13BT_RX3

What is the flow path of the cooling water through the cold startup fast idle thermal-wax valve thingie?

I blocked it off when I first installed my engine and now I have decided to put it back on.

13BT_RX3

Does it just connect to the ports on the waterpump housing sharing the return with the turbo return? Oh yeah, it's a Cosmo 13B.

13BT_RX3

The factory service manual did not show the details of the connections. I have three water tap ports on the motor. Two on the water pump housing and one in the back of the block. I just want to confirm that the connections to the fasat idle system are from the waterpump housing only.

Aaron J Williams

On my NA there is one at the back of the water pump housing and the other is at the back of the block right next to the engine lifting bracket.

Go48

iTrader: (7)

Aaron is essentially correct. In an NA, there are two points of connection for coolant hoses on the back of the throttle body--an upper and a lower. A hose from the back of the BAC valve connects to the top one, and a hose from the rear engine housing, under the UIM, connects with the lower connection point on the throttle body. If you need images I can provide some.

13BT_RX3

I think I get it.
Thanks.
I'll post picks to confirm.

13BT_RX3

OK.

I have tagged the ins and outs with what I think I know. Are the tags correct?

Phantomkid

That hose is a pain when your taking off you inake manifold. Anyway on my t2 there are no hoses coming from the waterpump its all hard lined and runs to the block. But the first picture you have is positioned differently then mine but i believe thats the feed or return and runs to the last picture you have on the block itself the second picture i believe is either feed and return and on my motor runs behind the BACV, then hard lined to the block but on your probably to the water pump no sure exactly. but im sure someone has dealt with your motor and can tell you exactly hope that helps alittle

NZConvertible

Nope. I'm not entirely familiar with JC engines but I'm pretty sure the coolant flows are exactly like on FC's.

The first photo shows the coolant inlet on the bottom of the TB, which connects to the coolant outlet on the rear plate shown in the last photo.

The second photo shows the coolant outlet on the thermowax, and the coolant return on the rear of the water pump.

The third photo correctly shows the turbo coolant return on the bottom of the water pump.

13BT_RX3

OK...So let's recap.

The bottom line of the thermo wax (pic 1) connects to the port at the back of the block (pic 4).

The lines shown in pic 2 connect to each other. (I.E. - Topmost line on water pump housing connects to the upper line of the thermowax.)

The turbo return is accurately shown in the 3rd pic.

But, which connection is for the supply to the turbo? The connection at the back of the block or the upper connection on the water pump housing.

Rx7TyreBurna

iTrader: (1)

On my engine, looking at the engine bay from the front of the car. There was a coolant hose that connected from the water pump nipple to the right hand side of the cold start. Then the connection on the left of the cold start went to the engine.

It looks like yours is different though. My car is / was an S4. Now an S4 / S5

NZConvertible

Correct.

That would work.

Correct.

I don't actually know where the stock turbos got there water from, but if you put a tee in the line from the nipple of the rear port you could feed both the thermowax and the turbo from there.

Ignore all the FC info you're being given...

13BT_RX3

Thanks All

ryder2489

please post a pic