In case anyone needs a radiator replaced before winter, I did this yesterday in my 2003 3.4, wasn't too bad, here are some notes, but no where near as helpful as the how-to:
Footnotes - 3.4 2003 Impala Radiator replacement.
1) Tools needed:
Cable activated hose clamp piers (not required but a HUGE time saver)
Metric sockets/ratchets
Small screwdriver for Trans cooler line retaining clips
Pliers
Metric line wrenches or open ended wrenches for cooler lines.
2) Parts:
Radiator (Raked over coals for 133 bucks @ Autozone, but car not worth a better brand).
New upper/lower Radiator hoses (Optional, might as well, while it's apart. My lower was getting thin so I replaced it.)
Dex-Cool (Orange) AntiFreeze
New Radiator cap (Maybe optional? If yours doesn't look so hot?)
Notes - Wait til engine has cooled down. I jacked up front of car and secured on jackstands, this helped
immensely. You will need to spend a little time under the car to get to everything. Also, my
radiator did not have a coolant level sensor on it like some of the other year/makes/models. From beg to end
not counting time to get parts, this took me about 2 hours.
1) Remove angled cross members going from front to back of the hood. There is one on each side of the
engine bay, going at a 45 degree angle front to back. One goes over the battery,
the other over the airbox. Airbox is in three sections, from rear to front of car:
rear section houses aircleaner, middle
section joins the middle to the back where the PCM computer module is, and then the front portion
houses the PCM and routes to the inside of the driver's side headbulb. You may have to remove the
driver side headlamp assembly to jostle the airbox loose. Do not mess with or disconnect the PCM
wires at all - it should all be moveable just to get it out of your way.
2) Disconnect battery cables, disconnect battery hold down, and remove the battery. You will have to remove from an angle, it's a tight squeeze.
3) Loosen clamp @ air box connecting the snorkel going from the throtte body to the airbox itself.
Move snorkel out of your way.
4) Unclip the air cleaner housing (two clips, then lift up).
5) Remove air cleaner.
6) Loosen and remove screws @ top of airbox holding airbox to the remainder of the airbox housing.
Remove middle section.
7) Move the airbox/PCM enough to gain easier access to upper radiator hose and electric fans.
8) Remove the lower air dam underneath the bumper - 4 10mm bolts secure it in place.
9) Remove the radiator cap.
10) Disconnect the lower radiator hose from the radiator. This will drain your antifreeze, so make sure
you can catch it or drain it somewhere safe away from you and pets, grass, etc. This is where the
cable activated pliers come in the most handy.
11) On each side of the front of the hood, you will see two brackets securing the front motor mounts to
the core support. Loosen and remove the three bolts on each side, and swing the brackets out of your
way. The engine might move a little when you do this - that is ok since it is meant to pivot.
12) Disconnect hose at radiator leading to the coolant overflow reservoir.
13) Disconnect upper radiator hose from the radiator using pliers.
14) You should have somewhat easier access to the electric fans now. You will see two plugs going into
your elec. fans. Mark each one so you know which side they go on. Unclamp the harness from the fan,
then remove the plugs from each side of the fan. Make sure the harness is completely free from the
fans.
15) Loosen the two transmission cooler lines from the radiator. 19 MM line wrench will do the job. On
the bottom of the fan assembly, there is a bracket securing the cooler lines. Carefully pry the lines
out of the bracket.
16) Four bolts and a pin secure the fans to your radiator. Two bolts are on each side of the fan assembly,
and two are at the top held in with brackets. Note how the upper brackets are assembled. The bottom
pin will pop out with a screw driver, you will see it on the driver's side bottom portion of the
fan assembly. Loosen and remove all brackets, bolts, and pin from fan assembly.
17) Gently lift the fan assembly out of the engine bay and carefully set aside.
18) The radiator should come out next. Gently lift it out of engine bay. At this point, it's the
easiest time to set up your new upper/lower rad hose, or you can wait until #25. The bottom rubber
mounts may or may not come with it, but make sure the new radiator has mounts on it. More to come
later on that.
19) The new radiator I purchased came with new cooler line fittings. In order to replace the existing
cooler line fittings, you will see a small metal clip retaining the fittings on the lines. Take a
tiny screwdriver, and pry the retaining rings off of the cooler line fittings. Once the little retaining clips are off, the existing fittings should pop right off. Follow the instructions that
come with the new fittings to replace. Take your time and read carefully, you don't want to deal
with cooler line leaks.
20) The bottom of the radiator should have two rubber mounts that slide right onto the radiaor.
Make sure the bottom radiator mounts are secured onto your new radiator. Lower new radiator into the
engine bay, and make sure it's secure.
21) Next, install the elec fans back onto the new radiator with the four mounting bolts. You could do
this before you install the radiator, but I had an easier time lowering the radiator in, and then
attaching the fans to the radiator while it was in the engine bay. When it's all said and done,
the fans and the radiator are an assembly, attached to eachother with bolts and brackets.
