cubsfan24 Posted May 16, 2010 Report Share Posted May 16, 2010 Ya my brothers got a 94 Regal GS with 130k that sometimes shakes really bad when accelerating. I will try my best to explain the issue. I was going around a clover leaf on ramp at around 35mph and as soon as I punched the gas to get on the interstate the car would slowly accelerate but would shake really badly. Tried to watch the tach and it was staying the same. It also shook when I was accelerating from 55mph to 70mph. Basically most of the time you are going 50+ you can stomp on the accelerator and have it start shaking. Although from stops it seems to accelerate great. Although I think I may have felt a very slight jerk once from a stop but can't confirm that. Any ideas? Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted May 16, 2010 Report Share Posted May 16, 2010 Check the engine mounts. Park the car. Pull the handbrake. Put the car in drive. Pop the hood. Walk out, and tap the throttle. Repeat in reverse. If at any point during your tapping the throttle the engine moves in the engine bay significantly, one (or more) of your engine mounts are broken. Actually very common for Series 1 3800's. In the last 12 months I went through 3 front lower engine mounts 2 rear lower mounts, and 7 engine torque mounts. Then again, my engine is modified, and I do like to punch the throttle...a lot. Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 16, 2010 Author Report Share Posted May 16, 2010 Ya I was searching google and sounds like it could either be a engine mount or a cv joint that is going bad. How does one check a cv joint? Oh have you ever experience this shaking/jerking under acceleration? Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted May 16, 2010 Report Share Posted May 16, 2010 What you describe sounds like a bad coil or plug wires to me. If one of those was bad, you'd have a weak spark. A weak spark may be able to ignite the fuel/air mixture ok at a low load on the engine, but be insufficient when more is asked from the motor. When was the last time the plugs/wires changed? Are the coils original? Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 16, 2010 Author Report Share Posted May 16, 2010 Plugs and wires were changed last year. Not more than 1-2K miles ago. I would assume the coils are original but haven't looked into that far. What is weird is I can do a wot run from the stop and it accelerates like a dream. Its like it doesn't want to accelerate fast when its moving fairly fast. edit: The plugs and wires were changed because this problem. Although last year the issue wasn't nearly as bad as it is now. Which leads me to believe it is a engine mount or axle. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 16, 2010 Report Share Posted May 16, 2010 that sounds like almost exactly what happened when my 3100 lower mount self-destructed... any time the TCC was locked, it shook like i was going over continuous 4" bumpstrips.... interestingly, it quit after a few minutes, but i assume that's when it completely tore apart. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted May 16, 2010 Report Share Posted May 16, 2010 What you describe sounds like a bad coil or plug wires to me. If one of those was bad, you'd have a weak spark. A weak spark may be able to ignite the fuel/air mixture ok at a low load on the engine, but be insufficient when more is asked from the motor. When was the last time the plugs/wires changed? Are the coils original? I had this problem on the TGP and it shook the car fiercly when tcc was locked and a little throttle was applied. Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 16, 2010 Author Report Share Posted May 16, 2010 I had this problem on the TGP and it shook the car fiercly when tcc was locked and a little throttle was applied. Did you replace your coil packs or the plugs/wires? I didn't have time to look at the car today but may have time tomorrow. Is there anyway of testing a coil to see if it could be bad? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 16, 2010 Report Share Posted May 16, 2010 Is there anyway of testing a coil to see if it could be bad? yeah, grab the cleanest piece of exposed metal that you see with one hand, grab the coil post with the other and have someone else try to crank the car. if you die, it's probably a good coil. oh, i guess the other way involves measuring the resistance of the secondary winding... if you get between 10K-13K Ohms, it MIGHT be good. Quote Link to comment Share on other sites More sharing options...
