Syncro + Subaru Cooling Issues

[Syncro Jael]

Keep the optimism - GOOD KARMA - you have a nice Syncro that will bring you years of happiness.

You are lucky to be close to RMW, they can fix you up for sure!

Let us know what you find out. I will go on record that you have a simple fix ahead and send some good vibes your way. You will sleep better.

You can expect the worst then when you find out you are prepared. But then life was always the worst, so I expect the best then deal with what comes.

[ftp2leta]

[flomulgator]

Thanks for the education Ben! I'll be staring at that EG33 cutaway for a while now
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She's built like a steakhouse, but she handles like a bistro!

[furrylittleotter]

Like I said, this is exactly what happened with my SVX. it was on again off again, and I tried a million things, then it was fine. Until.

BTW, for what it's worth I tested the coolant for hydrocarbons a dozen times and there never were any, even right up until the gasket blew. When it blew it was Very obvious. Typical huge plume of smoke, running horribly and then DEATH. OIl in water, water in oil. it was a mess. In hindsight I believe I had a small compression cylinder to coolant cylinder leak which created airlock around the thermostat./pump. How that could happen on the BOTTOM of the motor is beyond me and seems impossible.

One thing KEP suggested back in the day was adding a bleed valve at the top of the radiator or replacing the radiator with a unit that has a cap on top like the Subaru does.

[insyncro]

I run Subaru coolant conditioner in all of my conversions if I personally did not reseal the engine at the time of converting...most are JDM engines with 50k miles or less when purchased.

I have an EG33 with well over 100k Vanagon miles on it (~150k total) and it works very hard towing.
No issues to date.

All have reversed coolant manifold routing.

[Howesight]

Knocking wood as I type this, but . . . never had a cooling problem on my SVX syncro to date.

I have the Smallcar setup with their bellhousing. Yes, it is a lot of work to get at the thermostat. I have a couple clues and comments:

1. Your expansion tank should have a pressure relief cap with an attached hose connecting to an overflow tank. Looking at the pics in your first post, I see no hose attached to the expansion tank. You need to use both the expansion tank and the overflow tank and have a pressure cap that functions within spec.

2. I do believe that the Subaru factory thermostat is superior to any aftermarket design. It includes a "jingle" valve (Subaru's own word!) that keeps the tiny bypass port built in to the thermostat from clogging. The specs for checking the thermostat are: Starts to open at 169F to 176F, and Fully Open at 196F.

3. The Smallcar SVX conversion "kit" uses a very stiff piece of hose attaching to their stainless steel 90degree pipe. After a few heating/cooling cycles, the provided hose clamp needs tightening again or else it leaks. A spring clamp added beside the worm-gear clamp might be a good idea.

4. With all due respect to Mr. Libby and his disciples, (and since I have a steeply-sloped driveway) I still think the best way to bleed a Vanagon cooling system is with the rear of the van much higher than the front, (to make the expansion tank the highest point in the system) and the bleed valve on the rad open (or removed), and to add coolant to the expansion tank until coolant streams out of the radiator bleed valve. Then run the engine to temp, heater valves open, run at, say, 2,000 rpm for a few minutes, let cool and repeat. The Vanagon system (1986 and later) has a good self-bleed capability to get air out of the heater hoses and cores. The rad hoses attach to the rad at a very low position on the rad and you must force coolant by gravity (my approach) or pressure (bong style) to displace all the air from the rad.

5. I see no mention of ensuring the rear heater core was bled properly. It has a separate coolant valve. If that valve is "closed", it still allows a very small amount of coolant flow, but not enough flow to allow the self-bleeding capability to work.

6. The ad in the OP's first post says the Subaru conversion was done in 2003. It's definitely time for a new rad if it has not been changed since 2003. Cheap insurance - - $176 is a lot less than the OP has spent so far.

http://www.van-cafe.com/home/van/page_312_1144/radiator-p312.html

7. The Subaru Factory Service Manual specifies a rad cap pressure range of 11 to 14 psi. Ensure that your VW expansion tank cap falls in this range.

I have a PDF version of the SVX Factory Service Manual that I can PM to the OP if desired. Let me know.
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'86 Syncro Westy SVX

[insyncro]

Howe is right about bleeding.
My choice of tools to easily and completely fill Vanagon systems is either a Wurth or Snap On vacuum filling device.
It also is a pressure tester, so the expense of it can be justified.
Reading how so many have issues with bleeding, I am surprised more have kicked down for a quality tool...no offense to all those who use bongs .

The tool and using it have been posted in numerous threads, but if people need to see it again, let me know and I will post it.
New they are $200+ and an adapter is needed if you don't buy the complete kit for an additional $40.
They sell every day on ebay used for $100 or much less depending upon how used they are.