22) Tighten and secure the trans cooler lines onto your new radiator. Finger tighten as much as you can
first in order to prevent cross threading of the new lines. I was able to finger tighten mine quite
a bit before wrench tightening. Be careful, cross threading will void any warranty. Make sure the
lines are also secured in the bracket on the bottom of the fans.
23) Replace fan plugs and secure fan wiring harness back onto the fan assembly. Make sure wires are
free and clear of any moving parts, and that you plugged them back in the same exact place.
24) Reconnect the two upper motor mount to core support brackets from step 11 - you may need to
carefully pry the engine forward to secure the three bolts on each side.
25) Replace and/or re-attach lower radiator hose, upper radiator hose.
26) Reassemble the air box assembly, and re-attach the snorkel to your airbox. Make sure this is
secure to prevent any malfunction of MAP sensor or IAT sensor. Verify the airbox and snorkel is
assembled and secure.
27) Place battery back into engine compartment. Re-attach battery cables.
28) Put the lower airdam back into place underneath the bumper.
29) Reattach cross member brackets in engine bay. Recall there is one on each side, driver and passenger.
30) Reattach the overflow tank hose to new radiator. You may need a new clamp, I did since the OEM
radiator had a slightly smaller inlet.
31) Double check to make sure you re-installed all hoses and wiring.
32) Dilute Dex-Cool 50/50 if not already diluted and fill up the overflow tank slightly above the fill
line. Might took roughtly 1.5 gallons of diluted antifreeze when it was all said and done.
33) Fill up the radiator as much as possible with 50/50 Dex Cool mix. Put Radiator cap on.
34) Start car with heater on. Run for approx 15 seconds. Remove radiator cap, and fill radiator to top.
35) Replace cap. Fill overflow tank to fill line if necessary.
36) Slightly loosen the bleed fitting on the thermostat housing. You have air in your cooling system,
and so it needs to be bled.
37) Start car, and let run with heater running as well. Note the temp on the dashboard. Do not overheat.
The goal here is to bleed the cooling system, and fill as needed. If you are not getting heat after
your engine is running to temp (approx 180-210 degrees), then you either are low on coolant, and/or there
is excessive air in the system.
38) Once the bleeder on the thermostat is bleeding some coolant without air bubbles, then your system
is close to bled. You will know if there's air in the system if you hear gurgling coming from under
the dashboard. It took me approx 20 minutes to get all air out of the cooling system. Re-tighten the
bleeder screw. Make sure the bleeder screw is not left loosened while operating the vehicle.
39) Let the car run with the heat on. Check for leaks at all hoses as well. Confirm that your elec.
fans are running as well. If you have steady engine temp, no leaks, good heat, fans running, no gurgling, and a properly filled overflow tank, you should be good to go.
Footnotes - 3.4 2003 Impala Radiator replacement.
1) Tools needed:
Cable activated hose clamp piers (not required but a HUGE time saver)
Metric sockets/ratchets
Small screwdriver for Trans cooler line retaining clips
Pliers
Metric line wrenches or open ended wrenches for cooler lines.
2) Parts:
Radiator (Raked over coals for 133 bucks @ Autozone, but car not worth a better brand).
New upper/lower Radiator hoses (Optional, might as well, while it's apart. My lower was getting thin so I replaced it.)
Dex-Cool (Orange) AntiFreeze
New Radiator cap (Maybe optional? If yours doesn't look so hot?)
Notes - Wait til engine has cooled down. I jacked up front of car and secured on jackstands, this helped
immensely. You will need to spend a little time under the car to get to everything. Also, my
radiator did not have a coolant level sensor on it like some of the other year/makes/models. From beg to end
not counting time to get parts, this took me about 2 hours.
1) Remove angled cross members going from front to back of the hood. There is one on each side of the
engine bay, going at a 45 degree angle front to back. One goes over the battery,
the other over the airbox. Airbox is in three sections, from rear to front of car:
rear section houses aircleaner, middle
section joins the middle to the back where the PCM computer module is, and then the front portion
houses the PCM and routes to the inside of the driver's side headbulb. You may have to remove the
driver side headlamp assembly to jostle the airbox loose. Do not mess with or disconnect the PCM
wires at all - it should all be moveable just to get it out of your way.
2) Disconnect battery cables, disconnect battery hold down, and remove the battery. You will have to remove from an angle, it's a tight squeeze.
3) Loosen clamp @ air box connecting the snorkel going from the throtte body to the airbox itself.
Move snorkel out of your way.
4) Unclip the air cleaner housing (two clips, then lift up).
5) Remove air cleaner.
6) Loosen and remove screws @ top of airbox holding airbox to the remainder of the airbox housing.
Remove middle section.
7) Move the airbox/PCM enough to gain easier access to upper radiator hose and electric fans.
8) Remove the lower air dam underneath the bumper - 4 10mm bolts secure it in place.
9) Remove the radiator cap.
10) Disconnect the lower radiator hose from the radiator. This will drain your antifreeze, so make sure
you can catch it or drain it somewhere safe away from you and pets, grass, etc. This is where the
cable activated pliers come in the most handy.
