Transmission rpms & What is that noise?

Bowbina · July 25, 2017

Hi guys! Newbie here. I have a 2005 is300 automatic with no mods. Here are my questions:

1. When there is a problem with the transmission or the fuel pump, would the check engine light come on?

Transmission rpms.

2. Is 3500 to 4000 rpms at 70-75 mph about right or do I need to take my car to a transmission shop? I've had this car for years but I guess I haven't looked at the rpms at that speed. I would mention that I'm a girl but it could be argued it's not an excuse and I kinda agree so I won't. But hey when I was on the freeway and wanted to go around someone I felt the poor response of the gas pedal and expected it to down shift but it didn't. So I turned my music down to hear the engine and it seemed loud and a bit strained so I slowed to 65 and the rpms dropped to just under 3500 and the engine sounded better. Does all of this sound normal? I have long drive up a hill in a few days and am a bit worried.

3. If something is wrong with the transmission an OBD reader would show codes for it right? Also, if there were codes but they were accidentally cleared (oops) how long does it typically take for them to come back?

What is that noise?

4. I've been hearing an intermittent motor-like noise or whine coming from under the cab of my car for a few months now. When a code came back for heated oxygen sensor 2 bank 2 and I learned that it was in the same area as the noise I was stoked and got it replaced. Well I'm guessing the sensor wasn't the source of the noise because it has returned, or it was never gone. I'm not quite sure, but never mind that. So if it wasn't the sensor what else could it be? The fuel pump?

Thank you for your time.

Tina

gdh300 · July 25, 2017

Hi Tina, welcome to LOC!

Might be worth a look at this post which seems to list every single code an IS can ping. A quick scan shows there are codes for fuel pump and transmission, but really without the code it could be anything. Well worth investing in a cheap OBDC reader of your own if you haven't so far. My reoccurring P430 code comes back about 50-100 miles of driving, but if you have something different might not come back in six weeks, or ever!

I think your revs are off, almost like overdrive (fifth) isn't engaging. On the ~~motorway~~ freeway (!) I my IS sits at 2500rpm at an indicated 70mph. Fourth would be about 3300rpm I think. Have you checked the transmission fluid level, and what condition it is in?

As for the whirring noise, could it be the cruise control motor gone bad?

Bowbina · July 26, 2017

Thank you for your reply. If the cruise control motor is under the cab of the car then maybe that's it. I will definitely check that. I'm really concerned about my transmission. It turns out I have to go out of town tomorrow. Should I not be driving it? Part of my drive is up a really long pretty steep hill. If I drive slow will it be ok?

gdh300 · July 26, 2017

Well, you said you've had it years and it hasn't gone bang so far, so I'm sure a trip tomorrow will be OK (but I'm not guaranteeing it!). If all it is doing is not changing up to fifth then it's just costing you gas. I would though check the fluid level as soon as you can.

When you say the whirring is under the cab, I'm not sure where you mean?

Bowbina · July 26, 2017

LOL well no bang yet and I've done half my trip! YaY! Bad news is I haven't gone up the hill yet. I totally get what you're saying and no no it's not like that. You see, I don't know if its been like this the whole time I've had it or not. And I mean the rpms as well as the noise I hear....and here's why. About 6 months ago I got the rear wheel bearings fixed and they were terribly loud. They needed to be fixed..well let's just say for way too long! So I really couldn't hear much except for the low, as in decibel low, hum coming from the darn wheel bearings or my stereo! So to be honest I really don't remember what it should sound like. Strange I know. If someone would just let me take theirs out for a spin then I would know and who knows, maybe all my problems would be fixed! lol The last six months after fixing the bearings Ive unfortunately been sick most of the time and haven't really been driving it much. So there's my story. Hopefully that's makes things more understood.

So today while on my trip I've been watching the rpms of course and wanted to mention that I decided to continue accelerating to see what would happen and the rpm's continued to go up past 4000.

I checked the fluid and it seems to be ok. I mean, it wasn't too low or too high, it was kind of in the middle of the two lines. That's where it should be right? So I'm thinking I need to skip the trip up the hill. Any thoughts?

As far as the noise goes I don't know how to describe it. I guess it may sounds a bit like a lawn mower or leaf blower from a block away. lol Its really hard to tell where it is for some reason. Sitting in the drivers seat it sounds like it's sort of in the back in the middle but sitting in the backseat it sounds like it's in the front somewhere. I also think that it starts after the car has been running for a while. I will continue to pay attention to that, but I might just have to have a mechanic sit in my car.

Anyway thanks again. Back on the road I go.

Bowbina · July 26, 2017

I just noticed when Im sitting at an idle the noise changes. And yea, its definitely in the back. There's nothing back there is there? LOL I swear I'm not hearing things it's been confirmed from friends. Maybe they're just being nice.

Bowbina · July 26, 2017

I just noticed when Im sitting at an idle the noise changes. And yea, its definitely in the back. There's nothing back there is there? LOL I swear I'm not hearing things it's been confirmed from friends. Maybe they're just being nice.

