ArmyofOne

I edited the thread title to more accurately reflect the thread. Seems the OP has gone MIA and will probably not be back.

mitsuguy

iTrader: (2)

So, I did a little test today... took off this morning, got the car nice and warm, 10 minute drive or so... Then, I found a parking lot and tried two different things - 1, I logged RPM vs injector pulsewidth while in neutral, no accessories or anything on, and then 2, I logged RPM vs injector pulsewidth with the car in drive and foot on the brake... After allowing each to stabilize, I found that in neutral, injector open time was 1.9 milliseconds at 700 rpm, while in drive, injector open time was longer @ 2.1 milliseconds, but at 560 rpm.

If you do the math, you actually find that there is less total open time per minute, even though the injectors are open longer while in drive with foot on brake, the engine speed drops more than enough to compensate for it...

So, again, you may actually be using more fuel by putting the car in neutral, even at a stop...

mitsuguy

iTrader: (2)

First off, is the check engine light on?

If so, please find someone with a code reader and retrieve the codes stored. If not, well, might make it a little more difficult.

Either way, some more specific info would be great. Really slow as in? 5 mph, 10 mph? less? Any other symptoms at all? jerking, bucking, etc?

imherenow

what r your views on nitrogen tire instead of oxygen one?incase if the tire get blow out ..or is having less air can i fill it up with oxygen ..or no mix match? thanks

mitsuguy

iTrader: (2)

how bout this one... it doesn't matter...

if you can get nitrogen for free, by all means, do it... if it costs anything, then I ask, why? Some of the claims are that it doesn't change pressure with temperature changes, that it doesn't "seep" through the inner liner of tires as much and that there is less moisture in it...

All of these claims are true - now, here's the kicker - none of them really matter that much...

Temperature / Pressure change: if you were able to get the tire filled with 100% nitrogen, in theory, tire pressure should be very stable. It is great for track cars as it is easier to set pressures for the amount of roll the tire has to it. In day to day driving, you won't notice the 2-3 psi variance from cold to hot, or the small drop in pressure because it got cold all of a sudden

Doesn't lose pressure over time: there was actually a test done with this in which a few identical tires were filled with air and nitrogen, left for a year, and at the end of the year, the variance was within 1 psi of each other - all tires were low on pressure, but all were relatively equal, regardless of what they were filled with. Also, just because there is nitrogen in a tire doesn't mean it won't leak and it doesn't need to be checked regularly - a nail or screw will completely negate any capacity that nitrogen may have had to keep the tire from losing pressure

Doesn't have moisture in it: sure, it doesn't, and neither does a proper shop air supply. Nitrogen is very dry, but a proper shop air supply has a drier in the system - this prevents issues with tools and adding air to tires. Compare nitrogen (At a shop) to air at a shop and you will find the same - virtually no moisture. Compare either to a home air compressor without a drier or a gas station compressor and there will be moisture in the air - this is bad because it can corrode the wheel inside the tire, and more importantly, at the tire to wheel interface

Air is 79% (Roughly) nitrogen anyways... The only way to get all of the "air" out of a tire and replace it completely with nitrogen is with dual valve stems, or to cycle a tire - fill a tire with nitrogen, completely empty it, fill it again and repeat a few tires... No tire shop is going to do this as standard practice as it is very time consuming and costly...

imherenow

haha looks like i m having lot of qs these days..but have this one for u :

so my car takes 205/60/16 tire.but i found my friend who is selling his BF goodrich winter tire but is 205/55/16..so will that be a problem for in terms of handling/driving/turning/MPG n so on..????

ArmyofOne

No, its 5mm of sidewall height difference. It wont hurt anything, except maybe your wheels if you hit a pothole too hard...but 55 is still a decent sidewall, you should be good until you get down into 45/40 series.

mitsuguy

iTrader: (2)

Actually, that is incorrect. In tire sizing, the first number (205) is the section width (widest point to widest point of the tire), the second number is the aspect ratio. Notice I said ratio. It is actually 60% or 55%, 60 or 55 series, of the width, which is 205. Then of course the wheel diameter.


