Hello everyone of LS4 Performance, I'm new to ls1tech but have been on here for months since purchasing my 06' GP GXP in February. I love my car and have put a lot of time and minor repairs into it for only owning it a few months. A lot of the info I've read on here has been very helpful in my trivial pursuits to get this car to what I want, however I am experiencing a few issues I'd like to bring up to everyone here, as I am very mechanically inclined and have worked on cars for years, but I do not want to just throw parts at it and hope it fixes these minor issues to no prevail. I want to get info from people who have had these cars longer and have probably already gone through what I'm going through now at some point or another. I apologize in advance for the novel of words but I want to fit this all in at once.

To begin, I have a metallic rattling sound coming from what sounds like my driver side upper quadrant area whenever I'm going over bumps or uneven roads. It gets louder depending on the severity of the surface being driven on. I've had a similar issue in my 98 GT a few years ago. I replaced the front struts (monroe ready mounts) and it was gone. However, the bilsteins on the car seem good as there is no excessisive bounce or anything. I'm thinking it could be the top mount/bearing, what do you guys think? I've already replaced front out tie rods, loaded LCA's, and sway bar links. Nothing else is visually wrong besides some corrosion on the top mounts, which only backs my theory.

This next issue may coexist with my bad upper mount theory, but it seems I am getting bad tramlining whenever traveling on uneven roads. The steering wheel will pull to which ever direction the road curve is. I know a little wander is normal with a car that has wider tires up front, but I've had a few instances where I feared for my safety due to loosing some steering control on really bad roads. Based on research, I've found that this can be caused by misalignment, as I have some uneven wear on the outer edge of my tire on the driver side. I bought the car from a local dodge dealer, and durning the test drive everything was tight and solid. It has slowly degraded and become worse over time, as it is my DD and I work in Detroit...self explanatory lol. Any ideas on where I should start with this one?

Last thing that I want to be in order before I start modding, I get a vibration when coming to a stop, say at a light, when decelerating at about 15-20mph, when the car slows to about 10 it stops. I feel it mostly in the wheel and I don't have any reason to believe it's brake related, as I've replaced the pads and rotors on it, properly, greasing the slide pins and cleaning the shims really good. This is actually the reason I replaced the brakes when I got it, I didn't really notice it until 2-3 days after buying it. I'm hoping it's not trans related, as I am at 92k and have no previous service records so it may be the original trans for all I know. There is no rpm fluctuation when the vibration occurs.

Whew, lol, again sorry for the long paragraphs, just want to get detailed information about my case so you guys can help me more effectively. I have big plans for this beautiful car, and I'll be on here a lot now that I finally registered with the forum. I already have an idea for what I want to do to it, I'm going to see how it responds to basic bolt on's (exhaust, CAI, maybe an overkill pcm) first before I decide if I want to start swapping for some other LS parts. A Transcooler seems to be a must for this car so that will be a first as well. Thanks a lot guys, I'd appreciate any help I can get here!

-Zach





This is her, she's a beaut. Haven't done much yet due to my work hours and time of year but that will soon change!

 

Nice car. I'm no expert but that sounds like strut mount to me also. My car also pulls a bit on uneven roads same as you are describing, just waiting for the pot hole repair to begin before I get it aligned as it started this winter . If you have no records check the trans fluid smell and if its even close to burnt smelling do a filter and fluid change. Read as many post here as you car, lots of good info on this site. Good luck with the car!

 

Thanks a lot, I appreciate it. Yeah that's what I have my money on, I'll probably replace them either tomorrow or Tuesday, my only concern is getting the top nut off that holds the mount to the shock. I've heard different things, I just don't want the shaft to spin when I try to break it loose. That may or may not be applicable in this situation, as all strut assemblies are different and I haven't taken one of these apart yet. Aside from the spring compressor I shouldn't need anything else I'm hoping, maybe an angled wrench to fit the top nut just in case the shaft does spin when trying to loosen. I'll figure it out

Yeah I'm in the same boat, I want my suspension solid before I get it aligned, pointless otherwise. And I have pulled the dipstick for the trans, fluid is still bright red which indicates it may have been changed previously, I highly doubt it would've gone 92k and still looked as good as it did. Having no service records, that's settling to know. I do not, however, recall if it had a burning smell to it. But I will pull it again and check it after I get home from work tonight. Thanks again, appreciate the info

 

Sounds to me like the vibration is the wheels needing balanced if you've already replaced the rotors. As far as the noise, its sounds to me like upper strut plate/mount upperbushing etc.

