S70 2000 N/A B5244S engine, 180K on the clock.

The car has been in storage for 6 months because of a surgery but started right away when I decided to re-used it. I used a float charger the maintain the battery fully charged. The car ran fine like usual but after approximately 10 miles, the low engine oil pressure indicator lamp started to flash intermittently but more and more often to finally remain on all the time regardless the speed and/or RPM. I stopped to check the oil level but it was right at full mark. I continued driving thinking that it was the oil pressure
sensor that was probably "more sensitive" because of all those months of inactivity and I didn't worry. It's when I got back home that I've noticed that the engine was making a strange noise never heard before, a loud ticking kind of noise meaning that the valve train is probably missing serious lubrication. Checked the oil level again and it was still a top mark. Started the car the next day and everything was fine, no low pressure indicator lamp and no noise but after only 2-3 miles of driving, the same problems reappeared again with a bonus of the check engine light that came on. Checked the code and it was P1672. After searching, found that this code is for a system called Continuously Variable Valve Timing which uses oil pressure to change cam timing based on engine load and the low oil pressure is probably caused by the seals in the oil pan that can be bad. The same problems reappeared again when I used the car this morning that I've decided not to use it anymore. There's definitely something defective with the oil pump system. Probably all those months of inactivity had dried up the seals.

Question: what should I do with this problem?

Thanks a lot guys and sorry for this long post
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Norm

I once owned a 2000 S70 Turbo. It would do the same thing, oil pressure light on and full of oil. I was told that this is caused by bad seals between the oil pan and the block. This causes the oil pump to suck air and get foamy and result in low pressure. I dropped the pan and replaced the seal which is an O ring. No fix.
What I later learned was that the oil passages in the head were so clogged that all the oil was being pumped up to the top of the engine and having a slow return to the sump. This is caused by sludge build up when the is only used for short trips often and not getting up to temperature. The PO of my S70 were seniors who only drove the car on short trips (groceries and church) and most likely never changed the oil. It had 60K on it when I bought it. I replaced the engine with a used one from Erie Vovo but probably could have cleaned it up. Still have it in my garage. I have pictures but never could fugure out how to post them.
You might be able to clean it up by running ATF mixed with oil but I doubt it. Probably have to remove the valve/cam cover and clean it up.
Good luck,
Tom

While it could be bad seals, I suspect your problem is sludge collecting on the oil pick up tube in the sump. There is only one definitive way to fit this: drop the oil pan, replace the seals and clean out the screen.

You could check the top of the engine by removing the oil filler cap and taking a look at the cams, they should be dripping with oil.

If you do not want to drop the oil pan, it is a hard task even with a lift, then I suggest using some sort of cleaner in your oil. A quart or two of ATF, kerosene, or some such 'home' remedy. 5 minutes of idling, 20 minutes of cool down, 5 minutes of idling. Then check the oil pressure. If no pressure, repeat the next day. Followed by an oil flush/filter replacement, and fill with synthetic oil.

If the 'home' cleaners do not work, please do not call me or my lawyer.

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Keeping it running is better than buying new

Don't worry, I will not call you nor your lawyer!

One thing that bugs me is the probability of sludge in the system because everything is fine when the engine is cold meaning that the oil pressure is normal, its when the engine is about to reach his normal operating temperature that the low oil pressure indicator lamp will start to come on. This would imply that the oil is getting more fluid when hot. Consequently the lower oil pressure
in the system.

Let me think about your suggestion.

Thanks
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Norm

Or, the sludge drips down to the bottom of the sump as the engine cools.

This would be a good time to change the oil/filter, and let the oil drain for about 30 minutes - take a beer break?

Take a look under the oil filler cap and see if the cams look nice and clean. If they are brown, I suggest cleaning the inside of the engine.
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Keeping it running is better than buying new

I did an oil/filter change and I let it drain overnight to be sure that all the shit went out. The cams look perfect. I've put Mobil 1 10W30 synthetic with a bottle of "No Smoke + Stop Leak Bardahl". It took about 30 miles to have the oil mixed with the Bardahl and to have pressure indicator lamp to go out. It'll flash once in a while and no more valve train noise. I'm happy and keeping my fingers crossed as it's only a short term cure but I'll have to replace the oil pump seals eventually. Big job ahead.
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Norm