E46 Cold Start questions

[GPGrobler]

Hallo all,

Is the E46 320i "moody" when it comes to cold starts?

I am asking the question because the car does the following:

1.) I Need to start the car twice or more before the engine keeps running.

2.) The car does not start with my foot off the accelerator pedal.

3.) The engine "cycles" between 500 and 800 rpm for about 60 seconds before it picks up rpm and starts to idle evenly at about 1000 rpm.

4.) With temp the needle off the cold mark, about 1/4 up, the engine does the same "cycling" thing when I put the car in gear and slowly drive the car forward or in reverse.

So, is it the same problem as with the E30, the cold start sensor(s) is/are defective, or is the MAF dirty or the DISA faulty?

 

[Pho3niX90]

The DISA is easy to inspect, will take about 15min to remove and you will see if the flap is broken / loose / chewed / or extremely dirty and gunky.

With all your problems you are receiving I would suggest to get the codes read instead before going on a replacement spree, in the meantime have a look at the DISA as it won't hurt to give it a good clean if it's fine.

 

[GPGrobler]

Thank you, I am really impressed with the car so far, as I have been with my E30 for many years, so I'll definitely give it a chance. I will also contact the seller because he has a connection who can pull the codes and see if any serious problems exist.

Also, do these engines warm up to the halfway mark on the temperature meter?
I checked the coolant level and it is fine and the coolant also seems to be fresh.
I am not used to this reading because my E30's temperature only goes to the first quarter of the meter, and only in heavy traffic does it go to the halfway mark.

 

[Kyle]

Thank you, I am really impressed with the car so far, as I have been with my E30 for many years, so I'll definitely give it a chance. I will also contact the seller because he has a connection who can pull the codes and see if any serious problems exist.

Also, do these engines warm up to the halfway mark on the temperature meter?
I checked the coolant level and it is fine and the coolant also seems to be fresh.
I am not used to this reading because my E30's temperature only goes to the first quarter of the meter, and only in heavy traffic does it go to the halfway mark.

Halfway is normal :thumbs:

 

[Pho3niX90]

Yes should sit at the center, shouldn't really ever change unless there are problems.

 

[Philip Foglar]

I think your best bet is to have the codes read!

But to mirror what was said above: Normal operating temperature the temp gauge sits halfway, the engine should start and not hunt at all from cold. And the engine should not need you to press the throttle down when starting - in fact, you are not actually supposed to do this anyway on modern EFI cars.

 

[alucard]

Vacuum leak was the cause on my car (E46 330i, totally different engine though). But only idle hicupped,no stalling or starting 2x times ect.

The hose going down from CCV (Crank Case Ventilation) was torn near the connector.

Worth checking for vacuum leaks first before diagnosing the electronic bits as a vacuum leak can throw them off too!And its a cheap fix.

Sent from my Nokia 3310

 

[Philip Foglar]

Vacuum leak was the cause on my car (E46 330i, totally different engine though). But only idle hicupped,no stalling or starting 2x times ect.

The hose going down from CCV (Crank Case Ventilation) was torn near the connector.

Worth checking for vacuum leaks first before diagnosing the electronic bits as a vacuum leak can throw them off too!And its a cheap fix.

Sent from my Nokia 3310

Well, different capacity, but much the same engine in reality - M54B22 vs M54B30. So definitely things for the OP to take note of above! :thumbs:

 

[GPGrobler]

Feedback, this car is weird - this problem fixed itself! The car simply no longer does any of the above :roflol:

 

[Philip Foglar]

Was it "struggling" to start mostly on hot days, or basically considerably warmer than it is now? I wonder if you don't have an issue with your MAF sensor (is measures ambient temperature and air flow)...

 

[GPGrobler]

Hi Philip,

The car stopped doing all of this altogether, in any temperature. She had a very serious misfire the first week I had her, that turned out to be condernsation in the spark plug chambers and underneath the valve cover. After that it did the funny running in the morning a few times, now it is gone, to me this all points to condensation in the wrong place, because the car was parked outside for a week in wet conditions without the car being driven.

