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I have read this thread with much interest, as I just had to pay $2,000 to have the rear main seal replaced. My GMC Terrain is just 3 years old with 70000 miles.
Someone please tell me if I am wrong, but as I understand this 2.4 liter ecotech engine, there is no pcv valve. The pcv system consists of a small metering hole in the intake manifold which vents to all four cylinders through the intake ports. This let's the crankcase pressure be let into the intake system to be burned. Then there is also the valve cover vent tube from the valve cover to the air intake and then through the throttle body. This leads me to think that if that little whole in the intake manifold plugged, the pressure could still vent through the valve cover vent. Is this correct? Also this would mean the pcv vent AND the valve cover vent would half to plug ( as in freezing weather) to blow the seal. Is this correct? If so, installing an oil catch can in the valve cover vent would prevent this problem?

Mark
 

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This leads me to think that if that little whole in the intake manifold plugged, the pressure could still vent through the valve cover vent. Is this correct?
Yes that is correct if the inlet tube and the air intake plenum are not blocked by ice - goo - etc.
Also this would mean the pcv vent AND the valve cover vent would half to plug ( as in freezing weather) to blow the seal. Is this correct?
That question really has no clear answer, the PCV orfice opening into the intake manifold is tiny and with an older engine having higher blowby, it might still build enough pressure to blow out the rear main seal. ( or more likely just freeze over )
If so, installing an oil catch can in the valve cover vent would prevent this problem?
No, it might help, but the air inlet plenum has a chamber where water vapour condenses and freezes. ( take off your inlet plenum turn it over and look where the tube connects... ) The valve cover vent tube enters that chamber at the bottom and gets blocked by ice etc. I would recommend that you relocate that valve cover vent tube so that it enters at the top of the chamber above any ice etc. and have all plumbing slope so that nothing can collect and freeze.
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Hello- I have a 2013 Terrain 2.4 Ecotec. Well within the SB 14882 limits. A few months back, I had been running some errands (all short drives). Weather was about 6 degrees. Engine began to run a bit sluggish and no lights on instrument panel. Pulled into a gas station and stalled. I thought that maybe I had some moisture in the gas, so I added some fuel cleaner and filled up my tank. I went to drive home which is about 3/4 mile from the gas station. It stalled again in the parking lot of the gas station but re-started. I got home and parked in the driveway. Overnight temps were about 2 degrees. Went to start my car and the entire engine shook. Oil light did NOT come on but the CEL did. Terrain wouldn't start. Saw a huge puddle of oil underneath. Ended up being a frozen PCV. No prior warnings about low oil, no indication about excess oil consumption (never even got any notices about the Excess Oil Consumption Litigation. Had it towed to a GM Dealer. I was told that the only way to repair the engine was to replace it. Was never told what failed. The advisor said that GM would kick in $640 and my share would be $5,700. Called GM and had a ticket opened and asked for a District Manager. Talked to him and he he said that GM would do a 25/75 split. My end would be just over $1,500. Negotiated it down to $1,111. Was told that I would get a NEW engine. Ended up with a remanufactured engine. Drove to NC for my daughter's wedding a few days after I got it back and it died on the freeway (I did make it to my daughter's wedding). I was told that there was oil sludge and metal shavings in the intake manifold that got into the #1 cylinder and blew it up. Now I have a 2nd remanufactured engine. Dealer also replaced the Intake Manifold (because of the oil sludge and metal shavings) and the Catalytic Converted (because GM was concerned that the sludge/shavings made their way tot he converted). GM says that my VIN isn't linked to the 14882 bulleting which I find odd since it is linked to the Excess Oil Consumption Litigation as well as a new one involving the Catalytic Converter.

What is unusual is that out of the 3 issues, GM has only linked 2 of them to my VIN. No explanation of why the 14882 bulleting is not listed. I was told that the Brand Quality Managers tried getting more VINs linked but they got turned down. I was also told that I had to have an Excess Oil Consumption problem BEFORE 14882 for the frozen PCV issue came into play. By the way, Excess Oil Consumption has nothing to do with a frozen PCV in my opinion. Can the sludge in the Intake be caused by excess oil consumption?
 

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By the way, Excess Oil Consumption has nothing to do with a frozen PCV in my opinion.
No its the other way around... A frozen PCV system is more likely to happen in an engine with excess oil consumption.
If oil can get past the rings into the combustion chamber causing oil consumption then combustion chamber gases will certainly get past the rings into the crankcase. These gases are mostly water vapour ( like what comes out of the exhaust ) and as they pass through the cold PCV system, they condense, collect and freeze. Yes there is always some blowby even in a healthy engine, but there is more blowby in a worn engine. ( one that needs new pistons and rings )
 

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I see a lot of mention about the vented oil fill cap. Is there a part number for these two caps and if so what is it?

Mark
 

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I see a lot of mention about the vented oil fill cap. Is there a part number for these two caps and if so what is it?

