Low idle issue, with a twist
12-29-06, 05:46 AM
#76
Vibration is gone on my car as well. I bit the bullet, gave it to my Lexus buddy, and $340 later, I have a new feeling car. No more vibration with lights off, in drive, in park, ac on/off, nothing. The car feels like it is not even on with any combination. He only did both the engine mounts, and road force balanced my tires, oh and a new oil filter because mine had to come off for the mount. By the way, I have those mounts in my garage, they are messed up. Both have a rip all the way around, but still connected with the centers. Crazy, what a difference. Thanks all.
12-29-06, 07:14 AM
#77
Lead Lap
Thread Starter
Vibration is gone on my car as well. I bit the bullet, gave it to my Lexus buddy, and $340 later, I have a new feeling car. No more vibration with lights off, in drive, in park, ac on/off, nothing. The car feels like it is not even on with any combination. He only did both the engine mounts, and road force balanced my tires, oh and a new oil filter because mine had to come off for the mount. By the way, I have those mounts in my garage, they are messed up. Both have a rip all the way around, but still connected with the centers. Crazy, what a difference. Thanks all.
So does the car still idle low with all the accessories off, but it just doesn't vibrate any more because of the new engine mounts?
12-29-06, 07:58 AM
#78
Lexus Fanatic
damn you slick. now I have to get new motor mounts....
I just left a message at lex dealer to find out when my drivetrain warranty is up( I think it's april) and schedule an appointment to try for new mounts.
I'd kinda like to take my car to the track once before the new mounts go in.....
I just left a message at lex dealer to find out when my drivetrain warranty is up( I think it's april) and schedule an appointment to try for new mounts.
I'd kinda like to take my car to the track once before the new mounts go in.....
12-29-06, 10:50 AM
#79
GOOD JOB, SLICKGT1. I see that you had broken mounts too. This is OFTEN overlooked, as folks change everything under the sun but to no avail.
I WILL say that adjusting the throttle cable raised my speed slightly when everything is turned off, but my engine was smooth without fluctuation. Some folks have TPS issues and ect causing erratic idle speeds up and down, but for those folks whose engines idle smooth and EVEN but still running too slow, the throttle cable adjustment may just help. Sorry for the drive-by-wire GS430's, as they have no cable to adjust. For them, I would look at cleaning up everything, including the throttle body and idle speed motor, checking the throttle position sensor and the accelerator rheostat under the pedal.
I adjusted my cable, and though the engine was smooth in "park", it still vibrated when in drive, like it was misfiring. But of course it wasn't, because it was smooth with the A/C on.
Shifting to "drive" with the hood open and holding the brakes down hard while quickly and firmly tapping the accelerator on and off revealed that the entire left side of the engine raised and lowered with the accelerator pedal. I had broken motor mounts, but you couldn't see it until the mount was removed.
I bought the mounts a few months earlier because I suspected them, but didn't want to tackle the job until I was sure.
Grabbing at straws, I drove a new 2006 GS430 at a dealership and noticed that though the engine was obviously very smooth, the idle was also about 400 rpm with A/C and all accessories off, and about 600 to 650 with accessories on....just like my car. I also noticed the engine did not move when changing directions forward and reverse, and decided right then that I would change my motor mounts. Now my car feels just like the new car. Man was I glad I finally did it.
There was a giant crack all the way around on the outside, but the middle part was the only part still holding on, and it moved up ad down as the engine moved. These mounts are oil-filled, and most of my oil was gone.
If your situation is the same, you may want to check into it. The drivers side is usually worse because the engine naturally twists from left to right while going forward, and right to left when going in reverse. With new mounts, the engine barely BUDGES, and holds the engine steady at all engine speeds and directions. 400 rpm with no accessories on is all the speed you need if the mounts are good. It feels right. We are just so used to having the AC on to smooth things out. I realize now that I really have to hold the brakes with headlights and a/c on when I am at traffic lights. It really is smooth all the time.
As far as using the A/C in freezing weather, there are safety devices in place to prevent the compressor from operating when such operation could cause it to freeze up and seize. There is a "low-pressure switch" designed to stop the compressor when "suction" or "low" pressure drops too low, or all the refrigerant leaks out. The colder the refrigerant, the lower this pressure drops until the switch opens the electrical contact, shutting off the compressor until the pressure rises again. Jumping this switch will keep the compressor on, but compressor damage will result, along with other components.
Fixing the idle problem if possible is the best bet, and then the heater can be used when you are cold wthout worrying about the compressor.
I WILL say that adjusting the throttle cable raised my speed slightly when everything is turned off, but my engine was smooth without fluctuation. Some folks have TPS issues and ect causing erratic idle speeds up and down, but for those folks whose engines idle smooth and EVEN but still running too slow, the throttle cable adjustment may just help. Sorry for the drive-by-wire GS430's, as they have no cable to adjust. For them, I would look at cleaning up everything, including the throttle body and idle speed motor, checking the throttle position sensor and the accelerator rheostat under the pedal.
I adjusted my cable, and though the engine was smooth in "park", it still vibrated when in drive, like it was misfiring. But of course it wasn't, because it was smooth with the A/C on.
Shifting to "drive" with the hood open and holding the brakes down hard while quickly and firmly tapping the accelerator on and off revealed that the entire left side of the engine raised and lowered with the accelerator pedal. I had broken motor mounts, but you couldn't see it until the mount was removed.
