MAF left unplugged, engine started now HORRIBLE rattling noise!!
06-26-15, 03:49 PM
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MAF left unplugged, engine started now HORRIBLE rattling noise!!
Hi, I recently purchased a 2000 ES300, I like the car so far. I was trying to troubleshoot a p0171 code and in the process I thought it was the MAF sensor. So I unplugged it and engine ran rough so I turned it off and plugged it back in but now it makes this loud rattling noise! I disconnected the battery for hours took out the maf sensor and still nothing makes a loud rattling noise! Anyone else experience this? I have read people do this all the time with no problems.....
06-26-15, 04:01 PM
#2
Why would you disconnect it and run it? That wouldn't prove anything and only result would be a very rough running engine. Where does the rattling noise sound like its coming from? P0171 that I've dealt are almost always a clogged PCV or a faulty oxygen center. I've never replaced a single MAF so far while working, just sometimes they need to be cleaned. A cheap OBD II scanner could help you diagnosis the P0171 much better than just replacing parts.
06-26-15, 04:15 PM
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The only reason I disconnected it is because that's what others do to see if they notice a difference, everyone said it would not hurt the engine. The noise sounds like its coming from inside the engine somewhere. took off a valve cover but didn't see and damage
06-27-15, 12:37 AM
#4
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I'm surprised it ran without the MAF connected at all, but I guess the ECU used a base map to compensate.
A rattle is a pretty hard noise to help someone over the internet with. You really need to record the sound in a video, at least 2-3 minutes long, and at various rpms. Load that to youtube, embed the video here, you'll get some helpful advice that way.
you rev'd it didn't you ... I bet you did. ... *sigh* conrod knock, caused by lean out + a cooked a/f or o2 sensor.
there was good oil in the engine right ?
A rattle is a pretty hard noise to help someone over the internet with. You really need to record the sound in a video, at least 2-3 minutes long, and at various rpms. Load that to youtube, embed the video here, you'll get some helpful advice that way.
you rev'd it didn't you ... I bet you did. ... *sigh* conrod knock, caused by lean out + a cooked a/f or o2 sensor.
there was good oil in the engine right ?
Last edited by ES300NZ; 06-27-15 at 01:05 AM.
06-27-15, 01:41 AM
#5
I'm surprised it ran without the MAF connected at all, but I guess the ECU used a base map to compensate.
A rattle is a pretty hard noise to help someone over the internet with. You really need to record the sound in a video, at least 2-3 minutes long, and at various rpms. Load that to youtube, embed the video here, you'll get some helpful advice that way.
you rev'd it didn't you ... I bet you did. ... *sigh* conrod knock, caused by lean out + a cooked a/f or o2 sensor.
there was good oil in the engine right ?
A rattle is a pretty hard noise to help someone over the internet with. You really need to record the sound in a video, at least 2-3 minutes long, and at various rpms. Load that to youtube, embed the video here, you'll get some helpful advice that way.
you rev'd it didn't you ... I bet you did. ... *sigh* conrod knock, caused by lean out + a cooked a/f or o2 sensor.
there was good oil in the engine right ?
Wonder where you found the idea to disconnect the MAF...
I can't think of a single way for it to prove the MAF is bad. They typically only need cleaning and rarely ever fail.
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