'96 Ls400 Noise After Car Is Turned Off

[Chrissy]

Hi:

When I turn the car off there is a noise under the hood that sounds like a honking goose. It continues for almost 5 minutes. I know Toyota's and Honda do keep running for a minute or so after you shut them off (had a Honda) but this is different. Does anyone know what this could be?

I did try looking this issue up in the search engine...

Christina

[1990LS400]

I don't know what the problem is but I have found that an automotive stethoscope can be useful for pinpointing the source of noises and rattles. There is a photo of one here: http://www.sears.com/shc/s/p_10153_12605_0...20070921x00003a

Be careful when using a stethoscope around moving engine parts!

My favorite usage of an auto stethoscope was to find a loud ticking sound in my first LS400 shortly after I bought it in 1990 -- it turned out to be something silly like my ticking wrist watch or a loose setting in my ring. LOL

[yotoy82]

Did you ever pinpoint the problem? I just bought a 1996 LS400 and when the car is off, specially on warmer summer days, every 2-5 minutes it makes sort of a farting/goose kinda sound, like Guzzz, then stops. I don't notice it as much in the winter. Sometimes in the summer even like a day later I can still hear the intermittent groaning sound. I have all the paperwork for the car, and apparently it made this same sound when it was brand new, and the first owner made complaints to lexus dealers 3 times and they couldn't pinpoint it or find the problem either. My dad has a 95 LS400 and it doesn't have this sound either. I mean there are no problems with the car, it drove 200,000 miles till now so obviously that goose sound isn't hurting anything, but its still awkward!

[Banshee365]

I bet you guy's have air struts.

[yotoy82]

I bet you guy's have air struts.

Nope, mine doesn't have the air suspension.

[billydpowell]

one of my older LS's did that, and it was a small box behind the grille. didnt bother anything so I forgot it, and it went with the trade...

[steve2006]

Mine also does it and I found it was the coolant system cooling down and depressurizing.

To confirm carefully open the coolant pressure cap on the expansion slightly bottle to release the pressure and the noise will then stop.

[yotoy82]

Mine also does it and I found it was the coolant system cooling down and depressurizing.

To confirm carefully open the coolant pressure cap on the expansion slightly bottle to release the pressure and the noise will then stop.

The coolant/radiator cap you mean?

[landar]

Yep, that would be my guess too, coolant reservoir tank pulling air into the system when cooling down and causing noise. Either that or...say, you didnt run into a gaggle of Geese did you? :o :)

Replace the reservoir cap. You may also have a leaking hose and/or cracked reservoir tank.

[yotoy82]

Yep, that would be my guess too, coolant reservoir tank pulling air into the system when cooling down and causing noise. Either that or...say, you didnt run into a gaggle of Geese did you? :o :)

Replace the reservoir cap. You may also have a leaking hose and/or cracked reservoir tank.

Haha, no geese here. The car has been doing it since it was brand new, I even have the lexus dealer service paper saying "car makes goose noise, could not locate a problem , may be due to system depressurizing" or something like that. I have a new radiator cap too, only does it when the weather is warm though! No leaks or anything. Guess its just the way it will be

[steve2006]

Mine also does it and I found it was the coolant system cooling down and depressurizing.

To confirm carefully open the coolant pressure cap on the expansion slightly bottle to release the pressure and the noise will then stop.

The coolant/radiator cap you mean?

Yes that's the one sorry mixed a few words up there plus I'm a Brit! lol

[yotoy82]

Welp, I think I may have found the problem. There was a TSB released on this in March 1997. This makes me a little angry though because the original owner complained specifically about this noise to an Authorized Lexus Dealer who just excused it off saying they could not pinpoint it or that it was a "normal cooling off sound" (3 times he complained, I still have the paper work to show it). This was in November 1997, WELL AFTER the TSB was released. The problem was never fixed. Now 14 years later I see this TSB. Is there a way to show this TSB to Lexus and have them replace the part? Because the part alone seems to cost $250.

EG003-97

Title:

EVAP CHARCOAL CANISTER NOISE

Models:

'96 LS 400

DATE:

March 7, 1997

Introduction

In some cases 1996 LS 400s may exhibit a slight "buzzing" noise, heard from the EVAP charcoal canister, when the engine is turned off after driving. To minimize this noise, an air chamber has been added to the charcoal canister assembly on 1997 models.

Affected Vehicles

^ 1996 model year LS 400 (UFC20).

Parts Information

Previous Part Number 77740-50042 New Part Number 77740-50043 (although I've read online that this part has also been replaced by 77740-50044)

NOTE: Previous part is fully interchangeable with current part.

Repair Procedure

Replace the Charcoal Canister Assembly on affected vehicles which exhibit this condition.

[1990LS400]

Now 14 years later I see this TSB. Is there a way to show this TSB to Lexus and have them replace the part?

No, unless you like to be laughed at.

[yotoy82]

Well I contacted Lexus via email and this is the response I received (paraphrased)

"If you would like Lexus to review for possible assistance with repair costs outside of warranty, we ask that you first have your vehicle inspected at a Lexus dealership. Once the dealership has an opportunity to diagnose your vehicle and recommend repairs, you may contact Lexus Customer Satisfaction at 1-800-255-3987, option 3 and we would be happy to review your request further. I apologize, assistance with repairs outside of the warranty period is not guaranteed."

I'm wondering if I can take it to a Toyota Dealer. Driving to a Lexus dealer from where I live would cost a ton in fuel anyway, and they will probably charge just as much to simply diagnose it, and then there is no guarantee they would "assist" anyway. But I have my paper work of dealer complaints, a copy of the TSB, and a LS400 that makes a goose mating call.

I'm sure being a bit insistent might go a long way.