Grand Moff Joseph Posted August 14, 2009 Report Share Posted August 14, 2009 Beginning this morning, I have been hearing a pretty loud rattle sound coming from the car at highway speeds (60+). The noise goes away as soon as I slow down from highway speed for more than a minute or so. Conditions needed to replicate issue: -Run car to operating temp -Drive at highway speeds for more than 15 minutes Symptoms: -Car begins low rattle, quickly picking up in volume within a few minutes; rattle seems to be preceded by a small burning smell coming through the vents. A/C status has no effect on smell though. -Rattle drops down significantly if foot off gas, gets a lot louder when gas is back on, or if speed increases -Rattle continues once car slows down for ~1 minute, then goes away Other factors: -All fluid levels are correct and healthy -Idle is normal, power levels at normal levels (read: no slower than usual, lol) VIDEO! (plays with QTime) http://www.mst.edu/~jricca/car1.3g2 http://www.mst.edu/~jricca/car2.3g2 ------------ My first thought is to look at the exhaust, specifically the cat. Any other ideas folks? Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted August 14, 2009 Report Share Posted August 14, 2009 Exhaust was my first thought Quote Link to comment Share on other sites More sharing options...
gp13069 Posted August 14, 2009 Report Share Posted August 14, 2009 how about the rear sub frame bushings or even bad transmission mount. just some thoughts Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 14, 2009 Author Report Share Posted August 14, 2009 how about the rear sub frame bushings or even bad transmission mount. just some thoughts Good ideas, but I figure if any of those parts had finally gone bad, the subsequent symptoms would not be on/off in nature. Worth checking over them anyway though. Quote Link to comment Share on other sites More sharing options...
jman093 Posted August 14, 2009 Report Share Posted August 14, 2009 Hard to tell but it does kind of sound like an exhaust leak in that first video. Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 14, 2009 Author Report Share Posted August 14, 2009 Sorry about the video quality, though I was surprised how good my cameraphone was able to do at this task. Quote Link to comment Share on other sites More sharing options...
gp13069 Posted August 14, 2009 Report Share Posted August 14, 2009 is that a 3.4 duel cam engine ? when the timming belt replaced. Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted August 14, 2009 Report Share Posted August 14, 2009 no. 3.1 3 speed Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 14, 2009 Author Report Share Posted August 14, 2009 no. 3.1 3 speed Well, since you know so much about my car, how about you come over here and fix it too? Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted August 14, 2009 Report Share Posted August 14, 2009 let me throw on my magnet suit and I'll hang on the bottom Quote Link to comment Share on other sites More sharing options...
GP4U2NV Posted August 14, 2009 Report Share Posted August 14, 2009 Exhaust was my first thought x2 Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 14, 2009 Author Report Share Posted August 14, 2009 OK, well at least other people are thinking exhaust -makes feel a little less crazy. So, where should I start looking? pipe brackets? cat itself? manifold? Also, any good ways to identify a broken seal/gasket/etc.? Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted August 14, 2009 Report Share Posted August 14, 2009 I'd check the DP. jackt the car up, get a few extensions and a swivel and a 13mm socket and make sure it's tight. or, pull the motor forward like you are doing plugs and climb on top. You can get to it that way too Quote Link to comment Share on other sites More sharing options...
Brian P Posted August 14, 2009 Report Share Posted August 14, 2009 I wonder if you can get this rattle to appear while in park and revving the engine around 2000 rpm or so. My first thought is catalyst or something exhaust related. Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted August 14, 2009 Report Share Posted August 14, 2009 I listened to the video, and talked to MothMan... The tick I hear sounds more mechanical than anything... I think he is having a oil pressure issue. His oil pressure, when stopped at a red light, after running on the highway, is just at the first hash mark, 1/4 of the guage. I know this pic is metric, but we should be able to get the same idea.. (Borrowed pic from 1990Lumina) Now on my TGP, and 6000, when cold, it reads about 3/4 of the guage, and when warm, it reads at 1/2 guage, or maybe just slightly under the halfway mark, then going to 2/3 when the rpms go up. He said that his, when hot, at idle was at 1/4, and I think he said that his was at 1/3 when under rpms. This, to me, makes me think that their might be some oil starvation going on. I suggested that he change his oil to a 10w40 regular dino oil to see if this helps with it... But first, just to make sure it isnt a exhaust leak, take it to an exhaust shop, and let them look at it. It could be a gasket or doughnut ring, or something along those lines. Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 17, 2009 Author Report Share Posted August 17, 2009 After speaking with Brian, I decided to document the oil pressure activity on the car - at least what the GM oil gauge tells me anyway. Cold start: Oil is pegged at near 80, regardless of engine speed Warming up: Oil sits around half-3/4, regardless of engine speed Hot idle: Oil hovers near first hash mark (1/4) Hot @ speed: Oil jumps to 1/2 or better, depending on engine speed. VIDEO while engine is hot and in park: http://www.mst.edu/~jricca/car3.3g2 Quote Link to comment Share on other sites More sharing options...
