900se v6 oil cooler/ thermostat [Archive] - SaabCentral Forums

: 900se v6 oil cooler/ thermostat


horzman
20th April 2007, 11:37 AM
Hi all,
I have 95 900SE V-6 convertible, I have leak in the oil cooler which seemed to be the reason form my thermostat failure.
pulled everything all the way to the lower manifold, unscrewed the oil cooler but I still have to unscrew it from the side, the Rain started so I had to stop.
in the process I was also trying to replace the thermostat which is easier said than done... I got the thermostat unbolted but because the area is so tight i had great difficulty turning it around, the thermostat is attached to the 90 degree so I have to replace the whole thing ( what a poor design!).
I'm still having problem separating the thermostat assembly from the neck, which is the only way to be able to pull it out.... any one can tell how do that please?

As far as the Manifolds Gaskets , do I just put them on dry?

anyone knows how to add Pics to a thread... I tried to attach few photos but it's not working.

ragtopcav
20th April 2007, 01:34 PM
When you say unscrew the cooler from the side you mean detatch the pipes right? Get the oil filter and maybe the crank speed sensor out of the way too, and ideally use a proper flare nut spanner for these fittings, the steels is very soft and tends to deform with a normal open end spanner. Wriggle these pipes out of the way and you'll see two large nuts that hold the cooler to its top plate - undo these before you remove the covers screws! Now lift off the cover and remove the old cooler.
Assembly is the reverse sequence, use a good quality flexible flange sealer when attaching the plate [rtv silicone will work].
Yes, the gaskets are fine dry.
Change the rear sparkplugs whilt you are in there; check for leaks from the rear rocker cover too, if any hint deal with this too whilst the top manifold is removed.

The themostat assembly; yes understand your pain, the long pipe that passes under the head and faces forward to join the rubber hose is just pushed into the 90deg elbow housing and secured with 2 O rings - it is an absolute ******** to seperate in situe, it should just pull apart. There's some horror stories of people smashing off this pipe and replacing all three bits [stat, elbow housing and long pipe].

horzman
20th April 2007, 03:02 PM
Thank you Ragtopcav, please help me understand this.

I pulled the oil cooler, the cooler itself doesn't have any water in it, however the pan that the cooler was sitting in has water and oil goo... does that mean that the cooler is ok? if the oil is leaking out of the oil cooler to the coolant, shouldn't the coolant be able to get in the oil cooler? or does the engine pressure prevent it from happening?

on the other hand I have still no success in pulling the Tstat elbow from the neck.... I ried to pull, tried to pry and still nothing.

Thank you

ragtopcav
20th April 2007, 03:49 PM
I pulled the oil cooler, the cooler itself doesn't have any water in it, however the pan that the cooler was sitting in has water and oil goo... does that mean that the cooler is ok? if the oil is leaking out of the oil cooler to the coolant, shouldn't the coolant be able to get in the oil cooler? or does the engine pressure prevent it from happening?


As I understand things, the oil runs at a much higher pressure than the water so it's one way traffic; oil into water, this emulsifies and you end up with brown pasty yuk in the water jacket/circuit. Water in the oil points to failed head gasket [or two in our case!].

Do this job right and you'll not need to do it again, the newest coolers look different, they're stainless steel and have a long working life.

I cannot add more about pulling off that pipe, it is notoriously difficult - is it feasable to get enough heat in there to destroy the O rings without harming anything else? :confused: