Remove spark plugs

[siliconvalley]

Hi, I am going to replace the bad water pump. When I tried to remove the crankshaft nut with the starter method, the service manual says I need to remove all the plugs. I understand we don't want the engine running when we try to get the nut off, but do I have to remove all the plugs? Can I just pull the ignition wires off? If I leave the plugs in, it's still possible that the engine fires off? If I leave the plugs in, does it damage the engine? Thanks.

[Mister_Perkins]

No, you wont damage the engine. The reason it suggests removing the spark plugs is because it helps let the engine rotate easier. The compression can escape through the spark plug holes

[fenixus]

yup, basically this step helps with rotating crank manually (with a box end wrench on the nut) to TDC. with spark plugs in, it makes it very hard and requires some monkey strength (you would be fighting the compression resistance on top of valvetrain spring tension)

starter blip method is the best one I know for easy crank bolt removal when you can't have access to impact air gun (e.g. working in a parking lot like I do). just remember that crank rotates clock wise, so place the breaker bar on the right side to avoid damage when it accidentally rotates the opposite way you expected

to avoid accidental plug firing (e.g. when wire falls into the hole and makes contact with a plug), just pull out the 15A EFI fuse (blue) from Main Engine Room fuse box on driver side - it disables the whole EFI circuit (igniters and spark plugs, fuel pump and ECU).

[siliconvalley]

Thanks Mister_Perkins and Fenixus. That makes sense and I will remove them. Easy engine rotating translates to more torque to break loose the nut.

On a side note, I broke a 1/2" to 3/4" drive socket adaptor lol. Silly me, I should have bought a 19mm 1/2" drive socket. Got a 25" loan breaker bar from Autozone and hope it can free that stubborn crankshaft nut(first time for me).

[04yfz]

Originally Posted by siliconvalley

Thanks Mister_Perkins and Fenixus. That makes sense and I will remove them. Easy engine rotating translates to more torque to break loose the nut.

On a side note, I broke a 1/2" to 3/4" drive socket adaptor lol. Silly me, I should have bought a 19mm 1/2" drive socket. Got a 25" loan breaker bar from Autozone and hope it can free that stubborn crankshaft nut(first time for me).

Those adaptors are worthless unless you get an impact rated one. On another note, I'd recommend using a 6 point socket as well, I'd had to have the bolt strip.

[siliconvalley]

Yeah, the 6 point socket makes a big difference. I would imagine it's really a pain on the ass to remove a stripped crankshaft bolt.

In fact, I almost stripped 2 of the 3 lower engine mounting bracket bolts with a combo 12point wrench(I tried the daisy chain method mentioned in dz63's thread but maybe my wrench is of poor quality). What I did was to remove the A/C line brackets so I had some room there and jacked up the engine about 1". Then I used a 6 point 14mm socket to move the bolts.

[04yfz]

Originally Posted by siliconvalley

Yeah, the 6 point socket makes a big difference. I would imagine it's really a pain on the ass to remove a stripped crankshaft bolt.

In fact, I almost stripped 2 of the 3 lower engine mounting bracket bolts with a combo 12point wrench(I tried the daisy chain method mentioned in dz63's thread but maybe my wrench is of poor quality). What I did was to remove the A/C line brackets so I had some room there and jacked up the engine about 1". Then I used a 6 point 14mm socket to move the bolts.

Are you talking about the bracket on the front of the engine in between the timing covers? If so that one is a real PITA. I found that what worked best was a short 14 mm socket on a 1/4 drive ratchet which fit right in there. Then just use a 3/8 ratchet with a short socket.

[ajkalian]

FWIW, you don't have to remove the spark plugs. If you loosen them two or three turns and that will be enough to let the air escape from the cylinders.

Doing it this way solves the problem of stuff falling in the holes, the spark plugs rolling off the fender, and hitting the concrete floor and cracking. It also keeps the chance of cross threading the plugs in the heads to a minimum.

It also keeps the moisture from getting in the cylinders and adding a thin film of rust that will keep the motor from turning over, depending on how long the spark plugs are removed.


.

[fenixus]

hmmm ... combo wrenches (daisy chained) worked for me on both lower mounting bracket bolts (14mm). mine aren't any expensive line either LOL

they were tuff as hell to budge, but it worked, I use Pittsburgh wrenches from HFT:
http://www.harborfreight.com/9-piece...set-42305.html

I think I used daisy chained combo wrenches on one of P/S pump bolts (either lock bolt or pivot bolt), don't remember which one.

[siliconvalley]

Originally Posted by 04yfz

Are you talking about the bracket on the front of the engine in between the timing covers? If so that one is a real PITA. I found that what worked best was a short 14 mm socket on a 1/4 drive ratchet which fit right in there. Then just use a 3/8 ratchet with a short socket.

Yes, that's the bracket. Good point on a short 14mm socket + 1/4 drive rachet. Time to go and grab a set of 1/4" socket sets and a rachet.

[siliconvalley]

Originally Posted by fenixus

hmmm ... combo wrenches (daisy chained) worked for me on both lower mounting bracket bolts (14mm). mine aren't any expensive line either LOL

they were tuff as hell to budge, but it worked, I use Pittsburgh wrenches from HFT:
http://www.harborfreight.com/9-piece...set-42305.html

I think I used daisy chained combo wrenches on one of P/S pump bolts (either lock bolt or pivot bolt), don't remember which one.

OK OK, sounds like I can't blame my 12pt combo wrench for stripping the bolt. Still, I won't admit I am an incompetent shade tree mechanic.

[siliconvalley]

Update: after I removed the spark plugs, with a 1/2" drive 19mm deep impact socket, busted the crankshaft nut loose at the first try with the starter. Lesson learned:

. don't use 3/4" to 1/2" socket adapter.
. remove spark plugs so you get more torque to break the nut.

Thanks to all who helped. This is a great site. The shop wanted to charge me $500 to replace the bad water pump. Looks like I can do it myself(first time on a water pump lol) with the help of you great people.

[pmesfun]

So much good information, now I have no excuse for screwing things up when I start tearing into the engine.