JimMadsen Posted September 8, 2013 Report Share Posted September 8, 2013 My engine has had a deep low rumble to it lately so I ordered a OBD2 cable on Amazon. I wrongly assumed it would have instructions and that I would be able to access their forum but that is not allowing me to register for some reason. Trying to wing it caused hardware issue with cable to program interface. So long story short, I grabbed another version of OBD2 scanner software and took a few minutes of readings. But now I am muddling around trying to find out what each reading is as well as what the norms are. Here is a csv of the short logging: http://www.2shared.com/file/aTrYQN55/jim_car.html Here is the actual log file using ScanXL Pro: http://www.2shared.com/file/EPB5jwRH/jim_car.html Around the 1 min mark where RPM's drop from @1000 to @700 is when I shifted it into drive. I did not go anywhere, this is all sitting in the driveway. The engine as I said has a low rumble to it noted mainly when sitting at a light with car in gear and not moving, or same as in test. If anyone can take a look and point me to something I need to look into or is able to point me in the right direction in the service manual, it would be appreciated. Quote Link to comment Share on other sites More sharing options...
crazyd Posted September 13, 2013 Report Share Posted September 13, 2013 We'd all like to be able to help you, but don't have a standard log reader we use like some other forums do. If you can record a video of the engine noise and post it here, that'd be something we could all use to help you troubleshoot. Are there any other symptoms associated with this? My guess would be your catalytic converter is having problems or the muffler is rotted out. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 15, 2013 Author Report Share Posted September 15, 2013 I can do that, will record a video later today and post it up. Muffler is new since I replaced everything back from the cat about 6 months ago. Did not replace the cat itself. I will also make a video of the screen playback of the log. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 15, 2013 Author Report Share Posted September 15, 2013 Youtube of scan log file: I do hve more readings that I can check for someone if they need it. Each time the screen changes, the file was restarted. The entire file was engine off to start to drive with foot on brake. I did not move the car at all. Youtube of engine in operation shifting from park to drive back to park and so on: Quote Link to comment Share on other sites More sharing options...
crazyd Posted September 16, 2013 Report Share Posted September 16, 2013 Jim, it sounds like that knocking noise might be a spun rod bearing ready to let go. Have you checked/ changed the oil lately? If not it might be a good time to drain some out of the oil pan and see if it's got some metal flakes in it or anything else out of the ordinary. 3100's are notorious for intake manifold gasket leaks, which causes the coolant to mix with the oil and turns it into a brown sludge that then clogs up the oil system and causes bearing failure. Also look for signs of a brown sludgy residue in your coolant overflow tank. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 16, 2013 Author Report Share Posted September 16, 2013 (edited) About 2 months ago I had stalling issues that turned out to be a bad new iac valve. A that time I had the throttle body cleaned out and I put the old still usable valve back in and replaced the iac under warranty. I then had a coolant drain (not flush) and refill cause dumb ole me listened to autozone who said green coolant can really mix with dexcool. So they got the brown sludge out that resulted. I was worried about gasket leak which is why I did not do it myself and they pressure tested the upper head gasket. I know that that is not the lower, but I am not too concerned there. My coolant is the color it should be and exhaust is running clear. i heard the usual ticking lifters this morning meaning oil change time. I still have a few weeks of life left but I will do the oil this weekend. My oil at change is usually a dark brown anyways. I will look for slivers in there. how can I properly diagnose the rod bearing? I thought it was just piston slap. thanks Edited September 16, 2013 by JimMadsen Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted September 17, 2013 Report Share Posted September 17, 2013 Thats not a rock knock. More than likely a combination of piston slap, lifter noise, injector noise... Especially is the motor is cold. My old 3100 sounded like that. Yours just sounds a little louder, but it could be the camera your using. Maybe its just my hearing, but I really dont hear anything out of the ordinary. Aside from the logs, what is the motor actually doing? Is there a vibration that goes with the RPM? Is it just a low rumble noise, is it doing anything else? Log files will only tell so much. Not everything. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 17, 2013 Author Report Share Posted September 17, 2013 I was afraid of the noise not coming through. I saw it was not as noticeable when recording. When engine is hot or cold, sitting at a stop in traffic, at a light etc... car in gear foot on brake I get a rumble vibration noise feeling that I can feel with foot on brake pedal. RPMs jump between say 700 and 900 while doing this. I will try and get something recorded from inside the car. My first instinct is to say a sputtering motor like a putt putt of a old boat motor but there is no semblance of balance to it. There is no common pattern to the noise. I was thinking along the lines of bad spark plug or something causing a combustion issue, thats why I got the cable to check things out, I just need to figure this all out. Thank you every one for the help. I am learning a lot with every repair. Speaking of the oil change above, I noted last change that there is gummed up oil around the seam at the bottom of the pan. I do not seem to have a leak (no oil where I park) and I was thinking at some point of dropping that and replacing the gasket. Looked at the service manual and the pan is actually pretty big, going up the sides of the engine? It was saying remove mounts and such. Should I not even bother as things are well enough alone or can I just take that bottom part off like I was thinking. Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted September 17, 2013 Report Share Posted September 17, 2013 Logging the car with cables and labtops and such, will NOT tell you if you have a bad plug or a bad wire or a bad coil. Even though it is OBD2, it will not tell you everything. You'll need to pull the plugs, check them, make sure they are properly gapped, check the plug wires. It could be many things. Once you have check ignition. Make sure fuel pressure is correct. Always check the basics before diving deeper in. That cable and setup is good to have, but for some issues, it's useless. As far as the pan gasket, if it ain't leaking, leave it alone. It's a bitch to change those. Sent from my iPhone Quote Link to comment Share on other sites More sharing options...
