[Viraat13]

Originally Posted by laxmanrk

Also the additional fan in front of the radiator used to turn on when the A/C was switched on, now it doesnt.

But during the testing we removed the temp sensor near the fuel filter and
the additional fan came on and just stayed on at full speed. once we put the sensor back the fan stopped.

I am also suspecting the duo valve which circulates hot water into the heater circuit.
Thanks all for your inputs and support - especially Varun and Viraat.

Doesn't the fan only come on after a few minutes?
Try cleaning the terminals of the temp sensor, the fan relay, and the fuse of the fan relay, and the main fuse of the fan and see if it gets you somewhere.
Is the blower motor working? No noise, vibration, etc?
And if the AC was functioning earlier, why did you feel the need to 'fix' it? :-/

A lot of people have disconnected the heat exchange valve, as have I in my E220. Try bypassing it to see if the problem solves itself?

I might have the wiring diagrams on my other computer. Will check tomorrow and upload if I have them.

[vikramvicky1984]

Originally Posted by Viraat13

A lot of people have disconnected the heat exchange valve, as have I in my E220. Try bypassing it to see if the problem solves itself?

I might have the wiring diagrams on my other computer. Will check tomorrow and upload if I have them.

I too faced the same problem as laxman for the AC. Sensor was bust.
Bypassing might not be a good idea, its there for a purpose, get a new one.
that's what my mechanic had done, he put a new sensor. Its perfect now

[911varun]

Originally Posted by laxmanrk

Have been using the car for the last 2~3 days and the temperature gauge in the instrument cluster is still not showing the right temperature. It just rises to 40~50 degrees and it stays there.

Now, had the A/C system charged today with gas and the A/C is nowhere near as efficient as it was before.

A/C guy says there is no leak whatsoever as he did the vacuum test and it passed.

Also the additional fan in front of the radiator used to turn on when the A/C was switched on, now it doesnt.

But during the testing we removed the temp sensor near the fuel filter and
the additional fan came on and just stayed on at full speed. once we put the sensor back the fan stopped.

I am also suspecting the duo valve which circulates hot water into the heater circuit.

Firstly I need the A/C electrical and vacuum diagram if any one has it.

Thanks all for your inputs and support - especially Varun and Viraat.

1. First try swapping the two wires on top of the pressure sensor beside the expansion bottle. Idling this should start the AC fan. If not, Replace both the coolant sensors and check the engine temp and AC fan actuation. These is not much electrical wiring to this system.

2.and for the vacuum I have already put the diagrams.

[Viraat13]

Originally Posted by vikramvicky1984

I too faced the same problem as laxman for the AC. Sensor was bust.
Bypassing might not be a good idea, its there for a purpose, get a new one.
that's what my mechanic had done, he put a new sensor. Its perfect now

It's only to use the heater AFAIK. And I never need to use it as I feel suffocated with the hot air, and mostly I end up using the AC even in winters. Having said that, it'll probably be replaced closer to next winter. Will need to hunt it down, it costs about 22K?

[laxmanrk]

Guys

I am overwhelmed by your inputs.

Firstly, the radiator and the A/C condenser were removed during my engine works.

So had the gas charging done again after 2~3 days of refitting everything.

Now, updates.

Yesterday we did a 200 km round trip to Yadgirigutta. Well mostly the car did well, but the engine coolant temperature is still not showing and the engine oil pressure was dropping quite badly during traffic stops.

Will try and upload some pics today.

Also, by the time we got home coolant started dripping down the interior of the car near the Hand brake/ foot rest area.

The mechanic suspected that the interior heat exchange radiator must have gone bust and this circuit was running permanently reducing A/C performance.

So the following works were carried out yesterday:

1) The car has duo valve that sits adjacent to the Fuse box. This was removed completely.

2) There exists a coolant circuit just to circulate the coolant from the block back through this duo valve back into the engine. This was re- connected with some additional piping.

3) There are 2 engine temperature sensors and removing either of these is making the additional fan run at full blast. Is there a way to check the sensors before replacing them?

