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kayakmaster Mon Jan 03, 2011 10:16 am

I have a 2.5 subaru conversion and just took my van up to the snow for the first time. Noticed that although my van never runs hot. I could not get the water temp up any higher than 147 degrees. Oil temp seemed low as well but not too low maybe 180. Problem is had I spent the night, my van would have never defrosted the window or generate any kind of heater for the four cold people in the van. I think my thermostat is working properly it was purchased new only about two years ago. anyone encounter something like that and have a fix. let me know.

Wildthings Mon Jan 03, 2011 10:31 am

Checking the thermostat again would be the place to start, there is never any guarantee that a new part will work to spec. Don't know enough about the Subaru, but if there are any "second" gaskets on the thermostat, and if your requires one and it is missing your engine will run just like the thermostat is stuck half open.

Does the 2.5 require the use of an added heater bypass hose like the 2.2? If so you may be running too much coolant through the bypass. How is yours set up? Pics?

Terry Kay Mon Jan 03, 2011 10:31 am

Front or rear heater?

r39o Mon Jan 03, 2011 11:07 am

First question is: Which coolant plumbing setup are you using?

Next, do you have the thermostat bypass gizmo?

I am in the process of setting up myself and have posted my question at:
http://www.thesamba.com/vw/forum/viewtopic.php?t=445880

That system setup in the referenced post is supposed to eliminate your kind of problem. My idea is a modified Shiels concept 5 which has been blessed by Tom S over on the Vanagon Subaru list. So I will be flying with that setup this time.

Jake de Villiers Mon Jan 03, 2011 11:42 am

kayakmaster wrote: I have a 2.5 subaru conversion and just took my van up to the snow for the first time. Noticed that although my van never runs hot. I could not get the water temp up any higher than 147 degrees. Oil temp seemed low as well but not too low maybe 180. Problem is had I spent the night, my van would have never defrosted the window or generate any kind of heater for the four cold people in the van. I think my thermostat is working properly it was purchased new only about two years ago. anyone encounter something like that and have a fix. let me know.

You don't say what cooling system you're using but its obviously not Tom Shiels' or you'd have heat.

Tom's 'Concept 4' with separate thermostat housing is the way to go.

http://subaruvanagon.com/tom/Cooling%20System.htm

http://subaruvanagon.com/tom/Thermostat%20housingk.htm

Any questions? ;)

Wildthings Mon Jan 03, 2011 12:11 pm

Why doesn't Subaru have a problem during cold weather? What is different about their heater design?

I think that if I did another conversion I would just weld a thermostat housing off of some Brand X vehicle from a wrecking yard onto the end of the coolant manifold and eliminate the bottom mounted thermostat altogether. I don't understand the advantages of having it mounted in the return water flow, verses the exit water flow. Just seems flawed to my old mind.

This has become a hijacked thread which I don't think has much to do with the OP problem.

Jon_slider Mon Jan 03, 2011 12:53 pm

In snow country my 2.2 powered syncro westy had almost no heat. And on the freeway the temperature needle would drop to the bottom of the gauge.

The Tom Shiels thermostat bypass housing solved both problems, but it did interfere with the syncro skidplate, which had to be cut.

Worms Mon Jan 03, 2011 2:04 pm

Wildthings wrote: Why doesn't Subaru have a problem during cold weather? What is different about their heater design?

I think that if I did another conversion I would just weld a thermostat housing off of some Brand X vehicle from a wrecking yard onto the end of the coolant manifold and eliminate the bottom mounted thermostat altogether. I don't understand the advantages of having it mounted in the return water flow, verses the exit water flow. Just seems flawed to my old mind.

I'd be very loath to do that. Subaru have spent a lot of time designing the system to suit their engine.

The water which has been heated by the engine is fed through the heater, and into the thermostat housing, onto the rear of the thermostat. It is actually a very good system.

The heater is so effective because it uses the heater feedback loop for temp control, the thermostat ONLY opens when the water from the heater return is hotter than the thermostat opening temp. A thermostat mounted on top of the engine, on the oulet, may open at other times, because the engine gets up to temp, but the heater feed is taken off elsewhere.

The thermostat takes little sips of water, which are mixed with the heater return. Any heat which has been lost from the heater, cools the engine slightly as well. When the thermostat is closed, the heater works like a little radiator, cooling the engine (while heating the cabin). When the thermostat is open, the excess heat is bled through the radiator. The heater matrix has constant flow, and the cabin air flow is altered to heat it or not.

The Subaru system has quite a high flow rate, to heat can be fed off to the cabin, but the water leaving the heater is still very hot.

