LQ1 common oil leak areas

[06goat75]

I know this has been discussed multiple times, but my google search skills are failing, not to mention the posts I do find are quite outdated (pictures missing).

I've read there are two common oil leak areas.  One being the distributor plug o ring, the other being the rectangle block next to it.  I don't know what that thing is called, nor do I know what to get to fix it.  

Is this accurate?  How do I do some preventive maintenance on it to prevent that rectangle block from leaking?

Picture for reference.

 

 

Edited January 23, 2020 by 06goat75

[55trucker]

That alloy cover in the middle of the valley is the Oil Distribution Cover. Within that assembly is a passage & check valve that opens & closes under different pressure situations. It's purpose is to  (when engine running/open) supply a route for oil pressure to the heads, when engine off/closed it prevents the engine oil in the heads from draining back down into the block/oilpan.

There is a gasket beneath it.

 

Edited January 23, 2020 by 55trucker

[06goat75]

On 1/23/2020 at 1:01 PM, 55trucker said:

That alloy cover in the middle of the valley is the Oil Distribution Cover. Within that assembly is a passage & check valve that opens & closes under different pressure situations. It's purpose is to  (when engine running/open) supply a route for oil pressure to the heads, when engine off/closed it prevents the engine oil in the heads from draining back down into the block/oilpan.

There is a gasket beneath it.

 

Thanks.  Found the part number searching the forum, and ordered one online.  Hopefully be here next week, and have the rest of the stuff coming, should have it back together next weekend.

 

 

[jiggity76]

Glad to have found this thread.  I'm in the process of replacing the intake gaskets on my LQ1.  

Is this the O-ring gasket that you guys are referring too?  If so, does this go under the Oil Distribution Cover?  I'm also wondering about oil coming from this area in the 1st pic.  There is silicone around the base of it and looks like a failure point.

 

Edited June 6, 2020 by jiggity76

[06goat75]

43 minutes ago, jiggity76 said:

Glad to have found this thread.  I'm in the process of replacing the intake gaskets on my LQ1.  

Is this the O-ring gasket that you guys are referring too?  If so, does this go under the Oil Distribution Cover?  I'm also wondering about oil coming from this area in the 1st pic.  There is silicone around the base of it and looks like a failure point.

 

 

There are two common oil leaks in that general area, one is the distributor plug seal/gasket (what you are looking at) and the other is the oil distribution cover.  The rectangle to the passenger side of the oil distributor plug.  It is the rectangle cover that has that "Z" shaped part on the top.  You can see the cover in the top picture, lower left.

 

The oil distribution cover gasket can be ordered from one of the GM part places, but it also comes in a set that I got off of RockAuto closeout stuff.  Much cheaper the RA way.  

Edited June 6, 2020 by 06goat75

[jiggity76]

4 minutes ago, 06goat75 said:

 

There are two common oil leaks in that general area, one is the distributor plug seal/gasket (what you are looking at) and the other is the oil distribution cover.  The rectangle to the passenger side of the oil distributor plug.  It is the rectangle cover that has that "Z" shaped part on the top.  You can see the cover in the top picture, lower left.

 

The oil distribution cover gasket can be ordered from one of the GM part places, but it also comes in a set that I got off of RockAuto closeout stuff.  Much cheaper the RA way.  

Ok, so I need to pull this bolt/part and reseal it with silicone or RTV.  The O-ring it sounds from looking at your old thread and 55trucker's is for the plenum to intake area under the throttle body?  I found a new gasket for the Oil Distribution Cover that you are referring too, that big square aluminum cover.  Am I correct?  And thank you so much for replying back.  I'm currently putting new gaskets in my LQ1 and some other preventative maintenance items.

[06goat75]

1 minute ago, jiggity76 said:

Ok, so I need to pull this bolt/part and reseal it with silicone or RTV.  The O-ring it sounds from looking at your old thread and 55trucker's is for the plenum to intake area under the throttle body?  I found a new gasket for the Oil Distribution Cover that you are referring too, that big square aluminum cover.  Am I correct?  And thank you so much for replying back.  I'm currently putting new gaskets in my LQ1 and some other preventative maintenance items.

