I drive a 2002 V70 T5 and I recently had my oil changed (5w40 fully synthetic). Including filter, air filter, new brake fluid, spark plugs etc.
Before the oil change the engine ran perfectly smooth and quiet. But since the oilchange there's a noticible ticking noise coming from the engine. I suspect from the valves.

Anybody heard about this before? How can this happen, and more important, how can I fix this?

Thanks!

 

The most common reason this pops up is an issue with the oil pickup. The pickup tube is two piece unit and they are sealed together with a plastic/rubber piece. The seal will crack with age and start sucking air which will get in the hydraulic lifters and that causes them to start ticking. If you go to a Volvo repair shop their knee-jerk reaction will be to replace that seal which is about $600.

Of course my V70 didn't have this "common failure". It actually had a sticky lifter. Probably because it was a fleet vehicle earlier in its life and the oil wasn't changed enough. R&Ring the head to go after the lifter was quoted as $1800 which is more then I was willing to cough up.
The repair place tried the old "put a quart of ATF in with the oil" trick to see if it would clean out with no luck. They couldn't think of anything else besides tearing it down, but there is another possible solution...

!!! Take Note !!! Any sort of "engine flush" type of treatment has a risk !!!
A "flush" type treatment is going to knock loose deposits. (That IS what you are trying to do...) And when gunk and deposits are knocked loose they are circulating until the filter collects them. It can cause an engine bearing failure. A very low chance but you are taking a calculated risk!

Anyway...
I put a healthy dose of Seafoam in the oil and a fresh Mahle filter and ran it for a couple days making sure that I didn't run the engine into boost or otherwise "lean on it". That cleared it up and since then I have made sure oil changes were done religiously. Seafoam is a very powerful varnish remover/cleaner.

 

Thanks for your reply! But I thought the Volvo's didnt have the hydraulic valvelifters?

 

They definitely have hydraulic lifters. A non-hydraulic lifter will always have a clatter to them plus requires maintenance so no manufacturer would do that in an everyday passenger car. They have a major incentive to have the engine go 100K miles with as little scheduled maintenance as possible.

The last production car I'm aware of that had a solid lifter arrangement was the 1994 Porsche 964 (911) and Porsche owners had been well trained to expect the 15K maintenance interval.

 

They really have solid lifters:

https://www.brickboard.com/AWD/volvo/162066/V70/volvo_engines_hydraulic_lifters_solid.html

http://forums.swedespeed.com/showthread.php?179935-Valve-Adjustments

 

Holy crappola!
I have to say that is another in a list of questionable technical choices in these cars. Mine is a 98 and who would guess that a manufacturer would consider stepping backward like that.

Ok, with solid lifters you will get noise that varies with temperature and age. It shouldn't change with an oil change unless the oil is of a radically different grade. Makes you wonder if it is really the tappets.
That said, the ticking sound of a solid tappet is not destructive. What IS destructive is if there isn't enough valve lash and the valve isn't seating firmly enough. If the valve isn't firmly in the seat it won't transfer heat and it will fail WAY faster.

(Solid tappets in a passenger car. Almost as stupid as the biodegradable insulation in the 80's wiring harnesses...)

 

Yesterday I visited a Volvo specialist and it turns out the ticking noise comes from the injectors. He told me all the Volvos have this sound...