ArMaNi S500

Hi I've already posted a thread of my problem in the w220 thread, as linked below, but here it is again. In a nutshell, I can't seem to start my car. It is a 2000 S500 with 80k. I've changed the MAF sensor several months ago when it would stall at idle but has been fine since. Recently I did notice a rough idle but no problems. Out of no where one day it wouldn't start. It would crank but not turn over. After waiting 15 mins it started again with no problems. This problem began occurring more and more frequently until recent where I started the car, it stayed on for a couple mins, shut off and couldn't get it to start since. I took the engine cover off to re-oil my air filters (havent done so in atleast a year) but I'm told the problem is either the CPS(cam position sensor) or the crank shaft sensor (according to two other members on the forum) Can you verify this or suggest which to do myself? I was leaning towards the crank shaft sensor but wouldn't want to waste $100 for nothing. Thank you very much!

https://mbworld.org/forums/newthread...ewthread&f=41# CPS(cam position sensor)

ScottCLS55

Hey,

Get someone to use a good scanner, not an autozone one. Or in best case, a STar diag. computer and pull the code. It could be either but I dont think one of them will stall the car. not sure. A snap on scanner or genisis scanner or star scanner should work. the code will tell you if it is the cam position sensor or the crank sensor. I dont want to tell you to get one and the other be bad.. btw, before scanning try cranking the car 3 times and leaving the key on the last time then scan, that way it will leave a code that you can scan. The code may disappear when key is off.

Good luck,
Scott

516mbtek

The problem likely was the crank sensor all along. A airmass sensor will rarely, if ever, cause a stalling condition....mabe under acceleration you will have no acceleration. Usually the crank sensor will go "open" at around 90 deg c...I guess. Now it has probably failed completly. Just go get one _$100 bucks is nothing. Plus, If you have never put one in then you need one anyway. I drive a Benz and carry one in my glovebox. This is the only sensor that WILL leave you stranded...all others have a fail-safe and revert to a nominal value input to the fuel computer in case of failure or disconnection.

ArMaNi S500

Could you tell me where I can buy one for my car? Thanks alot.

516mbtek

Get it from the dealer. It will be in stock.

ArMaNi S500

I talked to a friend who's a technician at Jaguar and he said that usually a check engine light comes on with a bad sensor. I told him this wasn't the case with me when my mass airflow sensor went bad and that there's no light on currently either. He guessed it had to be the bulb but when I click the key over the check engine light does in fact work. Can I be assured that the problem actually is the camshaft sensor or am I taking a risk? Please advise. Thanks.

purplegrog

williws, you said to get a good scanner, "not an autozone one". What scanner do you recommend that would be able to pull advanced level codes but isn't quite as hard to obtain as a star diagnostic system?

mleskovar

Any scanner that allows you to read and erase codes is all you need. Less than $50. The more expensive scanners do fancy things like read sensor values and operating characterisitics for advanced troubleshooting and tuning and historical operating values..... which, if you're asking which one to get, you don't know how to use anyway. Carry it with you so if you get an error that puts the car into limp mode you can clear it and be on your way....or not if the error is solid. It will be a good investment since all cars since 1995 are required to have the OBDII port.

ScottCLS55

Snap on or genisis scanner as I stated above. The only reason he would need it in this case is because they will pull codes for which would cause the car not to start. The "autozone special" will not pull any codes for no start syptoms. snap on and genisis and the $40k "easy to obtain" star diag. comp will pull them and or tell you where there is an open or short in a circuit. Unless you have some knowledge and want to work on your car, you really wont need a scanner period. Autozone will scan your car for free.

Scott

mleskovar

The scanner does nothing more than display the status codes stored in the OBDII memory and allow you to reset it. There are some codes that are manufacturer specific but they still get displayed.

516mbtek

With a cheap generic obd11 scanner is only good if you have codes. If the code is current...in this case..a no start situation...it should be---> if it is sensor related...the check engine light will come on w/ key and stay on. If no check engine light---then you dont have problem there...most likly. A bad ckp sensor does not always set a code---I have seen this. A scanner cannot diagnose this...unless you have a $25k Star...or mabe a $5k snap-on w/ $1.5k worth of software....or a ociliscope. I have never seen a cam sensor fail...o.k. mabe a couple...but have replaced 10000 crank sensors. You are wasting your time with a scanner unless you already have one. A scanner cannot diagnose a bad fuel pump either. If the engine cranks but doesent start---check the basics first, fuel, spark.....then just put a crank sensor in it..even if it doesent need it, takes 10 min tops. I am suprised this thread still exists.

ArMaNi S500

I'm a little confused..so the crank sensor differs from the camshaft sensor, correct? Because somebody suggested that I buy this: https://mbworld.org/forums/newreply....te=1&p=1416511

ArMaNi S500

Given I haven't ever had my spark plug changed but what do you mean by having that and the fuel checked? I heard it takes 2.8 hours to change the spark plug as well so I wouldn't want to do that myself..

ArMaNi S500

FLYNAVY

try posting this over on mercedesshop.com....they seem to be the most knowledgeable when it comes to maintenance issues; there are quite a few techs over there who can be very helpful, and I would trust their opinion on these types of issues, maybe more than the other MB boards that I am on

ArMaNi S500

Ok I took it to my friend at a dealership of a comparable company and nothing showed up on the scan. He narrowed it down to the crankshaft sensor (which is what I've been told could be it) and the fuel pump. I just bought the sensor for $70 and now need to install it. Could anyone offer instructions on how to do the job? I did a MAF sensor change which was easy so I hope this'll be the same. Thanks in advance !

KarlBenz

Replacement of L5 (crankshaft position sensor) is relatively easy with proper tools 1/4' 12 inch extension with flex socket on end connected to another 3" short extension and the proper socket,simply remove air cleaner assembly and with enough light to follow/see wire behind left cylinder head remove/loosen bolt holding L5 in place reinstalling by placing grease/white lube on bolt installing in sensor and then tightening down Note that on removal a long magnet might aid in retrieving of small bolt that could fall into abyss on engine Its a simple 15 minute change

Vader55

If nothing showed on the scan then, How long has it been since you replaced your key battery's ? I had similar type thing happen to me and I changed the key battery's and that was the ticket.

ps. Change your plugs too

ArMaNi S500

I actually did change the batteries to the key. Thanks for the tip. As for the plug... 2.8 hours for a spark plug change? I'll try to hold off for now. I need to get this car up and running so I can sell it ASAP. Why is it so much time for a simple spark plug??

ArMaNi S500

Btw, I apolgize for not saying this earlier but THANK YOU KarlBenz. You're advice was a great help considering the internet wouldn't come up with instructions on how to do this. I'm getting the tools from a friend now and going to attempt the job. Thanks again.

JimmyK

I seem to be having a similiar problem - any news? Did it work?

unlukky

Seems as if the common consensus is that if you car wont start, but then will after it sets awhile or never at all: Crankshaft Position Sensor.

If your car stalls at low speeds or seems like it wants to die: MAF

If your car misfires 'only' @ WOT: Catalytic Converters clogged.

These are obviously preliminary troubleshooting techniques. Most of the time a scanner will point u in the right direction. However, I have seen some problems not code at all.