Brian P Posted August 17, 2009 Report Share Posted August 17, 2009 what's wrong with that? Quote Link to comment Share on other sites More sharing options...
1990lumina Posted August 17, 2009 Report Share Posted August 17, 2009 My Lumina (same car as the picture on previous page) will go down to 1/4 on the guage sometimes when the motor is hot. @ 1100rpm it'll go to 5/8 or so though. I was told this is normal operation - something to do with the oil pump and not having special springs or something in it to keep the pressure higher when spinning slower. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted August 17, 2009 Report Share Posted August 17, 2009 To me that sounds like a fucked lifter or something ticking away. We had a Kia Sedona w/ the 3.5L in it on our lot that sounded like that all the time regardless of temperature. I put in two bottles of Forte Engine Flush, ran it hard in the shop and got it real warm. Then I drained the oil and put in new shit with a new filter and a bottle of Forte Oil Fortifier. The noise was still there so I left it out back running for an hour or so. When I went to go check on it the noise had gone away completely. Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 17, 2009 Author Report Share Posted August 17, 2009 what's wrong with that? Well, the new video seems to eliminate the oil starvation issue, assuming the gauge can be trusted. I'm having my mechanic to a manual pressure to check to verify the gfauge's accuracy. Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted August 17, 2009 Report Share Posted August 17, 2009 Yea, that vid eliminates the oil starvation issue, big sigh of relief there.. The key things here, after talking with MothMan, is that this noise started right after he got it out of the shop. It was in the shop getting the AC system replaced, and a oil change. I asked MothMan if the noise stopped when he turned off the AC, and he said it didnt. So I am in agreement with 1990Lumina, a lifter. Maybe some engine flush or whatever might fix it. When I looked in his engine when I was doing some work previously, the lifter areas in the valve covers looked flawless, and brand new almost. So the thinking is, its most likely not a oil starvation issue. Collapsed lifter? Valve lash? or??? He has it as his shop, and they will tell him whats up.. Hopefully its nothing major.. Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted August 17, 2009 Report Share Posted August 17, 2009 Run some seafoam through the oil. Quote Link to comment Share on other sites More sharing options...
Grand Moff Joseph Posted August 17, 2009 Author Report Share Posted August 17, 2009 Run some seafoam through the oil. Sounds like a good idea, Adam. The oil was just changed about a week ago, and there's less than 100 miles on the new oil. Should I add the seafoam to the existing oil, or add it in with a fresh batch? Either weay, I'll have to change it anyway once the seafoam is done, right? Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted August 17, 2009 Report Share Posted August 17, 2009 Well, here's a tidbit. a coworker has a 01 status with the 2.7 sludge master engine. he has over 150K on it now with no problems yet. i told him about the possible problem about 4 years ago and ever since, he puts in about half a can of seafoam with every oil change to possibly help keep it from sludging up and killing the motor. In your case, i'd put in about a quarter can, or 4ish oz and run it for a week to work and see if that possible suck lifter comes loose. That's my $.02. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted August 18, 2009 Report Share Posted August 18, 2009 We use this: Flush: http://www.forteuk.co.uk/Advanced_formula.htm Add this to the new oil: http://www.forteuk.co.uk/Oil_fortifier.htm Quote Link to comment Share on other sites More sharing options...
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