I bought the mounts a few months earlier because I suspected them, but didn't want to tackle the job until I was sure.
Grabbing at straws, I drove a new 2006 GS430 at a dealership and noticed that though the engine was obviously very smooth, the idle was also about 400 rpm with A/C and all accessories off, and about 600 to 650 with accessories on....just like my car. I also noticed the engine did not move when changing directions forward and reverse, and decided right then that I would change my motor mounts. Now my car feels just like the new car. Man was I glad I finally did it.
There was a giant crack all the way around on the outside, but the middle part was the only part still holding on, and it moved up ad down as the engine moved. These mounts are oil-filled, and most of my oil was gone.
If your situation is the same, you may want to check into it. The drivers side is usually worse because the engine naturally twists from left to right while going forward, and right to left when going in reverse. With new mounts, the engine barely BUDGES, and holds the engine steady at all engine speeds and directions. 400 rpm with no accessories on is all the speed you need if the mounts are good. It feels right. We are just so used to having the AC on to smooth things out. I realize now that I really have to hold the brakes with headlights and a/c on when I am at traffic lights. It really is smooth all the time.
As far as using the A/C in freezing weather, there are safety devices in place to prevent the compressor from operating when such operation could cause it to freeze up and seize. There is a "low-pressure switch" designed to stop the compressor when "suction" or "low" pressure drops too low, or all the refrigerant leaks out. The colder the refrigerant, the lower this pressure drops until the switch opens the electrical contact, shutting off the compressor until the pressure rises again. Jumping this switch will keep the compressor on, but compressor damage will result, along with other components.
Fixing the idle problem if possible is the best bet, and then the heater can be used when you are cold wthout worrying about the compressor.
Last edited by gserep1; 12-29-06 at 11:15 AM.
12-29-06, 11:00 AM
#80
Lead Lap
Thread Starter
Great info GSEREP1. Here's the strange thing. Since the day I started this thread, I haven't had the shakes anymore at low idle. In other words, on those freezing cold days when the compressor turns off and the RPMs drop to 400 in drive stopped at a stop light, I notice the RPMs are low (I can kind of sense it), but the car doesn't shake. The only time the car shakes is if I turn off the climate control and then the RPMs drop to 250 and the car feels like it's going to die out. But that has nothing to do with the motor mounts because the car really shouldn't be idling at 250 to begin with.
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12-29-06, 11:40 AM
#81
You are right.
Get that throttle cable adjusted to about 600 or so rpm in "park" and you should be at about 400 rpm in drive with no A/C, lights or other accessories on. Just take out the slack and don't make it too tight, or you wll have to hold the brakes while driving, and the TPS won't like it either.
There are tutorials on how to do this. We can walk you through it if necessary. PM me if you need to.
If your engine is smooth, the cable adjustment should do it. Make sure your throttle body is clean inside, and you have a clean air filter.
Good luck
Get that throttle cable adjusted to about 600 or so rpm in "park" and you should be at about 400 rpm in drive with no A/C, lights or other accessories on. Just take out the slack and don't make it too tight, or you wll have to hold the brakes while driving, and the TPS won't like it either.
There are tutorials on how to do this. We can walk you through it if necessary. PM me if you need to.
If your engine is smooth, the cable adjustment should do it. Make sure your throttle body is clean inside, and you have a clean air filter.
Good luck
12-29-06, 04:36 PM
#85
Lead Lap
Thread Starter
I'm pretty sure the motor mounts are fairly inexpensive, right (like around $100 for the pair)? How much labor is involved to install them? Is it any easier to have them installed while Lexus has my engine taken apart for the 90k (which I need to do in the next month or so)?
12-29-06, 07:10 PM
#86
Make a deal with them and have it all done at once. the mounts are behind the pace where the tming belt is, but it can be done. They should give you some kind of break on the deal.
Good luck!
And Oh, for the folks that have had the mounts replaced and the throttle cable adjusted, it really IS like getting a new car isn't it? I just LOVE driving my car again, as it is now so well-mannered as it should be. I am amazed each time I drve it. NICE!!
Good luck!
And Oh, for the folks that have had the mounts replaced and the throttle cable adjusted, it really IS like getting a new car isn't it? I just LOVE driving my car again, as it is now so well-mannered as it should be. I am amazed each time I drve it. NICE!!
12-29-06, 07:17 PM
#87
Lead Lap
Thread Starter
Make a deal with them and have it all done at once. the mounts are behind the pace where the tming belt is, but it can be done. They should give you some kind of break on the deal.
Good luck!
And Oh, for the folks that have had the mounts replaced and the throttle cable adjusted, it really IS like getting a new car isn't it? I just LOVE driving my car again, as it is now so well-mannered as it should be. I am amazed each time I drve it. NICE!!
Good luck!
And Oh, for the folks that have had the mounts replaced and the throttle cable adjusted, it really IS like getting a new car isn't it? I just LOVE driving my car again, as it is now so well-mannered as it should be. I am amazed each time I drve it. NICE!!
12-29-06, 09:04 PM
#89
Yeah, That would be nice. I took pictures of my mounts before I threw them away, but my pictures are on my computer at work. I'll be sure to send pictures of mine after the first of the year.
Last edited by gserep1; 12-30-06 at 09:18 PM.