It runs louder yhan should when excellerating only

5

Asked by Aug 21, 2012 at 11:48 PM about the 1998 Lexus LS 400 Base

Question type: Maintenance & Repair

Exhaust has been ruled out by dealer and another good shop.Low or high speed the noise is there. Dealer and another good shop dont know what it is but agree its not right. All major and minor maint has been done. Most exhaust parts are new. Im stumped. Dealer says there is no EGR valve for the 98. ? I have had many of this model 98-00 and never had this problem b4. Thier answer is wait for it to get louder to pinpoint the noise/problem. No engine lights go on. At times I hear a slight whistling noise when letting off the gas when leaving the house. Frustrated.

8 Answers

16,255

What does it sound like? Is the noise varying with the engine rpm or road speed?

5

Well it sounds like there is a exhaust leak and the rpm gage seems normal. It actually sounds slightly louder at a low speed. The noise is a huge mystery. There is no ticking.

16,255

So it will change pitch as your rpms go up or no

5

I would say its a lighter sound when x-pressway driving. But maybe the engine drowns it out a bit. If the car is still it is very quiet. The car has almost 130k on it. New timing belt, wtr pump. pcv valve. Everything flushed/gaskets. New valve cover gasket. At one point dealer said maybe a valve but there is no ticking. They do not want to take apart the pwr train to find it. Car shifts normal.

505

Hi Is the noise sound like a Wiesel or hissing .If it is it can b the brake booster or the hose or some vacuum hose . or the egr valve if ti has hard steal tub a small creak in it . PS I do not know if I;m right or not but its worth a look good luck.

Best Answer
5

Thanks dedell. I gotta feeling you are right with the egr. Its possible the shop dosen't want to do it because its supposed to be very hard to get to. Thanks to all who responed very much.

16,255

check the intake plenum for any loose parts or even cracked parts. the intake actualy does make noise during acceleration but with the stock plenum it muffles it to nothing. Maybe with an opening you could be hearing this noise. A vacuum leak should be more noticeable at idle or deceleration. During acceleration engine vacuum is redueced to little to none therefore wont leak out and hiss becasue it's not there already. EGR is a possibility, could make noise.

1 out of 1 people think this is helpful.
5

Andrew, Im taking the info you and dedell gave me to the shop tommorrow morning. Its a dam shame the Lexus dealer here in rochester, NY can't find the problem and its been a year. But it seems they dont really care and Im a pain in the rear even though I have dumped thousands in that place. THANK YOU!

Your Answer

Add photo

Related Questions

LS 400

Looking for a Used LS 400 in your area?

CarGurus has 230 nationwide LS 400 listings starting at $2,900.

ZIP:

Search Lexus LS 400 Questions

Lexus LS 400 Experts

#1 Tom Demyan
Tom Demyan
Reputation 400
#2 FordNut
FordNut
Reputation 340
#3 dandyoun
dandyoun
Reputation 210
View All

Related Models For Sale

Used Lexus GS 300
30 Great Deals out of 873 listings starting at $3,295
Used Lexus ES 300
17 Great Deals out of 1,062 listings starting at $2,499
Used BMW 7 Series
204 Great Deals out of 5,885 listings starting at $1,600
Used Mercedes-Benz S-Class
177 Great Deals out of 6,094 listings starting at $2,250
Used Honda Accord
1,263 Great Deals out of 78,832 listings starting at $969
Used Toyota Camry
1,523 Great Deals out of 101,602 listings starting at $700
Used Lexus SC 400
70 listings starting at $4,800
Used Toyota Avalon
350 Great Deals out of 15,813 listings starting at $2,100
Used Lexus LX 470
17 Great Deals out of 295 listings starting at $4,500
Used BMW 3 Series
1,830 Great Deals out of 41,344 listings starting at $1,250