pcv and oil smoke

stringger · Post by **stringger** » 26 Sep 2018, 15:44

I have 740 b230 f. Engine died and replaced it. First 400 miles everything ok. Then i changed oil and suddenly it starts using oil. Going down long grade oil smoke rolls out back. I thought it was pcv issue. Replaced flash back device and cleaned box. No difference and still using oil. I live in mountains so lots of hills. Does anyone have any suggestions? Car has great power but mileage off a little. Two hundred fifty plus miles. Runs good on interstate and climbs low speed good too

lummert · Post by **lummert** » 27 Sep 2018, 14:56

Intake valve guide seals?

stringger · Post by **stringger** » 27 Sep 2018, 15:07

I’m open to that but how do you tell?

93Regina · Post by **93Regina** » 27 Sep 2018, 21:37

stringger wrote: ↑26 Sep 2018, 15:44Going down long grade oil smoke rolls out back.

Here, intake has a high vacuum, so when an intake valve opens, this vacuum is sucking oil either from intake valve or piston rings.

Read Directions, and change oil/filter when done: Johnson Evinrude OMC Engine Tuner 777185

Also, cheap oil is cheap oil....and better oil can also act like cheap oil and get sucked in.. I prefer an oil with a gas/diesel rating.

Sometimes, adding 1/2 bottle of STP for 4 cylinders may assist, just after an oil change...sometimes, using a semi-truck oil with a gas rating may assist. If in a warmer environment, Rotella 15w-40 might work.

1987 VOLVO 740

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stringger · Post by **stringger** » 27 Sep 2018, 22:09

The oil i used and have used is castro’s high mileage. First 400 miles zero oil use then it used half a quart in 150 miles. No smoke cold and on reg interstate seems good.

Post by **RickHaleParker** » 27 Sep 2018, 22:18

Going down long grade oil smoke rolls out back.

That is the clue. Bad valve seals will show themselves during prolonged idling. During prolonged idling periods, the throttle valve remains closed, this results in high levels of vacuum at the intake manifold. The high vacuum attracts oil in the heads to congregate around the valve stems.

Try idling for a prolonged period and see if it starts smoking, if not then step on it and see if it smokes.
A bottle of ATP AT-205 Re-Seal might buy you some time but I won't call it a fix.

93Regina · Post by **93Regina** » 28 Sep 2018, 20:36

stringger wrote: ↑27 Sep 2018, 22:09castro’s high mileage

Shell ROTELLA T 15W-40 has SM, SL, SJ, and SH ratings

Good to about 10°F

Historically, Volvo has suggested heavier weight oils...I would never install 0w-40, 5w-30, or 5w-40 oils.

Semi-synthetic oils can be used in lower temps than indicated in that chart I posted above. 10w-30 in semi-synthetic has a lower temp rating.

I would stay away from synthetic or semi-synthetic oils, on an old engine.

Chances are, oil control rings and valve o-rings both have issues. If you do the engine ring clean-up, keep all pistons down 1/2 way before pouring in fluid, which will eat paint...ve careful...don't spill. I'd do it on a warmed up engine

stringger · Post by **stringger** » 28 Sep 2018, 20:52

I had a talk with my mechanic and i have added mystery oil to try to insure i am not having a stuck ring in the car. I did a rubber glove test for pcv function. That is why we are trying the additive.

Post by **RickHaleParker** » 28 Sep 2018, 23:47

Don't know about that Mechanic of yours, Rings would smoke all the time not just some of the time.
Be careful what you do, you don't want a to get a cocktail of additives in the oil.

93Regina · Post by **93Regina** » 30 Sep 2018, 12:18

RickHaleParker wrote: ↑28 Sep 2018, 23:47Rings would smoke all the time not just some of the time.

Any older engine has increased chance of "stuck" oil control rings. I re-ringed a 84B23F, and oil rings were stuck, and this was a high-mile engine.

Using additives....No, No, and No. Using a GM approved oil, and changing within 1,000 miles, might take care of ring issue. Start engine, then drive 2 miles to work, no fricken way. One has to drive much longer intervals.

Hence, using something desgined to clean rings is imperative....

Valves Oil Seals - I'm not convinced this is a real issue with redblock Volvos....on GM's previous V-8 engines, yes, when those valve seals fail, it will smoke on startup.

People who take "this is easy" shortcuts, are wasting money... Still buying HEET? Wasting your money if buy 10% alcohol fuel...a royal waste