The vanagon requires a heater bypass, because the vanagon system uses a valve in the heater system to stop coolant flow.

Because the Subaru system is a constant feedback system, the engine temp is very stable.

Those systems with the thremostat on the outlet, let "cold" water in until it reaches the thermostat (all the way over the other side of the engine) so the engine gets a large amount of cool water into it's water jackets.

The subaru engine takes a little sip of coolant, it's mixed with the heater return which is still quite hot, and the engine is only cooled slightly. These two water feeds are mixed thoroughly at the water pump. The setup Subaru uses is like stiring water in a big pot, and tipping in bits of cold to keep it cool.

There is a VERY good genuine Subaru tech article, which explains the system in great detail and why they did it.

I used to have it in my conversion files, but appear to have lost it :-(

PS, once the subaru engine is in a vanagon, the only way to really get it working right, is with the Tom Sheils thermostat adapter. While you could make one, I just ordered mine from Tom and had it sent all the way to NZ :-). Much easier :-) Mine is perfect :-)

Jeez, That got longer than planned... :lol:

Allan.

Wildthings Mon Jan 03, 2011 2:28 pm

The point is that the Subaru thermostat system doesn't work all that well with the Vanagon heating and cooling system. That people keep coming up with new and different ideas on what to do is evidence that there is a on going problem with mating the two systems. I installed my system as per the kit I bought and it worked fine for a year or so but then I started to have overheating unless I turned the heater on briefly so I contacted the kit manufacturer and made changes according to his suggestions. Again the system worked just fine, but this year I find that my heaters aren't putting out the same as they did last winter after the change was first made.

I just want a system that works. I want one that keeps the engine at the proper temperature at all time, summer and winter, heater on or off, and a system where the heater output is at least what it was originally. A top mounted thermostat with a bypass is well proven to be able to keep the engine temperature constant over a wide range of conditions and to work with a heater system utilizing coolant flow control valves as the Vanagon does.

The Subaru system is obviously a fine system when used with a Subaru heating system in a Subaru car. When installed into a Vanagon it looks to me like there are still lots of improvements to be made.

3konas Mon Jan 03, 2011 6:37 pm

Cheap solution for cold weather, cardboard over all or part of the rad. When I had a bra, I would slide in a piece between bra and grill, worked great.

WestyBob Mon Jan 03, 2011 6:45 pm

Wildthings wrote: The Subaru system is obviously a fine system when used with a Subaru heating system in a Subaru car. When installed into a Vanagon it looks to me like there are still lots of improvements to be made.

I haven't encountered that problem (heat) yet with my 2.5's and lots of winter mileage. It's seems to be the same as when the wbx-er was in there. Wondering if something else is going on.

phatveedub Mon Jan 03, 2011 8:33 pm

Jack,

A few questions:

Have you pulled/checked the t-stat to determine it's condition?

Did you change any heater hoses or heater cores?

Have you properly bled ALL the air from the cooling system? Are you sure?

When I did my conversion, I replaced the entire cooling system: radiator, hoses, heater cores, and only got rear heat - none from the front. I re-replaced the new "state of the art" front core with the original one and now the heat is back. It took me a long time to figure out - about a year before I finally got it all worked out.

Check all the heater lines under the van from front to back to be sure there are no kinks or pinches that are restricting coolant flow. If you havent changed the heater cores, they may be clogged or the heater valve may not be opening. Good luck.

presslab Mon Jan 03, 2011 8:56 pm

Use ONLY an OEM thermostat. Compare a Stant to OEM and it's a huge difference.

My EJ22 is piped up using the KEP scheme. The rear heater valve is left open. The coldest I've driven in is only 20 F, but I had tons of heat at that temp.

The only 'problem' I have is that it takes a while to warm the van up, I guess it's because of all the coolant in the system. My old Subaru warms up faster than any car I know, about 2 minutes to warm toes.

IdahoDoug Mon Jan 03, 2011 9:05 pm

My '97 Sube Wagon with the 2.2 had an amazing heater. No matter the outside temps, including below zero at freeway speeds, the thing would cook you. The thermostat was a pain to change and finicky - people advised to use only the OEM thermostat. The cover was also finicky (allen bolt?) as I recall and you were never sure you had it fully seated down as the bottoming point was vague and mushy.

DougM

ftp2leta Mon Jan 03, 2011 9:16 pm

At 147 T-stat is stuck open. No mater what system cooling you have.

