Need Help sorting out cooling system.

[ImpulseRocket89]

Yep, I am lost. I guess this is the big downside to buying someone else's completely torn apart project.

First, I am trying to sort out the heater hose setup. From what I can tell, the pipe that crosses over the back of the block feeds into the inlet of the heater core? The only two hoses I have left are the one to the valve, and the U-bend that links that pipe with a slip fitting on the pipe that goes to the coolant return pipe at the water pump. I would be happy with just a picture of those hoses and how they all connect so I could sort it out, because I have nothing to go off of.

Also, where does that pipe across the back of the block get its coolant feed from? I am assuming somewhere on the intake manifold?

The other cooling conundrum that I have is the turbocharger coolant feed and return ports. As I don't have the stock lines I have no idea where they come from or go to. Since I am doing a 2.6 swap, I have a feeling that they aren't even present on the 2.6. Unless the smaller slip fitting on the coolant return pipe is for the turbo coolant return.... (the little port sticking up right before the 90* bend into the water pump)


I am just trying to sort out options for new feeds and returns as my new turbocharger is liquid cooled, and my PTE unit was not (so I didn't give it much thought). I am trying to keep the length of all of the lines to a minimum, but I know that it may not be entirely possible, such as the oil feed port on the 2.0 block that doesn't exist on the 2.6. I know I can utlilize and/or tap a fitting for that onto the oil filter housing or somewhere on the block.

It's all making me go cross eyed...

[Bugle]

There's a pipe that bolts to two of the top bellhousing bolts and goes from under the intake manifold across to the other side of the engine. Then that pipe along with the one in the picture going to the back of the block are connected to the heater core. The two pipes also have a small heater core bypass hose too which is what that little pipe poking out the side is for.

That little nipple on the large pipe is the turbo coolant return, turbo coolant feed is on the block between cyls 1-2.

[ImpulseRocket89]

There's a pipe that bolts to two of the top bellhousing bolts and goes from under the intake manifold across to the other side of the engine. Then that pipe along with the one in the picture going to the back of the block are connected to the heater core. The two pipes also have a small heater core bypass hose too which is what that little pipe poking out the side is for.

That little nipple on the large pipe is the turbo coolant return, turbo coolant feed is on the block between cyls 1-2.

I have the rear pipe that crosses the block installed, and included it in my description. It is setup for a rubber hose that hooks up somewhere on the right side (my passenger side) of the car. Looking at the stock 2.0L manifold it looks like a heater hose runs from the fitting on the bottom of the T-stat housing to that rear pipe. However, I would like confirmation on that one.

This is the best picture I have of that side with all the pipes on (hoses only somewhat hooked up)

As far as the hoses between the rear pipe and return pipe to the water pump, I know one loops down from the rear pipe using a smaller fitting on it to a fitting on the return pipe on the side. The larger hose on that rear pipe bends up and connects to the, I am assuming, shut-off valve, which then bends back around and hooks up to the heater core inlet. That leaves me with the open end of the return pipe on the side of the block that is open that a hose connects to from the heater core outlet. Correct me if I am wrong.

I am glad I was right about the coolant return. I guess I can always weld in a fitting on the rear cross over pipe before the heater core, or some type of splice into the heater core hose on the inlet. I went and looked at what is left of my stock 2.0L to try and figure some things out and compared it with the 2.6 more closely.

I think for the oil feed I am going to use that port that already exists just behind the oil filter housing. I just have to uncover the threaded fitting that is in place on the block that is still somewhat buried beneath a layer of clay and oil even after cleaning it some.

Now I need some help with another system. Can anybody take pictures of or have a diagram of, the factory AC lines. I'm not sure if I am missing any (I think at least one) and would love something to go off of for reference. It would be highly appreciated.

[ImpulseRocket89]

While I am here with pictures, maybe somebody can help me figure out the purpose of this slip fitting (Circled in yellow) on the right side of the oil pan. I am making the assumption that it was part of the PCV system and the oil separator block thing that mounts to the back of the stock 2.0L valve cover (As seen on my junk/scrap valve cover under the engine, just in front of the crank pulley)... Otherwise I can make no connection as to it's purpose.



Speaking of the fitting on this side of the block behind the oil filter housing (Red arrow). Anybody just happen to know what thread type/size it happens to be (I am figuring it is an NPT type thread). Just trying to save myself a bit of work with having to get it out of there with the motor installed the way it is lol.

[Bugle]

On mine there's a water gallery running through the manifold from the thermostat to between cyls 3/4 where a pipe exits the bottom and that is then hooked up to the pipe that runs across the back of the engine, so aslong as it comes out of the inlet manifold side of the thermostat it'll do.

There's no shutoff valve on the Piazza, it's just from that pipe over the rear of the engine to the heater core, then back out from the heater core into the pipe along side the engine.

AC lines are different between LHD and RHD so can't help much with that, the fittings are on the opposite side eof the firewall.

You got it right that fitting on sump is for the oil air separator drain.

[ImpulseRocket89]

Ok, thank you for confirming my suspicion on the hose that feeds that rear pipe. I guess I will have to put in some type of fitting on my T-stat housing for the new intake manifold to feed that pipe, but that shouldn't be too difficult.

For some reason there is a valve on the inlet hose to the heater core on mine. I planned on removing it anyway, so I guess there is no real loss there.

Thank you for confirming the function of that other drain fitting on the pan. I thought that is what it was, but it has been so long since I actually worked on an intact Impulse that some things are fuzzy to me still.

As far as the A/C lines, I figured that would be the case, but it never hurts to ask lol. I plan on making a road trip to another state to try and gather as many little bits as I can from a couple of different Impulses, and I guess I will just add in the smaller AC lines to that list. At least that way I could snap a couple of pictures of how they are routed so I know what pipe goes where.

Thanks for the help Bugle

[Bugle]

About that oil fitting I assume it's the same as the oil pressure switch thread?
Looking at the Tridon catalog they list that as being a "1/8 GAS" thread, another name for 1/8" BSP i think. Part TPS016 here http://www.tridon.com.au/Products/Produ ... 483&P=2011

Also check out the reverse light/neutral switches http://www.tridon.com.au/Products/Produ ... 483&P=2016 , the original is TRS028, needs to be a normally open equivalent of that switch for the cruise control, looks like there might be a couple that would work.

[Bugle]

Found someone who made a turbo oil feed off that hole on a G series engine and they say it's 1/8" BSP so it's likely to be the same on a 4Z.
http://www.ozgemini.com/forums/tech/vie ... 930#172930

[ImpulseRocket89]

Awesome, on both counts. Thank you, thank you, thank you.

That helps a great deal. Even if they aren't the same it gives me a great starting point with the oil feed.

Thanks for the link to those switches too.

[wedgenut]

Just an additional note on the drain hose from the breather/separator down through the manifold to the pipe on the right side of the sump, it should incorporate a small non return valve to prevent back pressure from the sump up to the breather.

[ImpulseRocket89]

Thanks for the info. I am not using the factory breather/separator on this application, but I was considering using it as part of a catch can/breather setup.

Either to plumb a pipe from the pan to the top of a catch can for better pressure evac, or as a drain line from the bottom of it with a ball valve that I can open to drain the oil out of it so I don't have to remove the whole can to do the job.