Excessive Engine Vibration!
#11
Your procedure for the rear mount is wrong and may be contributing to your problem. You should have installed all bolts connecting bracket to engine loosely, then install mount-bracket long bolt loosely, then tighten bracket-engine bolts, then mount-bracket long bolt.
That's what Honda shop manual says. Reason for this is to allow mount to be unloaded in the engine off -static condition.
Note, I'm not saying your procedure is the reason for vibration, but it could be.
Yes, the vibration occurs generally about 2000-2220 rpm under firm acceleration. Seems to be felt more in steering than through gas pedal, which made me suspect CV axle (relatively new AZ axles). I need someway to definitively establish if mounts are causing vibration or something else. I haven't come up w/ a fool-proof way yet and hate the thought of replacing the mount to find it's fine (which I suspect is the case).
good luck
That's what Honda shop manual says. Reason for this is to allow mount to be unloaded in the engine off -static condition.
Note, I'm not saying your procedure is the reason for vibration, but it could be.
Yes, the vibration occurs generally about 2000-2220 rpm under firm acceleration. Seems to be felt more in steering than through gas pedal, which made me suspect CV axle (relatively new AZ axles). I need someway to definitively establish if mounts are causing vibration or something else. I haven't come up w/ a fool-proof way yet and hate the thought of replacing the mount to find it's fine (which I suspect is the case).
good luck
Thats interesting about your vibration situation as well, when I had first bought my accord three years back there was a rattling noise at 1800rpm, after that or before that rpm range there was no rattling or vibration whatsoever, I was told it was the heat shield, possibly the catalytic converter. I went under the vehicle, applied various methods of reducing the vibration (shoving rags between the chassis and the heat shield to dampen any movement), and nothing worked, then I put a vise clamp on the flange where the catalytic converter bolts up to the exhaust headers, and the noise and vibration went away, so I suppose it was a bad gasket in my case. Something you might want to try, because thats not the first time something like that has happened with an accord of this gen either. Also, when I got my catback exhaust installed, the vibration jumped up from 1800 to 2200 rpm, (I bottomed out on a poorly made road and the clamp fell off lol), so I suspect its possible your exhaust could be the culprit. I guess it depends if you are revving the motor to an rpm when the car is parked or in neutral, mine would make that vibration noise at said rpm when revving it or driving it, so nothing to do with the drivetrain. If you sense its something more mechanical, thats quite a bit different, I've had my CV axles from AZ for a few months now, no clicking or anything, remans, I'm actually pretty happy with them so far, hopefully nothing bad has happened with your, if you suspect there is though you have a lifetime warranty.
Yes, I wish there were a better way of diagnosing this problem as well, as to prevent spending resources where they do not need to be spent, I keep thinking next I will get the solenoid that connects to the motor mount and intake manifold, but that could be yet another part installed that didn't need to be changed out.
I was going to post those pdf files so you could see the service bulletin I was reading, they exceed the filesize limit though, they did not mention anything like you had said about the procedure involved with tightening the bolts up, but then again the way you said it makes perfect sense.
Thanks again!
-Michael
#12
You may have to jack the engine slightly to allow alignment. Thinking about it, there may not be that much difference w/ your procedure. If you think a moment, how much differnence could bolt tightening sequence make, perhaps 50-100 mils difference. Hard to believe that would impact vibration.
Regarding the vacuum "damping" feature, I have tried w/ and w/o and couldn't see a dramatic difference. I also have an Acura 2.5TL that has two vaccum-switched motor mounts on the front. There also disabling vacuum made no discernible difference.
Idle speed seems to make more difference than anything. I would suggest adjusting idle speed to about 800 rpm per the shop manual procedure and make sure your IACV is compensating load.
good luck
Regarding the vacuum "damping" feature, I have tried w/ and w/o and couldn't see a dramatic difference. I also have an Acura 2.5TL that has two vaccum-switched motor mounts on the front. There also disabling vacuum made no discernible difference.
Idle speed seems to make more difference than anything. I would suggest adjusting idle speed to about 800 rpm per the shop manual procedure and make sure your IACV is compensating load.
good luck
#14
Does your intake have the egr valve that stands straight up on the passenger side. If so to the right of it and all along the valley down there do you see two rows of three egr port plugs they are round and a little less than 1/2 inch around. There are six total starting a couple of inches to the right of EGR valve and continue all the way to the right as I said in two rows a couple of inches apart. I had this exact problem you describe. I removed the EGR valve and drilled and slide hammered the caps out. Full of soft carbon. Fixed my problem. In the DIY section with avideo of the procedure. Mine is a 91 ex accord and may have a different configuration than yours. Take a look and good luck. BY the way I replaced the lower mount by removing the right side axel and using a good floor jack. Took me less than two hours.
