varnish on dipstick

Messages
176
Location
georgia
Is a thick black varnish on the top 10 inches of the dipstick a bad thing?Both of my chevy 2.2s have this problem.Also I notice that if i check the oil right after i cut the engine off that alot of smoke comes out of the dipstick hole.
 
Messages
2,233
Location
Wisconsin
Sounds like the crankcase is trying to ventilate out the dipstick tube. I'd make replacing the PCV valve a priority on my things to do list! [Smile]
 
Messages
3,558
Location
SE Pa
It could be normal for that engine. But then again you may have a malfunctioning or overworked PCV system and the crankcase is pressurizing up the tube. In extreme cases (like on some Volvos), a restricted PCV can blow out the RMS and pop out dipsticks. You may not have a replaceable valve, but you may have an air check, oil catch, or filtered intake of some sort. Make sure all lines on both intake and exhaust sides are clear and clean. You should run a compression test if the PCV system checks out ok.
 
Messages
2,338
Location
Charlotte Metro area
quote:
Originally posted by Triple_Se7en: The worst oil measurement is right after shutting off the engine. The best measurement is on level ground after the vehicle has sat off overnite.
The only accurate oil measurement is the one done with the correct viscosity oil under the conditions specified by the manufacturer. Each individual engine/manufacturer uses a specific set of conditions, with an appropriate device calibrated to correctly measure the level under those specific conditions.
 
Messages
3,558
Location
SE Pa
quote:
Originally posted by JohnBrowning: You should not have varnish,sludge or rust on a dipstick! If you do then you need to revise your oil change interval.
You can if the tube is being used as a crankcase exhaust, and the OCI has nothing to do with it. You'll routinely find the PCV exhaust lines coated like this even in well-maintained engines. Crankcase gases are a fairly filthy combination of blowby and oil vapors. Before the '60s, this stuff just exhausted out the bottom of the engine and into the next guy's wing vents.
 
Messages
3,558
Location
SE Pa
It's a bad thing when the cause of all of this is excessive blowby overwhelming the PCV system. Excessive blowby is the mark of an engine with cylinder sealing issues. The blowby pressurizes the crankcase and loads it up with very undesirable contaminants. Both are bad for the engine. The ringpacks eventually carbon up solid in the lands. Blowby, leaks and oil consumption gradually increase and compression and power gradually decline. It becomes an ugly downward spiral leading to a ring job. Years ago, there were very few other methods available to reverse this process once it started, and those used were often harder on the engine than the problem and rarely worked. That's why a compression test may be adviseable here if the PCV system checks out ok. This engine might also be good candidate for an ARX treatment if the root cause is deposit and not wear-related. If so, ARX might remedy it before it gets too far along. We didn't have ARX 30 years ago and were left reaching for the Perfect Circle catalog when this happened. So take advantage of it. But start with the PCV system, as some can restrict or clog up if not maintained.
 
Messages
47,770
Location
Everson WA - Pacific NW USA
No my dippy is clean.
quote:
Is a thick black varnish on the top 10 inches of the dipstick a bad thing?
If you have to ask......... My definition of "varnish" is NOT thick and black. From dictionary.com: "....a hard, glossy, transparent film." Sounds like sludge to me.
 
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