To ensure proper installation, could you please confirm that I have correctly connected the hoses to the respective ports on the heater valve? The correct configuration should have port #1 connected to the left metal pipe and port #2 connected to the right metal pipe, which is attached to the heater core, when facing the front of the car, is that correct? No sure this makes a diff

erence

 

Those hoses are less than a year old, which wouldn't explain the lack of cabin heat. Notably, both hoses are steaming hot when the car is warmed up.

 

According to the diagram and photo the two hoses have different part #'s and should be shaped slightly different. Can see which hose does to each port.

1 towards passenger side. 2 towards drivers side.

 

Tim,

after examining the receipt from my previous mechanic, I observed that a non-OEM water pump and thermostat were installed. Specifically, a -graf water pump and a uro thermostat were used instead of the genuine OEM Mercedes brand. I was charged for OEM parts, and I am now questioning the thermostat's reliability.

 

I would keep an eye on all the hoses - all the gunk you have used to clean may not have done them any good...

my 18 year old hoses to the expansion bottle look like brand new compared to the elephantine ones you have

 

I changed all these hoses and valves last year. The photo posted above syncs up easily with how everything should be oriented...you really can't mess it up if your car's setup looks like the photo. I have a Graf waterpump bought from FCP Euro, and it works fine. I wouldn't buy a Uro anything though--that might be something you should replace with a better brand.

 

Graf brand water pumps seem to have good reviews. I wouldnt replace it unless it was leaking.

Thermostat I would use either genuine Mercedes or I believe Whaler makes them for MB. The Mercedes brand thermostat on my M272 has Whaler stamped on it. They are only around $100 and simple to replace. If you are questioning whether it is functioning properly then sure replace it.

Can test the heating element using a multimeter. Says just measure the resistance.

I dug around for how it works in the car GF07.61-P-4016VB below.

 

Tim,

as I discussed with Botus, the fact that my car's vents require the engine to be idling or driving for a very long timeto attain 80-90 degrees suggests a potential issue with the thermostat. Notably, the heat has functioned sporadically, despite my replacement of nearly all parts, excluding the thermostat and water pump which were done now alittle over a year ago.

 

Tim & Botus,

I have fitted a new Mercedes thermostat, but unfortunately, it has not made a difference. The air from the vents is still cold. The readings from the Mercedes star computer have me stumped, with vent temperatures only just reaching 80 degrees, regardless of whether the vehicle is stationary or moving. I do not think the water pump is at fault, as I would expect other symptoms to manifest. I am becoming increasingly exasperated with this issue.

 

could it be that "strange" odd top hose connects in different ways ?

I was quite surprised to see the info Tim provided above, about how the thermostat operates with three independent modes based or temp vehicle use ?

could it be there was an old world other way to do stuff with coolant routes and or a thermostat that goes with odd hose and its metal elbow ?

or maybe the engine ECU and all the heater control must be on the same compatible software ? is the engine management on the last 2008 iteration - or was it chipped and they tweaked some stuff wrongly ? there's a whole world of insanity inside the engine ECU re coding

 

my ME9.7 was "chipped" and for some silly reason some coding now just says Code BSxxxxxx - I have added the correct Original coding translated from German in column F in blue text from a German developer download from my car BEFORE the ECU was flashed

 

The scanner can show the temp at each vent but can it show the temp of the heater core? I know it can show the temp at the evaporator.

If everything in the coolant and the heating system is functioning properly then that leaves the blend doors, right?

When I was messing around with my ac due to low refrigerant I still have odd issues with the air coming out warm. I'd have to turn it off then on again and I could hear the various doors in the dash opening/closing until cold air was coming out.

I was driving the other day and was paying attention to the coolant temp. From a cold start it took around 8 minutes for the temp gauge to get up to where it stays normally, for my M272 thats around 85 c. It was around 53 f outside and I drive normal rpm's 1,500-2,000.

But then also consider the temp gauge is not showing the actual coolant temp. Basically when the coolant temp is 80-110 the gauge will show around 90 constantly.