Now the A/C is working extremely well. It is really chilling to the bone.

But the engine temperature is still not showing in the instrument console. So i have no idea what temperature the engine is operating at.

[Viraat13]

Originally Posted by laxmanrk

.... the engine oil pressure was dropping quite badly during traffic stops.

...

3) There are 2 engine temperature sensors and removing either of these is making the additional fan run at full blast. Is there a way to check the sensors before replacing them?

...

But the engine temperature is still not showing in the instrument console. So i have no idea what temperature the engine is operating at.

Have you checked the oil pressure gauge sensor? If the sensor starts leaking, the oil pressure will seem to drop. As far as I can tell, 2 or a little under 2 on idle, and 3/full as soon as you start accelerating.

I don't know how you can check the sensors, but why don't you take some sandpaper and clean the terminals of the sensors and the ports and see if that helps. My fuel pump relay on the E220 had failed and I did this and it had started working and hasn't given me trouble since. I figure that you're talking about the last sensor on the engine head.

Was the instrument console removed? Are the wires of the temperature gauge connected? Maybe you should check the circuits to see if current is flowing properly before deciding to get a new sensor.

[laxmanrk]

Hey

The oil pressure sensor and the oil pressure gauge are doing fine.

But, the mechanic said - If the engine is operating at a temperature beyond the engine's normal operating range, the oil will become vapour inside the engine and hence drop in oil pressure.

So, the only way I know at the moment that my engine overheats is that the oil pressure starts getting low.

I have ordered both the temperature sensors

Part numbers of which are as below:

A 008 542 45 17 and
A 008 542 56 17

Also changing the Thermostat as an added measure - Part number 601 200 00 15.

Now has anyone read this thread - http://www.benzworld.org/forums/w124...ch-refill.html

I am also looking at sorting my viscous fan in the same way. I would like to know where i can get the silicone the guy has used or even the actual name/ spec of it so that i can source it.

[Viraat13]

The engine shouldn't be over heating. It's not even peak summer yet!

Check if the cooling fan clutch is worn out. To check, turn the fan with your hand while the car is off, if it moves freely, then you need to replace the fan clutch.

EDIT - I haven't read that thread from Benz World. Will get back to you on that.

Further EDIT - I went through the thread, and well, it seems like a good idea. But the fan clutch is available and not particularly expensive, so I think it makes more sense to go in for a more permanent/reliable solution. Also, see this - http://www.w124performance.com/movie...ch_engaged.mpg .

[DeepakMenon]

Ideally the E220 should not overheat irrespective of whether it is summer or winter; i think there are few things that need to be sorted out

1. Ensure that you have the right thermostat; or at least a working one
2. Radiators have no leaks
3. Fan; now i believe it is like a step up fan; as the temp goes up it switches its speed; now in most of the cars i have seen it does not not work in the way intended. So you can have a bit of overheating in traffic. The fan assembly is 12K MB original
4. Water Pump; this should be working well [New Pump 4.5K]
5. Lastly head gasket; if that is leaking then you will over heat no matter what

I have a E220; my fan needs to be replaced; as it does not increase its speed with increase in temp; but honestly it is not bothering as night time temp is 80 and day time 85-90; so not really bothering me much

[ayushagarwal26]

I may have significantly useless inputs at this point, but I faced a similar issue in the past - the car would overheat (not all the way, but above the 100 mark) in traffic with the AC on. This would cause the compressor to trip, and the AC to cool less (even when the compressor was on).

We finally figured the aux fan would go off at its own discretion. Tinkering with the fan helped, and although we could never figure out the core issue, the fan works ok now (it's been 6 months). I am not sure if its speed varies with engine temperature as it is supposed to, but the car more or less remains <100 and the AC cools fine. Let's see the progress this summer!

Also, I just gave my car a complete service at ~145k - Details here (In case the information helps someone): http://www.team-bhp.com/forum/test-d...ml#post3076060

[DeepakMenon]

Originally Posted by ayushagarwal26

I may have significantly useless inputs at this point, but I faced a similar issue in the past - the car would overheat (not all the way, but above the 100 mark) in traffic with the AC on. This would cause the compressor to trip, and the AC to cool less (even when the compressor was on).

