Engine rattle when revs

[BorisTheThird]

Hi all, recently bought myself a Volvo V70, 2001, 2.4 170 petrol manual, with about 140000 miles.

After 5 days of ownership it came up with the low oil pressure warning, I advoided driving it with this light, aside from getting to a safe place to stop. The last time this happened it developed a rattling noise when revs increase (even when the warning was off)

Yesterday I dropped the sump to change the O rings, put it back together and noise is still there. I've not driven it like this, but it had idled for about 10 min.


Any ideas where to look?

[abscate]

That sounds more like an exhaust leak than a knock but diagnosing sounds over the Internet is tough for me. I like that disappears when you lift the throttle as opposed Tom the other way, which is classic rod knock

Can you disconnect each fuel injector one By one and see if you can’t isolate it to a single cylinder?

[BorisTheThird]

Thanks, I'll try removing the caps tonight

[BorisTheThird]

If I remove cylinder no 3 it almost goes away entirely, the others make no difference

[BorisTheThird]

There's nothing recorded on the obd either (aside from my removing the spark plug leads)

[abscate]

Try inspecting the exhaust manifold close to the number three port and look/listen for leaks. You can run a bit of oil and look for smoke, too.

If there is no leak, its probably a rod bearing, which means an oil pan drop and bearing evaluation/replacement.

- Natasha