02 Impala 3.4L 185k: Front Cover Gasket

[Colt Hero]

Shop Manual says you need to remove the oil pan as part of the front cover gasket repair. Is that really true? Removing the oil pan on this car is a very complicated procedure. Want to make sure it's abosolutely necessary before continuing.

[rkvons]

Originally Posted by Colt Hero

Shop Manual says you need to remove the oil pan as part of the front cover gasket repair. Is that really true? Removing the oil pan on this car is a very complicated procedure. Want to make sure it's abosolutely necessary before continuing.

That sounds like the perfect thing to do when the engine is out of the vehicle, but you should be able to replace the front cover gasket without removing the oil pan. Go to Autozone and read their repair procedure.

[la1]

Why do you need to remove the front cover gasket?

[Colt Hero]

la1:

Front Cover gasket is original and there is a steady stream of coolant flowing (gushing?) from a crevice at the top left corner of the cover (where it "meets" the firewall-side head and lower intake). Problem is: the cover actually sits *forward* of the head and intake, with a narrow crevice behind, and you cannot tell exactly *where* the leak is coming from (without pulling parts off). Even with the alternator and tensioner removed, you still can't be sure. So I'm guessing it's the Front Cover gasket. If I'm wrong, it'll be the lower intake (again) or maybe even the head gasket. HOPE NOT.


Anyway ...

Cover removed, oil pan did not have to come off, but looking straight down from the top, you can see the pan bulging/bowing outward beyond the front face of the engine, and there is a narrow embedded gasket in it that *appears* to be intact, but when the cover goes back on and sits down atop it, I wonder if this seal will be a problem.

A few questions (of course):

1.) Should I put a dab of Black Permatex at the 90-degree seam where the horizontal pan protrudes past the vertical face of the front of the engine (and where the front cover will 'sit' atop the pan)? The Fel-Pro gasket will hang on the locator pins and seal the sides and top of the cover, but it merely sits atop the pan like the cover. There is no real "seal" where the cover sits atop the pan (except for that embedded rubber gasket in the lip of the pan which may not be as flexible as it once was).

2.) Should I coat the Fel-Pro front cover gasket with a thin film of Black Permatex, or is it sufficient just going on dry?

3.) Only ONE of the cover bolts (#3 on the left or firewall side), when removed, caused some residual coolant/water to gush out, however, it appears that there are FOUR of these larger-sized bolts surrounding the (2) water jacket 1.5" channels on either side. Should I put pipe sealant on these four bolts, medium-strength thread locker, or both? I used pipe sealant, which I bought at Home Depot, on my Taurus' front cover, but it's consistency was not smooth. It seemed like it had embedded *sand* in it, which made for a sloppy coating on the threads. Did I buy the wrong stuff?

4.) Check out the attached pictures.

1st Picture: The top of the timing chain and the intersection of the firewall-side head and lower intake (and front cover - if it was installed). Notice the (cast) pan-shaped "gouge" (for lack of better word) just under the head. I cleaned this area out (it had oil and grease in it). At first I thought it was a corroded hole and was the source of my leak, but it seems to be just the way the block was cast. Question is: I'm *not* going to pull the LIM and heads just yet. I'm going to put the cover back on, put it all back together, fill it up, and see if it still leaks. Should I fill in this gouge with Black Permatex?? If there's a pinhole leak here, maybe the Permatex will stop it good enough, but if not, I'll be taking it apart again down to at least the LIM (and maybe the heads). Just don't feel like tearing into this thing any more at this point.

2nd Picture: The harmonic balancer. Don't know if you can see it, but there is a feel-able groove in the outer surface of the hub. Apparently this is caused by the rubber seal contacting the outer surface of the hub as it spins??? Is that correct? I didn't buy the gasket kit with the sleeve, and I just tapped in the new seal. I should've bought the sleeve, right? It goes OVER the hub, and then the seal has a slightly wider-circumference opening ... is that how it works? Anyway, I didn't tap the new seal in as deeply as the original seal - which was just a hair past flush with the face of the hub. I'm thinking, this way, the new seal will be contacting the hub just a hair in front of that groove. The new seal is perfectly flush with the face of the hub. Do you think this will be OK?

http://s234.photobucket.com/user/pri...?sort=3&page=1

[rkvons]

Originally Posted by Colt Hero

la1:

Front Cover gasket is original and there is a steady stream of coolant flowing (gushing?) from a crevice at the top left corner of the cover (where it "meets" the firewall-side head and lower intake). Problem is: the cover actually sits *forward* of the head and intake, with a narrow crevice behind, and you cannot tell exactly *where* the leak is coming from (without pulling parts off). Even with the alternator and tensioner removed, you still can't be sure. So I'm guessing it's the Front Cover gasket. If I'm wrong, it'll be the lower intake (again) or maybe even the head gasket. HOPE NOT.


Anyway ...

Cover removed, oil pan did not have to come off, but looking straight down from the top, you can see the pan bulging/bowing outward beyond the front face of the engine, and there is a narrow embedded gasket in it that *appears* to be intact, but when the cover goes back on and sits down atop it, I wonder if this seal will be a problem.

A few questions (of course):

1.) Should I put a dab of Black Permatex at the 90-degree seam where the horizontal pan protrudes past the vertical face of the front of the engine (and where the front cover will 'sit' atop the pan)? The Fel-Pro gasket will hang on the locator pins and seal the sides and top of the cover, but it merely sits atop the pan like the cover. There is no real "seal" where the cover sits atop the pan (except for that embedded rubber gasket in the lip of the pan which may not be as flexible as it once was).

Answer: I think the instructions say to coat the bottom 1/4 inch or so of the paper gasket with some GM sealant. I would do that instead of what you are suggesting. Check AutoZone's repair instructions.

