Why a clean PCV valve is so important (pics)

[LckydevL]

Vehicle is a 2001 Silverado 4.8 with about 152k miles. I purchased it new and my truck has had 5k OCI's its entire life with Castrol GTX 5W30 (pre BITOG days). I NEVER miss and OCI.

Never had any oil consumption or major problems with motor other than the famous "cold piston slap" and valvetrain noises that these LS1 based motors are known for. Motor has never been into until now.

The ticking on the driver side valvetrain has gotten worse the last few years. Last winter, I tried a couple treatments of Kreen. The first treatment made a noticeable difference in noise and made for a smoother running motor. But I still had a good amount of ticking on the drivers side. The second treatment of Kreen did nothing for the noise. So, I left well enough alone and put a few thousand more miles on my truck. This last month, things became noisier and I decided to take a look under the valve covers.


This is passenger side valvetrain

This is the drivers side valvetrain, notice any difference?

These are two of the pushrods that came out of the drivers side. One was cleaned up and placed next to a dirty one. This varnish was thick and flaky. Disgusting isn't it?

This is drivers side valve cover, notice PCV grommet on far right side.

This is inside the valve cover, opposite the PCV grommet. Noice the tiny, tiny, tiny, stupid little hole that the engineers decided would be big enough to handle any kind of sludge or varnish to build up and still be able to vent.

 

[LckydevL]

PCV valve has been changed every 30k. I never re-use them, always a new one. There is no telling how long the PCV valve has been plugged up on this engine.

I replaced three rocker arms and pushrods on the drivers side due to wear and heavy varnish. Motor is running very strong now but still have a substantial ticking noise. Could be a lifter, I don't know.

I am going to let this motor breath again for awhile and cross my fingers that the lifter free's up and quiets down.

 

[tommygunn]

Doesn't look terrifically bad all things considered. So its uneven. Okay? What the problem be.

 

[sciphi]

A touch more varnish on the driver's side, I'm guessing from the PCV.

Looks good for 150k miles. Shows that regular oil changes keep things clean!

 

[OtisBlkR1]

other than varnish i dont think it looks bad, its not sludge.. Ive never heard a story of varnish killing a motor. so whats the ticking ? did you figure it out ?

 

[LckydevL]

Originally Posted By: tommygunn
Doesn't look terrifically bad all things considered. So its uneven. Okay? What the problem be.


PCV valve grommet hole was sludged up and totally blocked off due to bad design. Which caused heavy varnishing of one side of the motor and probably gummed up my lifters on that side of the motor.

I guess I should have taken better pics. The varnish was very thick and sticky. Most of the pushrods on that side had thick flakes falling off of them. I never though varnish could actually do any damage until seeing this.

Blocked off PCV valve had to be the culprit.

 

[EricG]

That's not bad, GM changed their PCV design due to oil consumption on some of these engines. If you look at the new improved fixed orifice PCV valve for these engines, the hole in the valve is smaller than the one on the picture most likely!

 

[Rand]

oem or aftermarket pcv valves?

 

[LckydevL]

I have had the new PCV valve design on my engine for several years.

Would not have made any difference as the PCV valve hole was sludged up. It is located in the rear of motor, very close to the firewall. Unless you use a mirror, there is no way to inspect the hole.


Always OEM PCV valves.

 

[LckydevL]

Originally Posted By: OtisBlkR1
other than varnish i dont think it looks bad, its not sludge.. Ive never heard a story of varnish killing a motor. so whats the ticking ? did you figure it out ?


I was hoping the ticking was going to be a rocker arm.

I happened upon a post on another forum that stated the LS1 based motors have known problems with the trunions on the rocker arms spitting out needle bearings when they cut loose. They even have kits so you can rebuild your stock rocker arms and make them bulletproof.

Mine were all fine, other than being coated with that orange devil snot. I am now hoping it is just a lifter varnished up that is creating all the racket.

 

[Hokiefyd]

Careful: around here, folks'll say it's a bad engine design if one bank looks worse than the other bank.

 

[Donald]

Try Auto-RX. Nothing to loose.

 

[LckydevL]

Originally Posted By: Hokiefyd
Careful: around here, folks'll say it's a bad engine design if one bank looks worse than the other bank.

