DanielDaskalo

Hey Guys.

This is my car: 2004 Mercedes Benz E320 4Matic.

A few months ago while driving the check engine light came on. Doing a test it showed that the crank shaft sensor is bad. I went ahead and replaced it, the check engine light went away.

The other day, i was trying to avoid an accident so I revved the car to avoid it and the check engine light came on and the car shut off. I pulled to the side of the road, put it in parking started it up again and it was fine, but the check engine light remained ON.

After putting it on the computer again this is what we have:

P0335 Crankshaft Position Sensor (Not sure how this is possible when i replaced it over a month ago)
P0300 Cylinder misfire detected - RANDOM cylinders
P0301 Cylinder misfire detected Cylinder #1
P0302 Cylinder misfire detected Cylinder #2
P0303 Cylinder misfire detected Cylinder #3

I am not sure what to do at this point :S

Please assist.

Plutoe

First clear all the faults----------run the car around if the CEL lights again read the faults and do the guided tests associated with the fault--the guided test will zero in on the problem(s)

DanielDaskalo

What i decided to do is a tune up.

1. I will change the crankshaft sensor with a new one since its under warranty.
2. Change ALL CABLES (for spark plugs)
3. Change ALL SPARK PLUGS

Now the question is where do I buy original spark plugs and cables?

Thanks

Plutoe

Well I think you are making a big mistake buying anything until you know what is wrong.

However you sound very typical spend 70 bucks here, spend 100 bucks there, spend 30 bucks over there and still have the problem----then you PAM when you go to a shop and wants to charge you for diagnostics.!!

AMGAffalterbach

The crankshaft sensor obviously isn't the problem if you replaced it and you're having a bunch of misfires and issues STILL. There's an underlying issue that should be diagnosed first via STAR diagnostics or a Mercedes independent mechanic.

DanielDaskalo

Hi,

The reason why I want to do that is because the benz just hit about 120K miles. It has NEVER been tuned up before. So a tune up is needed even if it does not fix the issue with the misfires. If it doesnt then I will take it to a mechanic to run a STAR diagnosis on it.


Thanks GUys

AMGAffalterbach

Well you should do regular tune-ups as part of the maintenance of the car anyway, but this isn't pertinent to the issue at hand. I have a feeling it might be some type of ECU-fault or electronic issue, but misfiring isn't always a safe situation for the engine so I would get it in as soon as possible and get scanned.

Good luck, let us know what the outcome is.

Critter

If the car has 120k miles and no tune up, then a set of spark plugs would be a good start. The plugs have been in the engine for a while so be careful when changing them out, only on a cold engine, after initial breaking of the "seal" of the plug to the engine block, spray some lubrication into the spark plug tube to lubricate the spark plug threads to ease removal. A small amount of never-seize is good practise for the new plugs going in.

vettdvr

My guess is CPS dropped out causing misfire which all was picked up on the codes. But you should follow MB maintenance and the plugs should be changed.

VII

If you are going to diagnose this your self you need to read up on the CPS and its part on the engine timing functions.
The CrankshaftPS works with the CamshaftPS to determine the position of respective cranck/cam shaft. The position is physically determined by the timing chain and the variable cam gears and fixed crank gear which bind the whole system.
The determined position from the sensors will determine cam gear adjust and firing time operation.

While a proper diagnosis is recommended prior to spending on parts I second vettdvr. A loss of CrankPS signal would leave the engine control module blind for a few moments and no/incorrect firing signal would be produced.
In this scenario remember that both the CPS and the wiring to it may be faulty and both should be checked. (I'm more inclined to think faulty wiring produces an open circuit with high engine vibration or loose CPS looses signal with high engine vibration. )

Goodluck!

VIPCHOI

I also just got the P0303 code on the E350 with 117K miles
Did changing the spark plugs work?

Also got P0015, P0025 code
where can I get camshaft position sensor? how many are there?

Plutoe

What is your VIN???

VIPCHOI

WDBUF56J76A807808

Plutoe

You have four camshaft hall sensors and you have four solenoids.

You are messing with things that are very technical and without the proper diagnostic tools------the question becomes----------which one if any are faulty.

Do yourself a huge favor and find an indy with a copy of DAS Xentry---he, they or them will make your life real simple!!