Error Code p0170

Fanatics:

My 2000 323i was experiencing poor driving at times, leaking oil, and SES. I took it to nearest dealership to have the problems diagnosed. They told me it was leaking from the valve cover gasket and the oil filter housing gasket. The SES was from a faulty camshaft position sensor (intake). I had replaced the CPS twice in the last year, so I was dubious that it was actually the cause. Also, the crankcase vent valve was bad and it, along with both intake boots needed to be replaced. Of course they wanted $1700 for all this. I bought the new ccv kit, intake boots and gaskets. I installed everything and she runs great, BUT... The SES light comes on occasionally now. If I let the car idle for more than a minute or two, the SES light comes on. It throws the cylinder misfire code - usually 1 and 3, but at times others and P0170. I have checked all the boots and hoses for tears or poor connections and find none. The thing is, if the SES light comes on while idling, I can turn the key off, restart, and the light goes off. If I go ahead and drive with the SES light on, it's very sluggish. I'm stumped. Help.

Is this occurring only when idling/warming up cold?

Do not warm up your car at idle.

People have had similar problems while warming up at idle.


Edit: the Sluggish part sounds like symptoms of a bad CPS...why it might have failed again? Not sure.

It had only happened when warming up, but today I left it on while I ran into to house to get something. I was away for about 2 minutes. When I came back the SES light was on. I read the codes, then turned the car off and restarted. No SES.

How do I warm up the car when it's freezing?

Originally Posted by Realtorscott

It had only happened when warming up, but today I left it on while I ran into to house to get something. I was away for about 2 minutes. When I came back the SES light was on. I read the codes, then turned the car off and restarted. No SES.

How do I warm up the car when it's freezing?

Drive it under 3-4k until operating temp is reached.

Sent from my SCH-R530M using Bimmer App

Not following any of the above discussion!! it seems to be grasping at straws.

With your description and multiple codes, I would first look for vacuum leaks in the intake system. Inspect the rubber boots going from the MAF (Mass Air Flow sensor) to the throttle body, especially the small leg that connects to the idle control valve, down by the throttle body. Additionally, inspect all vacuum and air handling hoses. Another common vacuum leak source is the crankcase ventilation system.

If you cannot find any obvious vacuum leaks, you can have the system

^Smoke tested...To finish my sentence

Heechkass:

I just replaced all the intake boots and have removed them again to make sure I didn't tear one or poke a hole in them. They're all good. I have also seen many posts about the hose from the bottom of the vent valve (oil separator) to the dipstick tube, but it is sound also. I have ordered one anyway. This morning, I warmed car up by hold the accelerator at about 2000 for a couple minutes. I drove my daughter to school with no problems. When I got home, my son's jeep wouldn't start so I left my car running while I got the jumper cables - 1 minute tops. SES light on, sputtering idle. I turned the key off and started again - no SES. I'm stumped. Nearest dealership is 250 miles away., so I can't just run down and have an expert check. Hopefully that sheds a little more light. Help!

Originally Posted by heechkass

Not following any of the above discussion!! it seems to be grasping at straws.

With your description and multiple codes, I would first look for vacuum leaks in the intake system. Inspect the rubber boots going from the MAF (Mass Air Flow sensor) to the throttle body, especially the small leg that connects to the idle control valve, down by the throttle body. Additionally, inspect all vacuum and air handling hoses. Another common vacuum leak source is the crankcase ventilation system.

If you cannot find any obvious vacuum leaks, you can have the system

Not to discount your advice, as I agree, but I have read about misfires caused specifically in 323's or m52tu b25's as a result of warming up on idle.

OP stated that this occurred while warming up at idle revs, so I am relaying the info.
Definitely NOT grasping at straws here, just starting with the easiest step first...following the manuals instruction is always a good start, as it does say do not warm up the car while idling.

I didn't know about cold idling. It seems to do it when idling warm too. The next step seems to be o2 sensors. I hate to spend that money if its not the problem. I have cleaned the MAF before, but its been a while. I guess I will try that and see if it helps.

A car should be able to warm up idle or revving without throwing codes. The fact that is throwing these specific codes after you did the ccv overhaul makes me believe that something happened during that process.
If I read correctly you weren't getting these codes until after the work. Is that right? If so, and you're confident all parts went back correctly, I think spending the money or time on the smoke test would be wiser than buying the O2 sensor.
Either way it will be interesting how you proceed and what you find.

I have to apologize, I remembered incorrectly on the warm up at idle causing the misfire. I was confusing a couple of topics.

I will stand by what I know the manual to say with regards to warm up procedure.
Where I was wrong was; that this alone does not cause the misfire, but that it usually manifests itself on cold starts.

Here is a thread that might be useful, particularly jofjs response...if nothing else use this, to see his SIG for more info.

http://forum.e46fanatics.com/showthr... advise needed

Originally Posted by jfoj

Suggest you read the first 2 links below in my signature.

Very common for misfire on cold start, shut car off and then restart things are fine. This is somewhat "normal" when you have vacuum leaks causing misfires with fuel shut off.

Suggest you check the SAP hose if you have one like suggested above. Check DISA and DISA O-ring and CCV lower oil return line, these are VERY common problem areas.

check your breather hose