As far as the control issue, any road rough enough to pull your steering from you, its HIGHLY unlikely an alignment issue. Its just the road is rough and its pulling you lol.... Put a little more strength into the wheel... lol

 

Lmao you shouldn't have to fight the car to such an extent as I do to keep it straight on uneven roads, it could be arnie behind the wheel... if your steering is messed up it can cause safety concerns. It's almost as if the tires follow the direction of the curve in the road and the steering wheel has a delayed effect in response to correction. Don't get me wrong it's not like I allow the car to vear off the road...it's simply a nuisance. I've driven cars a lot older and with a lot more miles that handle better on rough or uneven terrain. Frustrating is all. Especially after working 10 hours in an engine plant haha. You're right it could be the tires are unbalanced, just seems a bit odd that I would have these issues as I bought it from a "seemingly" reputable dealer.

I'll see where I'm at when the mounts and alignment are done. Hoping I won't have to replace a rack lol. Thanks for your helpful input.

 

If it as bad as you say it is, then the wheels might be wondering or you have bad tie rod ends or bad hubs.

First i would jack the car up and grab it with 2 hands 12oclock and 6 oclock and push with one hand , pull with the other . back and forth. If there is ANY movement, you have bad hubs " which common and can get pretty bad"

Now for tie rods. Put both hands on the wheels, 3 and 9 oclock , turn the wheel left and right. is there any clunking , significant movement , loose ness.

Does the other wheel follow along exactly with what you do to "whatever" wheel your turning by hand , etc.

May want to undo the tie rod end and see if there is any play in the ball joint "thats at the rack" by pushing and pulling on it. Should be zero horizontal play.

 

Also as far as the dealer comment, they will do the least possible to the car to sell it. There soul purpose is to make money. I would not put anything past Anyone these days

 

what kind of tires and what is size?

 

I agree with you 100%, it's a damn shame you can reset the oil % on the DIC just by pressing a reset button. Very misleading as I checked my oil after I brought it home and it was black and two quarts low... Needless to say I changed it right after finding that out, damn dealer.

I checked the wheels for play about a month ago when I did my outer tie rods, which were both seized with the boots split open. It seemed fine, but I'll have to check it again tomorrow just to make sure. I've heard that a loose rack-to-frame mount bolt can work itself loose over time and cause a similar issue, but I haven't had time to get under there and check lately so I can't say for sure if that is contributing to my problem. I have tomorrow and Tuesday to get this straightened out because I just got my tax refund and its modding season. Haha. Thanks for the advice, I'm beginning to learn more and more how helpful this forum really is.

 

Sorry about late reply to the tires question, work has been hectic haha

Front tires: Yokohama Avid ENVigor 18x8 255/45/R18

Rear tires: Same type of tire, 18x7 225/50/R18

Pretty sure these are same numbers as stock tires.

 

The reason I ask is because the avid actually follow ruts of road the most of tires I've had and I have had 5 diff kinds Yokosuka mich bridges town and I remember the avoids following the sort of tracks in road -the most traveled part and would pull when I tried to come out of traveled portion of road

 

That's very good to know, because these are the tires that came on the car when I bought it in February. Looks like I'll be in the market for tires in the very near future, as I have a bit of uneven wear on my driver side anyway. Which would you recommend out of all the tires you've had? Are they expensive as all hell? Best bang for the buck is what I'm after, appreciate the tip.

 

i like the mich pilot sport and i got them from walmart lol cheapest game in town like 780 for all 4 ratings are gonna be different w and y they are a/s 3 mich pilot sport this is my second set love them