11) On each side of the front of the hood, you will see two brackets securing the front motor mounts to
the core support. Loosen and remove the three bolts on each side, and swing the brackets out of your
way. The engine might move a little when you do this - that is ok since it is meant to pivot.
12) Disconnect hose at radiator leading to the coolant overflow reservoir.
13) Disconnect upper radiator hose from the radiator using pliers.
14) You should have somewhat easier access to the electric fans now. You will see two plugs going into
your elec. fans. Mark each one so you know which side they go on. Unclamp the harness from the fan,
then remove the plugs from each side of the fan. Make sure the harness is completely free from the
fans.
15) Loosen the two transmission cooler lines from the radiator. 19 MM line wrench will do the job. On
the bottom of the fan assembly, there is a bracket securing the cooler lines. Carefully pry the lines
out of the bracket.
16) Four bolts and a pin secure the fans to your radiator. Two bolts are on each side of the fan assembly,
and two are at the top held in with brackets. Note how the upper brackets are assembled. The bottom
pin will pop out with a screw driver, you will see it on the driver's side bottom portion of the
fan assembly. Loosen and remove all brackets, bolts, and pin from fan assembly.
17) Gently lift the fan assembly out of the engine bay and carefully set aside.
18) The radiator should come out next. Gently lift it out of engine bay. At this point, it's the
easiest time to set up your new upper/lower rad hose, or you can wait until #25. The bottom rubber
mounts may or may not come with it, but make sure the new radiator has mounts on it. More to come
later on that.
19) The new radiator I purchased came with new cooler line fittings. In order to replace the existing
cooler line fittings, you will see a small metal clip retaining the fittings on the lines. Take a
tiny screwdriver, and pry the retaining rings off of the cooler line fittings. Once the little retaining clips are off, the existing fittings should pop right off. Follow the instructions that
come with the new fittings to replace. Take your time and read carefully, you don't want to deal
with cooler line leaks.
20) The bottom of the radiator should have two rubber mounts that slide right onto the radiaor.
Make sure the bottom radiator mounts are secured onto your new radiator. Lower new radiator into the
engine bay, and make sure it's secure.
21) Next, install the elec fans back onto the new radiator with the four mounting bolts. You could do
this before you install the radiator, but I had an easier time lowering the radiator in, and then
attaching the fans to the radiator while it was in the engine bay. When it's all said and done,
the fans and the radiator are an assembly, attached to eachother with bolts and brackets.
22) Tighten and secure the trans cooler lines onto your new radiator. Finger tighten as much as you can
first in order to prevent cross threading of the new lines. I was able to finger tighten mine quite
a bit before wrench tightening. Be careful, cross threading will void any warranty. Make sure the
lines are also secured in the bracket on the bottom of the fans.
23) Replace fan plugs and secure fan wiring harness back onto the fan assembly. Make sure wires are
free and clear of any moving parts, and that you plugged them back in the same exact place.
24) Reconnect the two upper motor mount to core support brackets from step 11 - you may need to
carefully pry the engine forward to secure the three bolts on each side.
25) Replace and/or re-attach lower radiator hose, upper radiator hose.
26) Reassemble the air box assembly, and re-attach the snorkel to your airbox. Make sure this is
secure to prevent any malfunction of MAP sensor or IAT sensor. Verify the airbox and snorkel is
assembled and secure.
27) Place battery back into engine compartment. Re-attach battery cables.
28) Put the lower airdam back into place underneath the bumper.
29) Reattach cross member brackets in engine bay. Recall there is one on each side, driver and passenger.
30) Reattach the overflow tank hose to new radiator. You may need a new clamp, I did since the OEM
radiator had a slightly smaller inlet.
31) Double check to make sure you re-installed all hoses and wiring.
32) Dilute Dex-Cool 50/50 if not already diluted and fill up the overflow tank slightly above the fill
line. Might took roughtly 1.5 gallons of diluted antifreeze when it was all said and done.
33) Fill up the radiator as much as possible with 50/50 Dex Cool mix. Put Radiator cap on.
34) Start car with heater on. Run for approx 15 seconds. Remove radiator cap, and fill radiator to top.
35) Replace cap. Fill overflow tank to fill line if necessary.
36) Slightly loosen the bleed fitting on the thermostat housing. You have air in your cooling system,
and so it needs to be bled.
37) Start car, and let run with heater running as well. Note the temp on the dashboard. Do not overheat.
The goal here is to bleed the cooling system, and fill as needed. If you are not getting heat after
your engine is running to temp (approx 180-210 degrees), then you either are low on coolant, and/or there
is excessive air in the system.
38) Once the bleeder on the thermostat is bleeding some coolant without air bubbles, then your system
is close to bled. You will know if there's air in the system if you hear gurgling coming from under
the dashboard. It took me approx 20 minutes to get all air out of the cooling system. Re-tighten the
bleeder screw. Make sure the bleeder screw is not left loosened while operating the vehicle.
39) Let the car run with the heat on. Check for leaks at all hoses as well. Confirm that your elec.
fans are running as well. If you have steady engine temp, no leaks, good heat, fans running, no gurgling, and a properly filled overflow tank, you should be good to go.
