How to instaal seal "o-ring''

The thermostat housing is at the end of the upper radiator hose. There should only be 2 10mm bolts holding the thermostat housing to the engine. Remove the 2 bolts, pull the housing off of the engine. Remove the old thermostat. Clean everything around where the thermostat goes on the housing and the engine side. Install new thermostat with new o-ring seal. And reinstall housing. Top off cooling system and bleed any air out of system with bleeder that is ontop of housing.

The oil is probably leaking into the spark plug wells from the seals at the bottom of the pipes that constitute the wells. The wells may pull out with the plugs removed and have a seal at the top, but the bottom of the pipes may have been damaged if they are held in place by the plugs. Another method is to hold the pipes in place in the head with 'o' ring seals and these may have developed a leak, allowing oil from the tappet cover to get into the plug well.

The valve cover has rubber o-ring seals that fit into the valve cover and seal oil out of the spark plug wells. Over time, they get hard and shrink, allowing oil to enter the plug wells from the top of the engine. You need to remove the valve cover and replace the valve cover gasket and o-ring seals. The seals should come with the valve cover gasket set.

Hope this helps,
Dave

do both,that way you know its fitted properly
(have you tried lighting a cigarette, sat inside the car with all them fumes,,,,,cars do fly......)

You need talking with the parts guy at the GM dealer You need the "new" style thermostat housing to be able to change just the thermostat. So I ordered a new thermostat housing assembly. Here is what I got, a new aluminum two piece housing and thermostat. Hopefully tomorrow I can get this car back on the road and out of my shop.





2004-2007 Chevrolet Aveo Thermostat Housing MTC Part W0133-1624867

Or search HERE

Hope helped.

Two piece where the thermostate sandwitched in the middle with the O ring to seal the two.But why they blew appart would be a better question.

If you follow the top hose from the radiator to the motor you'll notice a housing where the hose meets the motor. Disconnect the hose and remove the two bolts holding the housing in place. Remove the housing and the thermostat is underneath. When you replace it make sure the old gasket is completely removed and replaced with a new one. If pieces of the old gasket remain you will nto get a good seal and will eventually end up with leaks.

If you are looking for where to buy the part then I'd recommend the dealership.
If you are trying to find out where the part goes then you will have to remove the transmission and then pull the torqconverter out and the seal is righ there.

You do not need to take the headlight assembly out. It is not a sealed beam. There is a ring that locks the light bulb in, found on the back. The drivers side is much easier if you remove the battery. As with all Halogen bulbs, do not touch the bulb with your fingers as it will shorten their life.

This is a notorious Aveo problem, These are poorly made.You need a new thermostat housing it includes the thermost on the 04-05' Aveo. It is all one sealed part from the factory.The original part is made of plastic. Chevy has an aluminum one now that won't break but it's MSRP price from the dealer is $91.78 got one and put it on my mothers car works fine now. So you can't just put a new thermostat in it you need the whole housing which already has the thermo. in it.