Ugly engine noise
Today, 12:12 PM
#1
9th Gear
Thread Starter
Ugly engine noise
Apologies for not being a pro with audio files, the attached is the noise from on our 2009 RX350 with 150k miles. The car is in the garage with the hood up, at around 20 seconds it sounds as though something is starting to vibrate (I've checked heat sheilds, etc, but cannot trace it - but that's not what's concerning me), the engine warms and at around 27 secs the RPM drops, whatever is vibrating vibrates louder then at 47 secs the rattle starts. I was moving the phone around a little but the sounds is consistent after that, increasing engine speed does not stop the noise. At 110 secs I shut the engine off; I paused the recording at that point, pls ignore anything after that. To me the rattle is pretty concerning.
Additional info...
(i) - Engine is always quiet when it starts, noise occurs after running for a few seconds. Sometimes the noise will stop for a few seconds but the majority of the time it is there.
(ii) - There is no noise if serpentine belt is removed. With car on jack stands I did put car in gear with serpentine removed still no noise.
(iii) - Have checked all driven items on serpentine, all appear good. The water pump had some pink buildup at the weep hole so I replaced it but no difference. There is some end play on the power steering pump but moving the steering, pressing on end of shaft when running, does not change noise, AC pulley spins freely, turning AC on and off makes no difference. Alternator spins freely.
(iv) - All fluids good, just replaced engine oil with MobilOne 5W30, new filter. Inspected old filter, no metal particles. New oil made no difference.
(v) - All serpentine pulleys are fine, tensioner appears good.
(vi) - The noise appears to come from the timing side, if I had to say towards the top and front of the engine, sounds internal to the engine. I went around with a long screwdriver and stethoscope and could hear rumbling but not the rattle. Put stethoscope on valve cover, did not hear metal on metal impact on the audio file.
Appreciate any suggestions,
Peter
Additional info...
(i) - Engine is always quiet when it starts, noise occurs after running for a few seconds. Sometimes the noise will stop for a few seconds but the majority of the time it is there.
(ii) - There is no noise if serpentine belt is removed. With car on jack stands I did put car in gear with serpentine removed still no noise.
(iii) - Have checked all driven items on serpentine, all appear good. The water pump had some pink buildup at the weep hole so I replaced it but no difference. There is some end play on the power steering pump but moving the steering, pressing on end of shaft when running, does not change noise, AC pulley spins freely, turning AC on and off makes no difference. Alternator spins freely.
(iv) - All fluids good, just replaced engine oil with MobilOne 5W30, new filter. Inspected old filter, no metal particles. New oil made no difference.
(v) - All serpentine pulleys are fine, tensioner appears good.
(vi) - The noise appears to come from the timing side, if I had to say towards the top and front of the engine, sounds internal to the engine. I went around with a long screwdriver and stethoscope and could hear rumbling but not the rattle. Put stethoscope on valve cover, did not hear metal on metal impact on the audio file.
Appreciate any suggestions,
Peter
Last edited by pwells; Today at 06:52 PM.
Today, 12:33 PM
#2
Pole Position
#2= Bingo no noise as you mentioned w/ the serpentine belt off.....The tensioner could look good, but how 'bout the tension & the bearing in the pulley. I replaced the whole tensioner w/ a Gates. Not just the pulley.
Today, 12:38 PM
#3
Possibly a power steering air leak causing cavitation noise. Remove that silly cover over the PS reservoir and see if the oil in there is like a milk shake or is ok when running.
Did you also replace the thermostat, coolant levels all good?
Hard to blame VVT rattle if no noise when serp belt off...
Did you also replace the thermostat, coolant levels all good?
Hard to blame VVT rattle if no noise when serp belt off...
Today, 01:48 PM
#4
9th Gear
Thread Starter
Thanks for the replies, in order...
(i) I looked at the bearings in all the pulleys and were good, regarding the tension from the tensioner, seems OK, requires some force to install the belt. The tensioner mechanism is not lose in any way, but will take a second look. The serpentine belt moves smoothly even when car is making noise.
(ii) PS fluid does not look milky however I don't see any fluid moving in the reservoir - should I? Will compare with other car. I like this idea as a new steering rack was fitted recently.
(iii) Yes, it has a new thermostat, can't be 100% sure about coolant level, did use bleed screws and noise is unchanged from before replacing water pump.
I'm going to wait for the engine too cool off and see if I can find out what is vibrating (20 sec into audio).
(i) I looked at the bearings in all the pulleys and were good, regarding the tension from the tensioner, seems OK, requires some force to install the belt. The tensioner mechanism is not lose in any way, but will take a second look. The serpentine belt moves smoothly even when car is making noise.
(ii) PS fluid does not look milky however I don't see any fluid moving in the reservoir - should I? Will compare with other car. I like this idea as a new steering rack was fitted recently.
(iii) Yes, it has a new thermostat, can't be 100% sure about coolant level, did use bleed screws and noise is unchanged from before replacing water pump.
I'm going to wait for the engine too cool off and see if I can find out what is vibrating (20 sec into audio).
Last edited by pwells; Today at 02:06 PM.
Today, 07:02 PM
#5
9th Gear
Thread Starter
So this is where things are...
(i) I bought a stethoscope with the metal extension and will go over things again tomorrow. The rattle is loud, surely I can figure out where it's coming from.
(ii) I'm thinking the belt tensioner and power steering pump are the most likely candidates powered by the serpentine belt, I'll focus on the PS pump. Looking at the end of the PS pump there is an internal thread, I'll get a bolt, remove the serpentine belt, and try driving the pump with a battery-operated drill. Not sure what I'll learn but hopefully I can replicate the noise.
(iii) The VVT oil lines are what I understand to be the old style (have a rubber section) I could update those and pull the valve covers - but I'm tempted to think if the noise was caused by something internal there would be metal in the oil by now and as reported above none was seen in the filter. Sometimes you just do what you can with the hope you'll bump into the problem along the way.
(i) I bought a stethoscope with the metal extension and will go over things again tomorrow. The rattle is loud, surely I can figure out where it's coming from.
(ii) I'm thinking the belt tensioner and power steering pump are the most likely candidates powered by the serpentine belt, I'll focus on the PS pump. Looking at the end of the PS pump there is an internal thread, I'll get a bolt, remove the serpentine belt, and try driving the pump with a battery-operated drill. Not sure what I'll learn but hopefully I can replicate the noise.
(iii) The VVT oil lines are what I understand to be the old style (have a rubber section) I could update those and pull the valve covers - but I'm tempted to think if the noise was caused by something internal there would be metal in the oil by now and as reported above none was seen in the filter. Sometimes you just do what you can with the hope you'll bump into the problem along the way.
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