We finally figured the aux fan would go off at its own discretion. Tinkering with the fan helped, and although we could never figure out the core issue, the fan works ok now (it's been 6 months). I am not sure if its speed varies with engine temperature as it is supposed to, but the car more or less remains <100 and the AC cools fine. Let's see the progress this summer!

[/url]

Check your AUX fan; it is not working the way it is supposed to; this happens due to either of the following

1. Bad Fan [Highly unlikely]
2. Relay not working / loose etc
3. AUX fan switch [ The one with the pg-tail] next to the pressure switch on the dryer
3. AC gas level low [ if this is low; the AC pressure switch kicks in and stops your compressor]

Check this link; it has trouble shooting steps for AC related issues [Worked like a charm for me]

http://www.benzworld.org/forums/w124...ond-all-2.html

[DeepakMenon]

I had a quick questions for you guys; i am planning to install 17" so was planning to lower a bit to get the look complete

- How many of you have a lowered the W124??
- Anyone knows what spring pad size a standard E220 has not front & Back??

[911varun]

Originally Posted by DeepakMenon

I had a quick questions for you guys; i am planning to install 17" so was planning to lower a bit to get the look complete

- How many of you have a lowered the W124??
- Anyone knows what spring pad size a standard E220 has not front & Back??

If you want to put 17s, it needs wheel arc flairing, the specs are available online

for lowering, Bilstein sports shocks and two no. pads at front and 3no. pads at rear

Have you found a goode set of 17s, let me know if you know of any good set of 17s i am also planning got lower it....

[DeepakMenon]

Originally Posted by 911varun

If you want to put 17s, it needs wheel arc flairing, the specs are available online

for lowering, Bilstein sports shocks and two no. pads at front and 3no. pads at rear

.

Hi Varun; you really do not need to flare the wheel arc as long as you stick to few offsets.

I am not really keen on lowering it too much so sport shock not on the card; i am just putting the standard replacemenr; however i know i can save some mm based on the pad i have; i am hoping we are using #4 pad; then i can go #1 on front and #2 at rear..


17" well have a few lined up;

[msaudf]

I came across a strange situation when i had to drive my friends car from Salem to Coimbatore on our way to Cochin a few weeks back. I found that the exhaust was blowing as it was noisier than usual for that car and a quick inspection by raising it on a ramp showed a cut in the downpipe of the car's exhaust.

It was a W124 Mercedes Benz E250, the five cylinder diesel. the car is a well maintained car and i guess my friend might have gone through some pot holed patches on road and hit something causing the cut. The mechanic said that they dont have welding gas so he cant weld the gap shut and said its ok to drive on, just that a bit noisier.

We hit the highway and just after 150kms I saw the temp gauge was at 100 degrees, my friend said it could be due to the higher ambient temperature here than Kerala, but i wasn't convinced as what he said made no sense and pulled over to a service lane and checked for leaks from the radiator or for any usual causes for the heating issue. we let the engine idle without the AC and kept the bonnet open and after about 10 mins the temp dropped to 80. the cooling fans were on full speed and when the temp seemed ok i turned off the engine. checked the main fan and it seemed ok, it turned ok and also viscous fan clutch held its resistance. after about 30 mins we set off again and when we were almost close to Coimbatore ie, another 40 odd kms from the last stop i see the gauge creeping up above the 80 degree zone.
As the only thing that was wrong with the car was the leaking exhaust i decided to try any workshop there and found one and fixed the leak. so now the exhaust leak was fixed i had some peace of mind. thats when we receive a call from Salem that we have to go back asap because of some accident at our work place. So now we head back but as we were in a hurry so it was pedal to the metal and redlining in every gear, but this time the engine stayed put in 80 (normal operating temp) and didn't even move.

Can a leak in the exhaust cause the engine to overheat or operate at a higher temp than normal?
(The cut in the exhaust was about 5cms long parallel to the pipe and about 1cm wide in the middle of the cut.)