: A river runs through it - valve covers and PCV baffles



AJxtcman
05-14-07, 09:37 PM
This will be edited from the initial posting! I left in Ewill I hope that is ok Ewill
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had a 99 seville in today with 4.6 mtr has a oil consumption problem
did the lower case half seal for leaking3000 miles ago came back performed ring cleaning prcedure2000 miles ago cust is still using regular unleaded fuel
so i was looking around and pulled the pcv valve while it was running to check the valve operation.. don't know quite why i looked in the grommet hole or what i was looking for.. imagine my suprise when at idle i had oil running down the inside of the baffel plate at idle not a lot but it was wet .so out of the blue i wonderedwhat happens at 1500 rpm and above? .so i pulled the throttle open with my pen light in the grommet faceing the #3 hole side and low and be hold a river runs through it!! it wasless than a pen width away from the seated pcv valve and it was a 3/4 inch wide river!!!then i thought about it the 1-3-5--7 intake cam throws oil to the center of the moter(and if you have ever run a northstar with the rocker cover off it's a bath) just happening to have another moter of the same vintage i pulled it's rocker cover the baffel plate has a large gap on the up hill side ,very large gap around the bolt hole indents so i pulled the rocker cover out of the car and it was the same i pulled the 8 bolts out and run sealant 12346193 around the perimiter starting at the #3 side of the baffel plate along the uphill sidefull lenght .leaving the down hill side open and the in let over #7 cyclndr iam going to call back some of my other consuption cases and see if this was an isolated case(tac had a few supposedly loose baffle plates mine was not) or a root cause in the others.. also saw a 97 in today same complaint pulled the pcv out and saw nothing but timming chain (been awhile and don't have one apart anyone else seen this?)isen't it supposed to have
a baffel as well?what stops the oil slung up from the timeing chain from being sucked out am i crazy? also the tec asistance guy told me that the crankcase should have zero pressure at all times just a thought to pass along calling all heavy duty guys is this just a fluke on this car or is it a bigger problem please respond p.s. the cust is going to keep me posted on consumption starting now as i think this is not an isolated case
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Posted: Jul 27 2004, 01:59 AM

Well, that's another thing I need to check on my friend's Aurora 4.0, referenced in another post.

I don't know how similar the 4.0 and the 4.6 are... they look like the same motor. I've been completely away from Cadillac (and Olds, for the most part) since 1990.
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Posted: Jul 27 2004, 05:26 AM

I seem to remember that this is one of the issues you should check for with oil consumption issues. That is also the rason for the orfice instead of the PCV valve. It was covered on a broadcast last year, maybe a powertrain townhall if I remember correctly.
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EWill3rd Posted: Jul 27 2004, 05:37 AM

Technician Moderation Team

Group: Service Technician Moderator
Member No.: 1153
Joined: 2-April 02

I can't respond to your consumption question but I just wanted to verify for ROM that the 4.0 and the 4.6 are essentially identical save for the displacement which leaves only a handful of different parts.

Thanks for the tip on what to check for oil consumption though!

EWill
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Posted: Jul 27 2004, 08:17 AM

QUOTE (roadrunner @ Jul 27 2004, 12:47 AM)
(and if you have ever run a northstar with the rocker cover off it's a bath)


That's probably one of the coolest things I've ever seen. Everyone I'm sure has seen engines run with the valve covers off and the rockers doin' their thing. Northstars whip those cams around like nobody's business and throw horrendous amounts of oil around in the process. It's pretty neat for about 30 seconds until all that oil hits the manifold. But yes, there's supposed to be an orifice back there.
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Posted: Aug 24 2004, 09:47 AM

You'd think someone in Powertrain would be paying attention, these PCV baffles in the cam covers and valve covers have been somewhat of a problem for decades! The first ones I knew of were the old Chevettes, brand new in 1976, these first ones had a real appetite for oil which was traced to the PCV baffles allowing large quantities of oil to be consumed. Since then several other engines suffered the same thing or close to the same thing in the PCV system. Whenaretheygonnalearn!

AJxtcman
05-14-07, 09:44 PM
I have resealed many baffles and replaced a few defective PCV valves. I have had valves smashed or malformed when pressed together. The sad thing is A robot did not install it in the valve cover at the factory.

AJxtcman
03-04-08, 05:36 PM
Pull the PCV valve out of the valve cover. Get a small Mag Light and look into the PCV hole in the valve cover. Rev the engine to 2000 and look for oil running through this area. You should not see oil running though this area!!!!!!
If you do you need to pull the rear valve cover and reseal the baffle.

