Topic: Burning oil

[paradisekid]

My 85 4runner has been using about 1 qt. of oil every 200 miles, but doesn't leak oil.  When I start it up it will kick out some blue smoke.  I did a compression check and it showed 165 across all cylinders.  The motor has 170K and I am thinking that a valve job would stop the oil consumption.  Is there any other reason it would be using oil?  And if so what are the possible reasons?

[WHITE_TRASH]

Do a leakdown test as just a compression test wont tell you how long the cylinders can hold the pressure.   Chances are your valveguides/seals are shot.  Time for a head job.

[RustyToy]

so a new head might fix this problem?

[Duffil]

you don't need a new head, just the valve guide seals.  pull the head, take it to a machine shop or garage to do the seals and see if it needs to be surfaced then throw it back on and you're golden.

[paradisekid [OP]]

So it is most likely the valve seals causing the problem, simply adjusting the values wouldn't correct the oil consumption?

[Duffil]

So it is most likely the valve seals causing the problem, simply adjusting the values wouldn't correct the oil consumption?

that is correct

[kyle_22r]

doing the seals is a snap if you have a valve spring compresser.

[79coyotefrg]

spend $30 for a valve spring compressor,  thread a piece of airhose into the sparkplug hole for the cylinder you want to work on ,  pressurize, then remove spring ,install new seal, reinstall spring,   then move to next cylinder,


yes it needs to be on the compression stroke,

[brainlessfool]

spend $30 for a valve spring compressor,  thread a piece of airhose into the sparkplug hole for the cylinder you want to work on ,  pressurize, then remove spring ,install new seal, reinstall spring,   then move to next cylinder,


yes it needs to be on the compression stroke,

Glen, Glen Glen, what are we going to do with you?

in fact it has to be on TDC compression, if it's just on the compression "stroke" it will move!


 (I know you know this I'm just giving you a hard time!   )

[paradisekid [OP]]

Thank you for all the input.  I am going to perform a "wet" compression test tomorrow and see if the compression increases.  When doing a compression test how many times should I crank the engine?  I cranked it 5 times the first test, but I was wondering if you continue to crank the engine will the readings continue to increase?  I am also going to look for a leakdown tester.

[WHITE_TRASH]

5 is generally suffiecient.  Thats all I do.

[kyle_22r]

spend $30 for a valve spring compressor,  thread a piece of airhose into the sparkplug hole for the cylinder you want to work on ,  pressurize, then remove spring ,install new seal, reinstall spring,   then move to next cylinder,


yes it needs to be on the compression stroke,

that's all fine and dandy, the only problem is that the rocker arms can take a bit of maneuvering to do the job with the head on the motor

[paradisekid [OP]]

I was reading tonight that it is possible to convert a compression gauge into a "poor man's" leakdown tester by taking out the valve on the end of the compression gauge and hook up an air compressor to the quick disconnect.  Turn your compressor up to around 18 psi and check and see if you are losing compression from the intake, exhaust, or dipstick tube.  Has anyone tried this and if so how accurate was it?