2003 Isuzu Ascender V8 5.3L Thermostat with Housing Assembly TRQ ECA92439

You wanna have a nice collection bucket, something that's gonna be able to collect and be able to recycle that coolant when we're done. We'll pull them over here, and if you were to look right up along the side of the radiator, on the bottom left-hand corner, you're gonna see right on the corner, there should be a little petcock, it's like a little twisty knob. You will turn that to the left and then, of course, as it turns to the left and started coming out, coolant will come out. It might make a mess, so, of course, be very careful. Now, our petcock is broken, but this is what it should look like right here. You would just grab this little knob, turn it counterclockwise, you can see it opening up and at this point, coolant will come out the side. If you were to look right down here, you're gonna see a clamp. If you were to look at the other end where it connects on to the throttle body, you're gonna see another clamp. You go ahead and loosen those up. Also, if you come right up here, you're gonna see an 8-millimeter bolt. If you loosen that up, you can take this right out. Once you have that out of the way, and the clamps are loosened, you can wiggle this around. I'm gonna draw it off of the throttle body right here. I'm gonna come right there, take it off right here, and remove it from the vehicle.

All right. You don't need to remove this, this is just for video purposes. At this point, we're gonna go ahead and use our serpentine belt tool or you can use a 15-millimeter socket. Get right on that tensioner, relieve tension, and slide the belt off of your idler pulley. There we are. I'd like to go ahead and take the belt right out of here so I can clearly inspect the whole thing. If you're worried about the routing, you can look right here. We're going to remove our AC belt. Some people will say that you don't necessarily need to, but I would recommend it because coolant's gonna be coming out and it could contaminate your belt. Twist that clockwise, and remove the belt. Now, we removed the fan clutch so you have a nice easy view for the video, but you don't necessarily need to do it for the job.

Next, we're gonna remove this clamp right here. Just loosen it up enough to get the hose off of your thermostat housing. As you can tell, this clamp is in poor condition and it's not functioning well, it needs to be replaced. Just give this a little tug, be careful because coolant could come out. Nice. Let's go ahead and remove that thermostat housing. Give it a little wiggle, should break right free. Now, we're just gonna clean up the area where the thermostat is gonna go. Now it's gonna be time to get our thermostat in here. You definitely wanna make sure that if you're not replacing the whole thermostat, you at least replace your gasket. Now we're gonna take our thermostat and our housing, we're gonna line up the gasket with this little air piton here. You can see it rattling around. That's going to line up right here, that's gonna be the upper area. Okay. Just slide that right in. Make sure the gasket's sitting flush and it's not damaged in any way or curled. I'm just gonna shoot off right towards the passenger side there. We'll go ahead and start in both the bolts before we tighten any of them down, and then we'll snug them up, and we'll torque them to 11 foot-pounds.

Now, it's time to get the hose on here. Just double-check your clamp, make sure it's in good condition. If it's not, go ahead and replace it. Just all the way on there. Slide it all the way so it bottoms out, and then snug up your clamp. Okay. Give it a nice check, make sure it can't spin around and it's definitely not sliding off. Next, we're gonna put on our AC belt. To do that, you're gonna use your ratchet with a short extension. Put the AC belt down in here where it's gonna go. It's gonna go right around the crack into that inner pulley area, okay? Line it up, bring it around. We'll get that close to the AC, just like that. I'm gonna see if I can get my extension and under here. Sometimes it can be difficult. If for some reason you can't, just go ahead and remove the belt a little bit, bring this down, and then put the belt over. Double-check it, make sure it's sitting inside all the grooves on all the pulleys. This feels good. Get this out of there. Awesome. Go ahead and get our serpentine belt on here. To do that, I'm gonna take the belt, and I'm gonna put it right around the crank just like this. I'm coming down along the passenger side of the water pump right here.

