Mercedes SLK World banner

1 - 20 of 28 Posts

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #1
Been on the lookout for a SLK the last several months and have read/watched a lot of videos about problems. I think I could repair roof cylinders and headlineers in my sleep now. :).

A new post opped up lat night. 98 230, under 100K miles. 6 monts ago, no start/turnover. New Battery, cranks but no fire. He is through messing with it. COuld be k40? CPS? other?

Question is, is a $1,500 gamble worth it? Best price so far was $4,500 for one with 118K, in pretty good shape in my area. Going to llok at it tonight wo verify mileage, interior and quick diagnosis like fan running, battery level...
584121
 

·
Administrator 2009 SLK 55 AMG/Founding Member 2006
Joined
·
99,463 Posts
bump to the top
 

·
Premium Member 2002 SLK320
Joined
·
754 Posts
If you've read many posts on here (which it looks like you've done) you'll likely know what the answer will be. Fan running and no crank is most likely the K40. Engine cranks but no start is commonly the CPS (as you've said). However, it could be many things.
Taking a gamble for $1500? That's a hard call to make remotely - we don't know your financial position, for instance. For purchase and repairs.
Buying a car without driving it is always a risk, but if you like tinkering and feel confident about car repairs, and the car's in decent condition then go for it. These cars aren't hard to fix, and this is a great forum with a lot of support.

Good luck, and let us know how you get on.
 

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #4
Looked at car. Super clean outside. No dents, rust or paint issues. First time battery was reconnected, a noise, possibly fan could be heard and owner disconnected battery terminal. Upon reconnecting, now horn honks non stop and lights flash. Door opened, door closed. Hood up or down. Key in or out. Also, no response from key fob for locks. Key fob appears to have been dropped/damaged and not solid like it should be. Neighbor who thought about buying it took k40 out and said it “looked” fine.
 

·
Administrator 2009 SLK 55 AMG/Founding Member 2006
Joined
·
99,463 Posts
cannot see the solder that has cracked. needs to be reflowed
post 12-14

 

·
Premium Member 2002 SLK320
Joined
·
754 Posts
That doesn't sound too bad. Horn and lights flashing could well be the alarm having a bad battery. If the owner disconnected the battery, didn't you see the cooling fan going 'round? No response from the key fob could be the key fob (like you say) of could be the PSE faulty. I assume the roof went up and down. Of course, by not driving (or even starting) the car still leaves it a gamble. Is he open to offers?
 

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #7
That doesn't sound too bad. Horn and lights flashing could well be the alarm having a bad battery. If the owner disconnected the battery, didn't you see the cooling fan going 'round? No response from the key fob could be the key fob (like you say) of could be the PSE faulty. I assume the roof went up and down. Of course, by not driving (or even starting) the car still leaves it a gamble. Is he open to offers?
 

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #8
roof not tested as horn noise was driving us crazy. I saw alarm battery issue.

$1500 was down from the $2k asking price.

how far do you think $500 spent at an non-dealer, experienced Mercedes shop would go towards electrical testing. I have 2K I’m willing to spend. To get buy and fix if needed.
 

·
Premium Member 2002 SLK320
Joined
·
754 Posts
Well, as many on here will tell you, you need to find someone with SDS diagnostic machine and experienced in using it. From what people say that would be around $100 to $200. It's impossible to guess further than that. That could well tell you all you need to know to fix things. I would think $2k would go a long way if you're fixing things yourself. Many have bought SDS. It's not all that expensive in the scheme of things.
 

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #11
My thought was if k40 reseat, alarm battery and good cleaning of all contacts doesn’t work, take it to a shop that reports they have diagnostic tools that could help. I’ll fix myself if needed and problem is identified by then. Kind of like a pre buy inspection on a used car but more expensive.
 

·
Premium Member 2002 SLK320
Joined
·
754 Posts
I get the impression you've been looking around this site, but if you haven't it's well worth searching. With 85k posts in the R170 General Discussion section alone, there's loads of information and most questions have been asked before. There's also an R170 DIY section. And all the stickies at the top.
 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
3,477 Posts
Three letters ................

SDS is the only machine to properly diagnose this age of SLK and this kind of problem, and you need to 100% know that the guy using it is very good, otherwise your $500 will be gone in an instant and you could very well still have a dead Car.

Not iCarsoft, Not Snap-On, Not Autel, Not Bosch KTS etc etc etc and most certainly not anything that costs less than the $500 SDS
to buy, a $35 Mobile phone app isn't gonna tell you what you need to know.