88red4cyl Posted May 16, 2010 Report Share Posted May 16, 2010 Auto Zone can test your coil... Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 16, 2010 Report Share Posted May 16, 2010 Auto Zone can test your coil... yeah, but they can also test alts and batteries, both of which can test good and instantly FAIL when installed, so i would take the results with a grain of salt... Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 17, 2010 Author Report Share Posted May 17, 2010 yeah, grab the cleanest piece of exposed metal that you see with one hand, grab the coil post with the other and have someone else try to crank the car. if you die, it's probably a good coil. Okay thanks, will try that when I get time. I will start with checking the motor mounts and see if the drive shafts have any play in them. If those check out I will look into the coil packs. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted May 17, 2010 Report Share Posted May 17, 2010 Did you replace your coil packs or the plugs/wires? I didn't have time to look at the car today but may have time tomorrow. Is there anyway of testing a coil to see if it could be bad? I tested the coils with a spark tester and one failed so I replaced it. Quote Link to comment Share on other sites More sharing options...
AL Posted May 17, 2010 Report Share Posted May 17, 2010 I also am suspecting a misfire... Ohm check the coils and if one is way different than the others, youll know... But it wouldnt hurt to spark check them either Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 17, 2010 Author Report Share Posted May 17, 2010 It was raining all day today and didn't have time to look into anything. When you say ohm check the coils, do you mean from the spark plug post to the bottom of the coil? Also if there was a misfire wouldn't there be a code thrown? Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 18, 2010 Author Report Share Posted May 18, 2010 Checked the resistance of the coils and two were 5.52k ohms and another was 5.59k ohms. Took the dog bone motor mount off and it has a bit of play one of the ends. The front motor mount looked to be in okay shape along with the tranny mount. I think there is another motor mount but couldn't find it. I put the car in drive with the ebrake on and revved it up while taking a video. You can clearly hear it stumbling when you blip the throttle. I was doing this on a gravel parking area so the car did move a bit. Before I start throwing money into the car randomly, does this look like bad motor mounts or a bad coil? [video=youtube;POFoivob-wM]http://www.youtube.com/watch?v=POFoivob-wM"]http://www.youtube.com/watch?v=POFoivob-wM Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 18, 2010 Author Report Share Posted May 18, 2010 sry double post. Internet was being comcastic. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 18, 2010 Report Share Posted May 18, 2010 way to tell if your lower mount is junked: stick your hand under the crank pulley; if you feel a bunch of oily crap and there is some rubber that just doesn't seem to belong, that's because your mount tore. Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 18, 2010 Author Report Share Posted May 18, 2010 I stuck my hand below the crank pulley and felt a bunch of oil but think it was 16 years or road grim and leaking oil. Although the oil was really black looking. What does motor mount juice look like? But right below the ac compressor felt the motor mount and it was clean/dry and intact. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 18, 2010 Report Share Posted May 18, 2010 the crap that came out of my mount was as black as could be... Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted May 18, 2010 Report Share Posted May 18, 2010 (edited) What does motor mount juice look like? LOLOL I'm doing to develop an energy drink for gear heads and call it Motor Mount Juice. :laugh: Edited May 18, 2010 by tornado_735 Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 18, 2010 Report Share Posted May 18, 2010 LOLOL I'm doing to develop an energy drink for gear heads and call it Motor Mount Juice. :laugh: just have coffee contrinuously brew for about a week... then you'll ALMOST have the consistency too! Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted May 18, 2010 Author Report Share Posted May 18, 2010 Made the discovery that my Lumina uses the same coil pack as the 3800 so I swapped one of mine over. However the car decided it actually wanted to work correctly tonight and run perfect. Seeing how it runs great now leads me to believe its not a motor mount because if it was it would be doing it all the time. Will have to wait for it to act up again to test a coil from my car. Also I made the discovery that the alternator bearing is squeaking a bit. Is there a way to just replace the bearing or do I need a entire new unit? Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted May 19, 2010 Report Share Posted May 19, 2010 Before I start throwing money into the car randomly, does this look like bad motor mounts or a bad coil? You definitely have a misfire, and I still think a coil is a likely culprit. But seeing how much movement you have from the motor, I'd say you need mounts as well. Also I made the discovery that the alternator bearing is squeaking a bit. Is there a way to just replace the bearing or do I need a entire new unit? I doubt you can get just the bearing, so you'd probably need to replace the whole alt. That being said, I've had alts on these motors squeak for year and not die, so I wouldn't necessarily worry about if it is just chirping a bit. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted May 19, 2010 Report Share Posted May 19, 2010 You definitely have a misfire, and I still think a coil is a likely culprit. But seeing how much movement you have from the motor, I'd say you need mounts as well. Agree Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.