AJxtcman
03-04-08, 10:52 PM
I happen to have a Valve Cover off an engine in my living room:eek:

Loose RTV
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/loosesealer1.jpg

Lacking RTV You can see that it was sucking in oil.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Lackofsealer1.jpg

Baffle Lacking RTV
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/baffle.jpg

Crown Vic Owner
03-05-08, 03:26 AM
In post 3 picture one, is that a molex connector in the background for a PC?


As well, is that a 4.0 or 4.6 valve cover?

AJxtcman
03-05-08, 06:43 AM
In post 3 picture one, is that a molex connector in the background for a PC?


As well, is that a 4.0 or 4.6 valve cover?

I am building 3 Northstar Fiero Harnesses and that is the real reason for the 4.6L in my living room.:histeric:

$800 a piece. So that would be a Fiero connector

foos
03-05-08, 10:11 AM
I know my PCV is sucking in oil because my intake manifold is full of sludge and it's always nasty behind the TB.
How difficult is it to pull the rear valve cover off and fix that? I'll have to check the PCV thing but I bet that's what it's doing. I'll post back and see if a river is running through mine :)
I'm still interested in doing the ring cleaning procedure anyway since it has over 100k miles on it, it might do some good.
Getting all that nasty crap out of my intake would be nice. There's literally 1/8" of sludge in there and it keeps coming back. THat doesn't seem right to me, even for a dry intake system.

Submariner409
03-05-08, 11:14 AM
Hey, AJ.............Put together a leaking PCV baffle, throttlebody crud buildup, some oil in the engine valley, and what do you get ???

A fair percentage of Northstar oil consumption complaints with no apparent mechanical failure !!!!

BINGO !!!!!

foos
03-05-08, 11:19 AM
Yea.. It's a good indication if the intake is full of sludge and the TB is always black on the inside. It also makes some smoke out the exhaust sometimes that smells funny probably because it's sucking oil and trying to burn it with the gas.. Ahh well! Hopefully this will fix my problem.. I will let you know as soon as I have a chance to look at it and I'll take pics when I fix it.. Probably sometime next week.

foos
03-05-08, 11:41 AM
Well I pulled out the PCV and the grommet and shined a light in there and there's no river going through it. THat doesn't mean it doesn't flow through when I'm driving around or turning corners or something but it's not doing it at idle or revving the engine 2-3k rpm in neutral. I was thinking of installing a catch can on the PCV and seeing how much oil it collects.. that would be a good reference point. Also, could the engine be vaporizing the oil in the crankcase so that it gets sucked out the PCV? I think that's what the ring cleaning thing was supposed to fix?

dwight.j.carter
03-05-08, 02:12 PM
My mechanic complained about how tricky it was to remove the rear valve cover on my 99 STS.
Is it that tough to get off while the motor is in the car ?

Submariner409
03-05-08, 02:33 PM
dj......I think you have to pull some cradle bolts (and maybe the fan/radiator assembly) and tilt the assembly forward.

Foos......The positive crankcase ventilation system is actually supposed to suck all the nasty combustion product vapors: oil, acid, and water, out of the crankcase. Engine oil runs HOT at proper temps: above 210 degrees, so you get some vapor there, too. The engine and cooling system is designed that way so that the above nasties "boil" off during normal operation. If they didn't, we would be back in the pre-60's situation of excessive crankcase sludge, which is really acidic tar. Did you know that, for every gallon of gasoline you burn, you liberate close to a gallon of water? It's all hydrocarbons in one form or another, and some of it blows by the piston rings, also perfectly normal. What's a jet aircraft contrail (condensation trail) mostly made of ?

Soooooo..... a certain amount of crap buildup is, unfortunately, bound to occur, and the cleanup is part of proper engine maintenance.

foos
03-05-08, 03:04 PM
Yea I know.. I just think that mine is very excessively doing this which is causing lots and lots of sludge in the intake, and the oil is always really nasty even after 3000 miles. That's not how it should be :/ I built engines in the past and they didn't run as nasty as this one or burn nearly as much oil. I'll try a catch can but I think the ring soak treatment if I can ever find the TSB for it might help. The car was babied for 50k miles until I bought it from the guy and started WOTing it every time I got on the highway :> :>

AJxtcman
03-05-08, 03:30 PM
Hey, AJ.............Put together a leaking PCV baffle, throttlebody crud buildup, some oil in the engine valley, and what do you get ???

A fair percentage of Northstar oil consumption complaints with no apparent mechanical failure !!!!

