Thermostat replace without removing crossover

[03Alerosil]

Hey guys,
I have to do a coolant flush in my wife's 3.4 2005 Impala. Same engine set up as our Alero's. While doing it I am going to replace the thermostat cuz god only knows how long it's been in the engine for the last 160,000 miles.

Is there an easier way to change the thermostat? I did the one on my 3.4 Alero but I did it when I did my LIMG. Everything I have seen says you have to remove the exhaust crossover. Is there a way around doing that? I'm not scared to remove it, I just don't feel like breaking exhaust bolts.

I should also add I'm doing this as regular maintenance and the fact that the Dex-Cool in it is original and turning to sludge.

[Starglow]

No...you do not need to remove the cross-over pipe to change the T-stat. The right side bolt hole on the T-stat housing is slotted so technically you don't have to remove that bolt entirely. It may help to remove the throttle body for better access to the T-stat housing bolts. I've done it without removing the T-body however you'll have to clamp open the spring loaded throttle plate in order to get tool access to the T-stat housing bolts. You'll need some decent wrenches, curved ones are even better. Expect to turn the bolts only 1/4-1/2 turn each time which is a slow process but patience is the key.

Regarding the Dexcool...I no longer use that in my GA and just use regular anti-freeze like many others have done without issues so you don't have to use the Dexcool. Just make sure you flush out the cooling system really well and there are engine block drain bolts on each side of the engine which is the bolt just to the right of the knock sensor "A" in this photo.

http://i10.photobucket.com/albums/a138/Starglow/DSCF0188_zps1bb1e584.jpg (http://s10.photobucket.com/user/Starglow/media/DSCF0188_zps1bb1e584.jpg.html)

[03Alerosil]

Cool. Thanks for the help man. I have big hands so I will probably remove the throttle body. It could probably use a cleaning anyway. Going to flush out the heater core too. Anyone know how many gallons the cooling system holds?

[Starglow]

Cool. Thanks for the help man. I have big hands so I will probably remove the throttle body. It could probably use a cleaning anyway. Going to flush out the heater core too. Anyone know how many gallons the cooling system holds?

I generally do my own 50/50 mix with water on a fresh full refill...so one gallon of the Prestone concentrate gives me 2-gallons of mixed antifreeze which is more than enough plus some extra left over for topping off as needed. You are supposed to only use distilled water for the cooling system but I have a reverse osmosis water treatment system which is fine for me...so you'd need one gallon of the concentrate and one gallon of distilled water to yield two gallons of 50/50 mix. You can also buy the 50/50 premixed which I sometimes do for topping off or partial drain refills but it's a bit more expensive.

[Starglow]

Going to flush out the heater core too.

If the heater core hoses connecting to the engine side metal coolant tubes still have the plastic quick connects present then you might want to remove those while you're in there because they're prone to get brittle from heat over time and eventually leak..ask me how I know. :lol: They are used for ease of assembly during vehicle manufacturing and are otherwise not required. I replaced the heater core rubber hoses with new ones from NAPA and they were plenty long enough to reach with the plastic quick connects removed. Something else you might also want to think about @ 160K is replacing all of the rubber cooling system hoses if they are known originals.

[03Alerosil]

If the heater core hoses connecting to the engine side metal coolant tubes still have the plastic quick connects present then you might want to remove those while you're in there because they're prone to get brittle from heat over time and eventually leak..ask me how I know. :lol: They are used for ease of assembly during vehicle manufacturing and are otherwise not required. I replaced the heater core rubber hoses with new ones from NAPA and they were plenty long enough to reach with the plastic quick connects removed. Something else you might also want to think about @ 160K is replacing all of the rubber cooling system hoses if they are known originals.

They are original with the exception of the bypass hose and the coolant pipe hoses under the throttle body. I will replace the upper and lower radiator hose.

[03Alerosil]

Well i went on Rockauto.com today and ordered the parts. All Gates brand. Upper and lower radiator hoses. 195* thermostat. Belt tensioner....makes noise. I also picked up a Wix oil and fuel filter cuz it's time for both of those and being I am doing it at school and have access to the hoist I figured good time to change both.

[aleros_eat_rice]

Good idea to replace the quick disconnects. Mine broke in the AutoZone parking lot (thankfully they had replacements in stock).
The rest of the time, you won't have the luxury of those waiting to break in a convenient place like that.

[zzyzzx]

I still have my original plastic ones (assuming that's what came with a 99 V6). Isn't there a metal (brass), presumably aftermarket option?

[03Alerosil]

How do you replace the quick disconnects? Could I just get did of them?

[03glgold]

in 03' the had a different system than with the early aleros, I believe it was another thing they changed in 01'

[Starglow]

How do you replace the quick disconnects? Could I just get did of them?

I got rid of them entirely on my '99 and connected the heater core hoses directly to the metal coolant pipes on the engine side with hose clamps...it's been like that for almost two years now without issue.

[03Alerosil]

I got rid of them entirely on my '99 and connected the heater core hoses directly to the metal coolant pipes on the engine side with hose clamps...it's been like that for almost two years now without issue.

Cool that's what I was wondering. My wife's Impala's engine bay is almost identical to my Alero so it's got the same quick disconnect system. I will just delete the quick disconnects if they look brittle or bad.

[aleros_eat_rice]

There probably is a metal replacement, I just went with the quickest option.

[Nas Escobar]

You can make your own replacements with a barb. That's what I did but I have the redhead 60 degree and I deleted it from the LIM to heater hose.

