Changing a 2.4 water pump
Thanks to kornshell for the article :)
I've put this guide together to help answer questions as far as changing the 2.4 water pump... I've done six of them now, and this has some of the things that I've forgotten or discovered along the way. It's not all inclusive, but combined with a shop manual, it'll hopefully give you everything you need to do the job.
1. Buy beer. LOTS. Cheap beer. Three cases. Five if you drink like me. You'll be so drunk due to sheer misery you won't care that it's Pabst Blue Ribbon. While you're out (before you start drinking) get the following things. This assumes you have a decent set of tools, a jack, and jack stands. You'll need several miscellaneous sockets that'd be in any set from Sears while you're at it, but I won't mention them because I can't remember. Most of them rolled under the car or I'd go check.
Hard Parts:
Water Pump
Timing Chain Tensioner
Timing Chain
Thermostat and Gasket Set (You're gonna be right there anyway, spend the $7 and do it now. It's a !@$! to get to later. )
Upper Motor Mount Insert (Optional)
Tools you might not already have:
1/2" Impact Socket and as many impact grade extensions as you can find.
1 1/16" Impact Socket (It's supposed to be 27mm, but get the SAE. You'll thank me later.)
18mm Wrench (Preferably 6 point and as long as possible)
Chunk of 2x12 (about 18" long) or similar sized chunk of 3/4" plywood
Harmonic Balancer Puller (Loan a tool at AutoZone... Just leave a deposit and you get it back when you're through with it)
Miscellaneous and/or Disposable:
PB Blaster (2 cans. You'll be drinking this when you run out of beer.)
Oil (5 qts.)
Oil Filter
Antifreeze (Dex-Cool, 2 gallons, or 3 gal. 50/50)
Ultra Black or Ultra Blue RTV (I prefer Ultra Black. My dad swears by Hylomar in the spray can.)
Red Loc-Tite
Exhaust manifold and flange gaskets
Gloves (I prefer Mechanix Fast-Fit, but your knuckles will thank you for the M-Pact ones. You're working in tight spaces. You WILL smack your hands. REPEATEDLY.)
Two 8mm Bolts, At least 40mm long. (Timing your cams is a pain. Buy these.)
Motor Mount Bolts (M12x1.75) These MUST be grade 10.9. Order them at a dealer.
Four 3/8-16 Bolts, about 1 1/4" long. These will replace the exhaust manifold to downpipe bolts. Rust is NOT your friend.
Nevr-Seez for said bolts. Don't use it on any other ones.
For those of you shopping at AutoZone, the chain, tensioner (for late 97 and up), and exhaust gaskets are special order items at 90% of the stores out there. Go shopping two days before you plan on starting... Otherwise you'll run out of beer while waiting for your parts. Or you can do like I did and do your front struts. The car'll be up anyway. Check on the strut mounts too. Only high-volume commercial stores carry them. Otherwise two days turns into four.
2. Start drinking. Heavily. Turn on the radio. Fire up the air compressor. Start praying. Call all your friends and make them pray too. You're about to go through an ordeal quite unlike anything you've ever been through before. I don't believe in God and I still prayed.
3. Drain the radiator and the oil. If you don't know how to do both of these, take your car off the jack stands and head directly to a dealer. You have no idea what you're getting yourself into. If you can't tell a muffler bearing from a main bearing at a quick glance, do the same. Have them change your blinker fluid too. Pull the lower radiator hose off and it'll help drain more coolant that'll otherwise end up all over you later on.
4. Jack the car, pull the wheels, and put it on jack stands. Leave as much room between the stands as possible. You'll be spending lots of time under here. While you're down there, slide the jack under the oil pan and set the wood on top of the plate. Pump the jack until it just makes contact with the pan. Don't lift it yet or you'll be replacing an upper mount. They're expensive. Don't forget to wiggle the car and make sure it doesn't fall off the stands. I usually set the wheels underneath the A-arms just to be on the safe side in case it does fall. As much as I hate working on cars, I hate the thought of getting squished even more. Don't mess around with this. Buy jack stands if you have to.
5. Using the 1/2 impact socket and lots of extensions, slide under the car and remove the four downpipe-to-manifold bolts. These WILL be a !@$!. PB Blaster. A torch will help if they're really rusted. This is usually the most grueling part of the process for me. Once all four are removed, gently wiggle the downpipe to get it to break loose. Watch your forehead... Ask me how I know.
6. Remove the O2 sensor and all those farking nuts and bolts holding the exhaust manifold. They'll be rusty. PB Blaster and a torch where necessary. When you get all of them and it still won't come loose, there's one just to the right of the dipstick on the bottom row. It's hard to see. Once you get that one out too, gently remove the exhaust manifold. It takes some wiggling. Removing the hose from the hard line above it helps. You may have to take the dipstick and fuel lines off the stud in the cam tower too. That manifold is heavy. Don't drop it. If you do, please wear your gloves. As it goes down, you WILL hit your hand off something hard. Told you your knuckles would thank me... and we haven't even got to the hard part yet.
7. Double check the jack and wood block under the oil pan. Check it one more time. Have a buddy check it too. Then, remove the two big (I don't know the size on these, I replaced mine with different bolts last time...) motor mount bolts going to the bracket on the block. These are gonna be some tough cookies. I cheat and use an impact gun, but it's doable with a breaker bar and some cojones. However, don't yank them the whole way with the impact. You want to go slow in case you need to go "OH !@$!" and move the jack back under the motor.
8. Remove the five 1/2" nuts holding the upper mount to the body. Lift the mount out of the way. Go order your upper mount insert if you didn't already. You've already got it out, so why not? It's only $15.