 

Well, there is an o-ring that goes from the plenum to intake under the TB.  

There is also an O ring that goes on the shaft on the distributor plug.  I'm not exactly sure which one you are holding in the picture.  

Replacing the O ring on the distributor plug shaft (where the oil leaks), the proper way, requires head removal.

Some people have had luck replacing the O ring by cutting the old one off, and fitting it over the distributor plug, I did not have luck doing that.  I left the O ring in place, got a distributor seal (they are all the same size from era of GM vehicles), put RTV on both sides and put it under the distributor plug.  That has worked so far, though it has only been a few months.  Other people have had luck doing that too.

Yes, the big, rectangle, aluminum cover is the oil distribution cover.  I purchased a Fel-pro set off of RA (MS95822) and it came with the oil distribution cover gasket (even though it isn't included in the picture).  They were under 5 bucks, so I bought two of them.  

[jiggity76]

1 minute ago, 06goat75 said:

 

Well, there is an o-ring that goes from the plenum to intake under the TB.  

There is also an O ring that goes on the shaft on the distributor plug.  I'm not exactly sure which one you are holding in the picture.  

Replacing the O ring on the distributor plug shaft (where the oil leaks), the proper way, requires head removal.

Some people have had luck replacing the O ring by cutting the old one off, and fitting it over the distributor plug, I did not have luck doing that.  I left the O ring in place, got a distributor seal (they are all the same size from era of GM vehicles), put RTV on both sides and put it under the distributor plug.  That has worked so far, though it has only been a few months.  Other people have had luck doing that too.

Yes, the big, rectangle, aluminum cover is the oil distribution cover.  I purchased a Fel-pro set off of RA (MS95822) and it came with the oil distribution cover gasket (even though it isn't included in the picture).  They were under 5 bucks, so I bought two of them.  

Hmm, I need to take that bolt out and look at that area.  This is the distributor shaft/plug area yes?  If you look, there is a greyish silicone bead around it.  I've heard that you can fix this area without taking off the head but this is new territory for me.  If this isn't the right O-ring, then I might have to reseal it with RTV.  I'm not sure if it's even leaking here but just trying to be pro-active while replacing the intake gaskets.

I might try your method as well once I get into it.  I just don't want any oil leaks obviously.

I ordered a new gasket for the Oil Distribution Cover from GMPartsGiant.  Might as well do that while I'm in there too.  I need two of them as well.  One for this car and one for my STE.  

I just wasn't sure (and still not 100% sure) where this O-ring goes that came with my intake gasket kit.  It's a Fel-Pro and included the O-ring, intake gaskets, and plenum gasket.  Maybe I just need to look at the packaging, LOL.  Hell, it might even say it right on the box!

[55trucker]

The O ring that was supplied in the intake gasket kit will the O ring for the throttle body passage in the intake manifold.

Gm really dropped the ball when it comes the cylinder head casting,  one thinks that after the head was put into place they realized that one cannot remove the distributor drive at all.

From that pic of your Greg, I do not see a terrible mess there, perhaps clean that area up before attempting to dislodge the O ring.

 

[jiggity76]

1 hour ago, 55trucker said:

The O ring that was supplied in the intake gasket kit will the O ring for the throttle body passage in the intake manifold.

Gm really dropped the ball when it comes the cylinder head casting,  one thinks that after the head was put into place they realized that one cannot remove the distributor drive at all.

From that pic of your Greg, I do not see a terrible mess there, perhaps clean that area up before attempting to dislodge the O ring.

 

So glad you chimed in!  I always appreciate your input as I'm treading new territory here.  

So this little O-ring gasket needs to go under this plug or whatever it's called.  Where someone has added silicone to the base of it?  I'm still a little hazy about where it needs to go.  Is there a specific procedure in our LQ1 manual?  Or does that require a cylinder head removal?  

Under this bolt and hold down tab?  If that's the case, could I just stretch the gasket over the top and down under the rim?  Probably would break though.

Crap, I'm not paying attention  AT ALL!  This gasket isn't even for that!  It's for the throttle body passage like you said.  So where's that at?  I'm not getting the terminology.  Pics would help out alot please.

