W208 CLK320 electrical gremlins. One solved, another furtile :(

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SeanWRX

New Member
Joined
Jan 14, 2017
Messages
19
Location
Epsom Downs-ish, Surrey
Car
w208 CLK320
Hi all. I am a newbie (introduction thread here: http://www.mbclub.co.uk/forums/new-member-introductions/218912-wrx-clk.html)

Borrowing a year 2000 w208 CLK320 off a mate, with a view to buying it off him if I get on with it and its auto gearbox (never driven an auto before).

I have two questions. The first I’m just curious about but the second I actually need advice on to help me fix.

1. The car had known a ‘warm start’ problem. It starts when cold, it starts when hot, it does NOT start when warm. It’s caught me out and even though it’s not my car (yet), I figured I’d try and sort the problem for once and for all. After a bit of Googling / forum lurking I took a punt and ordered a camshaft position sensor. Fitted that yesterday and that seems to have cured it (touch wood). But my question is this: The camshaft position sensor I removed was filthy. Layers of grime. Do you think it’s actually faulty or just in need of a very good scrub? And also what does it say about engine condition if such a part is so caked in soot & grime?

2. This is the question I actually need help with to get the car back on the road. After fixing the warm start problem I went out for a spirited drive to celebrate. At some point in the journey my indicators and wiper stopped working. As did the windscreen washer and the ability to flash other drivers with my main beam (though turning main beam on fully still works). What have I done? I’m near Epsom Racecourse and we had that snow the other day and while driving a lump of snow from trees landed on my windscreen. I used the wiper to flick it off. But if I’d burned out the wiper motor/fuse under load, would that in turn have the knock on effect of killing the indicators and washer?

The car was a ‘spare’ vehicle for my friend, and he, his wife, and my other friend were previously all using it if needed in an emergency. They could still ask to use it which concerns me as the ‘warm start’ problem could be tolerated (you just wait for the car to cool down completely) but now I’ve actually broken it properly and rendered it not roadworthy!!
 
I seem to remember all the features you mention are controlled from a single stalk. It happened on a car of mine, and replacing the stalk fixed it. I seem to recall the main dealer telling me that the twist, pull, push nature of the switch meant that the wiring inside gives up.
 
I would check fuses first, 22 and 41 from memory control both of those.

Even if they look OK, test them properly.
 
And the cause was............

.........drum roll............

.....fuse 22!!

Thanks gbjeppm. I have never had a single fuse fail on any of the 17 cars I've owned before, so I'm not even in the mindset of checking those first. Is this common on Mercs?

(PS: I now have a spare stalk and SAM module purchased in a panic if anyone in Surrey needs one at short notice).
 
It's common on all cars. As already mentioned - always start with fuses and don't stop with visual inspection.

I'd keep the spare stalk if I were you ;)
 
Alright, the original 'warm start' problem is back. This is after changing out the camshaft position sensor as mentioned above.

I assume now it's time to swap out the crankshaft one? Anything else I should be looking at first?

Also car really dithers when accelerating sometimes. Common consensus seems to be dirty MAF. Anything else likely to be the cause?
 
Alright so this car has a good few problems. It's now officially mine, which was perfect timing for the problems I hadn't witnessed before to all flare up at once. Any insight into these from anyone who has owned a w208 CLK320 (year 2000) much appreciated as I am used to Jap cars which are a lot less complicated.

1) The aforementioned 'warm start' problem. Changed camshaft sensor and I thought it had resolved this but it hasn't, I have a crank shaft sensor to go on, but won't have time to do that for a while.

2) Chronic battery drain. Car won't start if left for longer than 12 hours. That coupled with the difficult method of getting into the boot with a dead battery are really causing me a sense of humour failure, and my fingertips are raw from grappling with that skeleton key thing every couple of days. Thought it was a badly wired aftermarket stereo so have removed fuse 10 (fuse 3 already absent, should be the telephone but the car didn't come with one anyway) thinking this would solve, but no dice.

3) Incredibly rough car-shaking idle after the battery is reconnected. Sorts itself out after 5 mins of idle, and then if you stop the car and start it again later that day, it's fine, but remove the battery (which I am doing often to charge it) and you get the rough idle again. IMO the ECU is overcompensating for the rough idle and when you disconnect the battery it forgets those settings and has to re-learn the problem. ADVICE PLEASE.

4) Extreme unwillingness to accelerate. S mode has become unuseable, things are a bit better in W mode but you gotta stomp the accelerator like 3 times for it to notice that you're requesting an increase in acceleration. Car just sits there and if anything backs OFF the power when you apply more accelerator. Go figure.

5) Abrupt extra 'bite' from the ABS after applying brakes smoothly. Should be a simple fix, brakes need bleeding I guess.

