compression reading

[geo3xk]

I checked my oil the other day and realized it was a little low, so i picked some up and went to fill it up. Opened the cap and saw the dreaded milky oil on the inside of the cap. So i decided to do a compression test as a worst case scenario. can someone tell me whats the most difference between cylinders that should cause concern?

 

[SunlitComet]

milkiness is usually a head gasket being broke not low compression.

---------- Post added at 02:26 PM ---------- Previous post was at 02:25 PM ----------

and no more then 20% difference with 100psi minimum on every cylinder.

---------- Post added at 02:26 PM ---------- Previous post was at 02:26 PM ----------

But like I said you have a gasket issue.

 

[ezdaar]

Don't panic just yet. GM oil caps have a tendency to leak air, and can suck in moist air. causing the milky look inside the cap.

Remove the fill tube from the valve cover and look inside at the rockers and head.
Is there any milky oil?
Pull the PCV and look at its bottom, is it milky?
Lastly, after the vehical sits for aprox a hour after being fully warmed up, Carefully pull the dipstick, Look and see if the Top of the oil on the stick looks milky.
Rub it off with your fingers gently, does it look milky on your fingers?

If you have a Gasket issue it wont be a "tiny" amount. There will be ALOT of chocolate milk look everywhere in that motor.

 

[geo3xk]

milkiness is usually a head gasket being broke not low compression.

---------- Post added at 02:26 PM ---------- Previous post was at 02:25 PM ----------

and no more then 20% difference with 100psi minimum on every cylinder.

---------- Post added at 02:26 PM ---------- Previous post was at 02:26 PM ----------

But like I said you have a gasket issue.

Wouldn't a compression test show a bad head gasket?

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[geo3xk]

Don't panic just yet. GM oil caps have a tendency to leak air, and can suck in moist air. causing the milky look inside the cap.

Remove the fill tube from the valve cover and look inside at the rockers and head.
Is there any milky oil?
Pull the PCV and look at its bottom, is it milky?
Lastly, after the vehical sits for aprox a hour after being fully warmed up, Carefully pull the dipstick, Look and see if the Top of the oil on the stick looks milky.
Rub it off with your fingers gently, does it look milky on your fingers?

If you have a Gasket issue it wont be a "tiny" amount. There will be ALOT of chocolate milk look everywhere in that motor.

Well that's a relief, I have done all of the above and everything seems to be good. The only place with the milkyness was the cap and tube, but on a good note it sparked me to do a full tune up and oil change which has probably been due for a long time. Another question at the parts store I was picking up plugs and planned on changing them with the autolite double platinum which were in it but they were out of them. Instead they gave me platinum 4s at 3.09 a piece which is a deal just curious if anyone has any experience with them.

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[ezdaar]

take those back and get nkg tr6. i wont run anything else.

When you changed your oil, did the last lil bit of oil draining out look milky?
If there is any water in the oil, it generaly comes out last unless the oil is completly milked..
You will definatly see it in the oil catch container.

 

[SunlitComet]

It really depends on the pattern the gasket break takes. Just post your findings here I we will help you out.

 

[geo3xk]

take those back and get nkg tr6. i wont run anything else.

Too late already installed but will keep them in mind for the next time

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[SunlitComet]

Use only autolite champion or acdelco do not use plugs like bosch or ngk or othere import named plugs.

 

[geo3xk]

It really depends on the pattern the gasket break takes. Just post your findings here I we will help you out.

Cylinder#
1 141
2 150
3 141
4 130
5 140
6 135
7 145
8 155

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