I just picked up a 2006 trailblazer 91k miles. It takes 7quarts now I have a bunch of peak syn 5w30 and next gen 5w30 and some Qs 5w30. I know these 4.2l engines have a tendency to sludge so I am wondering if I should use a special oil for the extra 2 quarts when using 5quart jugs?? I see alot of people saying the M1 HM is a great cleaner. Just looking to see what people think is it worth it to mix 2 quarts of a cleaner oil or synthetic with 5 quarts of conventional???
So what 2 quarts should I use??
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Be sure the PVC valve is clean if you do not want it to sludge up.
This maybe covered under TSB
2006 Chevrolet Trailblazer Positive Crankcase Ventilation (PCV) TSBs
TSB Number: PIP-4492P NHTSA Number: 10036464 TSB Date: May 1, 2011 Date Added to File: March 16, 2011
Failing Component:
Engine And Engine Cooling:Exhaust System:Emission Control:Crankcase (Pcv)
Summary:
Buick/cadillac/chevrolet/GMC/HUMMER/pontiac/saab: oil consumption and/or exhaust smoke-possible pcv baffle or lifter concern. Upon inspection, obvious oil will be found in the intake manifold and/or pcv vacuum tube.
2006 Chevrolet Trailblazer Positive Crankcase Ventilation (PCV) TSBs
TSB Number: PIP-4492P NHTSA Number: 10036464 TSB Date: May 1, 2011 Date Added to File: March 16, 2011
Failing Component:
Engine And Engine Cooling:Exhaust System:Emission Control:Crankcase (Pcv)
Summary:
Buick/cadillac/chevrolet/GMC/HUMMER/pontiac/saab: oil consumption and/or exhaust smoke-possible pcv baffle or lifter concern. Upon inspection, obvious oil will be found in the intake manifold and/or pcv vacuum tube.
There is some more TSB's for Trailblazer's for various years. That is what I found for PCV on a 4.2 2006 if you do not want TSB #'s on potential problems that is fine with me.
All of the oils should be just fine for keeping things clean if you use them for a normal service interval. If you like to keep your oil in there for 20,000 miles or longer you'll need something special to keep it clean and you'd do well to use all special oil, not just 2 quarts mixed in.
Originally Posted By: Aerojoe
that tsb does not say anything and there is not a replaceable pcv on the engine. All I was is if there is a better oil to buy for the extra 2 quarts over the standard oil I am already using.
If you want to fix your problem you need that TSB information. With the information at hand you can find the repair procedures. Your oil mixing experiment at best is a band aid if that. You need this problem fixed.
I am trying to save you some $$$, time, and headaches.
that tsb does not say anything and there is not a replaceable pcv on the engine. All I was is if there is a better oil to buy for the extra 2 quarts over the standard oil I am already using.
If you want to fix your problem you need that TSB information. With the information at hand you can find the repair procedures. Your oil mixing experiment at best is a band aid if that. You need this problem fixed.
I am trying to save you some $$$, time, and headaches.
Originally Posted By: Aerojoe
the 4.2 inline 6 does NOT have a replaceable pcv valve hence the sludge problems!!!
I agree. I checked my service manual. It states:
"All models use a fixed orifice (PCV) system. The main component of the Positive Ventilation System is the PCV pipe. Fresh air flows from the air intake duct through a vent tube into the engine. Crankcase vapors are drawn from the crankcase by the PCV pipe. Other than checking to see that the pipe is attached and has no cracks or leaks there is no other service or maintenance required."
This jives with my experience of working on mine and I checked Rock Auto, Autozone and Napa and none of them list a replaceable PCV valve.
I never had any trouble with sludge on mine (lots of other problems but never any like that). I used mostly Mobil Clean 5000 or VWB. I followed the OLM and usually did somewhere around 7K - 9K mile OCI.
the 4.2 inline 6 does NOT have a replaceable pcv valve hence the sludge problems!!!
I agree. I checked my service manual. It states:
"All models use a fixed orifice (PCV) system. The main component of the Positive Ventilation System is the PCV pipe. Fresh air flows from the air intake duct through a vent tube into the engine. Crankcase vapors are drawn from the crankcase by the PCV pipe. Other than checking to see that the pipe is attached and has no cracks or leaks there is no other service or maintenance required."
This jives with my experience of working on mine and I checked Rock Auto, Autozone and Napa and none of them list a replaceable PCV valve.
I never had any trouble with sludge on mine (lots of other problems but never any like that). I used mostly Mobil Clean 5000 or VWB. I followed the OLM and usually did somewhere around 7K - 9K mile OCI.