At this point, I'm gonna take one side and I'm gonna go over the tensioner, and I'm just going to leave it there for a second. Then I'll bring this other side down underneath the power steering pump right here, and then up and over the alternator. You can see that it's nice and loose, that's because it needs to come underneath the idler. Before we do that, we're gonna come right here, and we're gonna make sure that our tensioner is in the open position. Bring this down, grab this, put it right under. Perfect. Let's get our air intake back on here. It's gonna go right underneath this hose here, line it up there. Grab this, slide it in, push it all the way in so it's up against the whole throttle body. Make sure your clamps are nice and tight. Your hose over here should have a little clippy-do. Ours is actually broken, but it's gonna push in right there and that'll hold it secure. Put this cover back on here, just slide it all the way back so it's sitting inside the pitons. Put this down, and tighten up your bolt. Real quick before we go too much further, let's go ahead and check that petcock, make sure it's nice and tight.

Now, it's gonna be time to fill your cooling system. When you fill the cooling system, it's important to use the proper coolant. You'd want to use Dex-Cool. Dex-Cool is going to be kind of like a reddish, pinkish fluid. If you don't have access to Dex-Cool, you could also use a universal fluid, but you definitely don't want to use green. I'm gonna use universal, that's what I have access to. I'm just gonna fill this right up and then we'll run it for a little while here. You wanna look for the full cold while the engine's cold. Once it heats up, of course, the coolant level is gonna come up a little bit. But to start, we want it to be at full cold, we're gonna run it for a little while, and then we're gonna double-check just to make sure it's full. All right, so now that we've run it for a little while, everything's nice and hot, I'm just going to put this cap on and then we're gonna take it for a road test.

Remove this cover, I'm gonna use an 8-millimeter socket. Loosen that bolt up and slide the cover out. And loosen up this worm clamp, you can use an 8-millimeter socket or a straight blade screwdriver. And the same with this one right here. Use a trim tool and just separate this retainer right there with that bracket. Now slide the snorkel off there and pull it out. Just to gain more access, I'm gonna pull this airbox off. Disconnect the mass air flow sensor. Grab the airbox, pull it straight up, then you can slide it out. There's two tabs, and this holds it in. I'm just gonna take the cap off the coolant reservoir, set it aside.

I'm gonna take the bottom radiator hose off. I need to drain the coolant, there's no coolant drain on this radiator. So I'm gonna use a hose clamp pliers that have the cable style. Remove that hose clamp. Make sure you have a drain bucket underneath. Squeeze that. And just let that drain out. Now I'm gonna take this hose off, just use some hose clamp pliers. And let's twist the hose a little bit. If you can't get it to break free just use a 90-degree pick, try to get underneath there, or a hose pick. Slide the hose off. There might be a little coolant in there.

Now there's two bolts, one here and one underneath the housing. Use a 10-millimeter socket, take those bolts out. So take both of those bolts out, should be able to slide it off. Keep the drain bucket underneath because it'll probably spill some more coolant out, and get it out. Just take a rag, just clean this area up. If you have a lot of corrosion on here just use a razor blade or a scraper, scrape some of that off, or even a wire brush. Now take the thermostat and housing, slide it in position. And take the two bolts, get them started. And torque these bolts to 11-foot-pounds.

Now take the hose, line the hose up with the clamp, use the hose clamp tool. And if these clamps seem weak, then replace them with a worm clamp. And slide the airbox back in position. What you want to do is slide this piece, that's gonna go right here. It's gonna slide there and then push the two pushpins straight down. Push down, it's good to go. Reconnect the mass air flow sensor. And put the snorkel back on. Line this up with the throttle and the airbox. And tighten up the worm clamps. And line this bracket back up. Put the cover on, slide it in the back, get the bolt started, snug it down.

Now you want to fill up the coolant reservoir. I fill it up about an inch or two above where the fill line is before we start the vehicle and start the vehicle with the cap off. And the level is gonna adjust, it's probably gonna suck some into the engine and then after that you're gonna adjust accordingly. Let the vehicle run for about 10 minutes, monitoring the level. While you're letting it run, monitor the temperature gauge, make sure it does not go over 210 degrees. If it does then shut the vehicle off. Let it cool down, top off the coolant and try it again.

Turn the heat on, put it on medium fan. Turn the heat all the way up to hot. Make sure you do feel some heat coming out of the vents, especially when the temperature starts getting up there. If you don't feel any heat, again your coolant level is gonna be too low, shut the vehicle off, top off the coolant. And then after that, after the thermostat has opened up when the hoses are nice and hot, shut the vehicle down, adjust accordingly, put the cap back on and you should be good to go.