Weird Shudder When Slowing, Help!

[gridlock13]

I was slowing down for a red light today when the car shuddered for a second. it's happened once before. the car was already running for about 20 mins and the engine temp read normal. it was 45 degrees out and i have no modifications at all. what could be the problem?

[dcfish]

Was it engine/transmission shudder or brake/suspension/wheel shudder ?

[gridlock13]

definitely from either the engine or transmission

[gridlock13]

it happened again today. i floored it for a second and then stopped at a light shortly after. the car was shaking, the tach was bobbing up and down between 400-600 RPM. put it into neutral and it bobbed between 600-800 RPM. this happened no more than 10 mins into driving. i started driving and then everything went back to normal the next time i stopped. i probably won't find a solution to this soon but i'm using the forum to keep a log so someone can use this in the future.

[timetotravel]

just out of curiousity, have you checked the basics i.e. a clean air filter?

This sounds like a hard one to diagnose.

[gridlock13]

just out of curiousity, have you checked the basics i.e. a clean air filter?

This sounds like a hard one to diagnose.

i haven't and u bring up a good point but i don't think that's it. i've noticed that it only does this when the engine hasn't been totally warmed up yet and i suddenly accelerate and let the revs climb briefly, then slow to a stop. this issue's been happening within the first 10 minutes of driving. members on the ClubLexus forum have been experiencing this too and no solution's been found =/

[Haris A]

just out of curiousity, have you checked the basics i.e. a clean air filter?

This sounds like a hard one to diagnose.

i haven't and u bring up a good point but i don't think that's it. i've noticed that it only does this when the engine hasn't been totally warmed up yet and i suddenly accelerate and let the revs climb briefly, then slow to a stop. this issue's been happening within the first 10 minutes of driving. members on the ClubLexus forum have been experiencing this too and no solution's been found =/

I have the exact same issue. But it's very random.

a: It sometimes happens during warm up. it's pretty cold here. So I let it warm up for 5 minutes before I drive.

Unlike yours. It sometimes happen even when the car is totally warm. Two things are consistent with yours.

a: I have 2006- GS300AWD

b: Mostly it happens when I brake and stop at a red light. lasts for about 3-5 sec.

Does your Lexus consume excessive Engine oil ? (Trying to find other commonalities ) example... half way through oil life - level drops to near low dot.

Regards,

Harris

[gridlock13]

it used to before i had it taken in for the engine TSB. did you get that done? haven't checked it recently but i don't remember the oil level dropping too much afterward

[Haris A]

it used to before i had it taken in for the engine TSB. did you get that done? haven't checked it recently but i don't remember the oil level dropping too much afterward

I am not aware of any engine TSBs. Which exact part does it relate to ? I'll definitely get it done.

Happy New Year,

Haris

[gridlock13]

there were 3 major TSBs that i had done on the car. i forgot exactly what they were but one was for the brakes, i think something about the rear brake shields. another was for the electric power steering. the third was for the engine. i'm pretty sure it was for an oil leak. i was sent something in the mail from lexus regarding it. you didn't get any notices?

[HomieG]

there were 3 major TSBs that i had done on the car. i forgot exactly what they were but one was for the brakes, i think something about the rear brake shields. another was for the electric power steering. the third was for the engine. i'm pretty sure it was for an oil leak. i was sent something in the mail from lexus regarding it. you didn't get any notices?

These were more than just TSB's, the were "campaigns" (recalls). The third one was for new fuel rails to be installed as the old ones could begin to rust.

You should be able to regiser your GS at lexus.com, and look to see if your car qualifies, and look at its service history to see if these were done. Here's more information:

Special Service Campaigns (SSC)

SSC 9LA Certain 2006 2007 GS, 2006 2008 IS and 2007 2008 LS Vehicles Fuel Delivery Pipe Replacement

SSC 9LB Certain 2006 2007 GS and IS Vehicles Rear Brake Caliper Inspection

SSC 9LC Certain2006 2007 GS, IS and RX 400h Vehicles Electric Power Steering Link (EPS) Assembly Replacement

On January 16, 2009, Toyota filed a Defect Information Report (DIR) with the National Highway Traffic Safety Administration (NHTSA) regarding certain 2006 2007 GS 300/350, 2006 2008 IS 250/350 and 2007 2008 LS 460/460L vehicles. The involved vehicles are equipped with aluminum fuel delivery pipes (fuel rails). Lexus has determined that ethanol fuels with low moisture content will corrode the internal surface of the fuel rails. As this condition progresses the engine malfunction light (MIL) may illuminate. Over time, the corrosion will create a pinhole resulting in fuel leakage. SSC 9LA will be launched to replace the Fuel Delivery Pipes in the affected vehicles.

There are approximately 43,700 GS 300 (24,500 2WD, 19,200 AWD), 23,700 GS 350 (14,000 2WD, 9,700 AWD), 85,800 IS 250 (54,000 2WD, 31,800 AWD), 24,900 IS 350, and 36,400 LS 460 (25,500 LS 460, 10,900 LS 460L) vehicles involved in the U.S.

Additionally, Lexus is launching two other SSCs.

9LB Certain 2006 2007 model GS and IS vehicles to inspect rear brake calipers. On certain Lexus vehicles, the slide pin in the rear brake calipers may not operate smoothly. If the vehicle continues to be operated under these conditions, the brake pads may make noise.

9LC Certain 2007 GS 450h, 2006 2007 GS, IS and RX 400h vehicles to replace the electric power steering link (EPS) assembly. Certain vehicles may experience a noticeable gradual increase in the steering effort necessary at low speeds when turning the steering wheel to the complete left or right position. This condition may be most perceptible when parking the vehicle.

A dealer package including vital information and reimbursement procedures will be sent to dealers (to the attention of the service manager) today.

Lexus will inform owners of the involved vehicles with a Special Service Campaign notification letter sent via first class mail beginning in late January 2009.

All customer inquires should be directed to the Lexus Customer Assistance Center at 1-800-255-3987.

If you are a dealership associate and have any questions, please contact your District Service and Parts Manager.

[Shon]

I was slowing down for a red light today when the car shuddered for a second. it's happened once before. the car was already running for about 20 mins and the engine temp read normal. it was 45 degrees out and i have no modifications at all. what could be the problem?

I also have this exact same problem. My 2006 GS300 has completed all the recalls listed. Because this only happens rarely Lexus was unable to reproduce the problem to solve the issue. Let me know if you ever figure it out. I don't think it's caused by the temp because mine occurs after the engine is at normal temp. and the outside temp was around 65 degrees. The car always has been maintained at regular intervals and there are no warning lights. I'm just dreading the thought of one day stalling in the middle of traffic.... This is the only thing wrong with my GS. Everything else is great.