 

[Philip Foglar]

Hi Philip,

The car stopped doing all of this altogether, in any temperature. She had a very serious misfire the first week I had her, that turned out to be condernsation in the spark plug chambers and underneath the valve cover. After that it did the funny running in the morning a few times, now it is gone, to me this all points to condensation in the wrong place, because the car was parked outside for a week in wet conditions without the car being driven.

Do you ever move the car a short distance in the morning from cold and then switch off? Or any short distance driving?

As you said above, condensation and especially if the engine was running from cold for a short period of time can cause this. It happened to my Wife's car a few years ago - she had moved the car out of the garage (think it was around this time of the year too) one morning, then ended up just bringing it back into the garage that night. So the car had two cold starts where it just moved a few metres. The next morning when she started the car it was spluttering and misfiring the whole time, thinking it would clear she drove off, nope, it continued to misfire! She phoned me to tell what it was doing and I told her to come back home so that I could hear what it's doing. When I got to the garage she had already parked and turned the engine off, fine, so she then started up again for me to hear - this time it was running fine.

Now she understands why I am so full of nonsense about not driving short distances or moving a car a short distance while it is still cold...

 

[GPGrobler]

I was going crazy, the car was running really badly only a few days after I bought it, I thought this time I really bought a lemon. To confirm the condensation thing even further, the car has what looks like a sneaky water leak ("newspaper detector" gets wet under car, but no puddle of water or no dripping, so it just oozes out from somewhere) which I will also look at when changing the Vanos seals. I'm just glad the water that seemed to be vanishing from the radiator was not vanishing into the engine.

 

[Peter@AEW]

Before you start work on the car disconnect the battery cable.
Do not disconnect any of the engine plugs whilst the battery is connected.

Whilst you are in the boot disconnect the positive and negative leads.
Then join them for about 5 minutes (take a jumper cable and join the positive lead to the negative lead) that will reset your adaptations and you can start the car with a fresh ecu memory.
If you have stored codes they will not be wiped.
Best you get a reader and see if any codes and erase.

When you reconnect the solenoid plugs spray some Q20 on them.

Only reconnect the battery once all electrical plugs have been reconnected.

 

[[email protected]]

My e46 did the very same thing 2 weeks ago. It had the exact same symptoms, and suddenly "fixed" itself, and has been lekker since then. I did some research and alot of e46 320i's seem to have this problem. Some say its the crank sensor. Other mentioned a decat solved the problem.

Please let me know if you find the problem...would love to know what it does it.

 

[GPGrobler]

Before I bought the car it was driven extremely short distances, taken out of storage, driven about 15 metres, put on display for the day, driven back into storage only about 15 metres at the end of the day too, for about six days in a row. I think Philip would have gone bonkers if he saw it!

---

My e46 did the very same thing 2 weeks ago. It had the exact same symptoms, and suddenly "fixed" itself, and has been lekker since then. I did some research and alot of e46 320i's seem to have this problem. Some say its the crank sensor. Other mentioned a decat solved the problem.

Please let me know if you find the problem...would love to know what it does it.

Did you decat the car and redo the Vanos as yet? My take on
The crank sensor is that the problem won't go away, as it is an electronic problem.

 

[[email protected]]

Before I bought the car it was driven extremely short distances, taken out of storage, driven about 15 metres, put on display for the day, driven back into storage only about 15 metres at the end of the day too, for about six days in a row. I think Philip would have gone bonkers if he saw it!

---

My e46 did the very same thing 2 weeks ago. It had the exact same symptoms, and suddenly "fixed" itself, and has been lekker since then. I did some research and alot of e46 320i's seem to have this problem. Some say its the crank sensor. Other mentioned a decat solved the problem.

Please let me know if you find the problem...would love to know what it does it.

Did you decat the car and redo the Vanos as yet? My take on
The crank sensor is that the problem won't go away, as it is an electronic problem.

---

Haven't done either of those yet. Planning on doing the VANOS real soon though. One thing I forgot to mention was that I fiddled with the coil packs when the car did it's funny. My boet told me he had a faulty coil pack on one of the cylinders on his e39 528i. This obviously caused hectic misfire at frequent intervals.

 

[GPGrobler]

Same here, we just took out the coil packs and put them back, but that was after the misfire already cleared up.