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Originally Posted By: dave1251
This maybe covered under TSB
2006 Chevrolet Trailblazer Positive Crankcase Ventilation (PCV) TSBs
TSB Number: PIP-4492P NHTSA Number: 10036464 TSB Date: May 1, 2011 Date Added to File: March 16, 2011
Failing Component:
Engine And Engine Cooling:Exhaust System:Emission Control:Crankcase (Pcv)
Summary:
Buick/cadillac/chevrolet/GMC/HUMMER/pontiac/saab: oil consumption and/or exhaust smoke-possible pcv baffle or lifter concern. Upon inspection, obvious oil will be found in the intake manifold and/or pcv vacuum tube.
That TSB states a problem, but what is the solution?
This maybe covered under TSB
2006 Chevrolet Trailblazer Positive Crankcase Ventilation (PCV) TSBs
TSB Number: PIP-4492P NHTSA Number: 10036464 TSB Date: May 1, 2011 Date Added to File: March 16, 2011
Failing Component:
Engine And Engine Cooling:Exhaust System:Emission Control:Crankcase (Pcv)
Summary:
Buick/cadillac/chevrolet/GMC/HUMMER/pontiac/saab: oil consumption and/or exhaust smoke-possible pcv baffle or lifter concern. Upon inspection, obvious oil will be found in the intake manifold and/or pcv vacuum tube.
That TSB states a problem, but what is the solution?
Sounds like the orifice might be too big, or the foul air pickup is in a bad location.
When you go to a fixed orifice PCV "valve" you are introducing a calibrated leak that is designed to pull air through the engine.
Unless the air goes sonic through the valve, you are operating on the principle of higer pressure ratio across the valve (baisically atmospheric pressure versus intake manifold pressure) makes higher flow. This means that in general, the higher the difference between the two, the more flow you get through the system. If you get a time when the engine is going fast (slinging oil, making mist, etc) AND the manifold pressure is low, you have a 4.2 liter oil suction device.
Sounds like that is the problem cited in the TSB. These can be maneuvers like going down an hill in a lower gear where the car is pushing the engine.
An actual "valve" was designed to restrict the flow at high ratios and not to restrict it a low ratios, these were introduced at a time when carb-a-tooters were the only technology we had and they could not tolerate an orifice PCV system. A "perfect" PCV valve would give you the same flow, regardless of pressure ratio. These have a few moving parts inside them, and have manufacturing variablity that affects flow more than you might think, so they are going the way of ox yokes and dodo birds.
An orifice PCV system has no moving parts, and the only tolerance that has an effect on the flow is the hole size, which is pretty easy to control. This means they tend to be more reliable, simpler, and do not drift over time the way a valve based design does.
However, putting a smaller orifice means that all of the time you are NOT pulling over oil, you are getting less overall flow. If the engine is a borderline sludge-monster to begin with, this could make a bad problem worse. If it were mine, I'd see what I could do about adding an external catch-can.
I'm not that familiar with the PCV system on that engine, and some of the GM ones are literally part of the intake manifold, which makes changes pretty tough. The TSB probably includes a different baffle system that separates the oil from the foul air better.
When you go to a fixed orifice PCV "valve" you are introducing a calibrated leak that is designed to pull air through the engine.
Unless the air goes sonic through the valve, you are operating on the principle of higer pressure ratio across the valve (baisically atmospheric pressure versus intake manifold pressure) makes higher flow. This means that in general, the higher the difference between the two, the more flow you get through the system. If you get a time when the engine is going fast (slinging oil, making mist, etc) AND the manifold pressure is low, you have a 4.2 liter oil suction device.
Sounds like that is the problem cited in the TSB. These can be maneuvers like going down an hill in a lower gear where the car is pushing the engine.
An actual "valve" was designed to restrict the flow at high ratios and not to restrict it a low ratios, these were introduced at a time when carb-a-tooters were the only technology we had and they could not tolerate an orifice PCV system. A "perfect" PCV valve would give you the same flow, regardless of pressure ratio. These have a few moving parts inside them, and have manufacturing variablity that affects flow more than you might think, so they are going the way of ox yokes and dodo birds.
An orifice PCV system has no moving parts, and the only tolerance that has an effect on the flow is the hole size, which is pretty easy to control. This means they tend to be more reliable, simpler, and do not drift over time the way a valve based design does.
However, putting a smaller orifice means that all of the time you are NOT pulling over oil, you are getting less overall flow. If the engine is a borderline sludge-monster to begin with, this could make a bad problem worse. If it were mine, I'd see what I could do about adding an external catch-can.
I'm not that familiar with the PCV system on that engine, and some of the GM ones are literally part of the intake manifold, which makes changes pretty tough. The TSB probably includes a different baffle system that separates the oil from the foul air better.
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Originally Posted By: oldmaninsc
Originally Posted By: dave1251
This maybe covered under TSB
2006 Chevrolet Trailblazer Positive Crankcase Ventilation (PCV) TSBs
TSB Number: PIP-4492P NHTSA Number: 10036464 TSB Date: May 1, 2011 Date Added to File: March 16, 2011
Failing Component:
Engine And Engine Cooling:Exhaust System:Emission Control:Crankcase (Pcv)
Summary:
Buick/cadillac/chevrolet/GMC/HUMMER/pontiac/saab: oil consumption and/or exhaust smoke-possible pcv baffle or lifter concern. Upon inspection, obvious oil will be found in the intake manifold and/or pcv vacuum tube.
