Hello, Allpar Forums member or visitor! If you were a member, you would not see this ad!

Register or log in at the top right of the page...

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

84 Daytona Turbo Z - severe vibration at idle

Discussion in 'Daytona and Laser' started by Bob Lincoln, Nov 12, 2016.

  1. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    Have owned this car since 2008, as a show car, but is now my daily driver. Since I bought it, it has had a severe vibration at idle. I checked motor mounts by rocking in 1st and reverse, and engine barely moved. Haven't done a good visual inspection yet. It does still have the bobble strut installed. The PO did give me 'spare' motor mounts, but unsure if they were the original, or that he had planned to install them.
    Steering column vibrates, badly, so that the turn signal stalk buzzes, key ring shakes and buzzes, door panels and dash panels buzz - none of these is good for electrical connections, and now that I'm driving it more, it's very annoying.
    Has anyone ever cured this by installing new stock motor mounts? I'm wondering if the PO installed poly or solid motor mounts for better launch. I also notice that the clutch takeup is more abrupt than on my other Daytonas, still takes some getting used to. In traffic, sometimes as I creep and engage the clutch, the hood and whole car shake. Will be inspecting the mounts today. Advice?
     
  2. Rickorino

    Rickorino Well-Known Member

    Joined:
    Jan 23, 2005
    Messages:
    741
    Likes:
    131
    I have had the same teeth chattering vibration(steering wheel shaking, dash rattling) with aftermarket motor mounts. Everything seemed fine(somewhat) until the colder weather set in, then things got really bad. It seemed the rubber really stiffened up in the cold. I did change them out with OEM mounts purchased from the dealer and everything was very smooth from there.
     
    #2 Rickorino, Nov 14, 2016
    Last edited: Nov 14, 2016
  3. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    Haven't taken them apart, from what I can see, though, the front mount is the standard rubber. Might be deteriorated. Or maybe replaced and installed with the wrong orientation.

    Can anyone confirm the orientation? I don't have my other Daytona anymore to compare. Can't find specifics online. From what I remember, the "V" in the center of the insert points toward the rear of the car and upward, so that the engine rocking back would pull the point of the V and the center bolt against the rubber arc. Is that correct? Does anyone have pictures of the factory setup that they are sure of? Thanks.
     
  4. Bob ONeill

    Bob ONeill 325,000+ miles and counting...
    Level 2 Supporter

    Joined:
    Jul 31, 2002
    Messages:
    29,618
    Likes:
    233
    Check the upper mount to see if it's collapsed. You should be able to notice it. Chances are that is the problem.

    IIRC the lower mount is oriented with the 'V' upside down.

    The tranny mount is a slider and rather easy to replace. You'll need to put the tranny on a jack, support it and remove the through bolt. Then lower the tranny after removing the bracket mounting bolts the transmission. R&R the mount and reverse the process.
     
  5. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    By upper mount, you mean the passenger side? It did this when I bought it in 2008, and in 2010 Soloflite helped me change the passenger mount at Carlisle with one we bought onsite, saying it had collapsed. The new one made no difference.

    If the front mount has the V pointing upside down, which way diagonally? Toward the radiator or engine? Thanks.
     
  6. Bob ONeill

    Bob ONeill 325,000+ miles and counting...
    Level 2 Supporter

    Joined:
    Jul 31, 2002
    Messages:
    29,618
    Likes:
    233
    IIRC, toward radiator.
     
  7. Rickorino

    Rickorino Well-Known Member

    Joined:
    Jan 23, 2005
    Messages:
    741
    Likes:
    131
    Unfortunately, I do not have the car or an old mount anymore. I did make a sketch in my manual, the "V" (open portion)is tilted toward the radiator. One time I purchased a complete OEM front mount assembly and I sketched it before I installed it. A five year old would laugh at my sketch.
     
    #7 Rickorino, Nov 14, 2016
    Last edited: Nov 14, 2016
    Bob Lincoln likes this.
  8. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    OK, so if the engine rocks back, the center bolt pushes down on the point of the V. I think I need to do all the mounts, just for piece of mind. Now that I'm driving the car often, the vibration is a huge nuisance. If I didn't know better, I'd say someone swapped the cam out, and that's why the idle shakes. But it gets 33-35 mpg and runs great. There is still vibration at highway speed, but not like at idle.
     
  9. Bob ONeill

    Bob ONeill 325,000+ miles and counting...
    Level 2 Supporter

    Joined:
    Jul 31, 2002
    Messages:
    29,618
    Likes:
    233
    I wouldn't rule out the possibility of the cam 'slipping' a tooth. Not saying that is the problem but not saying it isn't either.

    If I were you I'd look at all the mounts. If the upper mount on the passenger side is collapsed I would not be surprised if the one on the tranny is too.

    You could see what's up with the one on the front rather easily.

    I know you know this but I would do them one at a time in an attempt to keep the engine 'centered'. If, the upper mount and tranny mount have collapsed it may be possible for the engine to move right/left especially if the front mount is also gone.
     