Mark
Go to google and enter vented oil cap for 2.4L. Chev.
Lots of choices, I went with the FC 219 for my Equinox and Encore.
Cheers
 

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So the sludge in the intake was caused by excess oil consumption, even if it didn't go through a lot of oil? I always took my Terrain in for oil changes and never saw the dipstick to understand if it was going through oil.
 

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No its the other way around... A frozen PCV system is more likely to happen in an engine with excess oil consumption.
If oil can get past the rings into the combustion chamber causing oil consumption then combustion chamber gases will certainly get past the rings into the crankcase. These gases are mostly water vapour ( like what comes out of the exhaust ) and as they pass through the cold PCV system, they condense, collect and freeze. Yes there is always some blowby even in a healthy engine, but there is more blowby in a worn engine. ( one that needs new pistons and rings )
How do I show that the sludge in the intake manifold was caused by the blowby?
 

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Mods any chance we could create a section just for 2.4 owners? I'm not trying to be mean or inconsiderate but this chit really gets old...
 
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Go to google and enter vented oil cap for 2.4L. Chev.
Lots of choices, I went with the FC 219 for my Equinox and Encore.
Cheers
I looked up the fc219 cap. The photo looks like my cap, but it says it will not fit the 2017 Terrain. I have the 2.4 ecotec engine. I hate to order it if it won't fit.

Mark
 

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The Delco FC219 oil filler cap should fit on a 2.4L ecotec. Its the one I use. It may not be listed as the original cap has no pressure relief.
 

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This is just a follow-up to my initial concern. A month or so ago, my 2017 Terrain that I bought brand new in April of 2018 blew its main rear seal, puked all its oil and left me stranded on the interstate at about 70,000 miles. Until that moment, I was pleased with my vehicle purchase which is only half paid off. The repairs cost me $2,070 which upset me, but what really upset me is the fact that it will happen again sooner or later as this seems , in my opinion as a built in failure with that PVC system. My hours of reading on this forum helped me realize this and I began my quest for a solution to my problem of wanting security and dependability in a vehicle. Trading off my Terrain was my first thought, but I soon realized this was NOT the answer, as I soon discovered that every vehicle I began to research as a replacement, has its own set of new problems to worry about. So.
..... what to do?
I just had my oil changed at 3000 miles after the repairs and had a discussion with the service manager and mechanic at my local GM dealership as to options. They told me the FC219 oil fill cap I just bought for $11 and put on was a good idea as it may help prevent the problem. Amazingly, they also thought installing the oil catch can , (I bought for $22), to install in the breather line that runs from the valve cover to the air intake was also a decent option as long as it is installed slightly lower than the valve cover vent outlet ( which I planned anyway) and I empty it often. I am still deciding about that as I am not real crazy about the only small space available to put it.
I asked about the only other option that makes me feel better. That is, how costly would it be to have the intake removed and the PVC checked and cleaned at about every 30k miles , which is a couple years driving. They said it would be $195 to remove , clean , and reinstall the intake. Now to me, that is a bargain. I will have this done every 30k miles (or every two years) and with the vented oil fill cap , I feel better. $200 every two years is much better than $2000 every three or four years, in my humble opinion. So ....... I picked my battles. I have a nice vehicle. I know how to keep it running , more or less, and that to me seems better than trading it off for a new set of problems that could be worse.
I would like to thank you all for your input which has been a great help. I found this forum when my Terrain died recently and I wanted more information. I now believe that with the steps I am taking, this is a pretty good vehicle. The intake cleaning will just be considered as routine maintenance, just like brakes or belts and hoses and not expensive compared to many normal repairs. If I had known all this sooner, I could have avoided the expensive repair most likely. No vehicle will run for years without routine maintenance from wear and use. If you know the vehicle's needs and take care of it, it will not let you down.

Mark
 

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This is just a follow-up to my initial concern. A month or so ago, my 2017 Terrain that I bought brand new in April of 2018 blew its main rear seal, puked all its oil and left me stranded on the interstate at about 70,000 miles.
I asked about the only other option that makes me feel better. That is, how costly would it be to have the intake removed and the PVC checked and cleaned at about every 30k miles , which is a couple years driving. They said it would be $195 to remove , clean , and reinstall the intake. Now to me, that is a bargain. I will have this done every 30k miles (or every two years) and with the vented oil fill cap , =

Mark
The oil catch can and proper routing of the hoses to and from it are more important. As is use of the FC219 vented oil cap.
The 30K miles cleaning of the intake will not help a lot since moisture can build up in days or weeks of use in cold winter weather. All it takes is enough mater to build up and freeze in the PCV hose from the valve cover to the intake and the seal will blow again.
Here's another thing some have done. Just buy another standard OEM oil fill cap, drill a hole in it, install a 3/8" plumbing elbow in the top and run a length of hose downward to let vapors escape. Do that only in winter and cold operating conditions.
=
Yes, not really EPA approved . .. . but will keep the main seal from blowing in freezing winter conditions.

In summer or after return to warmer weather, install the vented FC219 to be kosher.
 

