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| Inconsistent Idle, Rattling Noise | |
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| Tweet Topic Started: Nov 29 2016, 10:33 AM (461 Views) | |
| VladTheImpala | Nov 29 2016, 10:33 AM Post #1 |
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My 1991 1.0L 3 Cylinder Automatic has been making a rattling sound during idle. here is an audio recording I made last night Notice also that the idle is inconsistent Any thoughts about what could be causing the rattle? Maybe motor mounts? Bought ramps last night but haven't elevated the car yet to check the underside. Any suggestions about how to pursue the diagnosis would be welcome. Any observations about the idle are welcome as well. Does it sound too low? Does the inconsistent idle imply another issue? Audio |
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| freegeo | Nov 29 2016, 11:56 AM Post #2 |
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I take it you don't have a tach to be able to check rpm's. The idle should be 850 +/- 50 rpm. If you don't have a tach and want to check it think about getting something like this. http://geometroforum.com/single/?p=1071134&t=6134884 The sound in the video almost sounds like a metal to metal contact of some sorts (like a exhaust sheild rattle). As loud as it is you shouldn't have much problem locating where it is coming from. |
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| VladTheImpala | Nov 29 2016, 01:34 PM Post #3 |
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Thanks a lot freegeo, I will definitely get myself one of these digital tachs! Once I finally get the car up on ramps and take a closer look, it will hopefully be pretty easy to spot where the rattling is coming from. Will keep you posted. Any other comments or suggestions are welcome. |
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| suzukitom | Nov 29 2016, 06:35 PM Post #4 |
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Tom
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I agree with freegeo's diagnosis. A second guess could be that a chunk of rusty metal from your exhaust system is rattling inside the catalytic convertor or muffler. |
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| VladTheImpala | Nov 29 2016, 07:33 PM Post #5 |
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Good thinking, Tom. I will check the muffler for rust. Now that we got those ramps it should be easy. I was planning on taking a look at the gas tank anyway to make sure there is no rust there. The car has no rust whatsoever on the outside or in the wheel wells, but I have never looked at the underside. |
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| ptcapboy | Nov 30 2016, 12:11 AM Post #6 |
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have you tried the ramps yet? I know on some of the cars I've had the front bumper will hit the inclined part of the ramp before the car starts going up-haven't tried it on the geo I think-would hate to see you damage your car- |
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| VladTheImpala | Nov 30 2016, 09:21 AM Post #7 |
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Haven't tried them yet. It's cold right now and we only have an unheated detached garage, so we're looking at buying a ceramic heater to keep in there while working on the car. The ramps we got are not tall so I'm hoping the bumper will clear.
Edited by VladTheImpala, Nov 30 2016, 09:21 AM.
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| Stupidmouth | Dec 8 2016, 02:40 AM Post #8 |
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I have black plastic ramps that work just fine. |
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| ptcapboy | Dec 8 2016, 03:46 PM Post #9 |
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good-I have some steel ramps that I got about 35 years ago when I had a 57 chevy but I don't think I've tried them on the metro- |
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| VladTheImpala | Dec 12 2016, 12:25 PM Post #10 |
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Mine are black plastic ramps too and they worked just fine when I use them last week to drain a small amount of tranny fluid in order to top it off with the Gunk stuff. The automatic transmission had some trouble shifting after a transmission flush, but adding some Lucas and Gunk brand Trans-Medic fixed it and it's shifting fine again. |
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