BINGO !!!!!
This is a 93 to 99 problem as far as I know.
They relocated the PCV valve in 00. Guess why?
That was another thing they fixed


Well I pulled out the PCV and the grommet and shined a light in there and there's no river going through it. THat doesn't mean it doesn't flow through when I'm driving around or turning corners or something but it's not doing it at idle or revving the engine 2-3k rpm in neutral. I was thinking of installing a catch can on the PCV and seeing how much oil it collects.. that would be a good reference point. Also, could the engine be vaporizing the oil in the crankcase so that it gets sucked out the PCV? I think that's what the ring cleaning thing was supposed to fix?
Many reasons to sludge up the intake


My mechanic complained about how tricky it was to remove the rear valve cover on my 99 STS.
Is it that tough to get off while the motor is in the car ?
The rear Valve cover is by far the easiest and quickest

dwight.j.carter
03-05-08, 05:52 PM
Well I don't have to much to worry about my car now is a 2000 so it has a good engine.
And I noticed with this one it burns so little oil I usually only have to top it off once between oil changes.

AJxtcman
03-05-08, 06:22 PM
Well I don't have to much to worry about my car now is a 2000 so it has a good engine.
And I noticed with this one it burns so little oil I usually only have to top it off once between oil changes.

Z-MAX
GM endorses it for use in Northstar's that burn oil that are out of warranty

dwight.j.carter
03-05-08, 06:52 PM
where does it show gm endorses it ?

AJxtcman
03-06-08, 06:35 AM
where does it show gm endorses it ?

I looked for about an hour and could not find it. Then I remember starting a thread on the GM forum. I looked for about another hour or more. It would not come up in a search so is had to go back a few years looking at every thread . I found it. :histeric:
I click on the link and it said Forbidden 404!:nono:
OK I listed the PI number, so I tried it :hmm:
They pulled the PI.

I guess GM passed on the PI and did not make it a bulletin:hide:

foos
03-06-08, 09:32 AM
So, what would you suggest for trying to squelch my oil consumption on my 99 STS?
Do you remember the TSB # for the ring procedure? And even though there's no 'river running through' my PCV port at idle or revving the engine up in neutral, it probably still gets in there somewhere during driving?
This stuff http://www.zmax.com/products/automotive.html is expensive if it doesn't work, and a good deal if it does work :)

blue_eldo
03-08-08, 02:02 AM
Chrysler had a similar, and well known problem with their Turbo 2.2 and 2.5 engines with a simple fix of pulling the valve cover and sealing the PCV baffle with RTV. The PCV system, in these turbo motors is a little different in the the PCV is plumbed into the airbox that would get oil soaked if the baffle was not properly sealed.
I still have a 89 Plymouth Voyager Turbo that runs strong and surprises a lot of people at red lights!

foos
03-10-08, 12:43 PM
So nobody knows the ring fix TSB? :/

foos
03-10-08, 12:46 PM
So I guess nobody remembers the TSB for the ring soak thing? :/

tateos
03-10-08, 01:41 PM
As I recall, you pour the cleaner through the PCV and let it stall the engine, let it soak for awhile, and then start the engine and blow out the crap.

AJxtcman
03-10-08, 01:56 PM
So I guess nobody remembers the TSB for the ring soak thing? :/
I have been busy
I will post it.

dad
03-18-08, 11:30 PM
is the pvc valve the one on the left side of the engine next to the oil fill cap on a 94 seville

AJxtcman
03-19-08, 06:27 AM
is the pvc valve the one on the left side of the engine next to the oil fill cap on a 94 seville

No it is in the rear valve cover

dad
03-20-08, 09:06 AM
is it difficult to pull the valve covers and check this BAFFEL?

on which side of the REAR valve cover is the PVC valve... i am talking about a 94 seville

Submariner409
03-20-08, 10:47 AM
If your engine has a plastic cover over the intake manifold and engine valley, remove it. The PCV sysem starts in the (looking at the engine from the front of the car) left front of the rear cam/valve cover, and has a 3/8" (plastic?) pipe which feeds into the intake manifold center plenum area. The PCV fresh air supply comes from the atmospheric side of the throttlebody and has a pipe which goes to the right front cam/valve cover.

The piping varies from model to model, and sometimes year to year, but the locations and theory are the same: the engine ingests vapor-laden crankcase gasses by sucking them into the intake manifold through a calibrated valve or orifice. This extra "vacuum leak" is constantly factored into the PCM calculations for fuel/air ratios, regardless of throttle opening..

