First off, many thanks to all the contributors on this site; as someone with little car experience, the info here has helped me tremendously. But it is really frustrating when instructions say to "remove so and so," and even though you see the thing, you have no idea how to do so. So I thought I would give back by describing some things I found when I did the coils/plugs/gaskets.
I have a 2002 V6 (82k miles) that started missing when accelerating right around 50mph. When it finally threw a code, it was PO306 (cylinder 6 misfire). Checked the plug, had lots of oil in the well, pointing to a VCG replacement (there's been oil on the garage floor for a couple years). Since the plugs/coils were over 10 yrs old, I figured I might as well go whole hog and replace everything (I actually had ordered the plugs and coils last year, but was too scared to tackle the manifold until forced by the misfire). Interesting that plugs 3 and 6 were the only ones w/ oil, like some others here have observed.
The service manual says to remove the cowl brace. I was able to do the job without doing so, but for sure you need to remove the passenger side cowl. There's not much you need to do by the firewall on the driver's side, so, considering the reports of broken bolts I saw here (and the fact that I couldn't get the damn wipers off anyways), I'd skip that step. Regarding the cowl, it's held by a row of plastic retainers; the circle in the middle is a shaft that holds the retainer in the hole. The cowl brace has a hole under all the retainers (except the middle one!) that allows you to poke up from the bottom (a bolt works well) to unlock the retainer. Didn't even know there was a cabin air filter until I found it under there (caked solid w/ dirt; new one is en route)!
You're also supposed to drain the radiator. I didn't. There are 2 coolant hoses that run from the manifold, the long return to the degas, and the short supply from the radiator. With the engine cold and after opening the degas (to depressurize), I didn't get any coolant squirting out when I pulled the hoses off (although maybe a few ounces leaked from the manifold and from the hoses while disassembled). Whatever leaked out of the hose from the radiator could conceivably introduce an air pocket, but I doubt it; I will do a bleed (easier than a full flush/fill) to be safe at some point. All hoses, btw, just pull straight off (including the ones going into the big tube going into the throttle body; they're strong, they won't rip), after moving any clamps, of course. I think it helped to use pliers to twist them a bit before pulling, to break them free.
Speaking of breaking, all electrical connectors (like sensos, coils, etc.) "click" closed; to remove, you have to push the lock tab down, either on the end or in the middle (use a screwdriver). I broke the cylinder six connector figuring this out.
All the work in the back (by the firewall) is a pain, but be especially careful in the middle; anything you drop around there (e.g. while working on the bracket/shield on the back of the manifold) won't fall to the ground. I had to pull the manifold a second time after dropping a bolt in that area. I also lost a little bracket nut there, but that was the only permanent casualty.
After the upper manifold comes off (surprising how light it is!), you have access to the valve covers. The PCV tube (makes a T, one end in each valve cover) must be removed. There is no obvious fastener, but the ends turn easily while seated, which made me think they had a screw type lock like the PCV valve. So of course, I tried twisting one side until the tube broke. They just pull straight out. A chunk of hose from autozone fiixed the broken tube.
To remove the covers, you must contend not only with the bolts (15 for the Gen 1, plus the temp sensor on the driver side), but also the factory applied sealant at the corners. I used the fat part of the cover (towards the front) as a handle; a couple hard yanks broke the sealant. Removing the sealant residue is a bitch (you want the mating surfaces to be as clean and smooth as possible). Don't scrape with anything metal (a gouge is sure to leak). I sprayed w/ brake cleaner and scraped w/ the square end of disposable chopsticks (wood is softer than metal but harder than silicone).
The Fel-Pro gaskets I got have little "feet" (molded squares) that not only provide guidance as to placement (which side out when pushing into the cover's groove), but I think are meant to provide extra material to fill the small seam in the engine where the factory applied sealant. So I used no sealant, on the advice of people here and on other forums.
The spark plug gasket (the rectangle inside the valve cover which surrounds the plugs) has a small semicircular nub jthat matches an indentation in the cover to guide installation. Specs say to torque bolts down to 7-8 lb ft, but I just eyeballed it (there's a thread here w/ pics, search for "ls v6 torque specs" -- also useful to see where stud bolts are, at least driver side, if you can't keep track as you go); my 3/8 ratchet is right around a foot long, so i just had to envision pulling an 8 lb weight. I think you can feel when the gasket is compressed. Two days and no oil so far. Interesting that on both sides, there were two bolts totally cranked down where the grommets were deformed (and had oil on the bolts). I would guess that the factory worker cranked down the two (probably in the middle) and then torqued the rest to avoid a second pass.
For completeness, I chose to replace the lower manifold gaskets as well; autozone sells the complete set (plenum/lower) for $30 (cheaper than just the plenum; must be a mistake)! The key to the lower manifold is the mount in front by the radiator; after removing the bolt, the bracket can move to the side so you can lift the entire assembly (w/ fuel rail) up. In the back, you either unscrew the bracket and pop out the fuel line, or pop out the hose and electrical connector. I unscrewed the bracket and expected fuel to squirt everywhere (as it's under pressure), but nothing really happened. The fuel injectors (under the fuel rail) must stay connected! I started taking it apart when trying to figure out how to get the lower manifold off, before I found the bracket in the front; I forgot to reconnect the injectors, and so the car ran really rough when I tried starting it, the engine shook like crazy. Luckily, I was able to stick a screwdriver under the plenum and reconnect all the injectors; runs like a dream now.
