#Vibration

U Relay Got A Problem? (photo courtesy: APaGttH)

TTAC Commentator APaGttH writes:

Sajeev!

Long time listener, first time caller. The patient: a 2005 Saturn Relay FWD3 with 151K miles, GM 3.5L V6 and 4-speed automatic. I am the fifth owner and this is our grocery getter and general abuse vehicle. I’m the longest owner – 4 years and about 55K of those 151K miles have been in my garage. I can’t comment on how well it was cared for from year 2 to year 6, but I have done everything by the book since 96K miles.

The Saturn developed a rough idle of sorts about a year ago. I swapped out the spark plugs, changed the fuel filter, and flushed the fuel injection. The car continues to idle rough. No CEL and no CEL history.

We had two updates to a previous Piston Slap this weekend, surprisingly within two hours of each other. Let’s hear from the OP first:

TTAC Commentator sundvl76 writes:

Sajeev, reporting back:

You may be interested in this, if for no other reason than to add to your diagnostic toolbox; my experience certainly can’t be unique: Several comments below your post also suggested the motor mount(s) as the problem. I more recently discussed this with a professional wrench acquaintance, who also said that the mounts can be expected to go south after ~80K miles; he suggested using a padded floor jack to lift slightly on the engine during a time when I detected the “rough” idle (the oil pan on this vehicle, and maybe all Duratec engines, is waffled cast aluminum). Bingo! The vibration ceased when I did that.

TTAC Commentator sundvl76 writes:

Sajeev,

Your post of 2 Mar 2011 was a great explanation regarding the cause of the “T” joint oil leak I’ve been experiencing. No one on any of the normal Ford sites has been able to pinpoint the problem, so I thank you for the information. (I’d discovered the source, but didn’t know the cause/fix until your post.) TTAC is now on my Favorites list!

TTAC Commentator jrominski writes:

Nice to see you are still at it on TTAC. (Back at it?)

So my story is a 2010 Audi A4, Quattro 2.0t Premium. Red, as it should be (No, it should be brown. Duh. – SM). Just turning 60k miles. The engine is an EA888 according to Wikipedia, twin chain driven counterbalance shafts as is known to work so well on I4s. Production commenced 2008 and its in all US A4 B8s with the 2.0 gas engine. Inside oil cap the gallery is clean as can be, I keep the VW spec Mobil 1 changed with my mityvac. New plugs, NGK of correct part number, air cleaner path is fine. The rest is original unmolested.

The issue is it runs rough. Slightly, as in the car does not shake but I feel it. Worst, dead cold, running at just above idle up a slight incline. A miss. Since 25k. Goes mostly away when warm or when power is asked for. No codes. Sort of feels like a tire flat spot but it did not go away with new tires.

Sajeev writes:

In our last installment of this particular ‘slap, a reader had a question about aftermarket wheels. The solution was rather simple, the wheels discussed were not hub-centric. But I also mentioned a horrible “death wobble” problem with my aftermarket reproduction SVT Cobra wheels on my Fox Cougar, solution TBD. It was a big problem until…

Hey Sajeev,

A long time (since roughtly 2006ish) TTAC reader, I thought you might be able to help me out a bit, or point me in the right direction. My car (2007 Honda Civic Si Sedan, 17300 miles when bought used off lease, now currently around 39000 miles) vibrates terribly at highway speed. Starts around 55mph, continues to increase until about 80-85 where it begins to smooth out again.

While Noise, Vibration, Harshness (NVH) control built into a modern machine is normally your friend, it often kills you with kindness. That’s when NVH hides things that should never be hidden. Shameful. Cowardly. Pathetic. And while I wasn’t expecting this level of deceit when merely replacing the shift knob on the otherwise stock transmission in my 2011 Ford Ranger…well it was thrust upon me. And it can happen to you, too.

Chris writes:

Thank you all for your input on my question. I took the truck to my mechanic and he gave it a good go over and could not find anything wrong. He was said it might be the heat shield on the exhaust system vibrating at that RPM however he could not find anything loose. I did get the transmission fluid changed and everything looked good there. Thanks to you and the readers of Piston Slap for all the good advice.