The water pump inlets are down next to the radiator hose at the thermostat. There are additional nipples down there that feed directly into the pump, bypassing the thermostat. My engine originally had 3 of these, heater return, drain from reservoir, and one from the water to oil cooler at the oil filter. I did away with the oil cooler and got a replacement pump from Outfront that only had 2 inlets. It can be confusing as the return from the heater had a short hose and hard line that runs up to the top of the motor (behind the timing belts), across and to the back to create a hard line connection right next to the one coming off the upper water manifold - these 2 connections go to the factory heater. I pulled that heater return hard line and now run directly into the nipple at the pump. These smaller lines all bypass the thermostat and constantly circulate, and also heat the thermostat up so it will function properly!
Just remember - water comes out at the top of the motor (main radiator hose, heater, turbo, etc.) and all return back in at the water pump inlets. The reservoir is just placed in-line with the smaller hoses to provide a fill location and to get the air out of the system.
Here's my diagram of the factory routing (maybe further confusing the issue???):
Here's another pic of my water pump - you can see the main radiator hose coming into the thermostat housing. 2 additional hoses connect to nipples at the pump that bypass the thermostat - the 2 blue hoses connect to those nipples. One is coming from my reservoir, the other will connect to the heater core (return).
Definitely take a couple of beers to get the hang of how this cooling system works!
Jeff
Today I had a realization. I was running the engine up to operating and the water/coolant kept bubbling up and started boiling out of the jetta tank. This tank is T'd off of the heater line coming from the coolant manifold on the top of the engine. I realized that I had to have a manual valve and treat this tank as only a fill tank. I went to the hardware store and got a ball valve. I installed it, ran a temp hose from the radiator overflow line into a bottle. When I ran the engine, the thermostat opened and everything did as it should. I need to get an overflow tank at the radiator but will need to mount it up by the fuel tank kind of like how the master cylinder reservoirs are mounted on the 70's beetles. Will this be a problem mounting it above the radiator?
Thanks Jeff for posting up your cooling layout. I didn't see it until after my previous post. Looking at it led me to consider another issue. I am not running an Idle Air Control Valve, I have a block off plate in it's place. My ECU does not have enough inputs, I can wire up either boost control or IAC. I believe that the previous owner of my Link ECU had gotten it from Outback, now Outfront Motorsports and the harness was not set up for an IAC. It's not the end of the world for me in Southern California where it's warmer more often than not. But I was thinking, if there was a way to make an electric dial switch up in the driver's area where I could use the IAC and manually dial in the idle speed separately from the Link ECU. Or another idea is that I still have a part of the original throttle cable on the engine that was cut when the engine was pulled. I was considering using it to fashion a cruise control. Maybe some sort of servo/stepper motor could be used to pull on that to raise the idle when cold.
If I don't get the cold idle worked out, then it'll just be like when I was running dual kadrons on one of my engines, it wouldn't idle well until it was warm.
I'd try it without the IAC valve Surf. I've read of others just playing with the timing and fuel settings during warm-up and not having to incorporate and IAC.
I'm not sure I follow your comment about valving off the coolant reservoir to make it work right? Usually, the reservoir is an integral part of the cooling system, allowing coolant to flow "through" it continuously. I'm dumping the turbo outlet and TB warm-up line into it, and it "drains" (flows) back into the water pump inlet. My pressure cap is on the reservoir (no radiator cap on my radiator) and an overflow reservoir is plumbed off the main reservoir.
Here's a pic of my set-up - reservoir (silver with Stant cap) and overflow (narrow black box) next to it. The reservoir only has one inlet port (on left), so I T-eed in the TB warm-up with turbo outlet - to the side inlet on the reservoir. One drain on the bottom, this runs down to the water pump. Overflow coming off the just under the radiator cap. The guys on the FFR 918 forums recommend adding a bleed fitting off the upper water manifold at the high point - just before it connects to the upper radiator hose. This connects to the reservoir and provides a continuous air bleed to get rid of air in the system. I'm hoping my TB warm-up line will provide a similar bleed - as it comes off the manifold at about the highest point.
