A little background. Actually very little as I do not know much about this motor. It's either a 1.7 or 1.8. EA code on the block but someone on this forum saw this car for sale a couple of years ago (entered the VIN into the data base) and it was advertised as a 1.8. Looks like work was done to the motor at some point. I believe this car say for awhile. Was bought by a dealership. A little work was done to sell it. I purchased it. I'm guessing it was off the road for 2-4 years. Compression on all four cylinders is about 90 psi. At low RPM I hear a rattle that sounds like it's coming from cylinders 1 or 2. Goes away at cruising speed. More pronounced when lugging the motor. It's not detonation. This is my first type 4 motor. Wondering if this is a sign of maybe a common problem with these motors as they get tired? I put in some Marvel mystery oil and drove it about 60 miles on a hot day. As the motor got hot my oil light was flickering at idle. Idle was a bit low and light went out as soon as the RPMs raised a bit. Any ideas? A second question? Is there a way to tell if this is a 1.8 or 1.7 looking at the heads? Any markings or numbers? I tried searching around but didn't find an answer. What do you experts think?

Your compression is low, assuming that the engine is properly tuned.
When you do compression testing the engine should be warm, throttle open.
Valves should be set to spec, etc.

Don't lug your engine. Air cooled engines don't react well to lugging.

How low is your idle? You should have 10psi per every 1000rpm. So, ideally, idle at 700 rpm should be 7psi oil pressure. The oil issue could be as easy as using the wrong oil weight. Try a good 20w50 oil like Brad Penn.

The rattle could be anything.

Zach

Thanks for the suggestions. Valve adjustment has been done. I don't normally lug the motor. Just an observation when I've done it on accident. Does it usually taking off from a stop. Under 1500 rpm I would say. I also want to say it may have gotten better after the first long drive. Noise definitely sounds like it's coming from the motor. Want to say from the head.

I'm in Santa Clarita and could take a listen if you think it's safe to drive. PM me. Could be Hydro lifters and Valve lash set for solids? could be a loose tin...?

Thanks for the offer Mike. That's an idea on the lifters. Not sure how to tell if they are hydro or solid without taking the heads off? I'll try to record a video and post it up first. See if that helps with a diagnosis.

I had a rattle years ago; turned out to be a stubby screwdriver in the fan tray... You might want to feel around in there and see whether something is bouncing around.

No. Definitely sounds internal. Just wandering if someone was going to respond and say something like "yeah that's usually a bad valve. Common on these engines when a head job is due". Before I start tearing Things apart.