3100 V6 Thermostat

[MrAbody]

Hi, is there a trick to replacing the thermostat on the 3100 v6? Mine is stuck behind the exhaust manifold that wraps around the engine, I see no way of getting a socket on the lower nut to the thermostat housing. Can anyone let me know if there is a 'trick' to this????? Thanks in advance!

[Anonymous]

Umm.. the 3100 thermostat housing is on the top of the engine, there is a hose that goes to the top of the rad.. I don't see how you could be having trouble with that unless you are trying to take apart something that is not the thermostat

[Rhedalert]

Re: 3100 V6 Thermostat

Hi, is there a trick to replacing the thermostat on the 3100 v6? Mine is stuck behind the exhaust manifold that wraps around the engine, I see no way of getting a socket on the lower nut to the thermostat housing. Can anyone let me know if there is a 'trick' to this????? Thanks in advance!

I think the procedure involves removal of the crossover pipe (6 bolts, 13mm), then you could get it no problem.

[v6h.o.]

no, dont remove the crossover, its a pain to do it htat way,

take it from a gm tech:
remove the air intake duct to the t/body,
unhook the coolant lines from the t/body,
remove the throttle body,
now there is two 13mm bolts.
the rear one actually has a slot in the therm housing, so you can leave it still in there by a few threads and pull the housing off, and get the t/stat out and put the new one it, put the housing back on and then just tighten that rear bolt. put the other bolt in and put it all back together.

[Cliff8928]

Umm.. the 3100 thermostat housing is on the top of the engine, there is a hose that goes to the top of the rad.. I don't see how you could be having trouble with that unless you are trying to take apart something that is not the thermostat

Actually, it's kinda crammed between the intake and crossover pipe..

easiest way to show it is here (picture from www.killerbv6.com)




Cliff Scott
89 BerettaGT
89 Volvo740

[montecarlols(z31)96]

just remove your intake and tb, then its very simple

[3100 MPFI]

removing the crossover is not that hard. I think that I would rather take the crossover off to change it out than try to get around it.

[lugnut111]

I just change the thermostat in my 98 Lumina with the 3.1, It was pretty easy. Remove the throttle body. leave the throttle and cruise control cables attached and set it aside. Removed the two small hoses and also removed the hose from the thermostat housing neck. This made it a little easier to maneuver the housing. Basically do what v6h.o. said. There still isn't much room to get a wrench in on the bottom bolt of the housing. I used a gear wrench to get it off.

[MasterJacko96]

I just change the thermostat in my 98 Lumina with the 3.1, It was pretty easy. Remove the throttle body. leave the throttle and cruise control cables attached and set it aside. Removed the two small hoses and also removed the hose from the thermostat housing neck. This made it a little easier to maneuver the housing. Basically do what v6h.o. said. There still isn't much room to get a wrench in on the bottom bolt of the housing. I used a gear wrench to get it off.

thats what i did

[acascianelli]

no, dont remove the crossover, its a pain to do it htat way,

take it from a gm tech:
remove the air intake duct to the t/body,
unhook the coolant lines from the t/body,
remove the throttle body,
now there is two 13mm bolts.
the rear one actually has a slot in the therm housing, so you can leave it still in there by a few threads and pull the housing off, and get the t/stat out and put the new one it, put the housing back on and then just tighten that rear bolt. put the other bolt in and put it all back together.

i still dont see how you can get to the lower bolt of the thermostat housing...do you have any pictures of a 3100 in a car where it would be easier to see this?

[Rhedalert]

As to the lower bolt, the hole on the housing for it is SLOTTED so you'd only need to turn it a few times, then lift the housing out and up. Just did it to my '95!

[acascianelli]

i still cant figure out how to get a socket or something to even turn the lower bolt.

[Rhedalert]

I'm pretty sure I just used a wrench, box end. Either that or a shallow socket with a U-joint behind it.

[dbtk2]

My crossover, due to using my stock turbo manifolds and crossover, didn't even clear the thermostat housing. I had to grind away on the outside of the crossover with a dremel, and then I had to grind away at the outside of the t-stat housing cover, so there was VERY little room in there. However, with everything else completely assembled (I had everything put together after my topend swap, except I was missing the t-stat housing so I was waiting on it) I didn't have any problem getting an open end wrench in there to tighten it down. The problem was getting the stupid housing and thermostat to go down in there with that little amount of clearance...I did it by some miracle though. But it shouldn't be THAT difficult to not remove anything and stick a wrench down in there, i could be wrong though.

Shawn

[acascianelli]

so to get a box end wrench on the lower bolt, do you need to remove the throttle body?