 

Botus& Tim

I recently encountered an issue with my vehicle where it failed to start. Upon turning the key, the dashboard lights illuminated, the gas gauge dropped to "e", and after a brief pause, the "red battery" icon appeared on my cluster. Notably, the Bosch OEM starter, which is only two years old, did not produce any audible noises. Furthermore, the driver's hood latch mechanism is stuck, requiring me to access it through the driver-side wheel well using a long screwdriver. I suspect that the cable may have come loose. What are your thoughts on the matter? I have already contacted ninjabenz for assistance, but the vehicle's voltage remains below 10.2 when the key is turned to the accessories position, even with a battery tender connected. I am confident that the batteries are not the issue, as I charged the rear battery overnight and it now reads 12v.

 

arrie has a post about the bonnet catch cable falling out of place - he said you can use a cable tie once its back in the correct place to stop it happening again

the electrics I don't know - I didn't realise it used old world carbon brushes on the "generator" and I'd covered it in wd40 ever since the light comes on, on the two times I've started it from cold - so today I squirted it with brake cleaner - the carbon brush brush pack can be changed and its not far off the usual miles to need one - so not sure - it seems if it doesn't see x volts after a certain time frame (seconds) from start it throws the red battery light on the cluster - If I rev it to 2K for a bit it goes out and stays out

batteries need a load test - to get whether its really got the grunt left its supposed to have - or whether it just needs a charge

 

I observed in ignition section on xentry that terminal 50 was off with the key in position 2 .. I have to check if there is a fuse or relay.

 

I saw a reference for a TIPS doc stating there is an EZS software update outstanding for all w221s - indeed for basically ALL Mercs ever built

I have not had it done - not sure I like the idea of it having a wobble as it might not start without connecting to home - but why the very late in the cars life is there an update to the ignition switch for ALL of them - I presume some naughty software and a time switch causing odd issues !

Number:2022110004
Title:Perform Scn Coding In N73 Electronic Ignition Lock Control Unit
Date:11/1/2022

 

Botus,

I am fairly certain that ninjabenz performed the update. Therefore, I plan to attempt to open the hood and inspect the relays for the starter, as well as the prefuse on the right side of the engine, to determine if any fuses have blown.

 

I had the hood latch thing happen to me also. For whatever reason, the cable pull through the wheel well would not release it. I ended up doing a long and tedious made up procedure of going in through the front grill and unscrewing the bolts holding the latch, one 1/4 turn at a time. It took forever but I got it done. However, the CL setup in the grill is a little different than the S, so maybe it won't apply. I now have zip ties holding the cords in place.

 

I was able to get the hood open by removing the front driver’s side wheel liner. Now this. lol




I have conducted a thorough examination of the front and rear Sam relays, as well as the fuses, utilizing a relay tester to verify their functionality. All components were found to be in good working order. I also inspected the prefuse in the engine bay and confirmed that all three fuses were intact. However, upon turning the key in the ignition, I observed no audible noises, such as clicking or humming, emanating from the starter. In light of this, I am inclined to suspect that the non-replaceable fuse on the prefuse may be the culprit. Furthermore, after watching a video, I am leaning towards the possibility that the EZS ignition switch may be faulty, as the 50 terminal fails to activate when monitored with Xentry. Additionally, within approximately 10 seconds of turning the key to position 2, the red battery icon appears on the dashboard.

i might need to get the EZS ignition switch replaced but.. a company wants 1k to fix it.Any places to get it fixed?

 

I would like to add that I consulted with a professional who specializes in repairing engine control modules (ECMs) and electronic ignition systems (EIS). The fact that the dashboard lights illuminate when I turn the key to position 2 indicates that the key is authorized and communicating with the vehicle. As I continue to troubleshoot the no crank, no start issue, I recalled purchasing a spare ECM last year, which was pre-programmed with my vehicle identification number (VIN). I decided to replace the existing ECM with the spare one, and I observed that the dashboard lights illuminated, and the gas gauge did not dip as it did with the original ECM. Although the vehicle did not start, it is clear that the spare ECM is functional but requires coding to the EIS.

 

Additionally, I am contemplating the replacement of the engine wiring harness, which bears the part number i2730100002, as it is probable that its wiring has become fragile at 200k miles. How hard is the process of replacing this component, taking into account that it is no longer sold brand new?

 

it seems to go everywhere.... a faff is the world I think u need
what you going to use - brand new or ?

 

'clb0099 check out this thread

he had weird battery voltages up front - got at the device using autel "flashed something" in the box of tricks N82/1 above the rear battery and its behaving

https://mbworld.org/forums/s-class-w...ml#post9226400