DSMTalk Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum banner
Cancel
Create thread New Garage Forums

Massive RPM based vibration!!!

1 reading
Jump to Latest
21 - 37 of 37 Posts
Discussion starter · #21 ·
KyleownsaGSX said:
Had a very similar experience to this with my '90 TSI. It turned out that the Fidanza flywheel had a crack in it. It literally made me feel like the car was just going to fall apart due to the vibration. Hope it's something like that for you and not a rotating assembly issue. BTW the crack that was in my flywheel was between two of the bolt holes which then allowed the flywheel to literally bounce around an 1/8 inch.
Click to expand...
I'll mention this to him since he's currently in the process of pulling the trans to inspect the clutch assembly.




P.S. thanks for the original idea, at this point it seems several people are just saying the same thing. That said i'll mention to him the thing about the marks lining up but the BS being 180* out as well. But I don't see how thats realistically possible since it was fine, I don't see how it could keep jumping teeth to that point and the belt not be destroyed / seriously messed up.
 
Discussion starter · #22 ·
Well, he pulled the trans the other day and says that the clutch and flywheel look fine. *sigh* I was really hoping it would be something related to the clutch/flywheel or balance shaft.

So I guess the next step is to pull the engine and start inspecting it. :wall:
 
#23 ·
Dude the Rear Balance shaft/Oil pump sprocket is out of phase, Stop munking around with the car and taking parts off that do not need to come off. Pull The T belt, Grab the oil pump sprocket and line it up according to the mark.

Turn it to the left some and see what happens. If it falls towards the mark its right if it falls away from the mark its out 180*


I hate to say this but it sounds as if neither of you know what you are doing, The car was never timed correctly from the get go.

Take it to someone that knows what they are doing and pay to have it fixed.
 
Discussion starter · #24 · (Edited)
This isn't me doing the work, it's my 65yr old GM tech father back in Georgia. I'm still in Germany. And it WAS timed correctly, I drove it without issue for several thousand miles once I replaced the timing belts, pulley's and tentioner. It was only shortly after I got it to Oklahoma where I WAS stationed at the time that the issue popped up. I had to trailer it back to Georgia before I left to Germany.

I don't really see how it's possible that the balance shaft got from where it's supposed to be to 180* out, but i'll advise him to check it again and send him some stuff I found on VFAQ to help him understand what he's looking for. Because I honestly don't see how it could be anything internal other than the BS either.
 
Discussion starter · #25 ·
Well the balance shaft's have been checked, and rechecked. My father found nothing so he pulled the engine, it's currently on a stand and re-checked it again before he started tearing it down. He found nothing wrong so now he's going to start tearing it down until he finds something wrong!

At this point me and him both are wondering just what the heck. Honestly I am very hesitant to bring this up but it has been in the back of my head but makes no sense to me. I have only ridden in two other peoples DSM's and owned two, this being my 2nd. The other two I road in both had poly mounts, but one had the balance shafts removed and the other did not. Here's the weird part, the first one was a 2g GS-T, oly mounts and still had it's balance shafts, it also shook horribly. The other a 1g like mine, AWD TSi, had them removed and had poly mounts and the vibrations from it were what I would have expected, a little vibration at idle and low rpm and that was honestly about it, nothing that bad at all. But isn't that backwards of what you should expect!?!?

I'm tempted to just order the B/S removal parts have him remove them, throw it back in and see how it is then.
 
Discussion starter · #26 ·
Ok, so my father basically confirmed today that it is not the balance shafts. Or at least it's not a result of them being out of phase. He left the spark plug in cyl 1, to make sure he was on the compression stroke, and at TDC all marks lined up perfect.

What he is thinking about doing is removing the belt off the front shaft, and then pulling the rear balance shaft, and since our next door neighbor has his own machine shop, turning down the weights on the rear lower shaft, then re-installing it. And seeing what happens. The idea behind doing this vs a normal removal is to avoid having to mess with high oil pressure issue and porting the oil filter housing relief port.

My question is, should the oil pressure be effected if the shafts are installed but not turning?


