3SGTE Cooling sytem problems /tech info required

[ONCE-NA]

Got the 3S going good enough to go for a drive (after warming up) and pretty quickly the temp dropped down to 60deg C. So I thought the thermostat was stuffed. I had a look and there was a gutted thermostat in there. ie just the base and rubber seal. "That explains it!" I thought.
So I sourced a new one a threw it in. Then had heaps of issues with it getting way too hot, and the heater wasing getting hot so I figured it had an airlock in the system, but I couldnt get it out. Tried drilling holes in the thermostat base -still got too hot. Fucked that off and made up a remote thermostat on the water outlet from the back of the head. Running an 82deg one with a couple of holes it still got too hot, around 100 +. I've put a 71 deg thermostat in now with a couple of holes but havent had a chance to test it.
What I want to know is, what is the definitive fix for this, I've had a search but havent found what i'm looking for. After reading the description of a bypass thermostat system in the Tridon catalogue it looks like its not such a good idea to take it out as hot coolant will tend to circulate in the engine without going to the radiator. Oh, the bypass pipes at the back of the pump are blocked off and the heater return comes into the bottom radiator hose.

[w810sc]

the thermostat should have a air bleed hole/notch to let any air out. For this to work you need to install it with the hole/notch at the top for the air bubble to pass out of the system.
thermos/fan not kicking in to keep temps down?
faulty temp gauge?
what are the results of the 71 deg thermostat? did you check the thermostats operation by putting them in boiling water and measuring with a thermometer to see if they opened up at the right temp?

[ONCE-NA]

Yeah put it in the right way up, tested them in a pot of water, havent tried it with the 71 deg yet, when I finish work, fans comming in und pulls it back down at idle but when driving it has issues still.

[The Real Roadrunner]

Oh, the bypass pipes at the back of the pump are blocked off and the heater return comes into the bottom radiator hose.

theres your problem dude,
it requires those lines to put hot water on the back of the thermostat spring to allow it ot open. tey are the orig heater lines and are therefore required.

one thing i have learnt from my time doing engine conversinos is dont stuff around with factory cooling systems as they are designed the way they are for a reason.(not having a go just making a point)

get another set of pipes that bolt on there and just loop them together, put an 82deg thermostat back in there and roberts your fathers brother.

cheers
linden

[ONCE-NA]

I got the motor like that, I was wondering if i should fix that up so those 2 pipes should go to either side of the heater core?

[The Real Roadrunner]

thats what they do stock but they also run thru the turbo and a couple of other things std so if you turn the heater tap off it will still have water flow at all times.

ive had many cars come in with the same sort of problems and most of the time its because theyve fitted aftermarket thermos to a stupidly thick core (in the belief it will work better than a clutch fan) or stuffed up the coolant pipes in some way.

if you need those pipes there is a set sitting here but youll have to PM DAVGT4 as he owns them.
i can send them off tues if needed.

cheers
linden

[ONCE-NA]

Yeah its blocked off with a plate so i'll need to get the pipes or make a plate with some hose barbs.

[ONCE-NA]

Okay just looping the pipes over doesn't seem to work. I found this pic and it looks like both need constant flow from the outlet at the back of the head (through other stuff, at least from the factory) Is this right?

[ONCE-NA]

I've got 2 outlets at the back of the head, one large going to to radiator and 1 small (heater hose size) so I was thinking I should put a t-piece on that and run 1 to the heater inlet and the other to the top pipe at the back of the water pump. Then run the heater outlet to the bottom pipe at the back of the pump yeah? So that is more or less how it looks in the diagram.

[TurboRA28]

I've had similar problems with my rwd 3s.

I have the 2 outlets all hooked up correctly I think but after reading this thread makes me think I should double check it.

The only fix I could find was drilling some 2mm holes in the thermostat. Stopped it over heating, but it's a bitch in winter as never gets warm.

[The Real Roadrunner]

i had mine setup so it looped through the turbo (this may have provided enough heat for it to work correctly) with 1/2" lines and still ran to the oil cooler.
it never got hot nor did it require any holes for the thermostat to work.

but mine was a gen3 so may be different.

cheers
linden

[ONCE-NA]

Still not right, looking at the diagram again I found another connection blocked of at the bottom of the pump, according to diagram that gets water via the oil cooler from the other side of the engine?

[The Real Roadrunner]

it tees off the 1 of 2 pipes that come out of the back of the pump then goes thru the oil cooler then back to the block.
but im pretty sure that you need to have a heat source in there somewhere for it to actually work correctly.

or just drill some holes in the thermostat

cheers
linden

[Crazyracer]

3SG(T)Es have a bit more complex cooling system than some cars.

Firstly the thermostat is not your ordinary open/closed type. It actually switches the water flow from one path to another. You need to make sure you have purchased the correct type (and preferably genuine). If you've got one from the local Auto store its probably the wrong type.

Secondly, you need at least one of those 2 pipes that comes out of the back of the thermostat housing connected. One is for the return pipe from the heater, which can be disconnected if you don't need a working heater, but the other is the water recirculation pipe which needs to be retained. This should run into the water outlet housing on the rear of the engine. If you block this off, the hot water never reaches the back of the thermostat to tell it to open and your motor will overheat.

The trick is figuring out which of the pipes coming out of the back of the thermostat housing is which, as you can't interchange them and their placing on the housing varies from model to model.

Hope this is of some help.

[The Real Roadrunner]

that would explain why mine worked coz it ran thru the tubo to provide the heat to open the thermostat.

cheers
linden

ps on gen3's the one that opens the thermostat is the one furthest from the block.

edit: on a gen2 its the one that enters the bottom of the pump at the back.