2002 s60 2.4T is it ok to mix 10w40 with 5w30 Synthetic

[Homebrand]

Hi All,
I recently did an oil and filter change on my Volvo.
I have had the car about 2 months with 157,000km on the clock.
I have no idea of the oil type used before this.

I used Nulon 5w30 Euro Fully Synthetic as it was recommended at the local store.

The car doesn't drip or burn oil that I'm aware of.

My problem (if it is a problem) is that it is eating about 500ml of oil per 1,000kms.

At the price of this oil - its an expensive appetite.

I am thinking maybe a heavier grade synthetic may help alleviate the consumption.
Would it be ok to top up with 10w40 Synthetic.
I need to buy some tomorrow so was seeking some thoughts from people who know more than I (or the local autobarn guys) know. I don't want to do a drain and fill as the oil in there already cost me nearly $100AUD

I have also done the pressure crank tests with the glove over the dipstick and oil filler location. The balloon doesn't inflate at all.
Thanks for any advice.

[vtl]

It's ok, I top up 5w-30 oil with 5w40 in one car or 5w40 with 5w30 in another on rare occasions when I ran out of one grade or another.

Heavy oil consumption is one of signs of clogged crankcase ventilation system (PCV). If not addressed immediately, it will blow crank/camshaft seals. Remove upper T-belt cover and inspect T-belt for grease stains: greasy belt indicates blown seal(s). To check PCV health do the following: with running engine put a glove over oil dipstick tube and see if it inflates or deflates. Inflating glove would mean dead PCV. On turbo do the same test under boost, i.e. ask somebody to gently rev engine to 2500 RPM.

Other contributing factor to oil consumption is stuck piston rings. It's possible to relief them, at least partially, without splitting up an engine. Use engine cleaner like Seafoam before you decide to replace oil next time: remove coils and plugs, remove front passenger wheel, pour a can or two of Seafoam into cylinder and let it sit for a day or overnight, moving crankshaft +/- 15 degree from time to time. Replace oil.

[oragex]

Got my car at 160000km too and switched to synthetic. Noticed about the same oil consumption. It's simply because you switched to synthetic. Check regularly the oil level and replace the filter (some oil will drip when the filter is removed) after about 2000km then again after 2000km. Then keep the oil change at the normal interval, mine stopped taking oil after about 5-7000km (my PCV is clean).

[Homebrand]

To check PCV health do the following: with running engine put a glove over oil dipstick tube and see if it inflates or deflates. Inflating glove would mean dead PCV. On turbo do the same test under boost, i.e. ask somebody to gently rev engine to 2500 RPM.

I didn't check mine under boost. I'll do this again tomorrow to be sure the PCV is ok.

Got my car at 160000km too and switched to synthetic. Noticed about the same oil consumption. It's simply because you switched to synthetic. Check regularly the oil level and replace the filter (some oil will drip when the filter is removed) after about 2000km then again after 2000km. Then keep the oil change at the normal interval, mine stopped taking oil after about 5-7000km (my PCV is clean).

I'll do a filter change tomorrow as well and then again in another 2,000km. I'll see if it helps.

Thanks for the responses.

[Homebrand]

Checked the PCV again whilst having it revved higher. No problem with it.
I'll check the fluid after the next 1,000 and report back.

[Vovo_merz]

If all else fails I would add some lucas oil with your next change ( not sure if you have it in Australia) that would be the only brand I trust and had some good results in the past on a land rover

[Homebrand]

Yes we have Lucas additives here.
I used a transmission one as a stop gap measure before repairing my transmission. It actually helped.
I'll keep an eye on the oil over the next few thousand k's.