Also as a recap, he checked and re-checked the flywheel, clutch disk, pressure plate, harmonic dampener and now confirmed the shafts are in sync. So before we try the above he's going to pull the oil pan just to make sure there isn't something funny going on with one of the shafts like the weight on one somehow damaged, or broken shaft etc.
 
Discussion starter · #28 ·
I did not, I have been sending PM's with a few questions to Loki, he brought that up as well. Which was the first time I had heard about that bolt. I e-mailed the information Loki PM'ed me to my old man. I'll call him tonight and make sure he got the e-mail. Since the engine is out on a stand it shouldn't take but a min to pull the bolt and check.


P.S.
I would like to thank Loki, Rook, Hot97 and anyone else I might be skipping over that has actually contributed to this thread.
 
#29 ·
http://vfaq.com/mods/timingbelt-1G.html

There's a picture of the bolt about 3/4 down. Since you have both shafts, you might as well check both going off of this.

Its common for guys to turn down the rear shaft and eliminate the front shaft all together. When doing that, you'll need to remove the front bearing and replace it with another, but put it in 180* off to block the oil passage. You will have some more oil pressure, but with still having the rear shaft working, won't be as much.
 
Discussion starter · #30 ·
Well, it would appear that for YEARS the rear lower balance shaft has been out of phase. I suppose that the installation of the polyurethane motor mounts just made it noticeable. I had the engine's timing set at a shop in Duluth Georgia, it was a DSM specific shop. I can't recall the name now, but anyway I guess the rubber worn out engine mounts just kept me from really noticing the vibration.

The reason I say this, is that my father just checked the inspection port for the rear lower shaft and it WAS 180* out. So he rotated it 180*, and tried sticking the screw driver in it again, and then it went in deeply without hitting anything like it should.

I suppose the thing that threw me, and him was just that I did not notice it YEARS ago. So I assumed that it was fine. So now he's going to address one or two other small things that are just a pita to do with the engine installed. And then put it back in and fire it up. I fully expect the problem to be gone now.

Thank you again Loki, Rook and any others that contributed. I will note if it in fact is resolved or not once the engine is back in and fired up.
 
#34 ·
Good to hear a fix, even if it was an easy and overlooked one. Those seem to be the most annoying ones.

One time I somehow changed 2 plug wires on my MM, and could not figure out why it would not run... But I never actually checked the wires cause I thought I had them right. LOL. I felt like an idiot after I finally figured it out.
 
Save
Reply Quote Like Like
Discussion starter · #35 · (Edited)
Sort of same thing here, the factory old as hell mounts masked the vibration so well, it must have been this way for YEARS! Since 2004 at least when I had a local DSM shop redo the timing.

So because of this, I was convinced there was no way it could be the lower shaft since it's run off the oil pump gear and it's not like it can just jump teeth or anything. So the problem only seemed to suddenly pop up after I installed the polyurethane mounts which confused the hell out of me.
 
#36 ·
And your right, for that long of a time to not notice I would be the same way, be hard to assume is something thats not been changed. Ive been told to double check everything even if it seems pointless, lesson learned.
 
Save
Reply Quote Like Like
Discussion starter · #37 ·
Well, my father got the engine re-installed the other day, new Mitsubishi Diaqueen gear oil in the trans, fresh heavy shock proof in the transfercase and rear diff. And he fixed a few other problems as well, I think he made one small goof with the starter bolts, but i'm not about to point it out after helping me out so much.

And the result........runs nice and smooth now. It was the rear lower balance shaft 180* out. I still can't hardly believe that the old OEM mounts hid the vibrations from it being out of time for so long.
 
21 - 37 of 37 Posts
About this Discussion
36 Replies
16 Participants
Last post:
Ripper_XX
DSMTalk Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum
posts
2.3M
members
104K
Since
2000
A forum community dedicated to Mitsubishi Eclipse, Plymouth Laser and Eagle Talon owners and enthusiasts. Come join the discussion about performance, turbos, builds, modifications, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General DSM Tech and Tuning Help! Tech Newbie Questions Forum Body Tech and Appearance Electronics Tech