crazyd Posted September 17, 2013 Report Share Posted September 17, 2013 The oil pan gasket is going to be a big job with that big automatic in the way. I'd say worry about the bigger issues first. Is the diagnostic software you're using picking up any misfires, either while this is happening or at any other time? That could point you to an ignition issue that might be plugs, wires or coils. I'm also wondering if it might be the TCC malfunctioning, though that's further out. Just brainstorming here, don't fire the parts cannon yet! If it were my car and the computer wasn't reporting any error codes, I would do as 19cutty said from his iPhone and: 1. check/clean plugs and regap them 2. test or replace plug wires 3. test or replace ignition coils Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 18, 2013 Author Report Share Posted September 18, 2013 http://www.2shared.com/photo/TVO27Cko/misfires.html Here is the misfire report for that same log file. Thinking about it and I bet it is the spark plugs. I have had the car coming up on 3 years, I know they were done by the guy I bought it from right before then. I have not changed them (do not put that many miles on every year) but I think it is time to get it done. I like simple first and see what happens. I will put in new wires and plugs this weekend and do a oil change same time. I will leave the pan alone. I use a valve (http://www.amazon.com/Fumoto-Drain-Valve-F105N-20mm-1-5/dp/B003VCG0KI/ref=sr_1_2?s=automotive&ie=UTF8&qid=1379543436&sr=1-2&keywords=f-105) which works really well so I am not worried about breaking the pan by overtightening or such. Not sure if the link was the one for the lumina or the mountaineer so nobody go buying it off my link! The only oil I spill is from the filter. Thanks! Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 19, 2013 Report Share Posted September 19, 2013 Good point a computer is not a replacement for mechanical skilk, it is an aid Logging the car with cables and labtops and such, will NOT tell you if you have a bad plug or a bad wire or a bad coil. Even though it is OBD2, it will not tell you everything. You'll need to pull the plugs, check them, make sure they are properly gapped, check the plug wires. It could be many things. Once you have check ignition. Make sure fuel pressure is correct. Always check the basics before diving deeper in. That cable and setup is good to have, but for some issues, it's useless. As far as the pan gasket, if it ain't leaking, leave it alone. It's a bitch to change those. Sent from my iPhone Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 19, 2013 Author Report Share Posted September 19, 2013 Update: Got to work this morning and smelled a faint burning oil smell. The engine lifter sound when I am getting low on oil is not as apparent as it usually is prior my change and I typically burn off (or leak someplace) about a quart every 3-4k. I only get 4 qts out for every 5 in. When I removed the oil fill cap to peek in, there was a faint almost barely visible smoke that quickly went away. My inclination is to bring it home tonight, stopping for plugs wires oil and filter and change the oil. Then this weekend change the plugs and wires. Should I look too deeply into the smell right now, or work on the misfires first. I only started changing my own oil last winter and the 4 out 5 in has been consistent. No shop has mentioned a problem before (but it is not like they actually check how much comes out, they do not even give a proper drain time). I replaced the harmonic balancer about a a year ago and the crankshaft seal looked fine then. I have no problem pulling that apart and changing it except I do not have oil spots under the car leading me to think that if I am leaking there it is minor. Next thought would be valve cover gaskets which appear pretty straight forward and only a short amount of work probably best done while oil is out. Should I factor that into the next change (or even this one) just to get it done. We are only talking about 15 in parts. But on the flip side, if the 3.1 burns some oil and losing a qt over 3-4k is fine, then I will let it be. Ok it is not fine but if at least acceptable! Quote Link to comment Share on other sites More sharing options...
crazyd Posted September 19, 2013 Report Share Posted September 19, 2013 Jim, losing that much oil over a standard change-span is perfectly normal. The spec is down to somewhere around a quart every 1000 miles. And a little smoke from the crankcase isn't unusual either, that was probably just water vapor evaporating which it's supposed to do. The misfire counts don't point to needing a full plug & wire change, they're centered around only one cylinder: #5. I'd check that one immediately. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 19, 2013 Author Report Share Posted September 19, 2013 Got it on the oil The number under 5 was where it was at when the screen shot was grabbed. The other cylinders were also up there at different times. If you look at the misfire max column it has the same reading. I do not want to just replace one spark plug when it is just as easy to replace all 6. Is there any reason not to replace all 6? By check, I assume you mean pull that one and look for proper gap, damage, discoloration of the cylinder and such. Replace (or if looks fine, re-gap) Put new cable on and start it up. If it continues, check the coils for faults and replace those if needed? Sorry to need so much direction, I just want to do it right the first time! Thanks Quote Link to comment Share on other sites More sharing options...
