Coolant leak...

[talon2swords]

1999 Lumina, 3.1L engine.

I got a mystery coolant leak that started today, but watery residue on bottom of chassis seems oily too.

I know it's the coolant because it was low and there was a puddle on ground. Oil seems ok--not milky or anything.

I put a new metal LIM in it a few months ago. I checked around the interface area, don't see anything unusual.

Checked usual suspects: hoses, water pump, etc. --just don't see anything in those areas.

It seem to be leaking in the area under the Harmonic balancer area and into the strange oval shaped transmission/engine mount thing. It's leaking outta the holes in the bottom of mount and onto the ground. I can't see very well in that area (too much stuff in the way). Are there any freeze plugs or anything else around there prone to leaking? It seems to be a slow leak, I'm trying to get it to leak again but it won't do it right off.

Thanks for input...

[IsaacHayes]

Probably the timing cover gasket is leaking. Coolant is routed through that through the block and also it's the housing of the water pump.

[talon2swords]

Oh, ok. I was kinda thinking something along those lines, but wasn't quite sure where/if coolant went through that cover. I need to see a diagram, maybe I can find a picture or something to get an idea how/where coolant flows thru it.

I just drove it around the block--no leak. Guess I will look up timing cover gasket replacement procedure in my book. Thanks.

[talon2swords]

OMG, I just read my Haynes manual and it wants me to remove everything but the kitchen sink.

Ok, so if it is the timing cover gasket, I just read this:

http://60degreev6.com/forum/showthread.php?t=39905&highlight=timing+cover

I hope I can do this by only removing the basics, like the pwr steering, balancer, water pump, etc.

My book wants me to take off the hood, suspend the engine, remove suspension components and the oil pan, etc etc.!

I'm not doing that (I hope). Can I assume correctly that I can just remove only the basic items and get the thing off and on again? Thanks.

[PCGUY112887]

Sadly this isn't that easy to you. First thing is take the belt off. The hardest thing that has to come off is the crank pulley, since you'll have to use a tool and probably do it from the pass side wheel well (pull back plastic shields to find crank pulley).

After that, power steering pump has to come off. You can leave it connected, but it has to come off the timing cover (it sides sorta UP).

Take front coolant line off...

There are a bunch of bolts all around it, take them off. You'll lose coolant and oil when you take this off.

This may be a good time to check your timing chain as well, since it's right there.

It's not a fun job really... hopefully you have enough room in the engine bay to do all of this (like I could in a GP) or you will actually be pulling the engine up to do this.

[IsaacHayes]

Yeah that thread is the same deal. Dont pull the pan and all that crap.

If I can do it in a beretta with 1" of space between the cover and the body of the car, with a side engine mount through the cover, you can do it in your W body car You have TONS more room.

[talon2swords]

I think there is enough room. I just don't want to have to remove the following:

The starter; the front exhaust manifold; the hood; the oil pan; the rt. side ball joint and lower control arm

[IsaacHayes]

WTF does that book come with a crack pipe too? WTF would you remove the exhaust manifold, hood, or control arm?? I can see the start if removing the oil pan, but removing the oil pan IS NOT NEEDED.

There is plenty of room in your car. In mine not so much, but I did it just fine.

[talon2swords]

It also, in Chapter 2, section 12, step #11, says to remove the pass. side upper engine mount and the mount support bracket from the front of the timing chain cover. Then tells me to remove other stuff as well and support engine, etc. I guess maybe this is required if I'm replacing timing chain and sprockets also(?). I'll have to go back and study car in more detail, but this sounds like overkill. I just want to take off the cover.

[Paul M]

Timing cover gasket

Talon,
If your Haynes manual says that you have to remove the starter; the front exhaust manifold; the hood; the oil pan; the rt. side ball joint and lower control arm;suspend the engine; remove suspension components etc,destroy the manual immediately !It was probably written by former GM LIM gasket engineers who got lost (losers) and left the job to the janitor who doesn't mind driving around with gallons of fresh coolant in the trunk and a Dex Cool mop.Seriously !

[talon2swords]

LOL. Also I think maybe it was written on Halloween in an attempt to frighten away back yard DIY amateur mechanics!

Thanks for the insights people.

[IsaacHayes]

Just use your eyes and see what you do and don't have to take off...

[talon2swords]

Hello,

I have spare vehicle(s) so I'm just getting around to replacing that timing cover gasket on the 99 Lumina. I have the cover off. I am going to follow the procedure from the other topic posted on this (see below).

So far I am cleaning all the old stuck on gasket off the surface(s).

I have a new Felpro paper gasket to go back in there. I have a couple questions though:

1) Should I apply "Permatex form-a-gasket sealant-2 (brown-stuff)" to the surfaces of the paper gasket, or just leave it bare?

2)What do I use to seal the threads on the bolts? I've been using this "Permatex high-temp thread sealant" when I did the LIMs on my vehicles. So far so good I guess, but what is recommended for sealing the bolts?

3)The exposed portion of the oil pan gasket-I guess I will follow the below instructions and re-use it and not disturb it. It seems to be ok (in good condition) in this vehicle I'm working on and its not torn (yet). I guess it will still hold back the oil. Thanks.

http://60degreev6.com/forum/showthread.php?t=39905&highlight=timing+cover

"I replaced mine in my car, which has a side mount and a LOT more cramped than yours.

Just be careful when removing the cover, to not tear the oil pan seal and you can leave the pan on. There are 2 pins in the block that hold the timing cover in place down low so when you take it off note that. You don't have to take the head bolts out... lol What torx bolts? Mine were all normal bolts.

Put silicone in the corner where the block and cover and oil pan meet when re-installing. You need to rent a crankshaft balancer puller. And you'll need to put a screw driver in the teeth of the flexplate to keep the motor from turning when loosening and tightening the dampener back on.

Not much to it really. You gotta seal the bolts going back in too.

Have you verified its the timing cover leaking? Mine was seeping but not dumping out.

Also might want to replace the timing chain and dampener while in there.....

I replaced my timing cover gasket at around 200,000. It's just a paper gasket which holds better than the LIM but does wear out after a long time."