Jump to content

17’ GMC 6.2 Whipple keeps blowing rear main seal

Tanner Smith

By Tanner Smith
in Engines & Drivetrain

 Share

Recommended Posts

Tanner Smith Enthusiast

Tanner Smith

Posted
Posted

My rear main seal keeps blowing out on my 2017 GMC 6.2. The truck has a 56,000 miles on it. The charger has been on it for 4,000 miles. Why does it keep blowing the rear main seal? I put a catch can on it and it still blew the seal. The catch can grabs about 5 ounces of oil for about 100 miles. That seems like alot. I have to constantly keep an eye on the motor oil. I am going to do a compression check on the motor to make sure the rings are not shot. Could it be a problem with the PCV system? PCV Valve not opening? Any input helps a bunch. Thanks. 

rlcole321 Enthusiast

rlcole321

Posted
Posted

Too much crankcase pressure, I imagine you have a cold air intake, where did you route the crankcase breather element?(maybe a picture), also are you running the 0W-20 recommended oil? Now the compression test would be a good idea. Also you could think about a vacuum pump system.

vacuum pump.jpg

pokismoki Senior Enthusiast

pokismoki

Posted
Posted (edited)
17 hours ago, Tanner Smith said:

My rear main seal keeps blowing out on my 2017 GMC 6.2. The truck has a 56,000 miles on it. The charger has been on it for 4,000 miles. Why does it keep blowing the rear main seal? I put a catch can on it and it still blew the seal. The catch can grabs about 5 ounces of oil for about 100 miles. That seems like alot. I have to constantly keep an eye on the motor oil. I am going to do a compression check on the motor to make sure the rings are not shot. Could it be a problem with the PCV system? PCV Valve not opening? Any input helps a bunch. Thanks. 

 check your pcv, .. you might have a backwards check valve in the catch can,

Edited by pokismoki
Tanner Smith Enthusiast

Tanner Smith

Posted
  • Author
Posted
9 hours ago, pokismoki said:

 check your pcv, .. you might have a backwards check valve in the catch can,

It blew the rear main seal before the catch can as well.

Tanner Smith Enthusiast

Tanner Smith

Posted
  • Author
Posted
12 hours ago, rlcole321 said:

Too much crankcase pressure, I imagine you have a cold air intake, where did you route the crankcase breather element?(maybe a picture), also are you running the 0W-20 recommended oil? Now the compression test would be a good idea. Also you could think about a vacuum pump system.

vacuum pump.jpg

The passenger valve cover breather tube is routed into the intake tube, Then the driver side tube off of the valve cover is routed into the catch can, and then the other hose from the catch can goes into the side of the charger. I will get pictures. I am running 0-20, I want to run 5W-30.

Tanner Smith Enthusiast

Tanner Smith

Posted
  • Author
Posted
12 hours ago, rlcole321 said:

Too much crankcase pressure, I imagine you have a cold air intake, where did you route the crankcase breather element?(maybe a picture), also are you running the 0W-20 recommended oil? Now the compression test would be a good idea. Also you could think about a vacuum pump system.

vacuum pump.jpg

 

B76186DC-B24D-4A28-BD06-2A0B1B97BD65.jpeg

Tanner Smith Enthusiast

Tanner Smith

Posted
  • Author
Posted
1 hour ago, pokismoki said:

must have installed the pcv incorrectly, did you install kit?

Yes, I installed it. I'm almost 100 percent positive to hooked all the PCV lines up properly, I checked and checked many of times. I guess what I can do Is take it to a local shop that installs these kits and have them look over the PCV system to make sure it was all done correctly. I did a Compression check and all cylinders were 190-200. So It is definetly not low on compression.   

Tanner Smith Enthusiast

Tanner Smith

Posted
  • Author
Posted
2 hours ago, pokismoki said:

any one make a breather that replaces the oil filler cap?

yeah I found a guy on youtube that had did a k&N filter for the oil fill cap and as well as for the other valve cover. I am going to install those. But I am still not sure why the catch can has so much oil in it.

pokismoki Senior Enthusiast

pokismoki

Posted
Posted (edited)

your piston rings are probably gumming up from oil being coked due to extreme heat, this bipasses oil into the pcv system and fills up the trap.

 

You have the wrong piston set up for a supercharger, get a set of  lower CR forgings and gapless rings

 your using the wrong oil if you use 0w20 not good!

 

i hope your not using the 220 F t-stat , your coolant temps are too high for boost? you have a lot of homework to do

Edited by pokismoki
Tanner Smith Enthusiast

Tanner Smith

Posted
  • Author
Posted
6 hours ago, pokismoki said:

your piston rings are probably gumming up from oil being coked due to extreme heat, this bipasses oil into the pcv system and fills up the trap.

 

You have the wrong piston set up for a supercharger, get a set of  lower CR forgings and gapless rings

 your using the wrong oil if you use 0w20 not good!

 

i hope your not using the 220 F t-stat , your coolant temps are too high for boost? you have a lot of homework to do

Yeah, I have read that these motors are fine supercharged for awhile. I know the piston and rings were not meant for the boost. I have the AFM Disabled. The truck put down 500 hp to the wheels. I am going to run 5W-30 and no more 0w-20, too thin!

pokismoki Senior Enthusiast

pokismoki

Posted
Posted

try adding 1 quart of dextron transfluid to the engine before oilchange,  drive couple miles till warmed up then change oil. this might free up stuck piston rings every 4000 mile oil change

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,840
    Total Members
    8,960
    Most Online
    appletrav
    Newest Member
    appletrav
    Joined

  • Who's Online   1 Member, 0 Anonymous, 450 Guests (See full list)

  • Latest Articles

  • Posts

    • newdude
      2 speed transfer case optional now?

      By newdude · Posted

      This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • newdude
      Different requirements for oil filters?

      By newdude · Posted

      2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Grumpy Bear
      Different requirements for oil filters?

      By Grumpy Bear · Posted

      Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉
    • Coastie05
      give me some tips to make my truck look better

      By Coastie05 · Posted

      Go back to OEM wheels. 
    • newdude
      2020 Trailboss 6.2 replacement

      By newdude · Posted

      Probably not their first rodeo, so it should go as planned most likely.  Typically the service manager or tech doing the swap will put some seat time to shake it down after they get it all put back together.  We usually put 50-100mi before we hand them back so if something happens, its not after you get it.  A coolant leaks, oil leaks, a ground left off or loose, vibration, etc.     The new engines so far have been good?  There's been a couple that have popped out there again (the replacement engine) but most have been okay.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...