New Member: E320CDI

[RFdesigner]

Hello folks.

I've been reading around these boards for a little and decided to join up.

I recently purchased a late '99 E320CDI estate facelift model with 52k on the clock and MB service history to back this up.

The car drives well, it's powerful comfortable and so on. Buying a slightly older car I expected the odd niggle and so I'm now entering the debug phase.

I changed the oil almost as soon as I got it (just in case) and reset the computer, putting in a 5W40 synthetic oil. I'm finding the fuel consumption a little high and am thinking about going round the engine bay and checking each thing in turn. Curiously the fuel consumption seems to be the same from about 30mph to about 70mph, at around 38mpg. (I used to get 33-36mpg out of my old 220CE), I suspect excess fluid clutch slip, the clutch locks almost solid on cruise at 70mph (2050 to 2100rpm) but at 60 the revs are all over the place (1500 to 2500 depending on gradient even with cc) and I do quite a lot of A-road driving so this matters to me.

I've seen Parrots explanation of doing a gearbox fluid change and am tempted to check/change the fluid, except that I seem to have to take the engine cover off to get at the dip stick, is this right?

I also need to sort myself out with a reader for the engine-brain.. any links gratefully received. (I have a laptop to plug in if necessary)

The other issue is the autodimming RVM doesn't, the LED light on the bottom of the mirror works so some power is getting to the unit. Any ideas on debugging this?

Thanks in advance.

Derek

 

[Blobcat]

Hi & Welcome,

You should be averaging on the trip computer 38-40mpg depending upon how you drive.
At 70 the revs are ~2200
WRT the dimming mirror, is the drivers door mirror dimming? As both the internal rear view mirror and the drivers door mirror should dim. The sensor is in the rear view mirror (photoelectric cell)

 

[RFdesigner]

Blobcat

Thanks,

You should be averaging on the trip computer 38-40mpg depending upon how you drive.

I only get this by driving 'extra-urban'. This morning I reset the pooter once the engine had warmed up and doing a very gentle mixture of 40 50 and 60mph I managed to squeak 41mpg, I never see anywhere near the 45mpg extra urban from the book. Of course any additional losses would stuff me, such as a sticky alternator or water pump or an electronic fault like the glow plugs not turning off. I suppose I ought to check the alternator output current.

At 70 the revs are ~2200

Mine are a shade lower, but that's only once this 'lock' kicks in, before it kicks the revs are indeed about 2200. The nice thing about the lock is that it holds the revs steady even when going up a 1:10 at 70, you can really hear the engine putting out the power. Funnily the lock refuses to kick in without the cruise engaged, no matter how steadily I drive.. However it's the performance at 50 - 60 that seems to be lacking.

WRT the dimming mirror, is the drivers door mirror dimming?

No, which makes me think it's sensor related or simply no power supply at all. I can see the rearward facing sensor, presumably it has another sensor facing forward or up so it can tell it's night time. Any pointers on disassembly?

I really need to get one of those CD/DVD manuals.

thanks

Derek

 

[malcolm E53 AMG]

Welcome to the forum.

I have owned my 320CDi (mileage 51K) for over two years now and can confirm that the mpg you are seeing is correct and corresponds exactly with what my car is returning.

26-28mpg short runs

34 ave (10K miles)

100 miles motorway at 70mph - 40mpg, 80mph - 38mpg

Best achieved - A roads, 50 mile journey in summer - 46mpg.


I never use the tiptronic as the power always seems to be there whatever speed I'm doing when I hit the throttle so I'm a little sirprised at the lack of power your experiencing around 50mph. From 2500rpm the acceleration and torque can only be described as impressive (mind you I'm not sure whether mine has been chipped).

Hope this helps!

 

[OlafMaxwell]

I have to agree with Malcolm. Mileages are pretty correct. Its a ig motor with lots of power.

However you do need to look out for things like glowplug light staying on, means you need to replace glowplugs [expect them to go 50-60k, normal wear]and its not really a diy job due othe risk of them breaking.

Other things are rust....and self levelling suspension. I also see a lost of posts about the rear seat catches breaking, worth replacing the locking mechanism as a failure prevention as once it breaks the seat back cant be lowered.

 

[Blobcat]

It must be carrying around all that extra air in the back of the estate that is killing the fuel economy.

WRT the Rear View Mirror, there is another Photocell in the front of the mirror so the car knows its gone dark.

 

[RFdesigner]

Many thanks.

The 'performance at 50-60' is not the acceleration, that's very brisk . It's the engine revs. As if the transmission is refusing to use the 'lock' that seems to engage from 70 onwards.

