Exhaust rumble from inside
12-05-15, 01:06 AM
#1
Driver School Candidate
Thread Starter
Exhaust rumble from inside
Hi everyone! The amount of advice on here is amazing and helped me decide to buy a 2000 RX AWD, with 174000 one owner miles. There is a long list of stuff that has been done to keep this guy in fantastic shape.
The only issue is a rumble from inside the vehicle, a deep, bass like sound. You can't hear it from the outside. It does quiet down while moving down the road though.
The only issue is a rumble from inside the vehicle, a deep, bass like sound. You can't hear it from the outside. It does quiet down while moving down the road though.
12-05-15, 08:19 AM
#2
Moderator
Welcome to Club Lexus.
Unless there is something very obvious, you would need a lift to raise the vehicle up, have some one sit inside and a person to check the exhaust. This is best done at a muffler shop and they would do the check for free, in hope that you will give them the work. You can give them some money for diagnosis or get the work done by them as often welding is required.
Assuming you have all original exhaust, RX are very quiet inside.
Sound travels by air or mechanical linkages. Since you experience more sound inside, I am going with the hunch that mechanical linkage is the problem. With the exhaust cold, try to shake the tail. There should be a give. Engine being the far end should the only fixed anchor. If it is too free you may have a broken first cat [can be confirmed with a leak test].
Next check for leaks by blocking the exhaust with a rag. Let go before the engine stalls.
Harmonics can also play a part. There is an appendage to the exhaust system that is there to quell harmonic resonance. This where the lift and 2 person set up helps. The person below uses rag or glove to touch and hold the exhaust at various points to dampen the vibrations.
Let us know what you find out.
Salim
Unless there is something very obvious, you would need a lift to raise the vehicle up, have some one sit inside and a person to check the exhaust. This is best done at a muffler shop and they would do the check for free, in hope that you will give them the work. You can give them some money for diagnosis or get the work done by them as often welding is required.
Assuming you have all original exhaust, RX are very quiet inside.
Sound travels by air or mechanical linkages. Since you experience more sound inside, I am going with the hunch that mechanical linkage is the problem. With the exhaust cold, try to shake the tail. There should be a give. Engine being the far end should the only fixed anchor. If it is too free you may have a broken first cat [can be confirmed with a leak test].
Next check for leaks by blocking the exhaust with a rag. Let go before the engine stalls.
Harmonics can also play a part. There is an appendage to the exhaust system that is there to quell harmonic resonance. This where the lift and 2 person set up helps. The person below uses rag or glove to touch and hold the exhaust at various points to dampen the vibrations.
Let us know what you find out.
Salim
Last edited by salimshah; 12-05-15 at 08:22 AM.
12-08-15, 07:52 AM
#3
Driver School Candidate
Thread Starter
Thanks Salim. I suspect it might be exhaust because there is a slight exhaust smell in the cabin. Taking it to a muffler shop in Dallas that has a good reputation with working on these.
12-08-15, 09:38 AM
#4
if you would like to attempt to locate a possible leak yourself, you can seafoam your car and temporarily block the exhaust when the exhaust is nice and smokey.
As an observation from posts on the forum, owners of the 1999 model RX mostly reported occurrences of exhaust manifold cracks happening. Some early 2000 models could possibly have been equipped with the remainder of the problematic lot of exhaust manifolds. If a cracked manifold is your cause, it can be welded depending on the severity.
Good luck
As an observation from posts on the forum, owners of the 1999 model RX mostly reported occurrences of exhaust manifold cracks happening. Some early 2000 models could possibly have been equipped with the remainder of the problematic lot of exhaust manifolds. If a cracked manifold is your cause, it can be welded depending on the severity.
Good luck
12-14-15, 10:30 AM
#6
Driver School Candidate
Thread Starter
Alright. Mechanic checked out the exhaust. Drove the vehicle. Couldn't find anything unusual except that the catalytic converter had two hole drilled in it and were re welded shut.
Since this noise happens mainly in gear, would it be an issue with the transmission?
Since this noise happens mainly in gear, would it be an issue with the transmission?
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12-14-15, 05:52 PM
#8
Mine has done this for years. I think it's just a resonance thing. See if the damper/weight puck thing is still on your exhaust. They put it there for a reason, I bet this is why.
Last edited by carguy07; 12-14-15 at 06:09 PM.
12-14-15, 06:19 PM
#10
Moderator
Salim
12-14-15, 08:33 PM
#11
Driver School Candidate
Thread Starter
He had the car for four hours and didn't charge me for the time or even attempt to sell me on a new part, so he has my trust.
I don't remember seeing that damper/weight when I looked again today. Is there replacements available?
I don't remember seeing that damper/weight when I looked again today. Is there replacements available?
12-14-15, 10:51 PM
#12
Moderator
Crooked to honest in dealing.
Competent to incompetent.
Also there are various skills ... auto-electrician, transmission, engine, emission and exhaust etc
And finally there is some element of luck (and bad luck)
I certainly did not mean to imply anything (good/bad) about your mechanic.
Carguy attached the picture of the damper (appendage in my earlier note in this thread).. If you went to an exhaust shop they should have done the two person test and by touching the exhaust at various points along the length, they would have discovered the standing wave (vibration).
Did you mention exhaust smell in the cabin? Keep in mind that what you smell is just a small portion of the exhaust .. there is Carbon monoxide which you cant smell.
Salim
12-15-15, 08:25 AM
#13
Driver School Candidate
Thread Starter
After doing a lot do research based on carguy07 photo, it does look like I am missing the damper. But, still going to get a second opinion. The "drone" or deep hum sound, just doesn't sound right. Will let you all know what I find out tomorrow. Thanks again for all the advice
12-15-15, 08:43 AM
#14
your statement about exhaust smell still seems disconcerting, a drone/rumble is usually the result of a leak. That is why i asked about the mechanic's method of determining everything ok.