    Bob Lincoln likes this.
  10. Rickorino

    Rickorino Well-Known Member

    Joined:
    Jan 23, 2005
    Messages:
    741
    Likes:
    131
    When a mount collapsed, I could tell by looking at the half shafts. They would be angled in a way going upward from the transaxle as if it was sitting low. After new mounts (especially side mounts) the shafts would be exactly parallel to the ground. The front mount had the biggest impact for excessive vibrations.
     
  11. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    I haven't looked closely yet, but I believe the orientation of the shafts is OK. All I can see of the center mount is that it appears to be the factory type vs a solid mount like Polybushings, and that it may be starting to shred. But I can't see until I disassemble it, and there's no time or daylight this week. Maybe Sat or Sun afternoon, if weather holds. My truck is down now while I replace the exhaust, so I can't risk taking another vehicle apart until that's fixed.
     
  12. DCTZ

    DCTZ Active Member

    Joined:
    Aug 25, 2010
    Messages:
    342
    Likes:
    13
    I do now remember many years ago now that Bob ONeill mentioned timing belt being off that I had a very bad engine vibration at idle 15+ years ago. There was no problem when driving and it zoomed and boosted great. The timing belt was off by one tooth. After replacing the belt and getting the timing correct the car idled perfect. I do remember back then (late 1990s early 2000s) that I did replaced the engine mounts because of the vibration which were not the cause. Engine mount I used I believe were the stiffer ones?

    There is a simple procedure to verify timing belt being correct by taking out the passenger side plastic plug from timing belt cover and setting the engine timing at 0 at the "window" on the trans bell housing. The hole in the cam sprocket should line up with the timing belt cover access hole if the cover is not deformed. A small mirror will be needed to do see the alignment. Some people stick in a pencil in the sprocket hole to see if it is in center with the cover. Bob O or Bob L might have even written that procedure?
     
    #12 DCTZ, Nov 15, 2016
    Last edited: Nov 15, 2016
    Bob Lincoln likes this.
  13. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    Yes. And I have never changed the timing belt on this car in the 8 years that I've had it, though I have been meaning to for a couple of years. Even bought the belt and new tensioner. Life is just too crazy to get to it. Until my garage is done, I really can't risk taking things apart that much outside, this time of year. It could be off a tooth. I know that a mechanic once advanced mine a tooth by mistake, on my 92. There were NO indications at all except I failed emissions for the first time ever - HC emissions were double. Power, idle, gas mileage were all the same before and after fixing it. But if it were retarded by one tooth... will check when I can. It's easier than changing a mount.
     
  14. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    Oh, and a big blunder for me not to mention - just as a matter of routine I checked codes a month ago and found a code 32 - EGR. Have not investigated it yet. Can't remember if I ever checked before. No Check Engine light on, ever. No stumbling or any indication of driveability associated with EGR showing up. Last few tankfuls were 33-34 mpg. Could be that it's trying to actuate EGR and nothing is happening, rather than it feeding EGR when it shouldn't.
     
  15. Doug D

    Doug D Virginia Gentleman

    Joined:
    Aug 10, 2000
    Messages:
    12,231
    Likes:
    1,720
    Bob - I wouldn't think a bad EGR would result in a severe vibration. When the EGR failed on my '90 Acclaim (2.5L) it had more of a loopy idle (almost stalling), but ran fine at speed.
     
  16. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,948
    Likes:
    3,336
    No, I'm sure it's unrelated. And since it runs great and gets great gas mileage, I think the code is from not getting EGR when the computer calls for it, rather than getting it when it shouldn't.
     
  17. ka9yhd

    ka9yhd Active Member

    Joined:
    Aug 17, 2013
    Messages:
    1,158
    Likes:
    220
    I had the timing belt skip a tooth once on my 1987 Shelby CSX and the engine did not sound right and was down on power.
    Also had to replace the upper motor mount on the passenger side because the rubber failed and it was metal on metal. Boy was that loud in the car. All of the vibrations and noise of the engine transmitted into the body of the car.
     
  18. Perrym1229

    Perrym1229 New Member

    Joined:
    Oct 26, 2016
    Messages:
    6
    Likes:
    1
    The top right (passenger side) motor mount might have been installed upside down. Very common back in the day when gas station mechanics changed them out. It's a very easy mount to change, remove the 2 bolts that hold the mount onto the frame, jack the motor up from the oil pan (passenger side) just enough so that you can take the long bolt off, flip the mount over, tighten the long bolt first, then lower the car slowly so you do not move any of the shims, tighten up the 2 bolts onto the frame and go for a ride. If that doesn't work and all the bolts are fine, then it could be the timing belt skipped a tooth. But I'm betting it's the mount being upside down.
    BTW, I was a mopar mechanic from 87-93, I was a snot nosed 18 year old when I started, my cousin who was an A mechanic brought me in as an apprentice (basically a C mechanic), did all their grunt work and they did the computer/electrical work. Best 6 years of my life until all the Mitsushities started coming in. Then I went from fixing em to insuring em.
     

Share This Page

Loading...