I was waiting in line yesterday with my truck in park. I've mentioned earlier that I get a strong vibration at about 55 mph. Well, thought I would see if there is a corresponding engine vibration, taking the rest of the drivetrain out of the equation.

Start slowly working the revs up, when suddenly at 1900 rpm there seems to be resonate frequency. Very narrow range maybe +/- 50 rpm. Went back and forth across many times - easily duplicated.

Then wanted to see whether there is multiple of this rpm. Start slowly climbing from 1900 rpm get to 3000 rpm, when suddenly the engine and truck start shaking pretty heavily. Keep going - and it doesn't disappear - just gets worse. Hmmmm....

Later in the day I took the truck to a small fix-it shop to remove the trailer hitch and see about raising the exhaust tips.

Trailer hitch - simple job - done in 5 minutes. Exhaust tips are another story. Thought there was just one pipe running into the front of the muffler. Not!! Okay, so we loosen everthing up and are able to raise the tips to where they look great. Mostly by heating the muffler hangers and bending them up. Tighten it all up.

Mechanic gets in passenger seat - want to show him the vibration. Fire it up and WOW if the vibration isn't muliplied by a factor of four. Straight up through his a$$. You can hear it, see it, even taste it. Back on the hoist and sure enough, the muffler has about a quarter inch clearance from the heat shield right under the passenger seat. So much for raised tips. I guess that when the engine twists it pulls the muffler right up to the floor. We could reduce it be getting out of the passenger seat. So we reversed the tip raising work and now I'm back to where I started vibration-wise.

Anywho - if any of you could do me a BIG favor in the next day or so, when you're in your trucks, could you slowly roll up the rpm's while in park or neutral and see whether you get this vibration? You won't miss it if you've got it.

Please report back ASAP if you could. I have a meeting on Monday with my dealer to try to get to the bottom of my problems.

Thanks in advance!!

(p.s. Sorry for the long post, but this vibration is driving me nuts!!!)

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2000 Red Lightning Born 3-8-00 / Delivered 3-22-00
22% Window Tint, Clear Corners

'99 Yukon Denali - Silver, Lowered 1", Borbet CW4's, 285/60R18 Toyo Proxes S/T's, Hotchkis AntiSways, Edelbrock Shocks

2000 Red Trans Am Ram Air WS6, 6 Speed - Delivered 2-15-00 - Awesome Looking Car




[This message has been edited by WHAT04 (edited 04-08-2000).]

 

WHAT04,

No vibration at any RPM!
My tips hang lower than some I've seen.

adp
#1530
Black '99

 

WHAT04-

I just got back from a trip to the mall, and I can't say that I've noticed this in my truck. My beast also has some lower hanging tips, but like Yoda I'm going to wait until I get a new whole system to fix this.

I'll definately pay more and particular attention on my next hop though.

~rick

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lightning_svt@hotmail.com
2000 Ford F-150 Lightning (red, no mods... yet)
1999 Ford Contour Sport (white, for the wife)


[This message has been edited by lightning_svt (edited 04-08-2000).]

 

O.K., from what I have seen of the 00's (well ok only 1 & that was Peter's) but his exhaust tips were much higher than mine. Looks like the way they should have been, located snuggly up in that exhaust-tip-cutout on the truck. Mine, as do most, hang lower "hu hu hu he said Hung Lower hu hu hu!!" but by taking a look, it seemed that they just rotated the whole assembly counter-clockwise so the tips were higher. I was thinking about getting in there & tryng to re-locate the tips, but figured I'd wait until I install a new exhuast system all-toghter.

BTW, you never did answer back on the W6S comparo to the "L" you have. Have you raced the 2 head-to-head? what was the outcome? which do you enjoy driving more?

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99' SVT Black Bolt NLOC #392
best run 13.54 @ 101.35

**The Storm over Phoenix**


[This message has been edited by Yoda (edited 04-08-2000).]

[This message has been edited by Yoda (edited 04-08-2000).]

 

Yoda, that is how some one I know who knows alot of info on the truck told me how to adjust the tips.


[This message has been edited by 2000Silverbulletonorder (edited 04-08-2000).]

 

ttt

Pleeeeaaaaasssse!!!

[This message has been edited by WHAT04 (edited 04-09-2000).]