That TSB states a problem, but what is the solution?
Find a GM dealer that will print it out or pay for a copy of the TSB.
Originally Posted By: dave1251
This maybe covered under TSB
2006 Chevrolet Trailblazer Positive Crankcase Ventilation (PCV) TSBs
TSB Number: PIP-4492P NHTSA Number: 10036464 TSB Date: May 1, 2011 Date Added to File: March 16, 2011
Failing Component:
Engine And Engine Cooling:Exhaust System:Emission Control:Crankcase (Pcv)
Summary:
Buick/cadillac/chevrolet/GMC/HUMMER/pontiac/saab: oil consumption and/or exhaust smoke-possible pcv baffle or lifter concern. Upon inspection, obvious oil will be found in the intake manifold and/or pcv vacuum tube.
That TSB states a problem, but what is the solution?
Find a GM dealer that will print it out or pay for a copy of the TSB.
Originally Posted By: LckydevL
If using multiple oils together, I would at least keep it in the same brand or add packs. I would not want to mix base oils or add packs for fear of the oils lessening or canceling each others good qualities out.
I really can't think this is much of an issue. I mix brands all the time.
If using multiple oils together, I would at least keep it in the same brand or add packs. I would not want to mix base oils or add packs for fear of the oils lessening or canceling each others good qualities out.
I really can't think this is much of an issue. I mix brands all the time.
Originally Posted By: dave1251
Find a GM dealer that will print it out or pay for a copy of the TSB.
Wow, okay that's a big help.
But I think we kind of got side tracked here. The o/p question was:
Originally Posted By: Aerojoe
Just looking to see what people think is it worth it to mix 2 quarts of a cleaner oil or synthetic with 5 quarts of conventional???
Personally I'd say no. I spent a lot of time over at a couple of the Trailblazer forums and I really don't remember sludge being a problem. Cylinder sleeves on the early models, tranny problems, bad valve seats, warped heads, bad ignition switches and other electrical problem, yes.
I'm just curious - why do you think these engines have a sludge problem? Not doubting you just asking.
Find a GM dealer that will print it out or pay for a copy of the TSB.
Wow, okay that's a big help.
But I think we kind of got side tracked here. The o/p question was:
Originally Posted By: Aerojoe
Just looking to see what people think is it worth it to mix 2 quarts of a cleaner oil or synthetic with 5 quarts of conventional???
Personally I'd say no. I spent a lot of time over at a couple of the Trailblazer forums and I really don't remember sludge being a problem. Cylinder sleeves on the early models, tranny problems, bad valve seats, warped heads, bad ignition switches and other electrical problem, yes.
I'm just curious - why do you think these engines have a sludge problem? Not doubting you just asking.
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I know of 4 people that had or have trailblazers that have sludge in the engine, 2 were to the point the engines had to be replaced. All were earlier year 02-04.
The mechanic that does all my heavy or nasty work is a 20yr Chevrolet dealer mechanic. I talked to him before buying my trailblazer and the first thing he told me to do was shine a flashlight down the fill hole and look for sludge. He said he has replaced a bunch of 4.2's because of sludge related problems. I guess the cam phasers are hydraulic controlled and when they get sludged up you get big problems.
There is no PVC valve, yes I have heard of the dealer having tsb's but those are not free, they are just that service bulletins. If the truck was under warranty yes they might tear half my engine down and replace a tube. Am I going to tear down or pay a shop to tear down half my engine for a problem I may or may not have, NOPE!!!!
I NEVER said my engine had a sludge problem. I just asked if there was a oil I should use or add in as the 2 extra quarts might help keep the engine clean. I have heard on this forum of people using M1 HM and it cleans varnish inside the engine, That was all I was looking for.
The mechanic that does all my heavy or nasty work is a 20yr Chevrolet dealer mechanic. I talked to him before buying my trailblazer and the first thing he told me to do was shine a flashlight down the fill hole and look for sludge. He said he has replaced a bunch of 4.2's because of sludge related problems. I guess the cam phasers are hydraulic controlled and when they get sludged up you get big problems.
There is no PVC valve, yes I have heard of the dealer having tsb's but those are not free, they are just that service bulletins. If the truck was under warranty yes they might tear half my engine down and replace a tube. Am I going to tear down or pay a shop to tear down half my engine for a problem I may or may not have, NOPE!!!!
I NEVER said my engine had a sludge problem. I just asked if there was a oil I should use or add in as the 2 extra quarts might help keep the engine clean. I have heard on this forum of people using M1 HM and it cleans varnish inside the engine, That was all I was looking for.
If I were you, I would run Pennzoil High Mileage and 4oz. Auto-RX at every change.
Aerojoe said:
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