ML270 CDI W163 coolant light on but coolant level OK...

[mickeystitch]

Just renewing the mass air flow sensor will probably sort out the first 3 on the list, not sure about the fan open circuit, does the fan rotate when the air con is turned on?

wow that has to be the way to go first then, was quoted £73.00 and told me that is from Mercedes so got to be worth doing first and I will also clean the egr as best I can.

Was going to buy the expansion bottle quoted £87.00 (as I understand it comes with the sensor and is the only way you can get it) and hope that that is perhaps the fan fault.

I have not tried the fan with the ac on but I think the garage may of because he said it was dead, but he also said the other one was duff and the guy I got it from is 110% that it was a working one when it came of other car.

 

[panason1c]

The expansion bottle comes out at about £53 inc vat from euro car parts link, below, use this discount code... mbclub25 .....you enter the code on the 'checkout' page and click on the 'update' button.

EIS Mercedes-Benz | Euro Car Parts UK?s No.1 Car Parts Retailer

 

[panason1c]

For the mas air flow sensor, same procedure as above with the discount code, comes out at £47 for a genuine pierburg

Pierburg Mercedes-Benz | Euro Car Parts UK?s No.1 Car Parts Retailer

 

[mickeystitch]

The expansion bottle comes out at about £53 inc vat from euro car parts link, below, use this discount code... mbclub25 .....you enter the code on the 'checkout' page and click on the 'update' button.

EIS Mercedes-Benz | Euro Car Parts UK?s No.1 Car Parts Retailer

you are a total star and thank you for taking the time and trouble to reply I really appreciate the help, I see they also do the airflow sensor for the same money do you think it would be the same quality as would be easier to get all the parts from one place, its the more expensive one made by pierburg Pierburg Mercedes-Benz | Euro Car Parts UK?s No.1 Car Parts Retailer

 

[mickeystitch]

ha ha we crossed posts I take it pierburg is the oe merc parts then

 

[panason1c]

Hi, Yes, pierburg is OE to MB, dont forget to enter the discount code. Put both items in the checkout basket and then enter the code

 

[panason1c]

Regarding the sensor in the expansion tank, before buying a new tank, try removing the 2 pin plug and bridging the contacts in the plug, if the light still stays on then it might not be the sensor/tank thats at fault.

 

[mickeystitch]

thanks for your help today, I will update again later in the week

 

[mickeystitch]

Update time !!!!!!!!!!

So firstly I massive THANK YOU to PANASONIC

Who online here and via private messaging has been a great help pointing me in the right direction and where to buy parts, but to be honest just having somebody that took the trouble to reply and being able to check bits I was not sure about has helped and chivvied me along and made me not want to give up on the problem.

so once again thank you PANASONIC you sir are TOP :bannana:

Right the nitty gritty so to speak,

Euro were having a sale this weekend when I logged on to order the bits so thought 'why not' ordered

EuroCarParts
Maf
Map
Expansion tank
and what I thought was EGR (turned out to be throttle jobbies so got refund on spot)
Oil
Oil filter & crush washer
Air filter

Merc main stealer
100 amp fuse for battery post £9.40 (indie who diagnostic blew it)

Saturday (yesterday) it was raining but my missus was not having any of it and sent me outside anyways as she said she would not put up with me whingeing about my broken motor and longer

Fitted Expansion tank, fuse and the light was still on (not happy at this point) so thought ah well fit other bits anyway.

Fitted Maf and Map sensors found pipe down to turbo just pulled off, fitted air filter and put all back together properly and tightened up properly as I'm sure it will help.

Took EGR of and spent hour cleaning it (will do manifold another time but that will have to wait) and refitted all that proper.

So that's it time for road test thinking ah well at least it will be out of limp mode and I can take it somewhere, bite the bullet and get new fan motor etc. (indie told me the one I had got from eBay was also duff).

Take it up road - NO DIFFERENT - right so now I'm wet got the hump and still no further, So I check every fuse, all good, the in the engine bay fuse box thought a hole in the back I spot some earths, now I also have a Honda Blackbird and they are known to have bad earths so I think 'got to be worth a try' had assumed indie checked al this in his 'extra hour to check connections and wiring' five little screws later and I've got cover off.

Found two relays that were just connected but laying in there
A fuse connecter again connected with two good fuses but again just laying in there ( by that I mean not clipped as if they were an after thought

And then slotted to the side was a fuse carrier that 'yes you've guessed it' had a blow 10 amp fuse in it, replaced fuse and radiator light went out, fan came on

Shut bonnet and took her down the road, be Jesus, she is now quicker than the star ship enterprise.

Now I'm not saying that it did not need any of the other bits as it certainly gets a shift on now but I am saying that the original fault was probably mainly that little 10 amp fuse that clearly had not even been looked at

Am popping in the indie's on way home tomorrow night to explain my dissatisfaction

 

[panason1c]

Glad you got it sorted!

Seems to me you diagnosed and fixed the problem yourself without any 'outside help'.

Well done.

 

[jay1983]

Glad you got it fixed. Any chance you could take a pic of the offending fuse and location?

 

[mickeystitch]

I can try to get picture but am not home all in the week at a sensible time, you really do not need one though, it is in the main fuse box under the bonnet over the passenger side.
Unclip front cover and you will see through a small hole in the back a hole about size of matchbox ( you can see some earth wires in there ) you then need to take off that cover, which is the rear part of the fuse box and comes off via 5 star screws and lifts off, in there I found two relays a double fuse holder and a single (the offending) fuse holder, now I do not know if this is a wiring upgrade or and previous repair but it was deffo the fault with mine, good luck and let me know if you still need that picture - oh and a thanks would be good if it sorts yours too.

