I am hopingsomeone can help me out with an issue i am currently having. Whenever I 1st start my 2000 E320 (cold weather usually)I have to let the car warm up about 10 minutes beforeI can put it into gear to take off or else the car shuts off. Keep in mind the car turns on perfectly.

In additionI tend to feel a little hesitation in the idle lately. I am wondering if these issues go hand in hand.I keep my car in great shape and i just cant seem to understand the problem. I am not getting a single error code.

I have changed the following parts in my car in the past few months.

- MAF sensor
- Fuel pump
- Spark Plugs
- Ignition coils
- Crank shaft sensor

The car has 145K miles. I have been getting so frustrated.. could anyone help me out?

 

Appears to be an air inlet leak.

Any additional info as to when the problem started. At a service interval maybe. Vac lead off / leaking / air cleaner correctly seated?

Stuart

 

This problem began approx a month ago. I thought it was the intake tube also that connects to the back of the engine but it turned out not to be. The entire intake is actually mounted 100% properly with no air leakage into the engine. I had my mechanic smoke and black light the unit for an airleak last week and it turnedout negative.

Iam not sure what you mean by the vac lead off or air cleaner seating.

 

So what happened about a month ago that might have initiated the problem? Service?

So why did you change the following over the last few months?
- MAF sensor
- Fuel pump
- Spark Plugs
- Ignition coils
- Crank shaft sensor

Looks like you have been looking for this problem longer than you suggest.

Crankcase breathing is thru the inlet system. If this is disconnected / open to atmosphere for any reason it allows air into the system which would give you symptoms similar to those you have. I still suspect an air leak.

Engine speed should be controlled by a closed loop system. The engine measures idle speed and alters idle to match specification thus taking into account high engine loads at idles. A/C, headlamps etc.

Is Air Con On or Off, or maybe it doesn't make a difference, when the problem occurs?

Sure there are no codes especially misfire.

Gut reaction. Have you confirmed cylinder pressures are OK and even?
Could be plug leads although I think not since no codes set.

Did the problem occur before or after the change of the above components. Were they OE parts?

Stuart

 

I have been trying to upgrade performance in the past couple months. Figuring its a 2000, i wanted to make it stronger.I have been feeling a lack of power with time. Its only the past month that the shutting off has been occuring in the mornings or when i first use the car. That is what has me going nuts. The car is lacking power and i feel it is diminishing more as time goes on. I sometimesfloor the gas and it just doesn't have the response it used to. It got worse when i took the car on a 155 mile ride to PA. Thats when i decided to change the fuel pump because the pump was making a pretty bad noise. It actually sounded like it wasn't letting the gas flow thru. At this time the lack of power makes the car shake a bit as if it wants to shut off. There is definately something preventing the gas from circulating (at least it feels that way). I changed the MAF sensor because someone saidit was a possibility that it would have been the problem.

The crank shaft sensor i changed towards the end of the summer because the car would shut off when it got too hot. I also changed the plugs and coils to give it a smoother ride. To be honest all changes helped the performance in one way or another.I also changed the bottom 2 O2 sensors. I was wondering if i should have changed the top also.

The readingI was getting from my mechanics computer shows that the cylinders are on point. I am not sure about the pressure of the cylinders but i am sure he would have measured everything. I am actually going to take it into the dealer next Friday to see if they can pin point this. The frustration is driving me up a god damn wall.

It really doesn't matter if the AC or the heater is on, the car reacts the same way. I just wish the car would just drop dead so we can finally figure out what is wrong.

By the way, i only buy dealer parts.It wouldn't pay to put aftermarket crap into my car so thatI can end up having to do the job twice or possibly even destroying something else because of its poor quality.

I appreciate you taking the time to help me out Stuart.

Diz

 

Hi Diz,

I now have a much clearer of your issue.
However I'm still not sure EXACTLY what you mean by loss of power. IF you mean the car is not quite as quick as you would like then maybe there is nothing much, if anything, other than the cold stall issue. Why not do a 0-60 mph standing start. How many seconds? How does this compare with the book figure?
IF however the power is significantly down and the pump was real noisy MAYBE the fuel filter strainer in the tank is clogged? However I would have expected at least a misfire code at high revs. Need to check fuel rail pressure to ensure that fuel is being delivered at the correct pressure to the injectors. If the pressure is low then the MAF would attempt to compensate and in the process possibly set codes 0170/3. C
So I'm not being much help but the trouble is I have no codes to go on other than words like "hesitation".

Make sure the garage do a compression check. Not something that they would normally do, I will be interested in what they find.

However here is my last (looong() shot at a possible cause. You associate the start of the problem with the ":upgrading" that you have been doing over the last few months.
Assuming that all the kit was MB spec and that it was new and functioning correctly (not doubting BUT...) then I wonder. Could you have replaced one of the plug leads incorrectly?
Each coil pack has an A and B output and its possible to mix leads and outputs . Two plugs per cylinder on M112., 320V6

Incidentally. The front O2 sensors do all the work. The rear sensors only confirm that the front sensor / MAF / ECU / Cat have resulted in the correct O2 level in the exhaust. If not it signals a cat ineffective code.

Good luck.

Stuart