Engine Mechanical problem
2002 Mercedes Benz CLK320 6 cyl Two Wheel Drive Automatic 98000 miles
Where is the fuel filter located on this car?
I drove up to an intersection fine and by the time the light changed my car would not go. It was still idling but you could not rev up the engine and you had to hold the gas pedal down and keep it there then it would finally move very slowly. Felt like it was completely loaded up but had no other problems.
This is more likely to be your throttle position sensor than a fuel filter. The TPS sensor transfers the motion of your foot on the throttle to the throttle body. When this sensor goes bad, no throttle response will be present.
February, 16, 2009 AT 7:39 AM
Thanks for the response. I did learn it was the TPS sensor (at least that is what I thought) but I changed the TPS sensor and exacty 2 weeks later it did the exact same thing so I thought I got a bad sensor, took it back to Mercedes and got another and exactly 2 weeks later the car did exactly the same problem again. Then it got to the point where it kept stopping over and over so I sent it to the place I bought the car and they had it for two weeks and never found a problem.
Again, car runs great, come to stop idles fine but then will not respond to throttle at all. If I disconnect the battery it will reset and then work fine so that I can drive home and actually drive for a week or two before it would do it again.
The car stopped doing this problem late last summer but I have no idea if it is fixed or what the actual problem was. I am afraid to trust it.
Do you have any ideas now?
February, 16, 2009 AT 11:14 AM
Here is another issue that is common to this vehicle. Often times the Crankshaft Position sensor will get moisture damage to the sensor itself as rain can often times collect around the sensor. The sensor can be viewed by placing yourself at the drivers fender with the hood open. Look behind the motor to the top of the transmission bell housing. You will see a sensor mounted in the upper side of the housing (only sensor mounted here, should be a 2 wire sensor). This is your crankshaft position sensor. When the sensor shorts it losses signal and the position of the crankshaft. When this happens the vehicle will turn off. It can often times be restarted later but will kill the car for a period of time. Many times by unplugging the battery you can get it to come back. I have seen this on a few MB vehicles and chasing the issue is not easy since often times the fault is so intermittent that is will set no fault codes giving nothing to diagnose off of. I would recommend inspecting the connectors at the Crankshaft sensor for rust or corrosion. Disconnect the electrical connector from the Crank sensor and inspect the inside contacts. If you see signs of rust or any sign of corrosion then this is more than likely your issue. You can use electrical component cleaner (available at auto parts stores) to clean up the contacts of the wires and sensor. However if corrosion is too bad you may need to replace the sensor and connector. Keep me posted as to what you find.
February, 16, 2009 AT 12:29 PM
Thanks again for the tip. I will check that out to see what I can find there. My only concern with what you are saying is about that sensor is that the car never dies. It always continues to run and it idles perfectly but when it acts up it just does not repsond to the throttle action. Is this still in the same area of the problem I am seeking?
Thank you for your help!
Lonnie from Indy
February, 16, 2009 AT 1:15 PM
If your not seeing a response in throttle. When you psuh on the accelerator when this happens do the RPM's rise and the car doesn't move, or is there no raise in RPM's, almost like the accelerator is not even attached to the engine?
February, 16, 2009 AT 1:32 PM
Sorry, I don't think I clarified this from my original message.
Once the car is stopped it still idles perfectly but there is no response from the foot accelorator/throttle. No RPMs, no nothing. Unless you push the throttle all the way down to the floor and hold it there and then the car will wind up like a rubber band and take off like a rocket but you can only move if you are completely rapped out in the lowest gear and once you let up it comes to a stop and you have to floor it and hold it down until it will move again.
Like I said though, I can unhook the battery and it will clear it and run fine. The guys that were working on my car claim they never found any codes showing this activity either. Maybe unhooking the battery was clearing the codes too?
Again, the car never dies. It always idles perfectly.
Sorry for any confusion, it has been awhile since I have been having the problem or working on the car so everything was not fresh in my mind. I believe you have the complete story now.
Lonnie from Indy
February, 16, 2009 AT 2:32 PM
This has to be a problem with the Throttle Sensor. From what you are describing the only component that can cause no throttle response is the TPS sensor. Since it has been replaced twice already and has not fixed the issue I would say possibly the sensor is not the problem however the Circuit that services the sensor may be. You may have poor contact at one of the connectors or perhaps there is a pinched wire in the circuit that is grounding out intermittently. If the sensor shorts to ground you will get no throttle response and it will be very intermittent if it is not hitting a ground point all the time.
February, 16, 2009 AT 2:58 PM
Ok, I am following you. Since the car has not been having the problem in quite a while and since I live in central Indiana I have not been driving my car the last couple of months (won't drive it in snow and ice) I cannot test or look for your suggestions on my car until it acts up again.
I can tell you that one shop that I talked to told me that if it wasn't the TPS Sensor then it had to be the Throttle Body and they said the Throttle Body would be about $900.00 by itself but they still did not make me feel like they knew what they were talking about. I have a real difficult time finding a shop that I can trust because I keep catching them trying to screw me when they think I have no clue what they are talking about.
Anyway, I am new to this website and the donation procedure. Please advise me as to what is acceptable in a donation here. I did not realize that I was suppose to give a donation when I posted my question or I guess I could have had an answer back 6 or 7 months ago when I really needed it.
February, 16, 2009 AT 5:35 PM
A donation is not necessary as this is a free service. However if you feel inclined to do so next time, it can be done when the question is asked and then your question will be responded to usually within 24hrs. I appreciate the gesture.
Now back to the problem. It's unfortunate that there are a lot of poeple just trying to make a buck but throwing parts at a car solves nothing most of the time, just empty's your wallet. Throwing a throttle body at it may work but if it doesn't your out another grand. Here's what I would try first. Below is a diagram. The circled image is your throttle body. The arrow is pointing to the connector at the throttle body. Now this image is reversed so the throttle body will actually be at the back of the motor. Find the connector I've draw the arrow to.
Now disconnect this (car off keys out). What I want you to do is look at the internal connectors (small pins). Do any of these have any sort of corrosion on them? Is their oil in the connector? Do they all look clean?
Next, holding the plastic connector in one hand pull on the wiring to it slightly and look at the pins. Do any of them move backwards? Do any appear to be very loose?
What we are checking here is to make sure that this is not being caused by a floating electrical pin. Sometimes the plastic retainers can become brittle over time and will actually pull out slightly due to movement of the motor. This creates a very intermittent and nearly untraceable issue.
After you have inspected the connector, plug it back in. Now with the vehicle in park and the motor running, rev the motor. If you have throttle response continue. Now have a friend lightly pull on the harness of the Throttle body. Give it throttle again. If you loose throttle response at anytime here your electrical connection is your problem and can be remedied by replacing the platstic electrical connector.
If you have no change, try this next time the issue happens. Turn the vehicle off and disconnect and then reconnect this electrical connector. I have a feeling that your issue is more wiring related than component related. Get back to me with any results, also next post if you can give me your vin # I will check for any know wiring or throttle issues for your particular vehicle.
February, 16, 2009 AT 7:40 PM
Here is the VIN # WDBLK65G62T114732
Is there a direct way to reach you because it may be a while before I am able to determine the problem on my car?
Thank you very much for you help and about the donation!