Here are some pics i took while driving ...and of course, the rpms dont look so bad. Am I right? Its Murphy messing with me as usual. Im almost positive. Ugghh...😕

gdh300 · July 27, 2017

If it sounds like its from the back I'd suspect fuel pump, which is suspended in the tank under the back seat, which explains why you struggled to locate it when sitting the car! I'd say your revs indicate that fifth isn't engaging. Looks like you are on the overun in that first picture; with some throttle I'd expect that goes to 3300rpm or so, which is fourth for me. Can you count the gears as you pull away?

Bowbina · July 28, 2017

When I went out last night I tried to count the gears several times and found it a bit hard to do for some reason. It seems to shift through 2nd and 3rd too quickly but I don't think it was consistent. It's been nearly 20 years since I've owned a vehicle with a manual trans but I remember that driving around town was typically in 3rd gear. So I guess that makes sense that its gets to 3rd fast. Does 2500 rpms for both 2nd and 3rd sound right? 4th gear was hard to get to around here but got it a couple times around r5 mph. Anyway, I suppose you were just wanting to make sure it was shifting? I will go where there's no traffic later today to get more info if I need to.

I checked and still no codes. Thats confusing to me. I also checked fluid again about 15. 20 minutes after I got home and it was fine. What concerns me is my ex-boyfriend who took care of most things himself for 6 years said he never performed maintenance on it but I thought I read it should be once a year?

Could it be possible that the ECU is causing this my car not to go into overdrive? If so, is it possible that something happened to the ECU when a locksmith made a new master key using an master key that came from my first is300? I ask because of something I read during my recent search online.

Btw, this is not important what-so-ever but I'm going to mention it anyway (i know, just like a girl) 😬. In one of my previous posts I was describing the sound of the wheel bearings I said the noise was a low hum as in decible low, but what I meant was it was a low hum NOT as in decible low. If that makes any sense at all. I seriously can't find any other way to describe it. 😕

Thanks again.

T.

gdh300 · July 29, 2017

I think round town it will change up to fourth even fifth and changing up will happen lower than 2500 on light throttle.

It's goof your fluid is the right level, but what colour is it? If it is a very deep red or burnt brown it could well be time to get it changed, Not something you'd do every year but after six years is a definite-maybe. It could just be the fluid is knackered; I'm not expert so I don't know if it could be a factor. First off you might want to try disconnecting the Battery for at least an hour so the ECU resets. You'll lose your radio stations and your clock, but can be worth doing.

I've just had a front wheel bearing done on mine; quite a slow build up of noise which I put down to tyres running down their tread. So much quieter now!

Bowbina · July 31, 2017

Ok so it's shifting 3 times but not 4. At least I couldn't get it. I'm glad you mentioned that it would shift into gear even at a low speed. I was wondering about that. If the same goes for 5th then that really sucks. I'm under the impression that changing out the tranny fluid can fix many things. Could I be so lucky? Could that actually fix this? I plan to take it in either tomorrow or Tuesday. Does it need to be a transmission shop? I wish I could do all of this myself!! lol

Bowbina · July 31, 2017

Oh and yeah, I've already disconnected the Battery. I did that a few weeks ago because of an error message I got on my stereo. Then today I read up on the code reader as well as learned how and when codes show up on the reader or make the CEL come on. So far Ive read no specific formula lol so I was trying to figure out how much I need to drive around to get them to come back, if there were any. I'm sure now that the noise I hear is the fuel pump. Wouldnt there be a code for it? Tranny and fuel both seem like key areas I'd think there would be some codes to help me diagnose this baby!! You feel me? Well G, you've helped me more than the OEM or ODE, whatever its called, youve been more helpful than its been. So thank you for that! 🍺 Im glad you are able to hear your car again too haha. I'd like to see a picture of it if you have one to share. 😊

Bowbina · August 2, 2017

Taken it to Lexus tomorrow. Thanks for your help G.

T.

gdh300 · August 2, 2017

My pleasure Tina, just wish I could be more helpful and given you a definitive answer! Hopefully a fluid change will all that it needs; I know they won't change up to fifth if they are too cold so may be they are viscosity sensitive. Fingers crossed, Lexus (in the UK anyway) are not the cheapest dealers to go and see. Let us know how you get on.

Yours is looking good there. Here's a picture I took just yesterday while I was away in North Wales:

Bowbina · August 8, 2017

Nice ride G. It looks very well taken care of. I like the color.

Well I'm happy to report that there is no longer a whinning noise! It was the fuel pump just as we thought. Total parts & labor to replace it, $618.00.

I also had the transmission drained and filled but that was all. I skipped having them perform any diagnostic testing at this time. I just couldn't afford it. I'm hoping that was all it needed but we will see.

Thanks for talking it through with me G. You may not feel that you helped but trust me you truly did!

Until next time. Take care.

T.

gdh300 · August 8, 2017

Glad you got the pump sorted, sounds like a reasonable price when I convert to UK pounds! And now you have new fluid in the box, at least you know that is good for another few years, with or without fifth.

Happy motoring, T!