Jeff,
I took out the factory surge tank that was inline from the turbo to the manifold coolant return and went directly from the turbo into the upper manifold. My coolant bottle only had one inlet for coolant at the bottom and a smaller one at the top for overflow. I mounted the tank up high and plumbed it into the hose from the upper manifold to the heater with a T fitting so there was no flowing through the tank. By putting a valve on the line going to the tank, it is forcing the water to stay in the system and use the radiator cap and overflow to another tank.
I think I get it Surf, the tank is not intended to be pressurized and just a fill point for the system? I guess where ever the pressure relief cap is, that needs to be the highest point in the system.
I'm more concerned about your description of plumbing the turbo outlet back into the water manifold. The OEM water supply for the turbo comes off the top of the engine, after the water has come into the pump at the bottom, pumped around the cylinders and heads and ready to be discharged out of the upper manifold. Not sure there would be enough pressure differential between the OEM engine outlet (for the turbo) and the upper manifold to get any flow? The water might be boiling in the turbo if it just sits there.
Study that diagram of the coolant flow - note that no matter where the water comes "out" of the engine, it only goes back "in" at the water pump. Duplicating that flow path, at least in my view, is key to proper cooling operation.
Jeff
I agree about duplicating flow path. I believe that I only removed the surge tank from in between the turbo and the coolant manifold, but also removed the IAC and it's coolant lines (years ago) so I do need to take a look at the stock coolant flow and compare it to my setup to ensure that I haven't created any headaches for myself.
If you do find you need more air cold, I suggest a CIS warm up air valve, it only needs 12v at low current, it heats up and closes off over a minute or so, very simple.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
I spent most of yesterday lowering the back of the car. It was too "stink bugged". I have adjustable sway away spring plates and they were at the end of the adjustment. A few years back, I moved them up and thought I'd have some room to adjust it down but I made a mistake that I got to fix yesterday. I did the driver's side first and then did the passenger side. I set the spring plate adjustments in the middle and used a degree measure tool to set the angle. Plus I'd found a chart on thesamba that showed how much change a combo of inner vs outer spline changes made. I think I got it right this time. I'll just need to fine tune the spring plate adjusters. Next will be installing the used Airkewld beam I was given. This beam is two inches narrowed instead of the 3 1/2 inch narrowed beam I have on their now and it has thru rods and air shocks.
Sounds like "slammer time" Surf! Probably take a little driving around and even sitting a few days for the new positions to settle in.
If you happen to get into it - I'd like to see how the thru rods interface with the trailing arms on your new beam? Always wondered how they handled rotation between rods and trailing arms. Does the new beam use coil-over shocks?
Jeff
Don't T the air lines together unless you have a huge roll bar.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Jeff,
I'll get some pictures of that. It uses Monroe air shocks, as Piledriver said, "poor man's air bags". I have brand new ball joints on my front end that's currently on the car. I plan to swap the beam itself but keep everything from the trailing arms out that way I won't have to press in/out balljoints. As for placing a T in the air line, I'm going to do some research but I think I can T the line only if I place one way check valves closer to the shocks and have separate drain valves. I really need to see what everyone does when setting it up.
Thanks Surf. I guess I'm most interested in how the beam and through rods "holds" the trailing arms in position? What controls the in and out motion of the T-arms? Also, what parts rotate against each other and how is that handled (lubrication points? thrust bearings?).
Installed the new Speedhut tachometer last week. Works great and was easy to program. It even came with a built in shift light and the provision to add an external shift light if needed. As for how the car runs, my biggest issue is that I'm new to how to set up the map and don't really have a clue. I called Outfront to see if I could buy a map from them, the Link ECU that I'm using originally came from them. The cost of a dyno run and tuning was less than a couple hundred over the cost of just a map and it would be set to exactly what the car needs, so that's my plan. I have to get my front suspension set up and make sure that I have no intake leaks. At that point, I'm thinking I'll load the car up and tow it up to Outfront Motorsports since I'm a couple of hours south of them.
For the front beam, I plan to use the Airlift gauge and Switches. This one has two needles and switches. I'll be able to use one air source but it splits separately to each front shock. They won't be tied together so no issues when cornering. I have seen some videos online where they just use a pump but no tank. I haven't decided yet which route I'm taking. Maybe I'll start with a pump only and add a tank if needed.
