Tight Vibration under throttle/during rain?

[SMOKE]

I’m getting an intermittent and very tight/throttle dependent vibration at
highway speeds with the Marauder.

This is after a new header-back exhaust with an H and a set of 4:10’s (and 2
new factory 28 spline axles, install pack, etc while they were in there).

It was cropping up during my commute down to Carlisle in June during – get
this – heavy rains.

Now, this past weekend heading back from LVD in upstate NY I got the
vibration again – get this – during heavy rain.

This is definitely coming from the front half of the car and either the engine or
trans. I don’t think the rear is binding up and I know the brakes out back are
tip top. The condition sort of crops up, no sudden bangs or pops and nothing
though the steering wheel.

I’ll ease off the car and coast around 60 – 65 for a few miles (or coincidentally
after the rain thins out) and the car will throttle up and behave normally.

When it starts the shudder/vibration the whole car feels it,
(cabin/cowl/floorboards) and I swear I hear the exhaust note change.

My sick mind tells me I’m sucking in water somehow but not sure it that is a
sound concept. I’m pretty sure I can’t get this to come up in dry weather but
I don’t drive the car all that much.

Mileage is at 45K and I’ve modded nothing else this year except exhaust and
gears. Prior bolt-ons were things like pullys and PHP spacer. Running those
and the Lidio tune (4:10 currently) for the last 3 or 4 years with no issues.

Any ideas? TC for example? I’ve searched trans stuff but come up mostly
with TC upgrade threads.

Best,
Jonathan

[justbob]

If this is heavy rain related, the first place I would look is the suspension/steering/ alignment. My escort was in tip top condition but absolutely could not be driven in the rain or snow. The alignment didn't feel bad at all but the tires were slight positive camber. They installed camber bolts in the strut and OMG totally different car. I honestly could not go above 45 before, it would start to vibrate and steer both ways at anytime it wanted before it would lose control. Just a guess here.

This may be the start of a bad steering component is all.

[Krytin]

You may also want to look at the coil covers and wires to the coils. If the exhaust note is changing you may be picking up a miss related to water shorting one or more coils.

[Blackened300a]

You may also want to look at the coil covers and wires to the coils. If the exhaust note is changing you may be picking up a miss related to water shorting one or more coils.

+1
Rain = moisture which can cause all kinds of ignition issues if a coil is damp inside.
The pain is trying to figure out which one without a CEL.

[SMOKE]

Thanks guys - I'm definitely going to troubleshoot the powertrain route as opposed to suspension
(as I know the alignment isn't all that great and I'm getting wear on the front tires but I don't drive
it very much and don't care yet...no pulls or vibration but I digress)...

This is definitely coming from the engine. The vib comes up and there is an exhaust note change and the power seems
to fall off (or I'm too concerned with applying more power through what sounds and feels like an impending catastrophic failure :lol:)

My first thought was that snorkel tube off the K&N got left off but it is hooked up nice and tight....

I've had the CC's off once before....siliconed up the back side of the cover where all the wires come through too.
But I think I'll pull them and take a look around...

Best,
Jonathan