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-   -   Erratic/High Idle, Low Power, Intermittent Stalling (http://forum.e46fanatics.com/showthread.php?t=968053)

BombCenter 01-28-2013 01:56 AM

Erratic/High Idle, Low Power, Intermittent Stalling
 
Hi all, first time poster here.

Subject pretty much says it all. I own a 2002 (09/01) BMW 330i Sedan w/ Sport Pkg, stock, which of late is having some problems.

When "behaving", idle hovers between 500-520rpm, which seems and feels a bit low (kinda rough). When acting up, idle fluctuates between 500-750rpm. When being a pain in the ass, idle remains high at 750-770rpm. At high idle, the car stalls/wants to stall under acceleration from stop, doesn't matter if its low/moderate/hard acceleration, though moderate acceleration will keep the engine from dying altogether. Power is low throughout the entire rpm range, though I'm reluctant to take it past 3500k.

So, I'm trying to fix the problem, here's the possible causes I've gathered so far:
1) Bad/Dirty MAF
2) Exh O2 Sensors bad?
3) ICV/IAC (I assume these are the same thing) Bad/Stuck
4) Vacuum Leak

I'm trying to fix the problem in the order of cheapest to most expensive. So I started with cleaning the MAF. No joy. Next, I want to start replacing vacuum hoses as I'm sure at least one is cracked, but have been unable to find a complete vacuum diagram. Does somebody have one? Couple hours of Googling yielded partial diagrams.

Also, gear shifts are clonky, though I think this is an unrelated problem -- I suppose you could technically use vacuum to do some sort of matching -- but I doubt that's how ZF does it.

Any other/obvious causes I might have overlooked? I'm not much of a car guy.

drbworld 01-28-2013 02:33 AM

CCV. Period. Same symptoms.

dmax 01-28-2013 06:09 AM

The lower intake boot often cracks. See jfoj's sig file for help with vac hoses. There is a vac diagram under the hood too that might help.

TB gets stuck so that can be cleaned too while cleaning the icv.

I don't know your mileage (which helps to know), but assuming it's like most cars here, there might be a number of other basic items not maintained--plugs, filters, belts, pulleys--but rather than guess, if you haven't done so yet, get your codes read and search for them here...add them to this thread. They'll help point you in some direction...hopefully the right one. Autozone reads them for free.

///mteknikk 01-28-2013 11:42 AM

first thing to do is always check your codes

BombCenter 01-28-2013 10:41 PM

Quote:

Originally Posted by dmax (Post 15102794)
The lower intake boot often cracks. See jfoj's sig file for help with vac hoses. There is a vac diagram under the hood too that might help.

TB gets stuck so that can be cleaned too while cleaning the icv.

I don't know your mileage (which helps to know), but assuming it's like most cars here, there might be a number of other basic items not maintained--plugs, filters, belts, pulleys--but rather than guess, if you haven't done so yet, get your codes read and search for them here...add them to this thread. They'll help point you in some direction...hopefully the right one. Autozone reads them for free.

-190096mi
-Plugs approx 26k. Bosch +4 Platinums (OEM)
-Belt (serpentine) approx 2yrs (serviced at 170k when trans hose burst on fwy)
-Air (K&N), Fuel, Trans, Cabin filters less than 1 yr/20k, Oil filter less than 5k.
-Trans fluid (Mechanic claimed Esso, didn't verify) less than 3yr/45k, Oil and Coolant less than 5k.
-Never touched a pulley

I'll stop by Kragen on the way home after work tomorrow, thx for the input.

BombCenter 01-28-2013 10:51 PM

Quote:

Originally Posted by drbworld (Post 15102647)
CCV. Period. Same symptoms.

From Bimmerfest:
"The crankcase vent valve and 4 associate hoses fail and cause a vacuum leak. The valve gets stuck open and the hoses crack. These last 70-120k miles and usually fail 80-90k miles. Here are a couple diagnoses.
At warm idle, place a small plastic freezer storage bag on its side over the oil fill hole. If the bag sits on top or gets slightly sucked in, ~1", the valve is good. If the bag gets significantly sucked in the hole the valve is stuck open and bad.
With the engine off and cold, carefully remove the hose at the valve cover front corner. Blow hard into the hole. You should hear oil bubbling in the oil pan. If you don't hear the bubbling the top or bottom hose is likely cracked. The bottom hose often breaks just below the valve connection. There can also be cracks in the other two hoses."