The engine has been reliable since day one and I am very happy with it. I honestly look for another 150k out of it.

I also forgot to mention that the passenger or clean side has its own breather tube on the valve cover that runs to the intake manifold. Which I imagine helped it from getting varnished up.

It is just a badly designed valve cover that messes up the PCV system. I have already done two 1k mile Kreen treatments on this engine. Which is probably why it looks as good as it does now.

 

[TFB1]

Originally Posted By: sciphi
A touch more varnish on the driver's side, I'm guessing from the PCV.

Looks good for 150k miles. Shows that regular oil changes keep things clean!


Without fail, on a V type engine with PCV in one of the valve covers, that side will be dirtier than the side receiving fresh air...

 

[ltslimjim]

Nice post. Thanks for sharing your experience.

It makes me want to take the breather chamber off of my little Civic like this youtube user:



Why? Because when I finally found the actual PCV valve on this vehicle, turns out it was the original and it was caked into the breather chamber.

 

[KB2008X]

Thanks, LckydvL, for the reminder to check our PCVs.

Keith

 

[Falken]

I hate to say it, but people may be ignoring the oil that was used.

Now, a stuck PCV valve would destroy any engine, and should be changed regularly and checked for operation (ticking when hose pinched). But lets never mind this for the sake of exploring and discussing.

I had a Chev Cobalt with a pushrod Ecotec, and one day there was a sale on Castrol GTX during the recession of 2007 and I stocked up for 9.99$ a 4L jug at Walmart. I totally bought into their anti-sludge claims and was very pleased with my 6 or 7 jugs I bought of 5W30.

Anyway, I changed my oil in the driveway every 6,000 km (severe service, short trips, cold weather) and changed the cartridge filter for FRAM at the same time. The oil that would come out would always look very black for the short mileage. And my fuel economy on that car was horrible. I'd get, at best, 12L / 100km. It was only on the highway for long distances that the car would get around 8L / 100km. And I suspected the oil. And changing the filter under the hood (cap style) i'd see orange metal where the filter drained back into the engine.

So now, the funny part of the story, I was in Auto Mech class doing our Engine module, and what are the engines we get? Chevrolet Cavalier pushrod 2.2L. So I pull mine apart over the next couple of weeks, and the color of the oil on the engine parts had that amber flaky, burned vegetable oil on pizza pan orange look. And man that varnish is tough. I remember holding the pushrods and they felt gummy.

The pistons looked like they were dipped in vegetable oil then cooked with a propane torch. The rings were stuck, with amber crusty varnish packed in tight like burned honey. The oil rings were a mess, and I had to soak everything overnight in Varsol. The crud came off, but the aluminum pistons still had a burned orange hue.

After that, I always paid attention to the oil I bought by researching here first, and I feel it makes all the difference.

Anyway, aside from scuffed skirts the engine for the age was in ok shape after I measured everything and checked all the specs on Mitchell and Alldata. It was just a mess of amber varnish that I found would cause some sort of issues aside from the rings. And the valve train was all gummy burned orange. Not thick, but TOUGH.

Another thing I found truly alarming was there were 2 engines that were SPOTLESS but had MAJOR piston skirt scuffing and the bearings and wear analysis weren't that great.

So am I a Castrol user now? No, I didn't do anything scientific but I would never dump Castrol GTX in another engine I personally own. Once you see that burned orange color the way it dyes metal and aluminum you always get a funny feeling what oil caused the issue.

So now, I always BITOG my oil before I stock up. Could cost you a car or getting reasonable wear and FE. Again, nothing scientific.

 

[Loobed]

Your 2001 should have a fixed orifice PCV valve. They never need to be cleaned or changed.

Here is an example.
http://www.impalasuperstore.com/naisso/forum2009/topic.asp?TOPIC_ID=47971

 

[cbear]

Originally Posted By: Falken
I had a Chev Cobalt with a pushrod Ecotec


Huh? Aren't all ECOTEC 4 cylinders DOHC?

 

[sasha]

that engine is not even that bad looking at all. My vq35de was worse when i tuned it and replaced the gaskets. The rear valve cover chamber had sludge in it. Not a lot but a couple of small pools. Especially the pcv outlet and valve was covered in a little sludge. IMO the pcv design on the vq35 is worse than the ohv chevy block.