All told, the job took me 12+ hrs spread over 4 days. So not easy, but doable. Could definitely do it in 3-5 hrs next time. Hope this helps someone!
I have a 2002 V6 (82k miles) that started missing when accelerating right around 50mph. When it finally threw a code, it was PO306 (cylinder 6 misfire). Checked the plug, had lots of oil in the well, pointing to a VCG replacement (there's been oil on the garage floor for a couple years). Since the plugs/coils were over 10 yrs old, I figured I might as well go whole hog and replace everything (I actually had ordered the plugs and coils last year, but was too scared to tackle the manifold until forced by the misfire). Interesting that plugs 3 and 6 were the only ones w/ oil, like some others here have observed.
The service manual says to remove the cowl brace. I was able to do the job without doing so, but for sure you need to remove the passenger side cowl. There's not much you need to do by the firewall on the driver's side, so, considering the reports of broken bolts I saw here (and the fact that I couldn't get the damn wipers off anyways), I'd skip that step. Regarding the cowl, it's held by a row of plastic retainers; the circle in the middle is a shaft that holds the retainer in the hole. The cowl brace has a hole under all the retainers (except the middle one!) that allows you to poke up from the bottom (a bolt works well) to unlock the retainer. Didn't even know there was a cabin air filter until I found it under there (caked solid w/ dirt; new one is en route)!
You're also supposed to drain the radiator. I didn't. There are 2 coolant hoses that run from the manifold, the long return to the degas, and the short supply from the radiator. With the engine cold and after opening the degas (to depressurize), I didn't get any coolant squirting out when I pulled the hoses off (although maybe a few ounces leaked from the manifold and from the hoses while disassembled). Whatever leaked out of the hose from the radiator could conceivably introduce an air pocket, but I doubt it; I will do a bleed (easier than a full flush/fill) to be safe at some point. All hoses, btw, just pull straight off (including the ones going into the big tube going into the throttle body; they're strong, they won't rip), after moving any clamps, of course. I think it helped to use pliers to twist them a bit before pulling, to break them free.
Speaking of breaking, all electrical connectors (like sensos, coils, etc.) "click" closed; to remove, you have to push the lock tab down, either on the end or in the middle (use a screwdriver). I broke the cylinder six connector figuring this out.
All the work in the back (by the firewall) is a pain, but be especially careful in the middle; anything you drop around there (e.g. while working on the bracket/shield on the back of the manifold) won't fall to the ground. I had to pull the manifold a second time after dropping a bolt in that area. I also lost a little bracket nut there, but that was the only permanent casualty.
After the upper manifold comes off (surprising how light it is!), you have access to the valve covers. The PCV tube (makes a T, one end in each valve cover) must be removed. There is no obvious fastener, but the ends turn easily while seated, which made me think they had a screw type lock like the PCV valve. So of course, I tried twisting one side until the tube broke. They just pull straight out. A chunk of hose from autozone fiixed the broken tube.
To remove the covers, you must contend not only with the bolts (15 for the Gen 1, plus the temp sensor on the driver side), but also the factory applied sealant at the corners. I used the fat part of the cover (towards the front) as a handle; a couple hard yanks broke the sealant. Removing the sealant residue is a bitch (you want the mating surfaces to be as clean and smooth as possible). Don't scrape with anything metal (a gouge is sure to leak). I sprayed w/ brake cleaner and scraped w/ the square end of disposable chopsticks (wood is softer than metal but harder than silicone).
The Fel-Pro gaskets I got have little "feet" (molded squares) that not only provide guidance as to placement (which side out when pushing into the cover's groove), but I think are meant to provide extra material to fill the small seam in the engine where the factory applied sealant. So I used no sealant, on the advice of people here and on other forums.
The spark plug gasket (the rectangle inside the valve cover which surrounds the plugs) has a small semicircular nub jthat matches an indentation in the cover to guide installation. Specs say to torque bolts down to 7-8 lb ft, but I just eyeballed it (there's a thread here w/ pics, search for "ls v6 torque specs" -- also useful to see where stud bolts are, at least driver side, if you can't keep track as you go); my 3/8 ratchet is right around a foot long, so i just had to envision pulling an 8 lb weight. I think you can feel when the gasket is compressed. Two days and no oil so far. Interesting that on both sides, there were two bolts totally cranked down where the grommets were deformed (and had oil on the bolts). I would guess that the factory worker cranked down the two (probably in the middle) and then torqued the rest to avoid a second pass.
For completeness, I chose to replace the lower manifold gaskets as well; autozone sells the complete set (plenum/lower) for $30 (cheaper than just the plenum; must be a mistake)! The key to the lower manifold is the mount in front by the radiator; after removing the bolt, the bracket can move to the side so you can lift the entire assembly (w/ fuel rail) up. In the back, you either unscrew the bracket and pop out the fuel line, or pop out the hose and electrical connector. I unscrewed the bracket and expected fuel to squirt everywhere (as it's under pressure), but nothing really happened. The fuel injectors (under the fuel rail) must stay connected! I started taking it apart when trying to figure out how to get the lower manifold off, before I found the bracket in the front; I forgot to reconnect the injectors, and so the car ran really rough when I tried starting it, the engine shook like crazy. Luckily, I was able to stick a screwdriver under the plenum and reconnect all the injectors; runs like a dream now.
All told, the job took me 12+ hrs spread over 4 days. So not easy, but doable. Could definitely do it in 3-5 hrs next time. Hope this helps someone!