Can also place a balloon over dipstick tube (with dipstick removed, obviously) and see if it inflates/partially inflates. Anyone got a balloon? =D

I suppose I'll start with the hoses before replacing the CCV/EGR/PCV/whatever.

drbworld 01-28-2013 11:11 PM

Quote:

Originally Posted by BombCenter (Post 15105974)
From Bimmerfest:
"The crankcase vent valve and 4 associate hoses fail and cause a vacuum leak. The valve gets stuck open and the hoses crack. These last 70-120k miles and usually fail 80-90k miles. Here are a couple diagnoses.
At warm idle, place a small plastic freezer storage bag on its side over the oil fill hole. If the bag sits on top or gets slightly sucked in, ~1", the valve is good. If the bag gets significantly sucked in the hole the valve is stuck open and bad.
With the engine off and cold, carefully remove the hose at the valve cover front corner. Blow hard into the hole. You should hear oil bubbling in the oil pan. If you don't hear the bubbling the top or bottom hose is likely cracked. The bottom hose often breaks just below the valve connection. There can also be cracks in the other two hoses."

Can also place a balloon over dipstick tube (with dipstick removed, obviously) and see if it inflates/partially inflates. Anyone got a balloon? =D

I suppose I'll start with the hoses before replacing the CCV/EGR/PCV/whatever.

This test didn't do anything for me. My hoses were fine, but my valve failed a different way.

BombCenter 01-28-2013 11:22 PM

Quote:

first thing to do is always check your codes
Will do. I should know better. Being IT, log data is invaluable; I've gotten people fired with it. Leak secrets on MY network, yea right.

On a side note, do codes always trigger CEL? With all the idle problems and no CEL sometimes I think my CEL led is broken, but it lights up on position 2 in ignition. I guess I kind of answered my own question. Last time I had codes checked all I had was trans slip, which I can't really do anything about without rebuilding the trans. Fluid and filter had less than 1000mi at that point.

BombCenter 01-28-2013 11:24 PM

Quote:

Originally Posted by drbworld (Post 15106029)
This test didn't do anything for me. My hoses were fine, but my valve failed a different way.

Ah, OK. Good to know. I'll forego the test then.

Any recommendations on E46 OBDII Scanner? There's so many, and some read only generic, some read factory, some only partially read factory, etc. I'd be willing to spend around $100-150.

EDIT: If it'll read codes from an E90/92 and an 06 Lotus Elise SC too, that'd be great, though not a requirement.

drbworld 01-28-2013 11:51 PM

Inpa. Absolutely the best. Unless u can get gt1.

dmax 01-29-2013 05:31 AM

autozone reads codes for free...but since you're IT, you'd probably enjoy playing with some program after you fix your issue.

jfoj 01-29-2013 05:31 AM

If you have a Droid device, Torque Pro for $5 and a $15 ELM327 OBD to Bluetooth adapter from Amazon is a good generic option.

Since you are in IT you likely have a laptop available? Another generic option for the laptop for under $30 is - http://forum.e46fanatics.com/showthread.php?t=967204

A nice generic stand alone tool that will read real time data and has some level of internal graphing is this tool, http://www.careucar.com/wholesale/la...de-reader.html

I have this and it is actually the 1st tool I always grab as it is dirt simple, reads real time data and can graph internally. Internal graphing is not the best, but it is useful at times. I do not know of another generic tool that has this option for the price.

BMW specific you likely would want either BMW Scanner 1.4.0 - http://www.xcar360.com/bmw-scanner-1...scan-tool.html

or http://www.newegg.com/Product/Produc...9SIA1PU0KJ1976 however this has shown out of stock for a while.

or since you also want E9x coverage as well, you might try this - http://www.xcar360.com/bmw-dash-scanner-3-in-1.html

Or this which also includes INPA and a 20-16 pin OBD adapter -
http://www.xcar360.com/bmw-diagnostic-interface.html

Unfortunately you really need a generic and BMW specific tool to really do everything you need to do.

GolfingDuck 01-29-2013 05:42 AM

You may find a cam position sensor fault too.

drbworld 01-29-2013 10:56 AM

1 Attachment(s)
I thought I would show how my ccv failed on me. the rubber seal was ripping, which caused it not to seal close on idle, which lead to unmetered air and oil from crankcase to be sucked into the intake manifold.


http://forum.e46fanatics.com/attachm...1&d=1359478515

jfoj 01-29-2013 12:01 PM

drbworld,

Thanks for posting the picture of the CCV failure.

What were your symptoms?

Did you ever look at fuel trims as well when this was bad?

