Intake Noise Accelerating
12-10-18, 09:14 AM
#1
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Intake Noise Accelerating
RX 450H three and a half years old I've had it from new.
There is what I would describe as an intake noise when accelerating, the noise is fine when accelerating hard but this is most noticeable when going from 50 to 60 or 60 to 70 so just firm press on the pedal.
At the same time the petrol consumption has dropped dramatically
There is what I would describe as an intake noise when accelerating, the noise is fine when accelerating hard but this is most noticeable when going from 50 to 60 or 60 to 70 so just firm press on the pedal.
At the same time the petrol consumption has dropped dramatically
12-10-18, 12:34 PM
#2
Moderator
I have seen the consumption fluctuate due to extreme weather conditions ... hot and cold. With moderate temperature, and mixed city-highway I get close 28.5 on pretty consistent basis and have gone over 30mpg since last fillup.
Best way is to have the live consumption on the display and notice what is going on. Your wot test certainly can impact mpg.
Have you noticed any drag ... hanging brake etc. How is the maintenance? All filters, oil, brake fluid etc hopefully are unto date.
Salim
Best way is to have the live consumption on the display and notice what is going on. Your wot test certainly can impact mpg.
Have you noticed any drag ... hanging brake etc. How is the maintenance? All filters, oil, brake fluid etc hopefully are unto date.
Salim
12-10-18, 01:09 PM
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I have seen the consumption fluctuate due to extreme weather conditions ... hot and cold. With moderate temperature, and mixed city-highway I get close 28.5 on pretty consistent basis and have gone over 30mpg since last fillup.
Best way is to have the live consumption on the display and notice what is going on. Your wot test certainly can impact mpg.
Have you noticed any drag ... hanging brake etc. How is the maintenance? All filters, oil, brake fluid etc hopefully are unto date.
Salim
Best way is to have the live consumption on the display and notice what is going on. Your wot test certainly can impact mpg.
Have you noticed any drag ... hanging brake etc. How is the maintenance? All filters, oil, brake fluid etc hopefully are unto date.
Salim
Yes you are pretty much correct 28.5 to 29 MPG can squeeze 33 out of it on a long run with careful driving.
Now down to 23.5 to 24MPG Temperature In Scotland at this time of year not that cold also i have had the car through 3 winters now without any real problem.
The intake noise is when i’m about. 1/3 to 1/2 throttle
Anway thanks again for your reply
12-10-18, 02:58 PM
#4
Well, you need to pop bonnet up and start with checking on all air duct connections. better off, have it up and have someone step on the gas pedal for you, so that you can pin point noise location. There should be no whooshing noises.
It's radical mpg drop. Something's not right.
It's radical mpg drop. Something's not right.
12-11-18, 08:57 AM
#6
Could be a vacuum leak.
What would happen is more air would be entering the intake somewhere after the AFM/MAP/MAF sensor (honestly don't know what sensor Lexus uses in this application.) This un-metered air would in turn cause some down stream sensor to read a lean condition and cause the ECU to start dumping more fuel.
The only happening at high load is another hint that points in this direction.
What would happen is more air would be entering the intake somewhere after the AFM/MAP/MAF sensor (honestly don't know what sensor Lexus uses in this application.) This un-metered air would in turn cause some down stream sensor to read a lean condition and cause the ECU to start dumping more fuel.
The only happening at high load is another hint that points in this direction.
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12-11-18, 01:59 PM
#8
You are welcome but "just looking" not going to cut the cheese, as they say here. You need to rev engine.
Btw, you have MAF sensor. Mass Air Flow. It's right past the filter box, in air duct.
I have no logical explanation, but I doubt it's air noise. On turboed engine - maybe. Not on naturally aspirated. They simply don't move that much air volume.
Btw, you have MAF sensor. Mass Air Flow. It's right past the filter box, in air duct.
I have no logical explanation, but I doubt it's air noise. On turboed engine - maybe. Not on naturally aspirated. They simply don't move that much air volume.
12-12-18, 12:49 AM
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Thanks again
Perhaps I have been a little misleading I have said it sounds like an intake noise, thats how it sounds not necessarily what it is.
I remember some years ago when I was younger and cars were simpler we would remove the air filter in the believe that this gave you better performance, it may not have given you better performance but it sounded cool!........ So thats the noise!
I guess the point of posting was to hope that someone else had, had the same problem, looks like it is going to be one of these situations where I go back and forward to the dealer until it is sorted!
I will definitely post here if and when they get it sorted!
Perhaps I have been a little misleading I have said it sounds like an intake noise, thats how it sounds not necessarily what it is.
I remember some years ago when I was younger and cars were simpler we would remove the air filter in the believe that this gave you better performance, it may not have given you better performance but it sounded cool!........ So thats the noise!
I guess the point of posting was to hope that someone else had, had the same problem, looks like it is going to be one of these situations where I go back and forward to the dealer until it is sorted!
I will definitely post here if and when they get it sorted!
12-12-18, 01:37 PM
#12
Intermediate
Plug a code scanner into the OBDII port and check for any errors. Perhaps you have an inlet manifold leak somewhere, and if this were the case, you may well get some codes (P0171 and P0174) which relate to fuel trim issues, but the underlying problem is an air leak.
12-14-18, 09:40 AM
#14
Driver School Candidate
I wonder if it could be an exhaust leak prior to the muffler or a hole in the muffler. That would yield a similar sound on sudden acceleration.
12-15-18, 07:33 AM
#15
Oh no! Exhaust leak is VERY different and VERY loud. I had several of them and know well, what exhaust leak sounds like. Starts with low pitch FRRRRRRRRRRRRRRRRRRRR and slowly turns into loud BOOM BOOM BOOM.
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