Actually, the proper inflation pressure is listed in the manual. It depends on the factory tires installed on your car, speed rating, and number of passangers. With our 2006 MCS, that means 30 psi at all 4 corners. 40 psi is way to high.

Maybe I didn't see it, but you never said which tire was the one that was leaking. But I'm guessing that it was a rear tire. When they jack up the rear of the car, it will throw the camber off when you put it back on the ground. But the minute you roll the car about 10-20 feet, the camber will be back to normal.

If the rear is growning under acceration, I would check:

-Rear suspension bushings (there's a lot of them)
-Parking brake stuck on?
-Sway bar bushing

It's odd that it's coming from the rear. There's not much that happens back there that owuld cause groaning noises. If you had an aftermarket rear sway bar I would check that first. But you don't.

Good luck!

 

Thanks. Actually, I did say which tire was leaking - front passenger (now, after rotating). But thanks for the input on tire inflation. Someone else in my local club has the same tires I do (not the stock runflats but Kumho ECSTA ASX W rated tire) and inflated them to 40 PSI for performance reasons and to reduce wear. I've seen others online recommend 40 for best performance w/this tire. Max PSI as marked is 51 and I believe minimum is 32 so I'm in the middle of the range. But if you think it would be better to go with what is in the door jamb I can. This was basically my disagreement with the Pep Boys mechanic, lol, b/c I'm not running stock tires.

No, I don't have a sway bar. I wonder though after reading the thread about the interface between the hub and wheel if I need to take them off one more time and make sure it's totally clean on both sides. While I cleaned the wheels pretty well I didn't clean the hub. I only used a small amount of anti-seize on the lug nuts (threads only) so I doubt I got any lubricant on the hub or wheel.

Yuck, bushings. Don't want to go there. Maybe it's not a complicated thing for you guys but I think that might be a bit out of my league and would require a visit to the dealer... If it turns out to be unrelated to the wheels though maybe it's just as simple as the parking brake being stuck. I have 43K on the vehicle if that makes a difference.

 

I would use the tire pressure listed on your tires, not whats on the door.

Art

 

The pressure listed on the tires is their max pressure. Don't think you'd want to be running around at 51psi. (Ok, you might, but not me. )

 

40 psi isnt to high. Just get your tires hot and make sure they dont go over 51 when they are hot (or whatever the tires say is their max, usually 51 tho). I am currently running 36 on all 4 cold, and if i remember from last summer, i think my tires ran in the upper 40s hot, so you might be right on the max. $0 really isnt requied for the street tho, autox if you want, or go right up to 50, just cuase they dont get to hot on autox. If you are trying the max out of your tires, buy a performance set of tires that stick better but arnt hard as rocks cause they are set at 40psi cold. Not sure what kinds of roads you got in laffayet, but if they arnt curvey, there is no point to running 40 anyway. I have killer curves i like totake at speed on a daily basis, hence my high pressure. IMHO

Beecher

 

just another thought, dont be affraid to mix and match pressure per axle. I used to run 36 front and 32 rear ( ithink), took a bit of understeer out, and decreased screaming. although not an ideal way to change handeling, it works...

Beecher

 

Ok, the tire will lists max pressure and unless your running fully loaded you would always have it set below. So in lowb35's case use 40 - 45psi.


Art

 

After looking at the chart on the door I reduced it to 36 PSI. Ranges listed are between 30-41 PSI depending on load and tire size. My tire size isn't on the door (205/55R-16) but this may be a happy medium. Though I've been running at 40 PSI for a good while now and while the rears were wearing a little bit faster than the fronts (thus why I wanted to rotate now before it was too late) they were wearing evenly and I think I'll be able to get 30K or more out of these tires no problem. Plus the ride was still a whole lot better than the hated run-flats. Early build MCSs apparently have a stiffer suspension than later ones and I don't really feel a huge difference in the ride with the change in tire pressure but felt a HUGE difference going to these tires from the run flats--much quieter and not as stiff, but still handle well. I overall love my tires and they handle especially well in the wet compared to the old runflats (a big issue here in Louisiana where it rains a lot!)

Also, it seems the noise is gone, hooray! I'm hoping it was just the e-brake. I'll check the torque one more time when I get home but unless the noise comes back I think I'm ok, other than being paranoid about my car!

 

Since you do have after market tires you should go by your tires requirements.


Art

 

Do you need to press the TPMS reset button after rotating? I think my MA said something about it at Motoring School but that was in November and can't remember precisely.

Thanks!

 

You shouldn't have to. The TPMS system works by detecting differences in the rotation rates of the two wheels opposite each other on the car (it compares front-left to front-right, and rear-left to rear-right).

If your two front tires were rotating at the same speed before, they should still be rotating at the same speed relative to one another after they've been moved to the back. Likewise with the back tires that just became the front tires.

 

Don't bother! For safety's sake, the best tires should always be mounted at the rear of any car. On a FWD car, the front tires naturally wear faster than the rears so the safest tire configuration is maintained as long as you don't rotate them. When the fronts wear out, buy two new tires to be installed at the rear and then rotate the previous rears to the front. Motor on and repeat ad nauseum. Provided the alignment and balance are maintained, this method will yield the same overall tire wear with less fuss and more safety than a conventional rotation regime. But it only works for FWD cars!

 

This is horrible advice, especially in a Front wheel drive car. Since the front wheels are responsible for steering and most of the braking you want as much traction as possible at those wheels, in a FWD car this becomes even more important since the front wheels are responsible for forward motivation as well as supporting around 60% of the vehicles wieght. Allowing the front wheels to wear excessively, while it will induce more "safe" understeer in some instances, will also make those tires more prone to hydroplaning. Proper tire rotation is key to maximum tire life and safe opperation of the vehicle.

 

I follow 911's plan....but I do not let the fronts wear down excessively......having a set of bald tires, front or rear, is bad on any typeofcar of course....once I see the wear bars, they are gone

 

The question to this answer was whether TPMS reset is needed after rotating the tires. Being a regular rotator, I wondered the same thing myself when I got a puncture in one run-flat, lost tire pressure, and could only tell by the different sound (TPMS didn't trigger even though the tire had nearly no air).

The puncture is repaired now, and I believe I should reset TPMS. I saw in the manual where it is recommended to reset after correcting the air pressure in the tires too. I have been doing that periodically, and not resetting , so I suppose THAT could be the reason why TPMS didn't wake up when I had the flat tire?

Whaddaya's think?

Tatt

 

^ all I know is that I reset after rotating, adding air, etc . . . why not? they couldn't have made it any easier for us. . .

 

^^ That is a good point, and thanks. Guilty I am, of over-thinking this... You know, if it aint broke, don't break it, etc.

Gratefully,
Tatt