AJxtcman
03-20-08, 01:42 PM
is it difficult to pull the valve covers and check this BAFFEL?

on which side of the REAR valve cover is the PVC valve... i am talking about a 94 seville

I have been told it depend on the month.
93s and some 94s had it on the left side of the rear valve cover. Then they switched it to the right side.

dad
03-21-08, 09:07 PM
I found the pvc valve on the rear cover on the left (passenger side of the engine). I checked by pulling out the valve and indeed there is lots of OIL in the cavity. So the next step... 1 pull the cover over the entire engine..2 pull the rear valve covers ..3 check the baffel and seal it as necessary/

will there be a gastket that i need to buy before starting this process

dad

tateos
03-22-08, 11:34 AM
dad - I think it is RTV

AJxtcman
03-22-08, 01:02 PM
I found the pvc valve on the rear cover on the left (passenger side of the engine). I checked by pulling out the valve and indeed there is lots of OIL in the cavity. So the next step... 1 pull the cover over the entire engine..2 pull the rear valve covers ..3 check the baffel and seal it as necessary/

will there be a gastket that i need to buy before starting this process

dad


dad - I think it is RTV

Correct RTV.
Make sure it is a good quality RTV. I think that the newer GM stuff is top shelf. Other OE's have good sealers also. I have seen a lot of crap at the parts stores. This will be inside of your engine. Temps are high and you have all that oil trying to break it down.

dad
03-24-08, 09:19 AM
ok what is RTV?

Submariner409
03-24-08, 09:46 AM
RTV stands for Room Temperature Vulcanizing, a process by which synthetic gels and creams cure to different hardnesses of rubber. "RTV" is now a generic catchall for the vast array of self-curing sealants which ranges from bathtub caulk to space shuttle work.

What AJ, and the directions, say is to use the correct product for the correct job.

GM used to use a bewildering number of special purpose RTV's, but has recently pared down to a couple of great products.

Go to your local big parts house and look at the rack of sealers and gasket maker products. Too many to count.

(BTW, silicone (yes, silicone) sealants and adhesives are different cats than RTV. NEVER use silicone sealants in automotive work.)

tateos
03-24-08, 01:08 PM
good point submariner - make sure the sealant is O2 sensor safe, dad!

dad
03-24-08, 10:31 PM
thanks gents... so a good RTV is in order

is that for the baffel fix...? what will i need to pull th valve covers..

or will that handle both..

bottom line i unscrew 8 bolts that hold on the rear valve cover and then what happens?

I think I look for the leaking baffel,, seal it... but then what trouble putting it back togethere

dad

tateos
03-25-08, 12:04 PM
Not sure if you should just re-seal the baffle, or remove it and the old sealer and then reseal it... I suspect you need to do the latter - not sure you could get everything clean enough for the RTV to bond otherwise.

I think you just remove the items attached to the valve cover and then the valve cover attaching bolts and then lift it off. Maybe you have to rock the engine forward? Not sure about that... maybe someone else can remember???

dad
03-25-08, 10:08 PM
just exactly what is " ROCK the engine forward" ...does that mean like disconnecting motor mounts ..you mean to say all that is needed to get the rear valve cover off?

dad

blue_eldo
03-25-08, 10:45 PM
Remove the two front dog bones, depending on year, and I placed a hardware store vatiety turnbuckle in the location on the drivers side dogbone and was able to rock the engine forward about 2" to replace my HVAC blower on my 96 deville.

dad
03-26-08, 09:12 AM
Has anyone out there removed the rear valve covers on a 94 Seville lately.

like can you tell me the toughes part

dad

tateos
03-26-08, 01:47 PM
blue_eldo:

Isn't it easier to just drop the cradle in the front? No motor mounts involved that way. Just loosen the bolts on the rear of the cradle and loosen or remove the ones in the front and then drop the front of the cradle as needed

AJxtcman
08-13-10, 03:18 PM
:horse:

http://i224.photobucket.com/albums/dd25/AJxtcman/smilies/av-192_5.gif

Submariner409
08-13-10, 03:31 PM
AJ's at it again.................:stirpot:

(you should put this in the thread from the member who rebuilt his engine and still burns oil at a great rate........)

(EDIT: Oooopppsss !! You did.)

AJxtcman
08-13-10, 04:53 PM
I did a search and couldn't find it.
I spent about 10 minutes looking through all the threads I started before I found it.
So it got a bump

turbol15
12-17-12, 12:15 PM
so where that pcv valve is should be completely free of oil?

Submariner409
12-17-12, 12:42 PM
A PCV is designed and installed specifically to suck oil vapor out of the crankcase, and the PCV system air supply comes from the atmospheric pressure clean side of the intake ducting or throttlebody. Different engines, different makers - do good, indifferent or poor jobs of shielding the PCV suction hose from ingesting solid oil droplets - you have NO idea how much oil flies around in a valve cover at 2,000 rpm much less at 6,000. Oil vapor does no harm to anything, but solid oil pools and screws up intake manifolds and deposits gunk on the intake ports and valves.