 

Edited June 6, 2020 by jiggity76

[jiggity76]

Ah, I see now!  You were letting me figure it out on my own, you knew I would get it.  Thanks 55!

 

[Schurkey]

The oil pump drive doesn't seem to be leaking.  LEAVE IT THE FUCK ALONE until it leaks.  Without pulling the head, and removing the pump drive for a new O-ring, you're more likely to make this worse than better.

If the oil distribution cover isn't leaking, I'd leave that alone, too.  At least that one can be removed, cleaned, and the gasket properly replaced as-is.  The oil pump drive can only be half-assed without removing the head.

[jiggity76]

6 hours ago, Schurkey said:

The oil pump drive doesn't seem to be leaking.  LEAVE IT THE FUCK ALONE until it leaks.  Without pulling the head, and removing the pump drive for a new O-ring, you're more likely to make this worse than better.

If the oil distribution cover isn't leaking, I'd leave that alone, too.  At least that one can be removed, cleaned, and the gasket properly replaced as-is.  The oil pump drive can only be half-assed without removing the head.

That's some rough street talk!

Yeah, I really don't think I should mess with it.  I don't mind coming back later and redoing it if it is infact leaking.  Thanks!

[bluecalais79]

I have had in the past these leaks since day one with my 1994 LQ 1. I lost a quart of oil every 1000 miles. That gets expensive when you are running Mobil one. . Earlier this year when I had both intake manifold gaskets replaced the mechanic replaced every exposed gasket possible while they were at it. They must have done something right, my disappearing oil problem is no more, it hasn't gone down a bit and that was 1500 miles ago.

[jiggity76]

I had the same issue when I first got my 96 CS sedan 3.1 car.  Ended up being the intake gaskets.  It was literally leaking all over the driveway after I drove it one day.  I think the biggest culprits are the intake gaskets and the oil pump shaft.  I don't know if they leak that excessive thru the oil pump shaft but when the intake gaskets let go, it made a huge mess.

[bluecalais79]

Agreed 100%. It just goes to show, when you buy one of these cars, really beware if the original intake manifold gaskets have not been replaced. They are going to fail someday and that cost has to be factored into what the given car is worth, 3.1 or 3.4. With the 3.4, the big 3 factors are: Intake Manifold Gaskets, Timing Belt, Alternator. If these have been replaced, proceed. If not, proceed with caution, big repair bills await you.

I'm on my 5th Alternator with my 3.4, with both Intake Manifold Gaskets just being freshly replaced. My Timing Belt was replaced in 1996. It's hanging in there (the mechanic advises it's in great shape) but I inspect it 2x a month. I need to get that done someday fairly soon.

Edited June 24, 2020 by bluecalais79

[Psych0matt]

I check my t belt a few times a season, I think it was replaced at some point before I got the car. I’ve had it almost 10 years now and haven’t done it but it still looks great. Replaced the alternator when I got it (partially why I got the car cheap), and once that was done and it was running figured out the LIM gaskets needed doing. That was all in 2011 and other than a few minor things mines been super reliable. Typing this sitting in it before heading in to work.

[jiggity76]

6 hours ago, Psych0matt said:

I check my t belt a few times a season, I think it was replaced at some point before I got the car. I’ve had it almost 10 years now and haven’t done it but it still looks great. Replaced the alternator when I got it (partially why I got the car cheap), and once that was done and it was running figured out the LIM gaskets needed doing. That was all in 2011 and other than a few minor things mines been super reliable. Typing this sitting in it before heading in to work.

None of what you just said makes any sense.  These LQ1's I've been told are complete pieces of junk!  No way you car has been that reliable, LOL!

[Psych0matt]

As much as I’ll admit that they’re oddly designed and a pain to work on for some things, I honestly don’t know why they get the hate that they do. The three that I’ve had have been maintained somewhere between mediocre and decent, and have been very good to me.

[jiggity76]

I'm still pretty new to the game but there is NOTHING that deters me from loving the LQ1.  I've been doing some interior work and thaaaattt suuuccckkks!!!!  I would much rather work on the motor.

[bluecalais79]

I like the 50 extra horses. It's worth the effort.