9. Remove the 3 18mm bolts holding the motor mount bracket to the block. I've found the easiest way to do this is to cut the open end off the wrench and weld a big cheater to what's left. PB Blaster doesn't help much because the threads are buried behind the bracket. Jack the motor up or down as necessary. If you feel resistance, STOP. You're either bouncing the motor off the radiator or the AC evaporator. Either way, it's expensive to fix.
10. Use the 1 1/16" socket to yank the bolt holding the crank pulley. A torch will help but be careful to not melt the seal. PB Blaster is your friend. If the pulley keeps rotating on you, wedge something between the spokes and the block. It'll hold it in place. Once this is done, use the balancer puller to remove the pulley. Don't use a normal 3-jaw puller. You'll tear something up. Probably your hands... But maybe the pulley too. Either way, it's not a good thing.
11. There are 22 (I think.) bolts/studs holding the timing cover on to the block. Use a 10mm socket/wrench to remove them. Slide the cover out of the way, being careful not to bend it. Same with the two gaskets that come off. They're expensive and special order only. If you don't tear them up, they're reusable.
12. Ahhh... Now on to the guts of the thing. Thread the crank bolt back in place and use it to turn the crank and thus the cam gears CLOCKWISE until you can fit those 8mm bolts into the holes in the block. This keeps everything all in one place. DO NOT TURN THE CRANK AFTER THE BOLTS ARE IN. DO NOT TURN THE CRANK COUNTER-CLOCKWISE. You'll have to re-time your motor and it's no fun. Severe engine damage may result. The bolt holes are somewhere just short of 6-o'clock for the right hand (intake) gear.
13. Using an 8mm socket, remove the timing chain tensioner. For 1997 cars, compare it to the one you bought. A lot of 97 motors have the newer two-piece style. If it doesn't match, go back to AutoZone and order the correct one... It's the one under "Can also be used" in their computer.
14. Slide the brown plastic timing chain guides out of their respective slots. I usually run them through the dishwasher in order to de-gunk them while they're out. After this, remove the timing chain. Throw it away and get a new one. They're cheap.
15. Now we can get to the pump and the housing. There's two 8mm bolts where the thermostat goes, two 10mm bolts where the housing connects to the block, and 3 1/2" nuts holding the pump to the timing chain housing. Don't forget that PITA quick disconnect. I usually remove the hose from the QD... Mine had a hose clamp there but your mileage may vary.
16. Remove the pipe that holds the thermostat. There's a 1/2" nut and stud directly behind the lower motor mount. This isn't strictly necessary, but I haven't done one yet where the thermostat sat right where it needed to be. This saves some headaches later in my opinion.
17. Remove the five bolts holding the pump to the housing. You might have to use a wood block and rubber mallet to get the pieces apart. Be sure to clean all the gasket surfaces (including the one on the block). I use a razor blade, and some acetone on the really tough ones. Take special care not to nick them up. You need these to seal or you'll be tearing everything apart again next weekend.
18. If you removed the lower coolant pipe, bolt the pump up to the housing. Remember to use the gasket and a thin coat of RTV. Put the rubber gasket onto the timing chain housing studs... The small lip goes inside the housing. I use a coat of RTV on this one as well. While you've got it out, put some on the gasket for the block also. I've had good luck getting the RTV to stick the gasket to the block... One less thing to line up in the next step. If you didn't remove the pipe, you'll have to mount the pump first, then assemble everything while leaning over the fender, or you'll never get the whole works over the thermostat and into place.
19. Install the pump onto the studs. Tighten down the nuts. Next up are the bolts to the block. This should be fairly uneventful.
20. Put the thermostat and gasket into the lower coolant pipe and pop that in place next. Line up the thermostat and bolt it in, then put the nut and stud in behind the lower mount.
21. This is where the manuals abandon you with a cheerful "Installation is the reverse of removal." Indeed, for once it IS that simple, so I'll just gloss over a few things that'll help you along the way:
Make sure all the slack in the timing chain is between the water pump and crank gear. The tensioner will take this up. It can't if it's further up between the cam gears or along the other side. Remember to take out the bolts holding the cam gears while you're at it too...
When re-installing the timing chain cover, use the same principle as tightening lug nuts. Do one bolt, then the one on the opposite side (or as close to it as possible)... This helps prevent oil leaks.
Remember the red Loctite on the mount bracket to block bolts. You don't want these vibrating loose. Bad things WILL happen.
Remember to put oil back in. I've nearly forgotten this twice. Once out of sheer drunkenness, once because I was too busy thinking "OMG it's done... fire it up already!" It sounds stupid, but the stupid things are always the ones you forget.
Don't forget the exhaust manifold gaskets.
Double check everything before starting the car. This is a fairly complicated process that will take some of us multiple days, and it's easy to forget things like tightening the lower radiator hose clamp, or the screwdriver you laid on the lower motor mount.
Check for oil and coolant leaks when you start the car back up for the first time... Don't just fire it up and head on a cross-country excursion.
I think this about does it as far as the water pump. I'm typing all of this from memory (did one this weekend), so please alert me to any inaccuracies or missed steps... Questions, comments, and free beer can also be directed to joefedele@gmail.com. Thanks for reading this far, and I hope this helps you.
I am NOT responsible for anything that happens as a result of following this guide. It is intended to be a supplement to the repair manual of your choosing. If you are unsure about any of the procedures described here, see a qualified mechanic, etc, etc... Basically, if your car blows up, it's not my fault.
Original thread is here for discussion:
http://www.j-body.org/forums/read.php?f=11&i=105204&t=105204