6) Windscreen squirty is dead. Should be a fuse, haven't got that far yet, every visit to the car (which I have to park in the next street due to lack of parking space in my street) is to address higher priority problems.


HELP!!
 
About 4) - you do know the throttle is electronic, right? W mode is harder on the transmission, so try to use it as little as possible.

I believe that a visit to a good independent mechanic will sort out most of your problems rather quickly.
 
3) Incredibly rough car-shaking idle after the battery is reconnected. Sorts itself out after 5 mins of idle, and then if you stop the car and start it again later that day, it's fine, but remove the battery (which I am doing often to charge it) and you get the rough idle again. IMO the ECU is overcompensating for the rough idle and when you disconnect the battery it forgets those settings and has to re-learn the problem. ADVICE PLEASE.

4) Extreme unwillingness to accelerate. S mode has become unuseable, things are a bit better in W mode but you gotta stomp the accelerator like 3 times for it to notice that you're requesting an increase in acceleration. Car just sits there and if anything backs OFF the power when you apply more accelerator. Go figure.

Sounds like the MAF - it was on mine and they are known to fail. Could also be the brake light switch (ECU is told the car is braking)

2) Chronic battery drain. Car won't start if left for longer than 12 hours. That coupled with the difficult method of getting into the boot with a dead battery are really causing me a sense of humour failure, and my fingertips are raw from grappling with that skeleton key thing every couple of days. Thought it was a badly wired aftermarket stereo so have removed fuse 10 (fuse 3 already absent, should be the telephone but the car didn't come with one anyway) thinking this would solve, but no dice.

First of all lubricate the boot lock well and keep it lubricated - common issue and it WILL catch you out when you need it.
Secondly a drain of a fully charged battery in 12 hours means that something is also getting warm - if the battery is around 80Ah then to go flat you are drawing around 5-6 amps which is 60 watts. Seat controllers are known to give this fault - I think they are in the doors, but a google/forum search should confirm.

Good luck - the C208 is a handsome chap, and the 320 M112 engine is a beauty, with surprisingly good fuel consumption.
 
Thanks for the replies.

shadenfroh - I had read that, yeah. I am only using W mode because acceleration is just about tolerable in it, whereas the car doesn’t really want to accelerate at all in S mode.

Ted - Been doing some investigating today. Popped the MAF off and it’s gleaming! As are the insides of the pipes connecting to it. I gave it a very light clean with cotton buds dipped in carb cleaner since I might as well. So yeah it certainly sounds like it might be broken, rather than simply filthy. I guess I’ll have to replace. Forgot to look into the brake light switch issue. How would I know, would the brake lights be coming on when I am not braking?

Boot lock - Given it a good lubing in anticipation of the next time I need to open it the hard way.

Went a different route investigating the battery drain. Saw lots of threads about how the most common cause is the permanent feed that memorises the seat positions. Seemed to be as easy as popping out a connector under both seats and living without electric seats while you prove/disprove that is the cause, but the seat module looks different from the one in this thread: http://www.mbclub.co.uk/forums/electronics/151760-w208-battery-drain-help.html

Here’s what mine looks like. I removed the one on the far right as per the thread mentioned, decided that isn’t the right thing, and have plugged it back in again…



If it’s the seat controllers can I pull a fuse to eliminate them? They don’t look the easiest things to remove.
 
Does the alarm siren work?

I would put money on it being a duff siren, causing the battery drain.

Pull the fuse for it, and see if it still starts after 12 hours.

Performance issue sounds like MAF, or possibly a fueling issue, when was the last time the fuel filter was changed?
 
Oh and fuel filter - no idea. Just ordered a MAF, if that makes no difference then I'll do fuel filter next.
 
Further observation: I get no 'chirp' from the alarm when I use the fob to lock the car/arm it.

Should I? I don't get it on the Scooby either so have got used to not listening out for one.
 
Only with a certain country coding (Netherlands I believe...), otherwise - no chirp. Just set off the alarm, but be aware - it's crazy loud, don't do it in a garage.
 
Did you look in the boot. Probably a 5 amp.

Removing the alarm fuse doesn’t kill the alarm siren as it has its own internal power supply by way of rechargeable batteries.


Dec

IMG-20120318-01386.jpg
 
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As shadenfroh set the alarm off, lock the car with button, the open the door with the key, and see if the alarm sounds.

If it does not sound, you need to get to the siren and either disconnect or replace it.
 
Alright, I've given up.

Due to bad weather/not finishing work til 6pm /other commitments I get to spend about 3 hours per weekend during daylight hours with the car. This is spent getting nowhere fast as I don't really have the knowledge or confidence for conclusive troubleshooting, and with the MOT up on 19th Feb, I'm running out of time.

So I've booked it in with TM Motors in West Molesey. Hopefully they can wave the magic wand at all these problems and make them vanish (the full list I'm giving them lists 7 problems all in all).
 

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