205 x .60 = 123 mm sidewall height
205 x .55 = 113 mm sidewall height

Now, there are two sidewalls in the diameter of a wheel and tire, so, we multiply that by 2, and you can see that by going from 205/60 to 205/55, you will lose 20mm in wheel/tire diameter, or just over 3/4". Now, that isn't a huge difference, but it will be noticeable. Not to mention, the smaller tire may not have the proper load carrying capabilities. The number after the size, 93h, 94w, etc is the service description. The number part is the load carrying part, the bigger the number, the more weight the tire will safely carry... The letter is the speed rating, but doesn't matter a whole lot with regards to snow tires...

This will result in you going slower than your speedometer indicates, by 3.5%. It will also put mileage on your car that much faster as well. If you drive 1000 actual miles on the road, the odometer will indicate that you actually drove 1035 miles. Not huge, but you should know.

Last but not least, fuel mileage... With a smaller diameter tire, to keep up with other traffic, your engine will be turning a higher RPM, however the injector duty cycle will be lower, so, it will just about even out. Probably won't be noticeable...

Cartune

iTrader: (3)

car suddenly have a whinning noise. check all the belt, looks good. it was replace 6 months ago. i notice, the power steering fluid was all over (not alot) the reservoir (sp?)? outside of it. poured some power sterring fluid. stil whinning, especially when you turn the steering wheel.

what should i do next?

safe to continue driving?

temperature have drop here, around 50-60 F. getting colder, i know cars when its cold, drive belt would make noise, and as it gets warm, it goes away but this continue driving still making noise.

appreciate the help

mitsuguy

iTrader: (2)

If it does it primarily, or worse when when turning, then I would check the fluid level yet again, don't be afraid to overfill it, worse case scenario is that it gets puked back out... chances are the pump is leaking which can be a relatively easy fix, or a complete pump replacement... many times its the hose to pump interface that just needs a new o-ring...

top it off completely, turn the steering wheel a bunch of times, it should go away... then, clean the area and start looking for where the leak is coming from...

ArmyofOne

Wow, I never knew that, I always thought it was measurements, in millimeters. I read that somewhere. My sincere apologies for the misinformation. Learn something new every day.

Power steering is definately one of the systems its ok to overfill. Wont usually hurt anything. What you might have though, is air in the system, in which case jacking the car up with the cap off of the reservoir and turning the wheel slowly from lock-to-lock about 25 times should clear it up.

DRELOC

iTrader: (3)

When it dies it fires right back up no problem but i guess you're right it's hard to diagnose over the net. This happens only on a hot day. Btw how hard is it to change the O-ring from hose to the power steering pump? I think mine is leaking since after i changed the alternator myself but i pour some Lucas ps stop leaks and seems to help a bit. Also to remove air out of the system do you have to turn the ignition to the "ON" position while turning the steering wheel lock to lock? Sorry for the multiple questions. Thanks

mitsuguy

iTrader: (2)

The o-ring is quite simple - remove the power steering line, remove the o-ring, find suitable replacement, reinstall... it will be a mess though, regardless how much fluid you get out of the reservoir first, there is still going to be a lot of fluid in the pump and hoses...

Yes, the engine has to be running, as the power steering system is completely inactive without the pump turning, which, in all cars until recently, is driven by the engine accessory belt... (many new cars may have electric power steering, which is quite a bit different)

As far as the car dying, as Army mentioned, hard to tell without more information... is the check engine light on?

ArmyofOne

Dont you know I almost edited your post instead of quoting it, Cody? LOL!!


And sorry, I forgot to mention that (yes) the engine has to be running.

Bdubs

My Rx350 was making a noise like a muted mini air compressor. Car had not been driven for two hours or more. I noticed it when retrieving something from garage. Once I turned on car and off it ceased. Ideas?