ALH coolant questions

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Raphvw

Member
Joined
Mar 15, 2018
Location
Wasaga Beach, ON
TDI
ALH Corrado
Hi, I am currently fitting a ALH into a MK2 body.

I won't use heater core nor expansion tank.
But I will keep the heat exchanger.

Do I need to customize the metal pipe from thermostat housing to go in heat exchanger?

From there, go back in the head and that's it? Flow is still correct?

Since I have no heater core, I have an extra port on that head flange that I won't use. Any option for flange or I cap that end?

Thank you
 
S

speedy223

Veteran Member
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Apr 8, 2015
Location
east texas
TDI
alh tdi new beetle 98, alh jetta 01, bew golf 04 all 5spds
hose to a y into the return pipe or something along those lines if you are not sending it into the heater core. or just cap it. i cant think of a reason that wouldnt work
 
R

Raphvw

Member
Joined
Mar 15, 2018
Location
Wasaga Beach, ON
TDI
ALH Corrado
speedy223 said:
hose to a y into the return pipe or something along those lines if you are not sending it into the heater core. or just cap it. i cant think of a reason that wouldnt work
Click to expand...
Good,
so how I plan to connect my heat exchanger is correct?

Since it won't be a perfect fit for hoses, any idea of what I could use?
Other than making everything out of aluminum and just use silicon connectors.
 
AndyBees

AndyBees

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Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
I believe you have the flow backwards in your mind. Coolant flows away from the head via any and all pipes, period.

The engine needs good flow to the T-stat housing via the black metal pipe. Also, the small pipe coming off the head allows air to escape, it needs to be tied into that constant circulation loop (preferable an expansion tank). The loop of coolant flow, which also includes the Oil Cooler coolant flow, is what heats the T-stat, thus opening in relation to engine temp. So, that flow is very important.

Why would you include the Heat exchanger? If you do not plan to include the heater core in the loop (for inside heat), I cannot imagine the need for the heat exchanger, unless you plan to have an active EGR.

How you plumb it, is a matter of personal preference, looks, etc., just make sure there is a path for constant flow back to the T-stat housing.

I have to assume you will be using the OE radiator on the MK2. If I remember correctly, that Rad has a small pipe on the right side (passenger side) at the top. That loop circulates back to the OE expansion tank. So, you don't want that hose connected to the small hose coming off the ALH head. The two flows would be hitting up against one another.

I cannot imagine this working without the use of the expansion tank.......... the system deposits any and all air bubbles there.
 
R

Raphvw

Member
Joined
Mar 15, 2018
Location
Wasaga Beach, ON
TDI
ALH Corrado
AndyBees said:
I believe you have the flow backwards in your mind. Coolant flows away from the head via any and all pipes, period.

The engine needs good flow to the T-stat housing via the black metal pipe. Also, the small pipe coming off the head allows air to escape, it needs to be tied into that constant circulation loop (preferable an expansion tank). The loop of coolant flow, which also includes the Oil Cooler coolant flow, is what heats the T-stat, thus opening in relation to engine temp. So, that flow is very important.

Why would you include the Heat exchanger? If you do not plan to include the heater core in the loop (for inside heat), I cannot imagine the need for the heat exchanger, unless you plan to have an active EGR.

How you plumb it, is a matter of personal preference, looks, etc., just make sure there is a path for constant flow back to the T-stat housing.

I have to assume you will be using the OE radiator on the MK2. If I remember correctly, that Rad has a small pipe on the right side (passenger side) at the top. That loop circulates back to the OE expansion tank. So, you don't want that hose connected to the small hose coming off the ALH head. The two flows would be hitting up against one another.

I cannot imagine this working without the use of the expansion tank.......... the system deposits any and all air bubbles there.
Click to expand...
The constant flow would go in the heat exchanger (I refer to the also called oem oil cooler in the filter housing) and back to T-stat housing trough that shortened metal tube. <- Here's the biggest part of my question, because I want to make sure, just like you said, that I don't route my setup the wrong way!!

The EGR and EGR heat exchanger aren't on the engine anymore.

"Mk2" is actually a corrado G60, the rad is oem and doesn't have that small return line to expansion tank. It is usually hooked to the metal pipe that I don't have. I prefer to not use the tank as it's cleaner and as long as my highest point is my filling cap, it will be ok for bleeding the air out.

Thanks
 
AndyBees

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Oil cooler - Heat exchanger, glad you cleared that up.

Well, you still have a small Stainless Steel nipple on the end of the ALH head that needs to be connected to something. It's location provides constant flow and is good to help eliminate air from the head. I cannot ever recall seeing a VW engine that didn't make use of the small hose(s) for continuous circulation which always returns at or near the T-stat via an expansion tank.

The big nipple on the coolant flange on the end of the head needs a hose going from it to the top of the rad. The bottom rad hose goes to the black plastic flange at the T-stat. (hot in the top and cold out the bottom).
 
R

Raphvw

Member
Joined
Mar 15, 2018
Location
Wasaga Beach, ON
TDI
ALH Corrado
AndyBees said:
Oil cooler - Heat exchanger, glad you cleared that up.

Well, you still have a small Stainless Steel nipple on the end of the ALH head that needs to be connected to something. It's location provides constant flow and is good to help eliminate air from the head. I cannot ever recall seeing a VW engine that didn't make use of the small hose(s) for continuous circulation which always returns at or near the T-stat via an expansion tank.

The big nipple on the coolant flange on the end of the head needs a hose going from it to the top of the rad. The bottom rad hose goes to the black plastic flange at the T-stat. (hot in the top and cold out the bottom).
Click to expand...
Ok, get it! So the filler adapter I'll use has a port for a small tube than I originally planned to cap. But I will use it for that hose.

Thanks
 
G

GEFP

Veteran Member
Joined
Jan 22, 2018
Location
Southern Alberta Canada
TDI
2- 2001 Jettas, 2 - 2002 Jettas (1 for parts) 2003 1.8t Jetta (parts) 2014 Jetta
Eventually plan on having a heater core in the car. I think that on cold mornings/late evenings your going to find that your windshield fogs up. Just my thoughts.
 
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