Why do I say that ?

Because no other machine can access all modules on these cars, and without information from all modules a proper diagnosis is not being done, you are just paying for someone else's best guess.
Depending upon how knowledgeable the guy is you could be just chucking $$$ down the toilet ;)

Having said that, I'd be hitting the seller hard with a $700 bid and settle between $1000 - 1100 or walk .....................

But that's easy for me to say, I have the equipment and knowledge to fix any Mercedes, and contacts to source new genuine parts cheap, also I know which parts I can buy good used or OEM and they won't give a problem in short order.

For example, if it is K40, never buy a used, never buy a pattern, only buy from MB.

If the Cooling Fan ran upon Ignition on there is a fair chance it is cracked solder or bad relay(s) within K40, which needs good equipment, skills and magnification to repair, easier to buy brand new from MB at circa $160. Trouble is with your descriptions above, there are a lot of other noises that one could here upon connecting a battery, things like Throttle Body motors run and normalise etc etc .

Did you here the Engine Crank over ?

Did it crank evenly rpm wise with no odd noises ?

HTH :)
 

·
Registered 1999 SLK230
Joined
·
9 Posts
I recently bought a 99 SLK230 with 100k miles, had been garaged 5 years and not run.

Trailer turned up at my house, chucked a new battery in it... cranks, no start. Spent ages looking at the K40, immobiliser etc that I forgot the basics.

Turned out the fuel pump was shot, a new one and it fired straight up.

They're not as complex as it seems on the surface. If they dont turn over and give a "start error" then its the immobiliser - either due to a bad K40 relay or a duff key etc. If its the K40 the cooling fan runs at maximum as a failsafe as the ECU wont have any power.

If its cranking but not firing, its either not getting fuel or not getting spark. There's no common issues that would cause no spark - they have 2 separate coils so even if one was shot you'd still get a sputtering or very rough running. So fuel is the only other thing - you can check by CAREFULLY pressing the schrader valve by the engine in while someone turns it over. Have a rag under it - if there's fuel it'll squirt out. You can also hear the pump run when you turn the ignition on, if there's no sound when you turn the key to position 2 (before cranking) then the pump isnt running for some reason.

The fuel pump IS driven by the K40 but in my case changing it didnt fix the problem. I verified by disconnecting the electrical connectors from the pump, running a wire to the battery and connecting it with the fuel valve open. Still no fuel, no buzzing from the pump - nothing.

The pump is a bit fiddly to change but definitely a DIY job. Its under the car not in the tank, you have to remove a plastic cover, clamp the hoses and then remove hoses and electrical connectors. It drops out in a bracket that also holds the fuel filter. You can swap the pump and filter on the workbench, then put the whole lot back in the car.

It sounds cheap enough and if it is the fuel pump - caused either by the K40 or the pump itself, neither are expensive or hard to resolve.
 

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #15
I use forums for a lot of "toys" i have fixed or kept running. This is as detailed of a forum and more DIY than any others. At this point, Im ready to buy it and roll the dice. First I need the horn/alarm to stop squaking when the battery is connected. It surely sounds like the horn continuously blowing, so can they be disconnected under the front grill to then do other diagnosis?

Motor has not cranked over. Only noise heard was slight noise when hooking battery up first time. Not the starter clicking becauset the key was never moved to crank postion. A minute later when the ballery lead was comnnected again, the horn just blasts away and nothing we did would stop it.
 

·
Administrator 2009 SLK 55 AMG/Founding Member 2006
Joined
·
99,463 Posts
alarm battery is going dead is why
 

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #17
Replace whole alarm? Sounds like just messing with the battery alone is not worth it?
 

·
Administrator 2009 SLK 55 AMG/Founding Member 2006
Joined
·
99,463 Posts

·
Registered (Looking SLK230/320)
Joined
·
12 Posts
Discussion Starter #19
Ok dumb newbie question. The issue is the horns honking continuously. Is that the alarm or is the Alarm an actual device mounted under the wipers that will blast in intervals instead of constant horn honking I thought I was hearing.
 

·
Administrator 2009 SLK 55 AMG/Founding Member 2006
Joined
·
99,463 Posts
probably the alarm
if a bad horn, it would blare continuously
bad alarm goes honk................honk...........honk......... etc
 
1 - 20 of 28 Posts
Top