Thermostat replacement On A 99

[DRW1000]

Hi Everyone,
I'm about to replace the thermostat on my 99. I did a search under "thermostat" and I read my chilton's but i am a bit confused. It looks like i will have to remove an exhaust crossover pipe. The photo in the Chilton's doesn't really show how to remove it. Is it necessary to remove? Is it starightforward? Does anyone have any tips about removing the crossover pipe? I think I need to remove a shield and then 3 bolts on the crossover. Is this correct? Do I only have to remove one end of this pipe? Any help would be appreciated.

[J-Ri]

You don't need to remove anything but the thermostat housing. But to do it that way, you will need swivel sockets (not a socket and a universal joint, there is one that has the two combined that fits in a tighter space), a ratcheting wrench, and a stubby wrench. It's a PITA, but I can do them in 1/3 of the flatrate time. You might find it easier to remove the heat shield from exhaust, and some people remove the throttle body. If I were you, I'd check the lower intake gasket, if it's leaking, replace the gasket and the thermostat at the same time. It's soooo much easier with the lower intake off the engine

[merc81]

The exhaust crossover is not hard to remove and you really should get in there to have a good look around for leaks--under the thermostat area is where many gasket leaks show up.
Its IS a pita, but really, any job on this engine takes time. Consider how much you are saving as you do the work. . .

[DRW1000]

Thanks for the hekp. I actually noticed I was low on coolant. I don't know where it's going but I needed about 4 to 5 litres. For now I will leave the tstat in place.

BTW It is amazing at how difficult it is to do anything on this engine. Even filling the brake fluid is hard. The air filter is almost inpossible. The battery is under the fuse box. The only thing that was easy was the water pump. Did that in about an hour,

[paprius4030]

Originally Posted by DRW1000

Thanks for the hekp. I actually noticed I was low on coolant. I don't know where it's going but I needed about 4 to 5 litres. For now I will leave the tstat in place.

BTW It is amazing at how difficult it is to do anything on this engine. Even filling the brake fluid is hard. The air filter is almost inpossible. The battery is under the fuse box. The only thing that was easy was the water pump. Did that in about an hour,

If you continue to be low on coolant and don't know where it's going be on the look out for an intake manifold leak, it will cause problems down the road if not fixed. These vans are notorious for this problem

[merc81]

Yea, the water pump is placed in a good spot
The engine isn't that hard to work on--its just a different kind of beast and takes getting to know your way around in there. Some things, like that T-stat are only coming out if you take off all the stuff in the way first. Those things are made to come off pretty quick though--like the exhaust crossover pipe.

Try working on a 2000 chevy Astro with the 4.3 engine shoehorned in there. There's a piece of work. You can't even reach the alternator without laying down on the engine and having long arms. I'll take the 3.4 in the venture any day over that.