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2006 chevy trailblazer_ss_lt
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Discussion Starter #1
Last Friday, I noticed there was a good sized puddle of oil under my vehicle. I put enough oil back in to make it to a mechanic, and his diagnosis was that the PCV port going through my I6 block is clogged, and the added engine pressure is pushing oil out the main seal where the transmission mates to the block. Should I try using the Sea Foam stuff to free any blockages BEFORE I take this thing to a better mechanic that actually knows what to do with it?
 

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2002 chevy trailblazer_ls
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1,121 Posts
Curious as to whatthe answer from the true gear heads here will be... There are some R-E-A-L-L-Y knowledgeable folks here...
 

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2002 olds bravada
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Seafoam wouldn't really help you in this case. Because our engines don't have a PCV VALVE, you would have to use the brake booster, and that sends it straight into the cylinders/intake manifold.
 

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2003 chevy trailblazer_ls
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5,267 Posts
thats what I thought... TB dont have PCV valves.
 

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2006 chevy trailblazer_ss_lt
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Discussion Starter #5
Friend of a friend

Is a former GM mechanic, and he is willing to take on the issue as a side project for cash. I just can't see myself taking this thing to the dealer and getting smacked with a $1K+ teardown service bill to tell me my engine is crap.

Also, if I continue to monitor the oil level and drive the thing, am I furthering damage to the engine?

Thanks
 

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Northwest Chapter
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The I6 actually does have a PCV valve, its just not servicable and attaches to the intake manifold between runners 3 and 4. And Im not sure why it was needed, exhaust VVT takes care of all the functions a PCV valve does...

If you're loosing oil out the rear main seal, you're going to need to pull the trans and replace the seal at least Im afraid. That seems to be a common occurrence with V8s, havent really heard much about the I6 needing it though.
 

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2002 olds bravada
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From what i understood, the I6 engines have PCV, just not the valves. I read this in another thread..but i may be wrong.
 

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2002 gmc envoy_slt
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Seafoam wouldn't really help you in this case. Because our engines don't have a PCV VALVE, you would have to use the brake booster, and that sends it straight into the cylinders/intake manifold.
:iagree:

I was watching this thread to see what was going to happen with the PCV valve. I was 99% sure there wasn't one, but these threads find the truth pretty quick.
 

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Western Canada Chapter
2003
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6,411 Posts
Seems like a lot of pressure would have to build to drive oil out the seal. My first impression would be that it would leak out though the dipstick first or even pop the hose from the intake box. :undecided

I think I would try an engine flush and see how dirty this motor really is inside. It would have to be so filthy that I would think catastrophic wear has taken place. :m2:
 

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2006 chevy trailblazer_ss_lt
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Discussion Starter #11
Results so far...

The mechanic that diagnosed the problem actually attempted to unclog the port by spraying throttle body cleaner into it. That didn't produce immediate results, but the truck sat for 2 days. After picking up from the mechanic, and driving to and from work with fresh dino 5w-30, there is very little leakage visible. I have inspected the ground under the truck 5 times throughout the day yesterday.

The PCM has picked up on the issue and my 'idiot' pressure gauge is showing a fluctuation of 40 psi at idle, maxing at 60 psi when under 3K+ rpm load.

Being broke at the moment, I can only minimize my drive time to two days a week until I can get some Sea Foam and do a complete oil and filter change. After tax returns, I will be sending the truck to my GM mechanic friend who can then assess the replacement of seals.

Thanks everyone for your input!

JT:bonk:
 

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2002 chevy trailblazer_ls
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The I6 actually does have a PCV valve, its just not servicable and attaches to the intake manifold between runners 3 and 4. And Im not sure why it was needed, exhaust VVT takes care of all the functions a PCV valve does...
Actually the VVT takes care of exhaust gas recirculation so the i6 does not have an EGR valve. The PCV system draws filtered air in through the intake resonator box and a rubber hose into the valve cover, through the engine and out through the PCV tube into the intake manifold to draw out oil vapors and combustion blow-by to be burned. If the PCV tube was clogged, crankcase pressure would be blowing the crankcase vapors back into the resonator box and get drawn into the intake of the throttle body. Should be making the throttle body very oily.
 

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PVC line clogged

So, how does one stop or unclog a pvc line that appears to have some oil reside coming from it and onto the exterior of it, please?
If I clean the throttle body, replace the air filter if needed....unclog or clean the pvc line ( there is no replaceable pvc)..what else is there to do or to prevent it from reclogging ? Thanks for anyone's help.
 

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2006 chevy trailblazer_lt
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Re: PCV Cleanliness

Please disregard/delete this exact entry. I had trouble with posting. On my end, the website stalled when trying to submit the original posting. My compete post is below this one.
 

