My '95 Del Sol SI D16Z6 SOHC recently had a bad head gasket. At 265,000 miles on the engine I wanted to completely rebuild it. Head gasket was bad so my mechanic took the head to a machine shop and had the head worked over but talked me out of completely rebuilding the engine. He said that the lower end looked good and that as long it was good it would be best left alone and better than any aftermarket rebuild parts. Long story short, the engine runs fine but I've noticed that it is consuming about a quarter of a quart of oil per week now. No oil leaks, no smoke from exhaust, no oil fouled plugs. It's been about 1000 miles since head was worked over. Is this normal for a fresh head rebuild and will settle back in or do i possibly need to add an oil stabiliser to an oil change to get it settled back in? Or maybe switch oil brand or weight. I've been using Mobile1 5W-30 Full Synthetic for several years. Any information or ideas would be appreciated. TIA.

 

a QUARTER OF A QUART a week?. How many miles is that? THe old adage is one quart per thousand miles. Me personally, I would change the oil now, write the milage down. Then check it at the 1000 mile and 2000 mile. making note as to how much oil it burned in the thousand miles. Then change it at 3000. If your burning more than a quart per thousand then you have a problem

 

The oil was changed at time of repairs with Mobile1 5W-30. Driven daily for a little over 1100 miles. Have added at least half a quart of oil in that mileage range. Oil brand or weight recommendations? It didn't have this issue prior to having head worked over. Before the repairs, I would have to add maybe 1 quart between oil changes and that was even with a slight oil pan gasket leak.

 

He definitely messed something up. Resurfacing the head isn’t considered a rebuild. You still have the same valves, springs and camshaft.

 

The head was machined and rebuilt. Read the post before replying.

 

what does “rebuilt” mean..? What parts were replaced? I’d bet those valves aren’t closing fully like they’re supposed to, or you wouldn’t be losing oil.
as far as oil recommendations, to slow it down, I’d recommend Dino-oil in place of the synthetic. If that doesn’t do enough to minimize it, you can try 10-30, so it’s a bit thicker.

 

My understanding is the the guides, seats, and seals were replaced. You may be on to something with the valves not closing. I should probably check the valve lash before switching oil. If they are adjusted good then maybe try a different oil. Thank you.

 

I’d say any time the head is off, you should verify valve lash again. Certainly after any head work is done. Good luck, and let us know.

ETA: it’s also possible you have an actual problem with the valves. Is the guy who did the head work someone you trust? He could have swapped a head he knew had bad valves with yours.. never know. Did you inspect the valves before you bolted the head back on?

 

I checked the valve lash today. I couldn't budge a .008 between any of the intake OR exhaust rockers.So I'd say it is very possible that some if not all valves weren't completely closing. I used .008 on intake and .010 on exhaust. I typically use the mid point for them. I'll drive it this week and see if that alleviates the oil consumption. Thanks for bouncing some ideas around.

 

Hope it helps.

 

We'll see. I'll update the post next weekend.

 

Why would valves being too tight cause oil consumption ?

 

I had the same thought.

On another note for OP. Your head gasket went bad so it started eating water in the cylinder(s)? The steam cleaning of the cylinder may have stripped the walls of oil and caused the oil rings to finally give up the ghost?

The other thought is if the valve seals were replaced, they could have been installed poorly. The way to see if your oil consumption is from seals is to let the engine idle once up to temp then rev the motor, if you get an oil cloud out the exhaust after idling for a duration, then your valve seals aren't working.

 

No smoke

 

If you don't see smoke after idling then revving, then it's not the head and it's the bottom end or it's going somewhere else through a leak. Have you checked your coolant after it's cool to make sure it's not oily? Is your motor clean or does it have oil caked to it? Have you smelled your exhaust while it's running? Does it smell like it is burning oil?

That much oil means it's going somewhere. Spec is 1 liter in 1500 Kilometer is considered okay if I remember right. Which is roughly 1 liter every 3 tankful of gas.

 

Update after adjusting valve lash last weekend. It appears that adjusting the rockers took care of the oil consumption. Little to no oil loss on the dipstick after a week of driving. Thanks to everyone for bouncing ideas around.

 

Happy to hear that helped!

 

I don't understand at all how that worked... but I am glad it did. Congratulations.