#15
You may have to jack the engine slightly to allow alignment. Thinking about it, there may not be that much difference w/ your procedure. If you think a moment, how much differnence could bolt tightening sequence make, perhaps 50-100 mils difference. Hard to believe that would impact vibration.
Regarding the vacuum "damping" feature, I have tried w/ and w/o and couldn't see a dramatic difference. I also have an Acura 2.5TL that has two vaccum-switched motor mounts on the front. There also disabling vacuum made no discernible difference.
Idle speed seems to make more difference than anything. I would suggest adjusting idle speed to about 800 rpm per the shop manual procedure and make sure your IACV is compensating load.
good luck
Regarding the vacuum "damping" feature, I have tried w/ and w/o and couldn't see a dramatic difference. I also have an Acura 2.5TL that has two vaccum-switched motor mounts on the front. There also disabling vacuum made no discernible difference.
Idle speed seems to make more difference than anything. I would suggest adjusting idle speed to about 800 rpm per the shop manual procedure and make sure your IACV is compensating load.
good luck
I just talked to a mechanic over the phone, hes going to look at it on Monday, he mentioned its probably going to be the balance shaft, it has all the symptoms of a broken balance shaft belt, or possibly the balance shaft, so I'm going to have him diagnose it, and see if the balance shaft belt is in need of changing. If its broken then ive got to be careful how I drive it, because the broken belt may be near to the timing belt, and I dont want to kill the entire motor with a belt fragment destroying the timing belt and then the valves, pistons, cylinder walls, etc.
I have a feeling thats what its going to be though, I'll research it a bit, but if thats the case then its something I cant handle myself.
-Michael
#16
I checked them out, they seem fine, but the vibration is more vibration than noise, if it were a heat shield it would be very loud, it really does feel like its from the engine, the entire car shakes very badly from it.
-Michael
#17
the pistons will not hit the valves in your engine unless the t-belt brakes at 6k rpm. WHen you take your foot off the throttle thats when the EGR works. If it was the balance shaft belt the vibration would not shake steering wheel or the hole engine bad. Also, you would feel it at idle out of gear. then the vibration would increase in speed as rpm rises. Also you would hear a whining sound from t-belt area. The belt has to be in there unless you have no t-belt cover. Assuming it's in there, there is very little room for it to go. You would not have this difficulty diagnosing your problem. And the engine will lift the car unless you take loose the motor mount by t-belt. But..Good luck
Last edited by Old Honda Dude; 03-20-2011 at 12:34 AM.
#18
Does your intake have the egr valve that stands straight up on the passenger side. If so to the right of it and all along the valley down there do you see two rows of three egr port plugs they are round and a little less than 1/2 inch around. There are six total starting a couple of inches to the right of EGR valve and continue all the way to the right as I said in two rows a couple of inches apart. I had this exact problem you describe. I removed the EGR valve and drilled and slide hammered the caps out. Full of soft carbon. Fixed my problem. In the DIY section with avideo of the procedure. Mine is a 91 ex accord and may have a different configuration than yours. Take a look and good luck. BY the way I replaced the lower mount by removing the right side axel and using a good floor jack. Took me less than two hours.
I'll definitely take a look at the EGR valve then, as well as those plugs, mine is on the passengers side, pointing up, I'll see about cleaning everything up if theres a chance of fixing this ridiculous problem.
Actually, there is a little bit of a whining sound, its more noticeable from inside of the car, its difficult to say where its coming from though... maybe it is the balance shaft belt, and the sound is hard to describe, kind of a low-medium pitched wobble? I can hear it winding down when I turn my engine off. I didn't really notice it too much until I turned it on today, I didn't think much of it until you mentioned it.
Thats good you were able to do it in 2 hours, I dont have much experience wrenching really, but I figured it was worth a try, if anything the rubber in the rear mount was going to crack eventually, so it was good to replace it, even if it took me like 5 times longer than you lol, plus my torque wrench is a gigantic 1/2 inch drive and like 2 feet long beast, no way was it going to fit under there with enough room to torque that last bolt into place, plus i doubted the bracket would allow enough room between the motor mount and the intake to remove it, did you have to contort it around quite a bit?
Thanks again,
-Michael
#19
Your 94 is much easier to access the EGR ports on the intake manifold.
Hondadude posted a writeup in the DIY Answers section at this link: http://www.hondaaccordforum.com/foru...cleaned-28456/
Copy and paste the link below in your browser. The last two pages of the pdf you download will show the 94-97 procedure. Its just a different writeup on the same procedure.
home.comcast.net/~em-engineering/T2T013.pdf
Hondadude posted a writeup in the DIY Answers section at this link: http://www.hondaaccordforum.com/foru...cleaned-28456/
Copy and paste the link below in your browser. The last two pages of the pdf you download will show the 94-97 procedure. Its just a different writeup on the same procedure.
home.comcast.net/~em-engineering/T2T013.pdf