AJ tried to inform people that the internal cam cover baffle is a big factor in this oil ingestion, particularly in the pre-2000 engines. If that baffle comes loose or is missing, these engines will EAT oil at a happy rate. The cam cover baffle check was another suggestion to lower oil consumption, but the work involved is daunting.

Some people put a BandAid on the problem with a "catch can", but that's a temporary Tylenol - the original problem still needs to be addressed. Our Northstars have the entire intake port and valves washed by the fuel injector spray, so we do not suffer from intake port crap like the newer DI engines. Our engines happily burn off any extra oil, whether it's from overfilling the crankcase or from the PCV system. BUT, due to where the PCV dirty air line enters the intake manifold, the manifold passages will develop a sticky oil vapor coating. Not a problem.

Short answer to your question: If the PCV dirty air line and valve/orifice does NOT have a small (tiny ?) bit of oil on/in it, something's wrong.

turbol15
12-17-12, 02:34 PM
well here is what i found a few minutes ago. i pulled off the pcv gromment and looked in the cam cover with a flashlight. i found a little pool of oil in the baffle. i reved it up and saw oil coming out of a hole on the lowest portion of the cam cover. it seems like this hole should be there as like a drain or something when the rpms went down the oil went back in this hole and vice versa. but for sure there was a mist of oil floating around in there. this certainly has to be the problem.

Submariner409
12-17-12, 06:04 PM
"Where that PCV valve is" is subjected to a staggering amount of oil flow and aeration due to cam, valve, and chain action. Some oil in the PCV grommet is inevitable - but baffling reduces the amount of "solid" oil that is passed through the valve/orifice itself. The trick is to determine if the baffle is still in place - some have loosened over time.

Here's a Northstar oil pan - see the 3 round "holes" on each side ? Those are the lower ends of the cylinder head (valve area) oil drain passages. When the engine is running at 2,000 rpm and every cubic inch of the interior is wetted by pumped/flying oil I'll bet there is less than 5 quarts of solid oil in the pan - the rest is doing work: Lubricating and cooling the rotating assemblies.

EDIT: Oil pan picture moved to my albums.

turbol15
12-17-12, 06:38 PM
so is that puddle and hole in the baffle normal? and is this the reason why my motor consumes so much oil?

Submariner409
12-18-12, 08:52 AM
Which engine ??? The Eldorado or CTS ?

But, yes, if the internal baffle has failed in the older engine, that might well contribute to excessive oil consumption. Mist and vapor is normal - solid oil is not.

turbol15
12-18-12, 09:16 AM
Sorry my 97 eldorado, yep found a puddle in lowest portion of baffle.

stoveguyy
12-18-12, 09:04 PM
I did my heads 5 yrs ago. I reused my VC gaskets and had a small oil leak on rear of motor. Finally changed rear VC gasket this spring and it was fine so I wasted some time but I do not recall if I even had a Pcv baffle in place. I cannot recall even looking at it. And I still leak oil. I had trans out in sept and case half seal area looked fine. Motor is not perfectly clean but it's not horrible. I

turbol15
12-19-12, 06:15 AM
its not that i leak oil which i dont. i burn it at a tremendous rate. i think i have found the answer.

Submariner409
12-19-12, 10:06 AM
Try running your oil level at the lower end of the dipstick hashmark and see if that lowers consumption. Northstars habitually consume oil if you try to keep it "topped off". Read the oil consumption article up in the black bar ^^^ Cadillac Technical Archive. Matter of fact, study the entire Archive.

Different car, different engine, different circumstances, but I run my oil level here on my dipstick and get over 5,000 miles/quart - and I can prove it with logs and oil receipts:

< === ADD XXXXXXXXXXX OPERATING RANGE ===============oo===============================O

turbol15
12-19-12, 11:56 AM
i wish i could get that. i get about 350-500 qt. horrible. i may just jettison it in the new year. kinda sick of opening the hood. even though i have ocd

codewize
08-15-13, 09:30 PM
OK so I'm using about 2 qts per 1000 miles on my 02 DTS. DO they have the same PCV baffle we're talking about? I know they don't have a PCV valve now.

I don't have time to read all 4 pages of this thread

AJxtcman
08-19-13, 06:12 PM
No you do not, but I have seen 2002's with PCV valves

codewize
08-20-13, 06:50 PM
Hi AJ, well I can tell you that mine has an orifice :) NO PCV valve. No baffle in the 02 ?

Submariner409
08-20-13, 08:58 PM
Baffle - been there. (Not mine - a 2002 DHS)