the SLK is on the naughty step :( suggestions plz

[gm]

i was ‘exploring the performance’ on my way home from work the other night, things were going well until the engine threw a strop and started running rough.

i pulled over and it stalled, after a few tries, it restarted but was spluttering and had no power - i nursed it home and dumped it on the drive for further investigation in the morning.

this is a 2.3 supercharged petrol, why does it run like a tractor ? 

i pulled the plugs which were black as coal, gave them all a clean and checked for spark on each, nothing obvious there

a vacuum line to the fuel regulator looked a bit perished so i nicked a bit off the exo and swapped it over 

it’s still rough but not quite as bad, 

until you give it some revs

feels like it hitting the limiter at 4k

and the engine shakes like a shitting dog 

i took it for a cautious drive round the block and it’s just about drivable but has no power  

i had a look for the OBD port

gah - too old for that  

do any local shiters have a reader to fit this ? 

any help / suggestions chaps ? 

it’s a 1999 mercedes slk230 auto btw

[wesacosa]

I thought OBDII was mandatory on petrol engines by 1999 🤔 

[New POD]

I had a similar symptom on a mk3 astra once.  The CAT was destroying itself, so under power above 3.5k the ceramic would rotate like a ball valve and block the exhaust. 

[Dave_Q]

It will be OBD but not a standard socket.

If you get one of these adaptors you should be able to plug in a generic code reader. 

https://www.ebay.co.uk/itm/303916283804

If you get really stuck I do have the STAR kit with that adaptor but you would need to drive down to borrow it, or I could post it up to you but its fairly heavy as includes a laptop.

[gm]

i’ve had it up to @scaryoldcortina’s garage and had the codes read - looks like the butterfly valve that feeds the supercharger is wonky, not helped by various perished hoses - hopefully a straightforward fix 

[gm]

 

[gm]

i dug out some old mx5 heater hoses which look like they have bends in most of the right places 

 

[gm]

fixed*

well, the air leaks are anyway. the valve may need to be replaced as it still runs like a bag of shite. idle is nice and smooth now though 

[gm]

then @DVee8 came round and we went to a car meet  

exo was fun on the way home in the rain, very sideways 

[gm]

4 hours ago, Dave_Q said:

It will be OBD but not a standard socket.

If you get one of these adaptors you should be able to plug in a generic code reader. 

https://www.ebay.co.uk/itm/303916283804

If you get really stuck I do have the STAR kit with that adaptor but you would need to drive down to borrow it, or I could post it up to you but its fairly heavy as includes a laptop.

i’ll probably order an adaptor but thanks for the offer. i’ll see about replacing the valve now i know where the problem is - presumably omg£££ from mercedes but i’ll see what i can find on ebay / breakers etc 

the crazy thing is that it was absolutely flying before it went ‘pop’, seemed to be much quicker than normal, maybe it’s been sticking for a while ?

[chaseracer]

11 minutes ago, gm said:

presumably omg£££ from mercedes

Worth an ask - you may be pleasantly surprised 🙂

[gm]

can’t do any harm, will ring round tomorrow 

[Conrad D. Conelrad]

Oh no  

Hope it's easily fixed. The only problems I had with it were a failed cam sensor and expansion tank. The latter I bought from Mercedes, it's worth asking because the prices aren't necessarily as scary as you'd assume - they support their old models better than most. I took my old W124 to a dealer (Europe's largest!) to ask about the SLS pipes and they made me a coffee while someone printed out all the parts diagrams. They treated me and my 25 year old shed the same as they would the guy with the three year old S class. 

The MB part number for the hose is A 111 018 16 82

 

[richardmorris]

2 minutes ago, Conrad D. Conelrad said:

Oh no  

Hope it's easily fixed. The only problems I had with it were a failed cam sensor and expansion tank. The latter I bought from Mercedes, it's worth asking because the prices aren't necessarily as scary as you'd assume - they support their old models better than most. I took my old W124 to a dealer (Europe's largest!) to ask about the SLS pipes and they made me a coffee while someone printed out all the parts diagrams. They treated me and my 25 year old shed the same as they would the guy with the three year old S class. 

The MB part number for the hose is A 111 018 16 82

 

My experience in ascot too with my 124 coupe, complete contrast to experiences in Citroen dealership who looked at me like I’d stepped in something on the way in.

[Dave_Q]

1 hour ago, gm said:

i dug out some old mx5 heater hoses which look like they have bends in most of the right places 

[Conrad D. Conelrad]

New wheels look great, btw

[mercedade]

21 hours ago, gm said:

feels like it hitting the limiter at 4k

it’s a 1999 mercedes slk230 auto btw

I can't help with the rough running, but they don't rev above 4k unless they're in drive.

Which would have been a useful thing for me to have known when I started diagnosing faults on the one I had!

[Dabooka]

4 minutes ago, mercedade said:

I can't help with the rough running, but they don't rev above 4k unless they're in drive.

Which would have been a useful thing for me to have known when I started diagnosing faults on the one I had!

I had a similar experience on the Cougar with the LIM opening the valves. Apparently it needs to be under load for the magic box to operate the actuators.

[gm]

i believe that this valve should do a full close / open self test on ignition - it appears to be mildly buggered

 

https://m.youtube.com/shorts/-RKUq_AGe8o

 

[gm]

stumbled across this whilst doing my research - a separate filter cone for the supercharger 

i wonder if it makes a sod of difference ?

 

[gm]

fault codes :

 

[Schaefft]

P0243 will most likely be the issue then. Clear and see if it returns now that you have the complete picture. And the massive vacuum leaks if that's still the case.

[gm]

having done a bit of homework, i removed the suspect valve and opened it up

there is a potentiometer track that feeds back the position of the valve to the ecu - i wonder if this might respond to a bit of contact cleaner ?

and you know what ? it did  

i gave it a good blast and wiped the track with cotton buds - plenty of muck came off which must have helped. 

once reassembled, i went for a test drive and it’s running better than ever - i only went a few miles but it’s definitely improved a lot  

[DaveDorson]

Do love a cheap fix.

 

I spent last weekend under the Mondeo because it's thrown an ABS warning light and the handbrake was playing silly fuckers on one calliper.

 

Me being me, I ordered a pair of wheel bearings, and a rear calliper so I could just do the job and not need to wait for parts.  I was ordering the servicing parts anyway so it made total sense to spend the extra £60 or so on bits.

 

Of course, I managed to sort out both issues without the parts... so now they're spares that live with the car.

ABS sensor was a broken sensor wire, and dirty sensor, sorted them both out and reset the codes and 30 miles later it's still good, so that's a win.  I do need to flush and bleed the brakes though as the fluid is manky as fuck, 

Handbrake I suspected was mal-adjustment of the self adjusting and the cable going a bit slack,  tester always has to lift the arm rest and give it a decent yank for the brake test come MOT time, so I got under the car and adjusted it properly, and the bastard still didn't work.

Applied a load of XCP to the lever and worked the shit out of it with a spanner on the lever arm and it started to work again, so re-assembled, cleaned, and now I have a working handbrake too.

[gm]

a cheap fix is always welcome  

it’s still a little sluggish off the mark but i reckon a good service should sort that - i’ll order up parts and give it a good seeing to next week when i’m off work