VVT Woes - 2008 S60 2.5T

SKim · Post by **SKim** » 08 Apr 2026, 18:52

Need some advise... 2008 S60 2.5T 185k miles. Check engine came on with fault on the VVT Solenoid (Exhaust). Replaced it with new one (Febi) from FCP, cleared codes. 3 starts later, same fault codes. 2nd round - checked the VVT Solenoid (applied power to it and heard it click), replaced the wiring harness, traced both wires back as far as I could till where it joins what seems like 100 wires leading to the ECU all looked good. Reset the codes and the codes came back after 3 starts!!! Any advise on what could be causing this? Hope not the ECU itself.....

Any advise would be greatly appreciated! - Thanks!

Post by **scot850** » 08 Apr 2026, 19:13

Did you check the timing has not jumped?

Neil.

Vova585 · Post by **Vova585** » 08 Apr 2026, 19:31

Great suggestion of checking the timming marks. What specific code you have?

Post by **cn90** » 08 Apr 2026, 20:23

Maybe the VVT hub is so much worn...

Post by **jonesg** » 08 Apr 2026, 23:29

SKim wrote: 08 Apr 2026, 18:52 Need some advise... 2008 S60 2.5T 185k miles. Check engine came on with fault on the VVT Solenoid (Exhaust). Replaced it with new one (Febi) from FCP, cleared codes. 3 starts later, same fault codes. 2nd round - checked the VVT Solenoid (applied power to it and heard it click), replaced the wiring harness, traced both wires back as far as I could till where it joins what seems like 100 wires leading to the ECU all looked good. Reset the codes and the codes came back after 3 starts!!! Any advise on what could be causing this? Hope not the ECU itself..... Any advise would be greatly appreciated! - Thanks!

I like the saying, codes are not part numbers.

Theres a VVT reaction test in vida that will detect if the VVT is slow reacting.
If reaction time is lagging , check oil pressure, if low, make sure you have the correct oil viscosity, or refresh the O rings in the oil pan.
Oil and filter change fixed mine.

Post by **volvolugnut** » 09 Apr 2026, 08:08

jonesg wrote: 08 Apr 2026, 23:29
SKim wrote: 08 Apr 2026, 18:52 Need some advise... 2008 S60 2.5T 185k miles. Check engine came on with fault on the VVT Solenoid (Exhaust). Replaced it with new one (Febi) from FCP, cleared codes. 3 starts later, same fault codes. 2nd round - checked the VVT Solenoid (applied power to it and heard it click), replaced the wiring harness, traced both wires back as far as I could till where it joins what seems like 100 wires leading to the ECU all looked good. Reset the codes and the codes came back after 3 starts!!! Any advise on what could be causing this? Hope not the ECU itself..... Any advise would be greatly appreciated! - Thanks!
I like the saying, codes are not part numbers.

Theres a VVT reaction test in vida that will detect if the VVT is slow reacting.
If reaction time is lagging , check oil pressure, if low, make sure you have the correct oil viscosity, or refresh the O rings in the oil pan.
Oil and filter change fixed mine.

Very good point about oil checks. We may be tempted to think of the VVT as just an electrical device. The electrical signal just moves the valve, but the oil pressure does the work. It must have good oil pressure and flow to operate. Also, the hub has a piston that must move to change the timing. See this is you want a lot of information viewtopic.php?p=604761&hilit=vvt+center+bolt#p604761
volvolugnut

SKim · Post by **SKim** » 09 Apr 2026, 13:59

Thanks for the responses, all. I’m not skilled enough to tackle the VVT hub, or even to understand most of the very detailed write up

, but thanks for the link, volvolugnut. Don’t have any oil leaks anywhere and I’m due for oil change, so I’ll take the easy way out for now and see what happens. Thanks all, will keep you posted.

Post by **vtl** » 10 Apr 2026, 07:27

Besides worn VVT hub, there's one more thing that may prevent VVT adjusting correctly: aerated oil. Air gets sucked in by oil pump, oil aerates, it can be now compressed, which results in pressure loss. This loss may be not sufficient to trigger low oil pressure check, but VVT won't have enough pressure to operate properly. Air sucked in happens when one of O-rings inside oil sump cracks or gets messed up during pan installation.

Post by **volvolugnut** » 10 Apr 2026, 07:47

I think, but am not sure, that foaming oil can be identified by checking oil level immediately after running the engine for several minutes. Although some oil will still be draining from the top of the engine, the foamed oil will show a higher fill level on the dip stick. Maybe even foam on the stick.
Others give your opinions on this please.
volvolugnut

SKim · Post by **SKim** » 13 Apr 2026, 09:31

Oil change done and no effect

Double checked the timing marks and both are right on. No oil leaks on either hubs either. How can I check the oil pressure?