Originally Posted by Colt Hero

2.) Should I coat the Fel-Pro front cover gasket with a thin film of Black Permatex, or is it sufficient just going on dry?

Answer: Dry. (except for bottom 1/4 inch on both sides, front and rear.)

Originally Posted by Colt Hero

3.) Only ONE of the cover bolts (#3 on the left or firewall side), when removed, caused some residual coolant/water to gush out, however, it appears that there are FOUR of these larger-sized bolts surrounding the (2) water jacket 1.5" channels on either side. Should I put pipe sealant on these four bolts, medium-strength thread locker, or both? I used pipe sealant, which I bought at Home Depot, on my Taurus' front cover, but it's consistency was not smooth. It seemed like it had embedded *sand* in it, which made for a sloppy coating on the threads. Did I buy the wrong stuff?

Answer: Go to the auto parts store and get Permatex thread sealer. Let the sealer cure in place for 24 hours before the system is pressurized. You should have been able to tell which bolts originally had thread sealer on them. Clean the threads real well and put the sealer on those. If you are not sure which ones, do them all, I guess.

Originally Posted by Colt Hero

4.) Check out the attached pictures.

1st Picture: The top of the timing chain and the intersection of the firewall-side head and lower intake (and front cover - if it was installed). Notice the (cast) pan-shaped "gouge" (for lack of better word) just under the head. I cleaned this area out (it had oil and grease in it). At first I thought it was a corroded hole and was the source of my leak, but it seems to be just the way the block was cast. Question is: I'm *not* going to pull the LIM and heads just yet. I'm going to put the cover back on, put it all back together, fill it up, and see if it still leaks. Should I fill in this gouge with Black Permatex??

Answer: I would say no here. Permatex will never be able to hold the coolant back when it is under pressure.

Originally Posted by Colt Hero

If there's a pinhole leak here, maybe the Permatex will stop it good enough, but if not, I'll be taking it apart again down to at least the LIM (and maybe the heads). Just don't feel like tearing into this thing any more at this point.

2nd Picture: The harmonic balancer. Don't know if you can see it, but there is a feel-able groove in the outer surface of the hub. Apparently this is caused by the rubber seal contacting the outer surface of the hub as it spins??? Is that correct? I didn't buy the gasket kit with the sleeve, and I just tapped in the new seal. I should've bought the sleeve, right? It goes OVER the hub, and then the seal has a slightly wider-circumference opening ... is that how it works? Anyway, I didn't tap the new seal in as deeply as the original seal - which was just a hair past flush with the face of the hub. I'm thinking, this way, the new seal will be contacting the hub just a hair in front of that groove. The new seal is perfectly flush with the face of the hub. Do you think this will be OK?

Answer: I wonder about this too. The crank seal has to seal against the harmonic balancer on one side, but I think it seals against the back of the front cover on the other side. So I think it needs to be fully seated. Put a little lubricant on the rubber seal before inserting the crank balancer. You don't want the rubber to be dry. The sleeve would probably be a good idea, but not sure how that works, to be honest. Also, clean up the slot in the crank balancer and the key in the crank shaft and put some of that black RTV, or silicone sealant in the slot. Without doing that, this is a way for oil to get out.

Originally Posted by Colt Hero

http://s234.photobucket.com/user/pri...?sort=3&page=1

[Colt Hero]

rkvons:

Thanks for your replies, but my son drives this car and he's running out of patience with me getting it back on the road, so I'm taking the mornings off from work and working evenings so I can get it back together ... and I started this morning (without first seeing your replies).

Here's what I ended up doing:

1.) I "painted" the entire back side of the paper gasket with the Ultra Black Permatex stuff. Came out pretty good, actually. Just dabbed it on from the caulking tube then spread it thinly using a very narrow awl turned sideways. Then just pushed it on the locator pegs and set it like wallpaper, pushing out the 'bubbles'

3.) I had some white pipe sealant from a previous job that was still good, so I put a thin coat on the (5) larger bolts. The (5) smaller bolts appeared to dead-end in the hole when I turned them in during the dry-run test, so I don't think any of them enter the water jacket (nor are they near it). I think only ONE bolt actually goes into the jacket, but I coated all (5) large bolts, which are located around the jacket holes

4.) For the 'cavity' below the head, and where the cover and lower intake also meet, I filled it with the Ultra Black the night before and leveled with putty knife. Next day it looked pretty good. Cover went over it (partially), so we'll see what happens.

5.) Crank Seal had already been installed into the cover. I'll remember to oil it up before installing the Balancer tomorrow. I think all this thing does is provide a 'curtain' around the crankshaft to try to keep the oil in there. It's not a perfect seal and I'd bet that they all leak a little, so I'm not worried about it. But you do have me thinking about how the Balancer interacts with it. I thought it just bolted onto the crankshaft and sat in front of the pulley. Nothing special ... but now I wonder ...

[Colt Hero]

Just wanted to report back that I finally got the car back together (about 3-4 weeks ago) and it *seems* to be holding coolant in the overflow tank. Runs smooth as glass (as good as when it was new, I'd say). The temp gauge *does* go slightly over mid-scale when sitting at a light (which is not normal), but otherwise it stays below mid-scale (say, on the interstate or just rolling along in town). Water pump was replaced just last June (2014), so maybe still be some air in there (or maybe air is getting back in?). I *do* have a check engine code of P0102, but I saw that one before all this coolant hemorrhaging started. Probably just need to clean the MAF sensor? Tried clearing the code, but it came back a day or two later. Think I'm done with this car for a little while. Now I'll just observe and see if the coolant starts disappearing.