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The oil catch can and proper routing of the hoses to and from it are more important. As is use of the FC219 vented oil cap.
The 30K miles cleaning of the intake will not help a lot since moisture can build up in days or weeks of use in cold winter weather. All it takes is enough mater to build up and freeze in the PCV hose from the valve cover to the intake and the seal will blow again.
Here's another thing some have done. Just buy another standard OEM oil fill cap, drill a hole in it, install a 3/8" plumbing elbow in the top and run a length of hose downward to let vapors escape. Do that only in winter and cold operating conditions.
=
Yes, not really EPA approved . .. . but will keep the main seal from blowing in freezing winter conditions.

In summer or after return to warmer weather, install the vented FC219 to be kosher.
That also sounds like a good idea.
I could be wrong ..... but the seal would only blow out if BOTH the PVC port and the valve cover vent are blocked ..... I think. What makes me ask that is, I believe when my seal let go ( it was very cold and I had been driving on the interstate for about a half hour), the service department indicated that the pvc port did need cleaning. I figure there must have been blockage in the vent line resulting in seal failure. I went through the first two winters with no problem
I figure after 70k miles, the port blocked and then when the line froze or plugged up, the seal let go.
Would it be a good idea to put a PVC valve in the top of the cap and then run a line down from it?

Mark
 

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That also sounds like a good idea.
I could be wrong ..... but the seal would only blow out if BOTH the PVC port and the valve cover vent are blocked ..... I think. What makes me ask that is, I believe when my seal let go ( it was very cold and I had been driving on the interstate for about a half hour), the service department indicated that the pvc port did need cleaning. I figure there must have been blockage in the vent line resulting in seal failure. I went through the first two winters with no problem
I figure after 70k miles, the port blocked and then when the line froze or plugged up, the seal let go.
Would it be a good idea to put a PVC valve in the top of the cap and then run a line down from it?

Mark
Yes. . I suppose you could install a PCV ball valve on the top of a drilled out oil cap. However, even that could become fouled with the typical yellow oil/water emmulsion that build up under the oil cap in cold weather. Once that happens it could freeze and back to square one.

From all we've seen here on the forum and other sources, the main cause of main seal blow out is the external PCV hose from the valve cover to the air intake freezing up. The small orifice (port) is more prone to getting carbon deposits and not responsible for main seal blow out. Some have drilled a hole into the intake right above the orifice and check or clean that small port with a wire periodically. They then plug the drilled hold with a screw or other means.
From what I've read, the internal orifice port is only used at idle conditions to route some vapors. It does not have the capacity that the intake hose PCV path has.
 

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Yes. . I suppose you could install a PCV ball valve on the top of a drilled out oil cap. However, even that could become fouled with the typical yellow oil/water emmulsion that build up under the oil cap in cold weather. Once that happens it could freeze and back to square one.

From all we've seen here on the forum and other sources, the main cause of main seal blow out is the external PCV hose from the valve cover to the air intake freezing up. The small orifice (port) is more prone to getting carbon deposits and not responsible for main seal blow out. Some have drilled a hole into the intake right above the orifice and check or clean that small port with a wire periodically. They then plug the drilled hold with a screw or other means.
From what I've read, the internal orifice port is only used at idle conditions to route some vapors. It does not have the capacity that the intake hose PCV path has.
That sounds very reasonable to me, ...... but so does the other arguments that were here about the pcv system. I guess my point is , I made it through two harsh winters with no problems, but once the port plugged, the line freezing caused the failure. ( at least that is how it seems). Another thing the dealer suggested, was more frequent oil changes and use only synthetic oil. I don't quite see how more oil changes helps , but I guess with the oil cap AND the catch can I am safest. Also having the port cleaned occasionally. There is nothing more than that one can do. Oh.... and the vent you suggested for the winter sounds very reasonable also.
 

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Under heavier throttle conditions, or when coasting down hill or up to stops, back flow will occur in the PVC air intake tube. Happens in all PCV systems.

That yellow sludge like stuff is oil/water emulsion from oil and water vapor that forms in cold or very humid weather conditions. Not much you can do about it. In newer engines they have both increased the diameter of the tubes and orifices and run the PCV path deeper into the engine internals to keep things warmer. The larger diameter tubes and path results in slower air flow and less cooling of the vapors. The deposits still form, but end up in the oil so freezing and deposits are less likely to form.
The downside is. .. change the oil more often in cold weather. I always change oil in October and again in January some time no matter the number of miles on the oil and filter. I reason it is worth it rather than having all the moisture build up.

Also, here is another idea. Buy another oil filer cap, drill a hole into it, and install one of these. * See pictures attached below. *
It won't reduce the moisture and crud build up, but if it does get very cold and the PCV orifice or path freezes or gets clogged, this pressure relief valve in an oil filler cap will release built up blow by pressure in the crankcase and prevent main seal blow out. . . . in theory. Run the modified oil filler cap in the cold winter months. Put the stock cap back on in summer.
 
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