[03Alerosil]

I got 4 gallons of 50/50 dexcool to use after the flush. Going to flush the radiator repeatedly. I am also going to flush the block until the water comes out clean of the lower radiator hose. Then I am going to flush everything out the block drains. Scrubbing all the crap out of the overflow tank as well. After it's all done I change out the thermostat, upper and lower radiator hoses, heater hoses as well. Already did the ones on the bypass pipe. Water pump should be ok as it only has 20,000 miles on it.

Car never had a cooling issue. So not worried about that. The dexcool just has 160,000 on it and never been changed.

Changing out the belt tensioner as well. Taking a road trip from Nebraska to Michigan next month and wanna be prepared

[Nas Escobar]

Take out the thermostat first so the water flows, otherwise you'll have to wait until the thermostat opens.

[03Alerosil]

I planned on taking the thermostat out first. That's the main reason I am replacing it cuz right now it works just fine. I just thought sense it's hard to get to and I'm going through the trouble of taking it out that I'm going to replace it.

[Starglow]

If the water pump is the original then @160K I'd replace that as well. Don't run the engine too long with just water cooling because doing so isn't good for the water pump bearings since the coolant also serves as a lubricant. Now if you do decide to replace the water pump then leave the old one installed during the water flush if you plan to run the engine.

[03Alerosil]

Water pump, to my knowledge, was replaced around 130k. She had it done before I met her. So I don't plan on changing it. I am going to flush the engine without running it hopefully. If I end up changing the water pump it's no big deal because they are cheap.

[03Alerosil]

Anyone know where the rear block drain is?

[rustyballs_69]

Its just to the left of the crank sensor. Kind of a pain to get to.

[03Alerosil]

What is the best coolant flush additive to use?

[rustyballs_69]

I wouldn't use any, just flush it out with a hose and water.

[03Alerosil]

I wouldn't use any, just flush it out with a hose and water.

Why? It's gelling up and my instructor suggested I use something like prestone to clean it with while using distilled water

[Starglow]

Anyone know where the rear block drain is?

You can see it here in this photo:

http://i10.photobucket.com/albums/a138/Starglow/DSCF0184_zps038d0610.jpg (http://s10.photobucket.com/user/Starglow/media/DSCF0184_zps038d0610.jpg.html)

[Starglow]

Why? It's gelling up and my instructor suggested I use something like prestone to clean it with while using distilled water

You can try the Prestone flush, but if it's gelling up that bad then you might need a new radiator & heater core. Hard to say without seeing it.

[03Alerosil]

Thanks starglow for the picture! It's not really bad that's why I'm flushing it now before something does clog up. The gel parts turn to liquid when you touch it. Heater works great and the car doesn't overheat at all so I'm convinced nothin is clogged.

[03Alerosil]

Went to the local NAPA and bought some Zerex Radiator flush, it will help clean it out without being an aggressive cleaner.

[rustyballs_69]

Why? It's gelling up and my instructor suggested I use something like prestone to clean it with while using distilled water

May or may not do more harm than good. Its just my opinion. If its gelling up you need to flush the coolant more often.

[03Alerosil]

I just found the gelling issue. That's why I got the flush, 6 gallons of distilled water, and 4 gallons of 50/50 dexcool to rectify the issue. My wife owned the car before I met her and she is not good with maintenance and I've only seen 20k put on the car since I met her. It wasn't gelling up when i first met her

[03Alerosil]

Well today is the day. Working on the wife's car and getting all that bad dex cool out as well as the few maintenance items. Wix filters for everything. Mobil 1 High mileage synthetic oil.

[Starglow]

Well today is the day. Working on the wife's car and getting all that bad dex cool out as well as the few maintenance items. Wix filters for everything. Mobil 1 High mileage synthetic oil.

Have fun and good luck. Just remember it's only nuts & bolts and if you start getting frustrated then take a short break. :awesome:

[03Alerosil]

I'm sure it will go ok. Can't be any worse than the transmission I put in a 22 year old Chevy farm truck. Now that was a chore

[03Alerosil]

Well I got the coolant switched out as well as the thermostat and hoses. The rear(firewall side) block drain in a 3.4 is a pain in the butt. I got it out alright using a bunch of extensions, a swivel socket, and a universal. I had to have a little guy put it back in for me because I couldn't get my hand up to it and the socket wouldn't hold it at the right angle. God bless the little people. Well he is little to me. I'm 6'8" 330lbs. He is 5'3" and like 105lbs.

Thermostat wasn't that bad actually. The S-shaped 13mm wrench I have made easy work of it. Sure beats taking the exhaust crossover off. I did remove the throttle body though, it needed a cleaning anyway, and gaskets are cheap.

[zzyzzx]

Well I got the coolant switched out as well as the thermostat and hoses. The rear(firewall side) block drain in a 3.4 is a pain in the butt. I got it out alright using a bunch of extensions, a swivel socket, and a universal. I had to have a little guy put it back in for me because I couldn't get my hand up to it and the socket wouldn't hold it at the right angle. God bless the little people. Well he is little to me. I'm 6'8" 330lbs. He is 5'3" and like 105lbs.

Thermostat wasn't that bad actually. The S-shaped 13mm wrench I have made easy work of it. Sure beats taking the exhaust crossover off. I did remove the throttle body though, it needed a cleaning anyway, and gaskets are cheap.

S shapes 13mm wrench. Got pic of it? There is a special wrench made for this:
http://atdtools.com/3310
http://atdtools.com/images/pics/ATD-3310.gif

http://www.amazon.com/ATD-Tools-3310-Thermostat-Wrench/dp/B00H2VV0UE

NAPA carries it as well.

[03Alerosil]

No I dont. It's just an S shaped snap on wrench that is closed on each end. 14mm on one side and 13mm on the other end.

[sleepyalero]

Ive never had to remove the cross over, its hard but doable with some thinking with a normal wrench.

[richardg]

^x2 I've done it both ways, with and without.