crazyd Posted September 19, 2013 Report Share Posted September 19, 2013 You got it. Might as well do all 6. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 20, 2013 Author Report Share Posted September 20, 2013 Wow, gap of .090! No wonder I was having issues. Supposed to be .060 for a gap. I replaced the front 3 with what turned out to be the same model plug. But they were different sizes, any problem with the picture? They are both the same model ac delco. I got some cut your own wires, I ain't afraid of some wiring assembly but do not want to cut those just yet. Since they are in effect universal right now, I would rather throw them on a shelf if I can in case my wifes car needs wires. The ones on the engine look to be in very good shape. I will test the ohms on them when I replace the rear ones this weekend. Lost the light and probably will not get to it tomorrow. Since I only replaced half, any problems driving the thing? I know I can and you did say just replace the one but better safe asking. I did find a thread on here describing either remove front top mounts and rotate engine forward with a strap and brace or maybe remove coils and wiggle around. Recommendations and advice anyone? Here is image: http://www.2shared.com/photo/5bXtnYHI/CAM00150.html Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 20, 2013 Report Share Posted September 20, 2013 You can park facing downhill and the motor will rotate itself when you undo the dogbones On sparkplugs always check the gap even if theyre "preset" dropping the box can change the gap Wow, gap of .090! No wonder I was having issues. Supposed to be .060 for a gap. I replaced the front 3 with what turned out to be the same model plug. But they were different sizes, any problem with the picture? They are both the same model ac delco. I got some cut your own wires, I ain't afraid of some wiring assembly but do not want to cut those just yet. Since they are in effect universal right now, I would rather throw them on a shelf if I can in case my wifes car needs wires. The ones on the engine look to be in very good shape. I will test the ohms on them when I replace the rear ones this weekend. Lost the light and probably will not get to it tomorrow. Since I only replaced half, any problems driving the thing? I know I can and you did say just replace the one but better safe asking. I did find a thread on here describing either remove front top mounts and rotate engine forward with a strap and brace or maybe remove coils and wiggle around. Recommendations and advice anyone? Here is image: http://www.2shared.com/photo/5bXtnYHI/CAM00150.html Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted September 20, 2013 Report Share Posted September 20, 2013 You'll be fine to drive it only replacing the front plugs. But if you wanna change the rear, I use a 6" extension and a spark plug socket that has te rubber grommet in it so the plug doesn't fall out, and a 3/8" ratchet. I get at them by the passengers side fender and go into it that way. But if you need more room, take the motor mounts off the top, only need to unbolt where it bolts to the radiator side, then get a ratchet strap and move the motor forward. Sent from my iPhone Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 20, 2013 Author Report Share Posted September 20, 2013 OK, I will do the back 3 this weekend. Car still sounds rough but I expect that until I finish them. The concern I had with the plug itself was not the gap, I used a dial to size it right before install so I knew it was good. Thinking more about how the new one is shorter overall than the old one. Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted September 20, 2013 Report Share Posted September 20, 2013 The plugs should be the same as what your replacing. What part number AC Delco did you use? Sent from my iPhone Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 20, 2013 Author Report Share Posted September 20, 2013 Old is stamped "AC 41-940 25177877" New one is "AC Delco 41-940" Maybe the old one is not AC Delco but they should still be the same size. Old White barrel: 14/16ths New White barrel: 15/16ths Old Socket part: 11/16ths New Socket part: 10/16ths Old Thread: 22/32nds New Thread: 21/32nds Old over all: 2 15/16ths New over all: 2 14/16ths Yeah it is close but shouldn't it be closer? The new one is 1/16th shorter but appears same proportions. Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted September 20, 2013 Report Share Posted September 20, 2013 I wouldnt worry about that then. Your good to go. I dont know when those old plugs were put in, but now, AC Delco plugs, most if not all, are now made by NGK. Minor differences been old and new. Quote Link to comment Share on other sites More sharing options...
crazyd Posted September 22, 2013 Report Share Posted September 22, 2013 Jim, while your attention to detail is commendable, there's no cause for concern. The stamping on the originals, "AC 41-940 25177877" means it was a GM OEM stamp. The AC is the supplier, 41-940 is the supplier part number, and 25177877 is the GM part number. Quote Link to comment Share on other sites More sharing options...
JimMadsen Posted September 23, 2013 Author Report Share Posted September 23, 2013 (edited) Got the back 3 done today and the car seems to be running better but still hearing some of the noise as before. The idle is going better though. I will run a log and see if there are any more misfires. I did not replace the cables as they looked ok but I wanted to be sure. The Ohms ranged anywhere from 1.000 (not 1. blank meaning open) and 1.400. The problem is that I cannot find what the readings should be. On another matter, I have had some clunking from the driver side that I need to figure out. The clunking has increased after the engine rotation. I should probably look into fixing it. I will be doing some reading about clunks over bumps and then post it up. Edited September 23, 2013 by JimMadsen Quote Link to comment Share on other sites More sharing options...
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