Is it normal to have oil inside the throttle body? 2000 Coupe MN6 82k

 

i got the same thing, i think its from the pcv valve thqt feeds right back into the intke manifold, i cant imagine its a bad thing, for a droo or 2 sitting there.

 

 

read this and buy one. it will stop the most of it. and yes, its pretty normal for these cars to have it in the intake and for some in the throttle body from leaking out the intake. do a search on "catch cans"
http://forums.corvetteforum.com/show....php?t=1577230

 

Before you hastily buy anything, you might want to read this primer that I wrote a while back.

http://www.conceptualpolymer.com/PCV...oval%20101.pdf

 

Dave, should I clean out the intake? Also the line from the valve cover to the throttle body has oil in it too.

Thanks for your help, Bill

 

Yep, very common. You should see it after a weekend open track event!

Get a good catch can and change the PCV valve often.

 

I would clean out as much as you feel comfortable with. Removing the intake is not a 30 minute job, but cleaning out the TB and replacing/cleaning oily hose shouldn't take too long. The key right now is to slow or stop the flow of oil into the intake.

BTW, as long as you change your oil when you're supposed to, there is no need to change the PCV valve often. In most cases, you can replace it when you change your spark plugs. If the PCV valve fails, your idle will drop, noticably.

 

Dave,
I respectfully disagree with this statement. I've got 4 years of used oil analysis reports on my Z06 that proves this incorrect. A PCV valve cycles over 3000 times a minute and it's impossible to tell when the spring is weak and the performance has degraded enough to cause deposits to form in the engine. A malfunctioning PCV valve will cause sludge build up and manifest it self as higher than normal water levels in the oil. Water contaminated oil is a very bad thing. Water attracts fuel and fuel encapsulates dirt carrying it through the oil system. This, very quickly I might add, leads to high levels of iron, tin, lead, and copper in UOA. Bottom line is it causes accelerated wear that you would not know about unless you were performing used oil analysis with expert interpretation.

Just my hard earned two cents worth......

 

3000 times a minute, what kind of pcv valve do you have? Even if the spring is weak you still have positive crankcase ventilation it is just a little slower to not throw off the idle quality. Just get a catch can and youll be good. You may try and run seafoam through the motor or k44 or something to that effect. I wouldnt pull the intake over oil. But the carbon deposits in the combustion chamber can lead to detonation. So I would run some kind of cleaner through it. Also if your pcv valves is working you will still get oil in the throttle body, Thats not the purpose of a pcv valve. And the main concern with water is teh formation of acids which as long as you change your oil like your supposed too youll be ok. Most synthetic oils have weak bases in them to counteract the acids as they are formed.

 

It doesn't matter how good of an oil you run, oil can only protect so well with none able to counteract high dirt ingress levels, water or fuel contamination. Oil very quickly breaks down when contaminated with fuel or water, causing the protection it's able to offer to quickly erode. Some oils can handle fuel contamination better than others, but none that I have used can handle water contamination.

If really want to destroy a motor quickly, run a K&N filter cleaned at recommended intervals and replace the PCV valve on an irregular schedule. With a good oil filter and changing the oil every 2000 miles, bearing and cylinder wear would be a serious problem. This would then quickly lead to deposits in the ring pack that cause a whole other cycle of destruction within the engine that keeps feeding off of itself.

I've seen runs on my Z06 where the TAN levels were still well within acceptable limits but water, fuel and dirt ingress caused rapid wear that the oil could not prevent.

Do you have UOA's that show to the contrary? If so, I would love to know what combination of oil, filter, and adds you use along with specifics about the car and how it's driven.

It's your car, do as you please.....Unless you are doing regular oil analysis with quality interpretation, you would never know anything irregular was happening until the motor started knocking or leak down levels exceeded acceptable levels and performance degraded.

 

[QUOTE=thetorch;1560618623]
A PCV valve cycles over 3000 times a minute and it's impossible to tell when the spring is weak and the performance has degraded enough to cause deposits to form in the engine.QUOTE]

over 3000 a minute? that would be over 50 times per sec....this requires no report to determine it is

 

[QUOTE=npm;1560634925]Please share your experience based on qualitative data. What information can you contribute other than this lame statement?

 

[QUOTE=thetorch;1560635181]Isn't PCV valve operation proportionate to engine vacuum? If that's the case, i cannot imagine vacuum fluctuating enough to fully cycle the valve 3000 times a second... On the other hand, I can see that the valve would be constantly adjusting due to fluctuation in vacuum due to engine rpm, throttle position, and load etc.

 

Some reading for you....

http://autorepair.about.com/cs/gener.../bldef_621.htm

http://autos.yahoo.com/maintain/repa...ques079_1.html

http://www.automedia.com/PCV_Valve/ccr20050101pv/2


The soonest any of these articles advise you to replace your PCV is 20,000 miles and most call for 30,000 - 50,000 miles. As I mentioned, there is no need to replace PCV valves every year or at every oil change as long as your oil is changed when the D.I.C. says so.

Then again, if it makes you feel better to change synthetic oil and a PCV valve every 3 months, go for it. Other than lightening your wallet, no harm will come of it.

Dave

 

Thanks for the links. I know what they all say, but actual testing tells me different.

As far as oil goes, I calculate the oil change interval based on oil analysis results. Sometimes it's a short OCI and sometimes it's an extended one, it just depends on the amount of track time, street driving, oil brand, and filter.

Based on oil analysis results, the Drivers Information Center (D.I.C.) does not accurately measure oil life for modified and open tracked cars. I have runs where the D.I.C. showed 60% and according to oil analysis the oil was depleted and warranted changing.

Just my experience.....

 

share my experience? i am not the one that make such bonus claims of pcv cycles over 3000 times per minute. it is you that made a lame statement without providing any data to back that up. there is no data that you will find to support this claim. not even our pcm makes this much adjustment in fuel (over 50 in a sec? not even close). you made the lame statement, you provide the documentation. i simple pointed out your error in wishful thinking / lame statement.

 

Here's a question for the 2004+ model year Vette owners.

Do you guys see any oil back steaming into the intake track or the hose going to the intake track (ie, the PCV fresh air hose) on your cars?

The reason I ask is because the PCV "valve" on the 2004+ model year cars is a fixed orifice (2.5 mm I believe) ... NOT a conventional PCV "valve" with the spring loaded pintel.

 

Of course, if you regulary beat the heck out of your engine at the track, you should change oil more often, along with many other parts that would normally last longer. However, most CF members don't and can safely wait at least 30,000 miles before changing the PCV valve.