1986 Automatic Vaporizing Oil?

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Elaine
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1986 Automatic Vaporizing Oil?

Post by Elaine »

I've owned my '86 for about 5 years, from 135K to about 165K where she is now. I drive it about 200-300 miles per month plus some long-distance trips. I add a quart of oil about once a year, usually in the summer, and keep up with regular oil changes. Recently I drove 600 miles in one day. At about 450 miles, the oil light came on. I have never even seen the oil light before. Also, I had checked the oil and fluids before starting the trip and all was fine. When I pulled over, I ended up adding 4 quarts to the engine. According to the owner's manual It only holds 4.2 quarts, or 3.7 according to the manual's oil change instructions. For the next 5 days I kept my eye on the dip stick. It stayed at the full level and didn't change. Then I again drove 600 miles on the return trip. This time the light came on at about 400 miles. I added 2 quarts. Since then (3 weeks ago) I have driven another 450 miles and I just added 1 quart. I cannot find a leak. There is no oil on the ground where it is parked. I read somewhere that driving at high speeds may burn off the oil. On the 600 mile trip South, it was rolling contentedly at 75 - not the usual cruising speed here in New England. Could the higher speeds have caused the engine to burn oil? It is not puffing black smoke either. Any ideas on what may be happening?

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spiffyguido
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Prelude Model: 1991 SE-SR
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Re: 1986 Automatic Vaporizing Oil?

Post by spiffyguido »

The higher speeds may have caused the engine to burn oil, simply because the engine would have been held at a higher rpm for a longer period of time. A few things you should check:

-Take a look in your coolant and see if there is oil in it. Most often, you can tell just by looking in the coolant reservoir. Otherwise, wait till the engine is cool and open the rad cap. Soak up some coolant with a rag or paper-towel from the open rad and see if it is stained brown with oil. If you find oil in your coolant than your head gasket is probably cracked and the oil is leaking into water-jacket of the engine.

-Watch for signs of blue smoke. On a long drive at highway speed these would be very hard to see. You're most likely to see a puff of blue smoke right when you start the car after it has sat for a few days. After a long drive, you can also swab the rear bumper where the exhaust exits and check to see if it is coated with oil that has spewed out the back.

-As a last option, check your air filter to see if it is soaked in oil. When engines run at high rpm, a small quantity of oil naturally exits the top of the engine and then gets ingested by the motor and burned away. Ordinarily, this process is metered by a valve called the PCV (Positive Crankcase Ventilation) valve. If this valve is defective, it is possible to lose more than a minute quantity of oil out the top of the motor. This won't hurt anything, but it will fill your air filter full of oil and run your oil dry after a while.

-Also, as always, check, check and check again for signs of any leaks. Just because you don't see oil under the car, doesn't mean there isn't a leak. Remember the oil only pressurizes when the engine is running so if you have an oil leak at the top of the engine you won't see it leaking unless the engine is running. Pay close attention to the timing belt side of the engine as the cam oil seals will often leak with age. Do this check with the engine OFF! I believe on the 2nd gen it is possible to pop an access port off the shroud that covers the timing belt. Stick your finger inside the shroud and see if the inside is coated with oil. If so, your cam oil seals are leaking and then the timing belt is throwing it all over the place. Again, never work around the belts when the engine is running. An engine belt will quickly remove a finger or even an arm if you give it the chance. Never do this check while the engine is running.



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