Rattle at low speeds and clunk noise after shutting off
#1
10-17-2019, 02:44 PM
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Rattle at low speeds and clunk noise after shutting off
Hi - I have a 2003 V70 Base with 175K miles that is starting to make a rattling noise upon acceleration from either a full stop or low speed. It seems to go away once I hit about 25 mph. I am also hearing a "clunk" noise after I turn off the car (like something is falling in a metal tube). It happens either immediately or within 20 seconds after shutoff. Not sure whether this is related, but I've also noticed a decrease in gas mileage (3-4 mpg).
Any ideas? Seems like the catalytic converter...
Any ideas? Seems like the catalytic converter...
#2
10-18-2019, 07:04 AM
Senior Member
ANY attempt at locating the source of the rattle? Get a friend or two to stand aside your car (or 20-30 feet down the lane) as you accelerate. At least try to get a fix on the source.
It could be a common heat shield. There are INEXCUSABLY CHEAP threaded studs on the body work which hold heat shields.
When they rust away there's nothing the shield.
At 175K a fatigued or destroyed engine mount or two can contribute to such noises.
As far as your "noise upon shutdown" goes, try shutting off your engine but immediately turning the key back to run so electrically powered options remain on.
As above, get a few more ears on the job. Lift the bonnet then turn the car off.
The engine mount beneath the crank pulley has a rubber chunk which collapses and allows metal (frame-engine) to bump. It could be that one
Also, there are blend doors in the HVAC system which often move upon shutdown. My suggestion keeps them in place and thus create no sound.
The fuel economy drop can be many things. I assume you have no codes. Does your CEL light up upon startup? If not, check for codes.
Your upstream oxygen sensor can be bad and that'll hit your fuel economy. It sure did hit mine. Mine died at 160K but as I recall, I got a CEL.
FYI: The Volvo pn for the sensor was 9497252. The DENSO equivalent was pn 234-9019.
Volvos are particular about their sensors but use of the correct DENSO unit is OK as DENSO made the sensor for our cars.
Have you given your 175K car the TLC it deserves? Inspections of air handling hoses and vacuum hoses, fuel filter, air filter, cleanliness of the ETM.
When were the sparky-pos last changed? Does you car have the Volvo, 3-prong spark plugs? Use no other.
Do see if your CEL lights up. Get back to us. G&K
It could be a common heat shield. There are INEXCUSABLY CHEAP threaded studs on the body work which hold heat shields.
When they rust away there's nothing the shield.
At 175K a fatigued or destroyed engine mount or two can contribute to such noises.
As far as your "noise upon shutdown" goes, try shutting off your engine but immediately turning the key back to run so electrically powered options remain on.
As above, get a few more ears on the job. Lift the bonnet then turn the car off.
The engine mount beneath the crank pulley has a rubber chunk which collapses and allows metal (frame-engine) to bump. It could be that one
Also, there are blend doors in the HVAC system which often move upon shutdown. My suggestion keeps them in place and thus create no sound.
The fuel economy drop can be many things. I assume you have no codes. Does your CEL light up upon startup? If not, check for codes.
Your upstream oxygen sensor can be bad and that'll hit your fuel economy. It sure did hit mine. Mine died at 160K but as I recall, I got a CEL.
FYI: The Volvo pn for the sensor was 9497252. The DENSO equivalent was pn 234-9019.
Volvos are particular about their sensors but use of the correct DENSO unit is OK as DENSO made the sensor for our cars.
Have you given your 175K car the TLC it deserves? Inspections of air handling hoses and vacuum hoses, fuel filter, air filter, cleanliness of the ETM.
When were the sparky-pos last changed? Does you car have the Volvo, 3-prong spark plugs? Use no other.
Do see if your CEL lights up. Get back to us. G&K
Last edited by Georgeandkira; 10-18-2019 at 07:23 AM.
#3
10-20-2019, 04:38 PM
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ANY attempt at locating the source of the rattle? Get a friend or two to stand aside your car (or 20-30 feet down the lane) as you accelerate. At least try to get a fix on the source.
It could be a common heat shield. There are INEXCUSABLY CHEAP threaded studs on the body work which hold heat shields.
When they rust away there's nothing the shield.
At 175K a fatigued or destroyed engine mount or two can contribute to such noises.
As far as your "noise upon shutdown" goes, try shutting off your engine but immediately turning the key back to run so electrically powered options remain on.
As above, get a few more ears on the job. Lift the bonnet then turn the car off.
The engine mount beneath the crank pulley has a rubber chunk which collapses and allows metal (frame-engine) to bump. It could be that one
Also, there are blend doors in the HVAC system which often move upon shutdown. My suggestion keeps them in place and thus create no sound.
The fuel economy drop can be many things. I assume you have no codes. Does your CEL light up upon startup? If not, check for codes.
Your upstream oxygen sensor can be bad and that'll hit your fuel economy. It sure did hit mine. Mine died at 160K but as I recall, I got a CEL.
FYI: The Volvo pn for the sensor was 9497252. The DENSO equivalent was pn 234-9019.
Volvos are particular about their sensors but use of the correct DENSO unit is OK as DENSO made the sensor for our cars.
Have you given your 175K car the TLC it deserves? Inspections of air handling hoses and vacuum hoses, fuel filter, air filter, cleanliness of the ETM.
When were the sparky-pos last changed? Does you car have the Volvo, 3-prong spark plugs? Use no other.