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2006 chevy trailblazer_lt
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Re: PCV Cleanliness

Though I am a newbie to enlisting to the Trailvoy forum, I have read it on and off through the years since getting my 2006 Trailblazer in 2013. With finally enlisting and coming across this thread, I can only face palm myself with the comments that were made in this thread. Yes, I do understand that this thread is old and at the time that this tread was new, the vehicles covered were new as well. But, a PCV valve is a PCV valve, regardless if it replaceable or not! :duh:

With the non-removable PCV valve in the I6 engine, all you have to do is physically clean out the damn thing with a pipe cleaner or cotton swab for the initial gunk removal, then spray carb cleaner/fuel injection cleaner in the top port and remove the remaining gunk! If you are heavy on the spray, you may have a bit of a tough time on initial restart. But, keep working with it to get the restart.

:tiphat
 

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2009 gmc envoy_sle
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Re: PCV Cleanliness

Though I am a newbie to enlisting to the Trailvoy forum, I have read it on and off through the years since getting my 2006 Trailblazer in 2013. With finally enlisting and coming across this thread, I can only face palm myself with the comments that were made in this thread. Yes, I do understand that this thread is old and at the time that this tread was new, the vehicles covered were new as well. But, a PCV valve is a PCV valve, regardless if it replaceable or not! :duh:

With the non-removable PCV valve in the I6 engine, all you have to do is physically clean out the damn thing with a pipe cleaner or cotton swab for the initial gunk removal, then spray carb cleaner/fuel injection cleaner in the top port and remove the remaining gunk! If you are heavy on the spray, you may have a bit of a tough time on initial restart. But, keep working with it to get the restart.

:tiphat
Do you have any pics of this that you can share as my Envoy is having this issue. Any idea how large in diameter the actual port opening is that needs to be cleaned out? Is it as simple as removing the black hose that connects at the top of the manifold next to the ECM and working a pipe cleaner or something similar thru it to clear out the gunk and then spraying it down with some throttle body cleaner?
 

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2006 chevy trailblazer_lt
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Do you have any pics of this that you can share as my Envoy is having this issue. Any idea how large in diameter the actual port opening is that needs to be cleaned out? Is it as simple as removing the black hose that connects at the top of the manifold next to the ECM and working a pipe cleaner or something similar thru it to clear out the gunk and then spraying it down with some throttle body cleaner?
H2O Guy,

I did not grab pictures of the PCV when I did my cleaning. When I did my cleaning, I did it quickly.

The inside diameter of the PCV is about a half inch. It is not on the driver's side of the engine. The PCV is on the passenger's front side of the engine. The hose connects the PCV to the air box for the throttle body.

If you are unsure how to clean out the PCV, consult YouTube or your local mechanic.
 

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The vacuum within the engine intake manifold pulls blow-by gases out of the crankcase into the combustion chamber along with the regular intake of air and fuel. A valve can become clogged with sludge and varnish deposits and trap blow-by gases in the crankcase
 

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I just had this issue with my 2002 Trailblazer EXT. To clean my PCV port, I bought a two foot piece of 1/2" heater hose and a can of "pour in the fuel tank" Berryman b12 injector cleaner (berryman part number 0116). After driving my TB to get it hot, I took off the PCV hose on the driver's side and attached one end of the 2" new hose to the fitting on the engine block. Then I jammed a small funnel in the other end of the hose and SLOWLY pourede the B12 into that hose WITH THE ENGINE NOT RUNNING. The heat of the warm engine combined with the characteristics of the B12 caused the B12 to boil and "off-gas" as it boiled out the port in the engine. It took me nearly 25 minutes to pour the whole can through the PCV fixed valve, but it fully opened up the port in my TB! In case you are wondering, my TB has 185,000 miles on her, and I've owned her less than a year. I want to thank everyone on the website for your valuable info on these vehicles. This info tremendously helps me to keep my ride running as well as possible!
 

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H2O Guy,

I did not grab pictures of the PCV when I did my cleaning. When I did my cleaning, I did it quickly.

The inside diameter of the PCV is about a half inch. It is not on the driver's side of the engine. The PCV is on the passenger's front side of the engine. The hose connects the PCV to the air box for the throttle body.

If you are unsure how to clean out the PCV, consult YouTube or your local mechanic.
Sorry to inform you, "IRISHROCKDOC", but you are dead wrong! The fitting you are talking about is the PCV CLEAN AIR INTAKE. look up the PCV hose on the GM PARTS website and you will see that there are two hoses... one listed with the word "clean air" and the other is listed with the words "dirty air". The true PCV port is ON THE DRIVER'S SIDE AND HAS A HOSE THAT HOOKS IT TO THE INTAKE MANIFOLD VACCUUM and that hose is the one listed "dirty". I know this because I just had to deal with mine being stopped up...Look at post 18...just above this post.
 
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