I might try going home tonight at 60 and see what I get in mpg (other than bored)

I also came up with an idea for a very repeatable test:

1. warm up engine.
2. reset 'from start' mpg program.
3. Drive for 3 or 4 miles.
4. stop and note mpg.
5. rev engine in neutral at say 1500rpm for 5 minutes.
6. note mpg.
7. do a bit of maths based on the difference in the two mpg readings to glean how much fuel was used during revving.

Using this it would be possible to determine the no load fuel consumption which should be very repeatable, any excess losses should also show up in this test. It could then give an upper limit for the best possible fuel consumption, I would hope it would work out well over 100mpg.

RVM: I've found the front sensor (tried covering it up to no effect) and found that you can pop the mirror off a kind of ball joint, except that there appears to be a wiring loom still holding it on and I don't like pulling looms in case I damage something, so it's been popped back on non-functioning.

I went over the car with a reasonably fine tooth comb before buying and got one patch of rust on the bottom of one of the passenger doors seen to, there's a very slight amount on the top of both the passenger doors which I will cover with silicon grease as soon as it turns up and a very small patch under the boot-lid lock. I can't find any rust on the body of the car itself, the suspension and supports etc. all look sound as do the wheel arches.

I'll watch out for the glow-plug lights.. the only thing that I've had to replace so far is a fog light.. which reminds me, how do you replace the front fog lights without having to jack up the car! my old 124 was a doddle to work on...... but this!

anyway many thanks to all.

Derek

 

[Blobcat]

I have just had one of the front fog lights out on mine - http://forums.mercedesclub.org.uk/showthread.php?t=23653
The procedure is listed in the owners manual, you do have to work blind though unless you can get under the front of the car. Lay on your back and undo the flap in the undershield with a 2p piece. Then reach in and unclip the bottom of the seal off the back of the fog light. Then reach in and unclip the metal bulb retaining spring. Then let pull the bulb out, let it hang on the wires then disconnect the wires. Reassembly is a reverse of the above...

 

[RFdesigner]

RE front fogs.

I have two issues here.

1. when using rotating catches that are not visable without jacking they should both operate in the normal and same direction, on the W210 they don't, one is clockwise and one anticlockwise, that is totally inexcusable.

2. The handbook does not give a sufficiently clear diagram/instructions of how to get the back of the lamp off. The direction of force on the lamp back catch needs to be different from the diagram, it's obvious once you've jacked the car up but should you need a jack to replace a bulb? (the team that wrote the manual presumably did not test the book with non-experts prior to publication)



Reassembly is a reverse of the above...

Possibly one of the most frightening phrases in the english language, along with "it can be shown that"

Derek

 

[Blobcat]

I wrote that procedure above, not MB..:!:
You can see the catches in the undershield if you lay on the ground. The catch on the back of the lamp is fairly easy as it just pulls from the bottom.

If you think MB are bad try replacing a headlamp bulb on most modern cars.

 

[RFdesigner]

Blobcat, sorry.

I wrote that procedure above, not MB..

I realised that, I could have followed your description. The "Reassembly is a reverse of the above..." brings back bad memories of a Haynes manual and a Mk2 cavalier with a 1000 broken plastic clips.

The worst one was 'offer up the sump'... 23rd time lucky!

many thanks anyway

Derek

 

[Blobcat]

No problem, I've followed a few Haynes books which is why I paraphrased them.
I wonder if bulb has actually failed in yours or corroded like mine. I have only had one bulb actually fail on my car (rear boot lid tail light). I have had a few of the 'standard' rear light failures which just require cleaning the bulb and holder contacts to get fixed.

 

[RFdesigner]

Funny you should say that, having gone through all the torture and cost of replacing the bulb (you should have seen the effort it took to open my wallet) I found the old bulb was fine, dodgy connection or something...

Ah-well... I now have a spare!

PS I also heard a horror story on the radio on the way in, RAC called out to a non-functioning car, everything dead, on closer inspection it is found that a 'helpful' and bored 11 year old had kindly removed all the fuses from the fuse box.

Now that's something they don't cover in the handbook!

 

[Parrot of Doom]

If you think MB are bad try replacing a headlamp bulb on most modern cars.

You should have tried it on my Chimaera. You have to remove the front grille, put your hand through the slim hole up and around the back of the lamp. Then, with the GRP bodywork ripping skin from your arm, you have to unplug the connector, unclip the bulb, and put the new one in - all without ever seeing what you're doing, and all while lying with your back on the floor.