Do see if your CEL lights up. Get back to us. G&K
It could be a common heat shield. There are INEXCUSABLY CHEAP threaded studs on the body work which hold heat shields.
When they rust away there's nothing the shield.
At 175K a fatigued or destroyed engine mount or two can contribute to such noises.
As far as your "noise upon shutdown" goes, try shutting off your engine but immediately turning the key back to run so electrically powered options remain on.
As above, get a few more ears on the job. Lift the bonnet then turn the car off.
The engine mount beneath the crank pulley has a rubber chunk which collapses and allows metal (frame-engine) to bump. It could be that one
Also, there are blend doors in the HVAC system which often move upon shutdown. My suggestion keeps them in place and thus create no sound.
The fuel economy drop can be many things. I assume you have no codes. Does your CEL light up upon startup? If not, check for codes.
Your upstream oxygen sensor can be bad and that'll hit your fuel economy. It sure did hit mine. Mine died at 160K but as I recall, I got a CEL.
FYI: The Volvo pn for the sensor was 9497252. The DENSO equivalent was pn 234-9019.
Volvos are particular about their sensors but use of the correct DENSO unit is OK as DENSO made the sensor for our cars.
Have you given your 175K car the TLC it deserves? Inspections of air handling hoses and vacuum hoses, fuel filter, air filter, cleanliness of the ETM.
When were the sparky-pos last changed? Does you car have the Volvo, 3-prong spark plugs? Use no other.
Do see if your CEL lights up. Get back to us. G&K
#4
10-20-2019, 07:30 PM
Senior Member
Often you'll read the advice of having your codes read for free at an auto parts store. Bring a pencil and paper.
Ask if any of your friends have a code reader.
There are so many to choose from. Pick a price point and go from there I suppose.
I have a first generation ScanGuage. It sold for $139. They're up to ScanGauge II now.
Autel has a line of readers as does Harbor Freight.
Read the features list and find one which has Volvo on it's compatibility chart.
Our cars, like so many, use a CANBUS system so the reader could say that in it's description.
However, CANBUS has been around so long it is likely not even mentioned.
Beware of real cheap $20-$30 units which may indeed be old stock which cannot communicate with CANBUS.
Many people get a plug in bluetooth gizmo and an app for their phone and swear by 'em. These are cheap too. I like my plug in tools.
I also have a BSR-PPC reader which was made "somehow in consort" with Volvo.
The licensing arrangement/agreement expired or some such and these once $500 readers are scarce-on-the-market-place.
My "$30-$50 reader" is from a European store called BILTEMA (Swedish). ....only if going to Scandinavia.
Ask if any of your friends have a code reader.
There are so many to choose from. Pick a price point and go from there I suppose.
I have a first generation ScanGuage. It sold for $139. They're up to ScanGauge II now.
Autel has a line of readers as does Harbor Freight.
Read the features list and find one which has Volvo on it's compatibility chart.
Our cars, like so many, use a CANBUS system so the reader could say that in it's description.
However, CANBUS has been around so long it is likely not even mentioned.
Beware of real cheap $20-$30 units which may indeed be old stock which cannot communicate with CANBUS.
Many people get a plug in bluetooth gizmo and an app for their phone and swear by 'em. These are cheap too. I like my plug in tools.
I also have a BSR-PPC reader which was made "somehow in consort" with Volvo.
The licensing arrangement/agreement expired or some such and these once $500 readers are scarce-on-the-market-place.
My "$30-$50 reader" is from a European store called BILTEMA (Swedish). ....only if going to Scandinavia.
#5
10-22-2019, 08:53 PM
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Bought a code reader but no DTCs were present. Not sure if it's a junky reader (Ancel AD530) but it seemed to read everything else fine (battery, RPMs, etc).
Additionally, I had someone turn on the car and rev the engine in neutral while I was on the ground. It sounded like the catalytic converter has a bunch of rocks in it!
I also had them turn it on and off. There's a metal on metal sound: clunk, like an aluminum can that was dropped on concrete. Makes me think the catalytic converter is shot.
Thoughts?
Additionally, I had someone turn on the car and rev the engine in neutral while I was on the ground. It sounded like the catalytic converter has a bunch of rocks in it!
I also had them turn it on and off. There's a metal on metal sound: clunk, like an aluminum can that was dropped on concrete. Makes me think the catalytic converter is shot.
Thoughts?
#6
10-23-2019, 11:38 AM
Senior Member
#7
03-22-2020, 09:58 PM
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Still Noisy
Still haven’t gotten the catalytic converter checked out. I’m wondering if it’s something else. Here are few audio clips that describe the noise.
clip 1
https://www.dropbox.com/s/lciug9lon0...e%201.m4a?dl=0
clip 2
https://www.dropbox.com/s/7kr6409fbc...e%202.m4a?dl=0
clip 1
https://www.dropbox.com/s/lciug9lon0...e%201.m4a?dl=0
clip 2
https://www.dropbox.com/s/7kr6409fbc...e%202.m4a?dl=0
#9
03-23-2020, 09:49 AM
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I plan to be more responsive...This is not a diesel.
Engine is B5244S R5 2.4L
Since I last posted, I changed oil/oil filter, air filter, and spark plugs (Volvo 3-prong, like you suggested), Planning to change the power steering suction hose since it's seeping.
Last edited by RoRoVolvo; 03-23-2020 at 11:24 AM.
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