BombCenter 01-30-2013 11:02 PM

That $25 software looks interesting. I have a couple laptops and a tablet that acts as a terminal for the PowerEdge 2U rackmount in my tech cave (aka closet). Scanner 1.4 seems like a good option too, I might be able to jury rig a Bluetooth transceiver on a USB A-B genderchanger and make it wireless, I dunno if OBD supplies power or not. If the tool doesn't read E9x, whatever, my bro can buy his own tools. Thanks for the recommendations.

I know I promised codes, and I intend on getting them, but I've had to work late the last 2 nights as we have a 12k sqft cleanroom (class 1000) undergoing startup with turnover to NASA scheduled for end of next week. And I'm in charge of all the networking (CAT6 & 50um MM OM3 16 Fiber LC-LC Duplex, and speccing/quoting transceivers and switches for connection to their existing network). I'll try again for codes tomorrow.

Thanks all for the feedback, been very helpful. I'll check into the camshaft position sensor also.

KuyaPatrick 02-02-2013 04:43 AM

does anyone have a DIY on a CCV/PCV removal and install?

THanks

e46blake 06-17-2015 12:46 AM

erractic rpm
 
So recently have been having some issues with my 2001 325I
Has a rough idel even worse when put in drive
Loud fan noise
When under acceleration rpm will drop from 3k down to 2k and back up or from 1500 to 1k and back and when this occurs I feel a vibration from the passenger side
Horrible fuel consumption

Here are the codes is have
P0171
P1083
P1085
P0174
P0102

jfoj 06-17-2015 01:09 AM

Get an OBDII smart phone/tablet App and interface, typically $30 or less. These Apps are usually best for drivability issues and they support Emission Readiness Monitor Status, Freeze Frame and Live/Realtime data. They are also great for Logging data for review after the car has been driven and can really help find usual problems.

Android - Touch Scan for $3.95 and ELM327 OBDII to Bluetooth interface.

iProduct - OBD Fusion for $9.95 and ELM327 OBDII to Wifi interface.

Read the 2 links below:

http://forum.e46fanatics.com/showthread.php?t=897616

http://forum.e46fanatics.com/showthread.php?t=929501

Need to see Freeze Frame info if the SES/CEL/MIL is on and Fuel Trim values at both warm idle and a steady highway cruise between 45-60 MPH.

P0102 means for some reason there is not likely a signal from the MAF. Verify if the MAF connector is properly plugged in, sometimes the female terminals in the connector are spread and loose on the MAF pins, sometimes there are broken wires inside the wiring harness between the MAF and the wiring box near the throttle body and sometimes the MAF just is bad with no output signal.

DO NOT buy a cheap ebay MAF, there are many Asian counterfeits on the market that do not work properly. See of there is an MAF reading in Grams/Sec. Most E46 have an idle MAF reading of between 3.5-4.0 Grams/Sec. If you replace the MAF, ALWAYS keep the original.

Note, there may or may not be Lean Codes showing up. Lean Codes usually trigger at around 10% Fuel Trim values or higher. Keep in mind that sometimes these engines can have a Lean condition that does not or only intermittently triggers Lean Codes. This is why monitoring the Fuel Trims in real time is important. Ideal Fuel Trim values are typically in the 0% to +2.5/+3.0% range.

Read this thread - http://forum.e46fanatics.com/showthread.php?t=1057387

Make ABSOLUTELY sure the O2 sensor wiring has not been mixed up, read these links:

http://forum.e46fanatics.com/showpos...0&postcount=27

http://forum.e46fanatics.com/showpos...0&postcount=26

Read my "BMW 20 Questions" comments in this thread - http://forum.e46fanatics.com/showthread.php?t=1059972

Check for or be aware of cracked valve covers and bad valve cover gaskets:

http://forum.e46fanatics.com/showthread.php?t=1021219

http://forum.e46fanatics.com/showthr...e=2&highlight=

http://forum.e46fanatics.com/showthread.php?t=1053359

This information ASSUMES that spark plugs have been checked/replaced. If they have not been inspected, you also need to check for oil filled spark plug wells due to a leaking/cracked valve cover gasket.

http://forum.e46fanatics.com/showpos...2&postcount=11

Search YouTube for Scotty Smoke Test. Do what Scotty does or build a tester from related video. Remove the oil fill cap and make sure the crankcase fills up with smoke, put the oil fill cap back on and check for leaks around the valve cover, oil fill cap, dipstick tube and CCV hoses. Cracked valve covers are pretty common on the E46 as it ages.

Note that the Scotty Smoke Test method is not so good for smaller air/vacuum leaks or fully filling the engine crankcase, for this you really need a smoke machine that can provide a solid and continuous low pressure smoke stream. So plan on building a smoke tester of you thing you will use if more than once or may have smaller and harder to find leaks.


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