 

[jay1983]

Cheers mickey. I know what you mean now. Tbh when mine was on it was the maxi fuse on positive battery terminal.

Was a great discovery by yourself and hopefully will help others to either fix or gives them an idea of where to check for a possible fault.

Would be interesting to know what the other relays are for tho.

 

[Fidelisz123]

Faulty fan

Oh and i now have a spare fan and fcu if anyone needs one.

Does your fan fit Ml 270cdi and how much do you want for it and the fcu.

 

[kie010]

possibly connected

I myself have yet had exactly same problem, nobody could say for sure what is wrong but and I am just presuming this that the electrics in and around the engine are so completely linked that a simple fault as your fuse could wipe out everything I would not have expected anyone to have the exact same symptoms as me but unfortunately I am glad that you did have these issues, not glad that you did but glad that I can now explore my options simpler, hope all is well now and I will let you know how I get on

 

[kie010]

All happy 35p fix wtf

thank you so much for your help, a little 10a fuse hidden away that was blown, car runs as it should but didn't half smoke, so going to stop manifold, egr oil separator and everything else as I am just presuming that the black smoke would be caused by running it around in limp mode for 4 months! Did yours smoke when you fixed the fuse

 

[Pedrossa71]

Had the same problem last week, took it to the garage, he told me it was the coolant bottle sensor, i bought a new one online for 42 quid, he fitted it and reset it for 20 quid.
Job done

 

[Pedrossa71]

I stand corrected, the light came back on, so as mickeystitch suggested i went for the fuse, and sure enough it was blown, well i wasted 70 quid for the bottle, but if it wasnt for the great advice on here i would undoubtedly have wasted hundreds on diagnostics etc and been driving round like a snail for a while, Once again many thanks. (cheeky place to put a fuse though)

 

[M271]

Thanks for the info

 

[Mr Crank]

Limp mode, coolant light on but not EPC, fuse blown, my experience and fix.

Pedrossa, I also had this fuse, under a cover behind the main fuse box somewhat on its own, blow. Coolant light was on, in limp mode but no EPC light. I know it is some months since you posted, but my experince may help others with the same problems if you have resolved your issue. I have been a forum reader, without posting, for some time and should give back. After some research, I found the fuse you have blown is connected to a number of things including the coolant recircualtion pump, inlet manifold flapper motor (M55 motor) PCV heater (really? I know) and some supply to the ECU. My experience was that diagnosis was time consuming and revealed a minor but troublesome systemic issue involving the inlet manifold butterflys, the M55 motor, the EGR gas and PCV mist/oil turning to carbon. A star report ( i no longer have it) showed 4 or 5 problems all at once, coolant pump and rad fan, PCV heater etc. That made no sense as all these separate elctrical things wont die all at once. I started by checking for things that were not working on the same circuit. The Coolant recircualtion pump was not turning, though it had power. I spent an evening taking it apart, found worn brushes down to the holder and spring, gently sanded some oversized brushes to fit and soldered them in. A new pump was around $280 from MB in Sydney. The pump worked on installation, the new fuse did not blow immedaitely but within 2km had blown again. Limp mode and coolant light back again. Then I checked the M55 motor (under the inlet manifold), It was covered in oil and felt glitchy moving it against its spring. You can get access to the M55 by taking off the wheel and removing the plastic inner guard. Removing and replacing the inlet manifold takes me about 10 to 12 hours. Ive done it twice. The M55 smelt burnt. I bought a new one froma German online supplier - about $240 delivered compared to $660 for local price. Replaced the M55 and limp went away as well as coolant light never to return. However, the underlying problem was the oil and carbon dripping onto the original M55 and frying it inside out. From my own experince and that of others reported on MB fora, the EGR gas mixes in the inlet manifold with PCV mist/oil to form carbon which then erodes the manifolds butterflys o ring and pivot. The butterflys pivot is a low point in the manifold so the PCV mist, that does not turn into carbon from the EGR gas, condenses and leaks out the eroded pivots and o rings. Mess down the side of the engine, onto the M55 and on the floor. Having removed the inlet manifold I can verify the carbon buildup is very surprising, up to a 2mm layer in some places on the inside of the manifold - at 125,000 on my car, lots of >6km trips and Sydney temperature. After bypassing the EGR from 125,000km, at 160,000 I removed the inlet manifild again to do the butterfly delete and blank off the pivot holes, no carbon in the manifold at all.


The better long term fix is:

• Bypass the EGR with an electronic shunt. Search for "EGR shunt, Oigle, Dieselman, Alex Crow. The instructions are very good.
• M55 and butterfly delete. Search for M55 delete, Stumo and Alex Crow.

Apologies to those not mentioned I'm writing from memory.

The EGR shunt has worked flawlessly for me for 40,000km. The inlet manifold butterfly removal has worked flawlessly for 15,000km. I reused my newish M55 rather than using a resistor as in the M55 delete procedure, but is just hangs from the firewall on a nylon tie connected only to the ECU, moving its arm back and forth to no effect.

The EGR shunt is easy but takes pluck even after triple checking the ECU wires. The inlet manifold butterfly and M55 delete, with good planning before you start, could be completed in a long day.