Ben

kayakmaster Wed Jan 05, 2011 6:00 am

I went with Small cars system. although the water manifold is reversed as it is supposed to be it does not have some of the componets that the Shiels system does, specifically at the thermostat itself. I did read the comment about if I am at 147 degrees my thermostat might be stuck open. What a pain to get at the thermostat in a syncro conversion. I have to carefully drop one side of my motor down a little just to access that position and the skid plate is right in the way. When I have a little more time I will investigate more. My van is not my daily ride. Thanks for all the comments. I will post again when I get down and dirty with the project.

DaveCA Wed Jan 05, 2011 7:28 am

I usually don't quote a person and respond like I am doing here, because it may look to them as if I am attacking them. Because the post i am repnding to seems to paint with a broad brush, I will respond with quotes from wildthings post in the interest of clarity.


>"The point is that the Subaru thermostat system doesn't work all that well with the Vanagon heating and cooling system."<

The two vans that I've converted have worked well for tens of thousands of miles. Other vanners ahave spoken well of their vans abilities. I believe most of them.

>"That people keep coming up with new and different ideas on what to do is evidence that there is a on going problem with mating the two systems.
"<

The problem must be the particular system applied by some. again, some systems work fine and other systems don't.

>" I installed my system as per the kit I bought and it worked fine for a year or so..."<

So why change it? Soethiung went wrong with some part of the cooling system that was there, in place.

>"... but then I started to have overheating unless I turned the heater on briefly so I contacted the kit manufacturer and made changes according to his suggestions... <"

It seems like a mistake to change the system, when it worked before but then stopped working after time.
If it was just a climate change that resulted in a problem with the system, then perhaps It is a reason to modify the system.

>" Again the system worked just fine, but this year I find that my heaters aren't putting out the same as they did last winter after the change was first made. "<

If you are sure of that, then I can only suggest repairing it back to what worked before and find the problem with the cooling as a separate issue.

>"I just want a system that works. I want one that keeps the engine at the proper temperature at all time, summer and winter, heater on or off, and a system where the heater output is at least what it was originally.>"

Mine works. I use the Burley reversed intake and his modified steel heater tube (bypass) which bleeds some heater flow to thermostat. the thermostat was bought at the Subaru dealerand is very different than aftermarket item.

">with the A top mounted thermostat with a bypass is well proven to be able to keep the engine temperature constant over a wide range of conditions and to work with a heater system utilizing coolant flow control valves as the Vanagon does. <"

I wouldn't ever want to get back to that system. I was so happy to say goodbye to so many special plastic parts and hoses while doing the conversion.

">The Subaru system is obviously a fine system when used with a Subaru heating system in a Subaru car. When installed into a Vanagon it looks to me like there are still lots of improvements to be made.>"

There are improvements to be made to many of the converted vans. I agree, some are not working as well as they could.

There are converted to Subaru vans with systems running reliably and well though.

Though they may not be the most popular, by numbers sold, I would name the Shiels and Burley system. The Sheils system is consistently well spoken of and I have seen the Burley parts work well for me.

Somebody please correct me if I have errors in this.

The intent of my post is to help you and others, not to attack, embarrass or in any way poo-poo your thoughts or the problem you are having with your van.

Dave

J Charlton Wed Jan 05, 2011 7:50 am

I used Tom Shiels concept 5 with his thermostat adapter in my 2.5 suby conversion. Lots of heat int he winter, and I am able to shut the heater core off completely in the summer. Rock steady 185F +/- 3deg at all times.

ftp2leta Wed Jan 05, 2011 8:13 am




That is all you need. Beware, the size of the metal nipple/tube is critical.
In most of my conversion people ask me to remove the leaky rear heater, if so, both T going to the rear heater need to be join as a preventive measure. If the rear heater remain, it should be left open but no worry if it as been close, the diff in temp is only 2-5 degree. If you don't have that mod on the heater coolant pipe you will blow the engine.

But the discussion here is not about running hot, it's about running cold and very cold. In general T-stat do fail open, still, 147 is VERY cold. Even with a fully open T-stat it should reach 185-190F at some point if idling for 40 minutes.

Ben

Wildthings Wed Jan 05, 2011 9:33 am

DaveCA wrote:
If you are sure of that, then I can only suggest repairing it back to what worked before and find the problem with the cooling as a separate issue.

The manufacturer of the kit admitted his kit (one of the best selling on the market) had a problem, so he addressed it by coming up with a fix. So you are basically saying to go back to what the kit manufacturer acknowledged doesn't work dependably.

Quote: I wouldn't ever want to get back to that system. I was so happy to say goodbye to so many special plastic parts and hoses while doing the conversion.

If I weld an aluminium thermostat housing to the end of the reversed manifold I get zero extra plastic pieces and no more hoses than any other conversion. I would also get an easy to access thermostat and a proven bypass design that would work well with any conceivable heater system.



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