Bimmerfest - BMW Forums

Bimmerfest - BMW Forums (
-   E46 M3 (2001-2006) (
-   -   prospect M3 purchase but had emissions issues (

ciback 07-05-2018 08:53 PM

prospect M3 purchase but had emissions issues
I am in the market for a E46 M3 and found a promising option. The only thing that stands out is that the car failed emissions test 4 times in the space of 4 months in Texas around the 87000 mile mark. Is that a red flag? I am looking for an M3 which is not be modified


geminiys 07-06-2018 09:30 AM

Failing emission could be a lot different things. In most part the issues is with OBDII emission monitors not been ready will cause Emission Failure. These issues are addressed by replacing part(s) at fault, clearing CEL if on, and driving for ~60 miles. You are done. Some monitors, especially Secondary Air Pump is very hard to diagnose, as if Pump is working and CEL is off the cause is unknown. In this case mechanic needs to find where the problem is. Most of the time it's the Secondary Air Pump Valve that blocks the airflow during cold starts. To diagnose this issue one can monitor O2 sensor voltage during Cold starts and compare in few minutes later. If no change in voltage swings, most likely the valve. The "lazy" O2 sensors can cause similar emission failures. Catalytic Converters will definitely cause emission failures too. Another one is if engine temp never reaches proper operating temp, will cause emission failures. This one could be due to incorrect (temperature) thermostat installed. Get an understanding of what exactly failed and do some research.

1bad540 07-22-2018 08:48 AM

Id check what failed, some of these cars were recalled due to non communication w the obd2. Mine was.

ciback 02-16-2019 06:42 PM

Thanks for the info. still in the market and am seeing that come up on multiple prospects, both of them are 2002. Having a PPI performed on one next week

Autoputzer 02-16-2019 07:00 PM

The early 2002's had the exploding engines. Make sure any 2002 you look at had the recall that changed out the connecting rod bearings.

ciback 02-17-2019 02:20 PM

I am concerned about that, was not on the carfax. I will appreciate any advice someone might have. I asked for a quote on a compression test and leak down test during the PPI but they wanted $250 each for the test. Did not think it was worth it unless they see something that makes it necessary

ciback 02-17-2019 02:34 PM

It has 117,000 miles on it. Supposedly no engine mods and not tracked

All times are GMT -7. The time now is 10:09 PM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
© 2001- VerticalScope Inc. All rights reserved.