me the car is running rich. It's on my to do list after the cooling system.

Will update as i make progress, thanks for help so far

 

[anfieldassasin]

Right guys,

Cars nose in the air as high as it would go, cap of reservoir, ran car for 30 mins and no bubbles came out, so undid bleed screw on top of thermostat no air came out just coolant, so undid bolt next to thermo vacum valve on the head (it's there to bleed the block of air) and again nothing coming out other than coolant.

If you all remember I had fitted a new fan clutch, sachs. In the morning from cold like I said before it roars for first 15 seconds or so. Today with car a smidge under 100 degrees I turned it off and the fan kept spinning rapidly! Once it eventually stopped a few seconds later I spun it by hand and it had no resistance what so ever, I could spin it and it would go round full circle a few times.

I'm assuming the new clutch is dead? But It doesn't make sense to me, if it was dead why would it roar from cold?

I've discounted the water pump as it seems to function fine, no bearing noise, no leaks as soon as car on the move or rev it, temp drops to acceptable level

 

[WDB124066]

I've had four Genuine MB fan clutches, non of them engaged on start up when cold.

Fan clutch is not supposed to engage till 96 through 104 Deg C.

If you want to stay below 100 try a fan clutch that engages from 92 till 100 as in the 129 & 201 chassis.

Have you had a chance to check the mixture...?

 

[anfieldassasin]

I've had four Genuine MB fan clutches, non of them engaged on start up when cold.

Fan clutch is not supposed to engage till 96 through 104 Deg C.

If you want to stay below 100 try a fan clutch that engages from 92 till 100 as in the 129 & 201 chassis.

Have you had a chance to check the mixture...?

I thought it's normal for it to engage when cold for the first 10 or 15 seconds?

Checking mixture tmrw afternoon if the gas analyser plays ball

 

[WDB124066]

That is something I have never experienced.

Use a new machine, old elements never give reliable results and they tend to be very expensive to replace. Even if you have to call the local sales rep and tell him you are thinking of buying a new one but want to see how they work first.

 

[anfieldassasin]

That is something I have never experienced.

Use a new machine, old elements never give reliable results and they tend to be very expensive to replace. Even if you have to call the local sales rep and tell him you are thinking of buying a new one but want to see how they work first.

So used the MOT gas analyser at a friendly local garage to adjust the Co. It was reading 0.65 at idle adjusted to 0.98-1.08 so much closer to the documented 1%. However this has had no effect on engine temp.

I've returned the old (new) sachs fan clutch and have ordered a new one direct from merc £170 (ouch!!) as the new sachs one was engaging for 15 secs from cold and then would disengage. When engine temp ran to 105-110 ish I stopped car and fan kept spinning for a good few seconds, spinning by hand at that point it would happily free wheel round and round as if it's not engaged at all.

It's almost like it's working backwards to what it should do lol.

Anyway once I replace it with the OE clutch I will report back.