tlake

After about 5000 mile of running synthetic oil the trucks oil useage has gone from less that a quart every 3000 miles to about a quart every 1000 mile.

The 87 22re in my truck has about 120,000 miles on it. Compression on all 4 cylinders is near 175 each. Spark plugs look great. The truck runs great.

I see no oil leaks. The PCV looks good.

It is time to do the timing chain so I will install EB's head with over size valves and 268 cam.

What are the chances of the new valve seals fixing my oil useage?

scuba

Very possible...

Jay351

Do you get a puff of blue smoke in the morning?

tlake

Yes, I sometimes get a blue puff in the morning and I swear I see blue smoke after(and while) coming down a very long steep hill under compression.

abecedarian

what weight synth oil are you using?

tlake

5w-30

abecedarian

where are you at? how warm (or cold even) is it outside, first thing in the morning?

(yep, these are things the synth advocates don't seem to take into account: mileage on the engine before using synth oil, the design of the engine, and what the temp outside is)

dbcx

Swapping over at 120k is nothing. Sound like when he fixes his head it should clear up. 1quart in 3000 mile is a good bit to have started with.
Location temps would be nice tho.

tlake

From Seattle, rarely below 30 and rarely above 80.

abecedarian

one qt in 3000 miles is a bit much, but when changing to synth, 1 qt in 1000 miles is more than a bit excessive- a 300% increase in oil consumption simply by switching to synth oil?

and considering replacing the cylinder head is an afterthought... so ignore that....

how is a 300% increase in oil consumption with an approximate 50-300% increase in cost (depending on the brand, etc) good for anyone other than the vendor / distributor?

dbcx

That gets close to that crap people beleive synthetic starts leaks. He has a problem if it smokes at startup. If it is the valve seals, maybe the synthetic made the problem worse. Not sure either what oil he was using previous or if there is any UOA to show which metals have been wearing. He has some smoke under acceleration also. Some may be going by the rings also

abecedarian

hmm... okay.... My experience...
Never dripped on drop... Valvoline 10w40 in my 88 4Runner from October 2006, up to and through May, 2008. Truck made several trips (three trips, actually) from the Los Angeles area of California to the San Francisco Bay and Monterey Bay areas... and only one oil change in the middle of those trips over those two years. From May through July 2008, the truck took a trip to Phoenix with a side trip to Tucson, then went back home, without an oil change.
Then in September was told, rather asked, if I could drive my truck to Texas to help with Hurricane Ike relief issues. Changed the oil since it had been about 5000 miles since the last oil change and put Mobil1 10w40 in thinking it would help my mileage. By the time I reached Phoenix I'd 'lost' about a quart of oil, according to the dipstick. Then later dripped (by the best of my reckoning from my Type IV VW years) about 1/4 quart on the ground at the motel in Tucson.
By the time I reached our camp in Texas, I'd replaced 3 quarts of oil with Rotella 10w40. It was still 'dripping' though.
Kept it topped up and drove home from Texas and only lost 1/2 quart... this being after replacing 10w40 Mobil1 with 10w40 Rotella as necessary tp keep the oil level at full on the dipstick.
So, 2 years of 10w40 conventional oil and not a drop on the ground... 1500 miles with 10w40 Mobil1 and lost... rather 'leaked'... 3 quarts from here to Texas.
My "First hand experience" tells me to not use synth oil in my truck.
What does your first hand experience tell you?

abecedarian

Even given my experience, I will be among the first to suggest using synth oil.

My experience may be a 'one-off' thing, but I'm really not that sure of that.

I am not going to write of the benefits of synth oil though. You just have to have an engine that can utilize it properly.

dbcx

Sounds like the oil did its job and cleaned the engie and revealed you had some sealing issues that were being covered up with crud and sludge inside.
I have been in both engines that have run purely on dino and purely on synthetic. The synthetic insides are always cleaner than any dino engine i have ever been in. Personally i have never had an oil leak caused or started from using synthetics. If you swap and get a leak of course it will be blamed on swapping over, its never the condition of the engine or its sealing components.