Help diagnosing bad engine sound *solved* Topic is solved

[greffel]

Questions:
We replaced the automatic gearbox 1,5 years ago, could this be a torque converter that got loose from the flywheel?

Options:
What's the easiest way to diagnose bad rod bearings ?
Can I remove the sparkplugs and press down feeling for play ?

More info:
The car runs normal, with no power loss och faults codes in VIDA
Between 1300 - 1800 rpm the sound is most prominent
If I remove the oil cap there is no more sound, it feels like a bottom engine problem ....

....please guide me

[cn90]

The Volvo 2.5T engine can sound like a diesel engine too.
If you have no issues, just keep an ear on the noise.
I change oil with synthetic every 6K-7K miles.

[jonesg]

Questions:
We replaced the automatic gearbox 1,5 years ago, could this be a torque converter that got loose from the flywheel?

Options:
What's the easiest way to diagnose bad rod bearings ?
Can I remove the sparkplugs and press down feeling for play ?

More info:
The car runs normal, with no power loss och faults codes in VIDA
Between 1300 - 1800 rpm the sound is most prominent
If I remove the oil cap there is no more sound, it feels like a bottom engine problem ....

....please guide me

Yes it could always be the previous work you did, always return to the scene of the crime....and double check.

rod bearing test, needs 2 people...
remove spark plugs, use a wood dowel to ride on top of the piston, rotate engine manually to just beyond tdc , as piston has started to descend, stop rotation and press down on the dowel. If theres any slop in the bearings you will feel it click.

I would say turbo or flywheel, they are easy to check
.
Engine cold, put your hand on the turbo and start it up, rev it til you hear the rattle, if its the turbo you will know .
Also check the wastegate isn't flapping around, the linkage can fail.

If nothing found, and before the engine warms up , move your hand quickly to the flywheel area and see if you can detect it by feel.

[Geraldt]

Hi,

My dad is currently away from home for a while. I will continue to troubleshoot along as I am comfortable with what I am doing. Tomorrow the plan is the following:
1. Remove the skid plate underneath the car and check whether or not I can feel any severe rattle.
2. Check if I can feel anything around the turbo. In a week I might be able to get my friend to help me do the rod bearing check.

I am very thankful for all the help and assistance

[abscate]

That’s the rear of the engine, left side of the car. I think that’s a bad rod knock. Try pulling the coils on 4 and 5 one at a time and see if the noise changes

replaced the automatic gearbox 1,5 years ago, could this be a torque converter that got loose from the flywheel?

That’s my plan B guess.

Pull starter and inspect. Maybe visible by removing crank sensor?

[vtl]

The engine is FUBAR. Rod knock.

Also in the next engine change oil more frequently than once a year.

[Geraldt]

Questions:
We replaced the automatic gearbox 1,5 years ago, could this be a torque converter that got loose from the flywheel?

Options:
What's the easiest way to diagnose bad rod bearings ?
Can I remove the sparkplugs and press down feeling for play ?

More info:
The car runs normal, with no power loss och faults codes in VIDA
Between 1300 - 1800 rpm the sound is most prominent
If I remove the oil cap there is no more sound, it feels like a bottom engine problem ....

....please guide me

Yes it could always be the previous work you did, always return to the scene of the crime....and double check.

rod bearing test, needs 2 people...
remove spark plugs, use a wood dowel to ride on top of the piston, rotate engine manually to just beyond tdc , as piston has started to descend, stop rotation and press down on the dowel. If theres any slop in the bearings you will feel it click.

I would say turbo or flywheel, they are easy to check
.
Engine cold, put your hand on the turbo and start it up, rev it til you hear the rattle, if its the turbo you will know .
Also check the wastegate isn't flapping around, the linkage can fail.

If nothing found, and before the engine warms up , move your hand quickly to the flywheel area and see if you can detect it by feel.

Hi,

I did check the turbo and flywheel using feel. I can't feel any unusual rattle or knocking. I'm a bit curious about the comments highlighting possible rod knock. As we said before the sound is only present when being on idle up to about 2k rpm. Can it be the flywheel getting stabilized because of the forces? If this was rod knock wouldn't the sound get worse when the RPM is higher? The engine sound fine when above 2k rpm. I have ordered a endoscope and I will do the piston check as soon as it gets here. When I check the pistons can I use anything that is hard enough and doesn't leave any kind of debris on the piston? For example the handle on a 3/8 ratchet?

[jonesg]

a mechanic could diagnose this in 2 minutes.

[greffel]

Back from vacation and one week to fix this issue

This morning we looked inside the cylinders with a endoscope and the cylinder walls and pistons look fine. ( see pictures)
Also we tried to feel for some play pressing down on the pistons but no play at all.
This was done with the pistons on the way down in the cylinders.
Then we tried to disconnect one ignition coil at the time but the sound does not go away.

It's so hard to tell 100% where the sound is coming from, is the next step removing the oil pan or can we do any other smart test ?

365282618_1331074537832522_2095714608636895670_n.jpg (88.32 KiB) Viewed 478 times

365332793_215547444822009_6428135146961221130_n.jpg (86.95 KiB) Viewed 478 times

365563006_313029651252871_5943780904655570132_n.jpg (77.17 KiB) Viewed 478 times

365824639_1407937793387165_5160653545353852921_n.jpg (74.22 KiB) Viewed 478 times

366368799_3633414026979925_6551861825622691676_n.jpg (84.59 KiB) Viewed 478 times

[vtl]

Removing oil pan, cleaning pickup tube screen, installing a new O-rings is a wise move for any P2 in 2023.

Third picture has some overheating signs.