[ftp2leta]

by the way, the refill tank on all my conversion is simply removed.
It doesn't work like the stock system.

Something I did years ago.


Link

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Working with rust, grease, dirt and dust is a sad truth.
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FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

[flomulgator]

[dbose]

Hi I have had similar problems, I have been running an SVX in a Syncro Westy for about 2 years now. Recently have been experiencing high temps on coolant as well. Tested OEM T-Stat working good. 2 years ago new water pump, stat, hoses, pipes and radiator.

What are others seeing for normal operating temps on the dash gauge? From what I remember last year I was running about half way or just over the LED. This year after about 30 minutes I'm at 7/8 gauge. Running the heaters brings it to about 5/8 on gauge.

This year have flushed the system and bleed many times after the temp problem started. Still have to try raising the rear end to see if that gets more air out. The rad fan works on both low and high speed. I have got about 13 liters into the system. Book called for 15.2L on 86 and up. Not sure since it has the SVX in it now but I would assume the SVX would take more coolant than the waterboxer.

Any thoughts?

[PDXSyncro]

Hi Folks,
I'm writing on this thread because I too have been dealing with SVX related cooling system issues and a number of things caught my attention in this thread so I wanted to validate my cooling system plumbing with you good folks!

I too have a subaru svx conversion that was initially done by Subagon and it has always given me heart ache! And when I saw Mike from RMW mention this in the thread:

[wesitarz]

Not sure if it makes any difference for you, but my expansion tank has hot coolant from the manifold entering thru the top and out the bottom (in my case to my heater circuit). In other diagrams I have it's the same flow including the JHA diagram I have on file for a SVX. (pdf only so I can't upload it). Also check that all your clamps are tight.

[PDXSyncro]

Thanks for chiming in! So if I were to swap my top and bottom then it sounds like I’d have your design equivalent, is that right?

Also do you know if that heater circuit that runs from the WP up to and on top of the right side of the engine is going to the heater core or returning from? I always that it was the return and going to the heaters was from the manifold but I’m unsure!

Many thanks!!!

[dobryan]

One way to confirm the direction of flow is to start with a cold engine and then place your hand on the heater lines until you notice which one is getting warm first.
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Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[PDXSyncro]

Quick update as I'm working through this now!

I changed the hoses out from top to bottom so now my current system diagram is this:

So now with the changed hoses at the expansion tank at start of engine I'm seeing flow into the expansion tank from the top tube coming from the line that goes from the coolant manifold to the rad! The other direction lines I've added but I'm unsure of as of yet. I'll go back and once cool feel around to see which go hot first!

I also ran a pressure test and found a few small leaks. One of which was at the coolant sensor on the expansion tank! It was small bubbles but slowly losing pressure. So I pull it off, cleaned it up and and put some new gasketing on the threads and re-installed. It's holding now! I tightened up the few areas that were showing some drippage and reran my pressure test holding 11 PSI for 30 min. All good!

Next filled it up and went for a drive and got it up to running temp. However the temp gauge is sitting only about a 1/4 up. It's halfway between the LED and the low end blue area of the gauge. After driving for a while and getting heat from the front heater I brought it back and checked temps at various areas. I found 193deg at the coolant manifold just before it goes to the hose heading to the rad. The next reading was 185deg at the coolant temp sensor on the coolant manifold. All seems quite low to me! No??

It's cooling now and I'll check for more air and refill.

Thanks again for the comments and please keep them coming!

[dobryan]

Not sure about the SVX but 180-190 at the coolant manifold is right where my EJ25 runs. That is a normal temp.

If your coolant gauge temp sender is not a stock VW sender you may get a different gauge reading at the dash. I have a stock VW sender tapped into my manifold and 185 is right on the LED at the gauge. I believe a resistor can be used to alter/calibrate the gauge reading.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[wesitarz]

On your diagram the purple line from the manifold to the WP might flow the other way if this is the feedback to the thermostat. After filling mine,I drive it around getting it up to temp,then park it nose down and check the expansion tank after it cools a few times. In between, I'll park it nose up,rev it a bit then open the bleed at the rad. Luckily,I have a slope in my front driveway.

[PDXSyncro]

Thanks for that! Yes I use a similar approach to remove air but I use some ramps that I have and the smaller incline in my driveway

Here's the latest system diagram:

Makes sense that all flow would go towards the WP/Thermostat! I've updated the arrows. I think the rest is correct based on what I'm seeing/feeling

Everything is tight and running well so far. I need to make a trip up the mountains though before I'm ready to call it good! Maybe later this week for a little ski day, we'll see.

Thanks for the posts/help! I'll update on how things go up the mountain!

[PDXSyncro]

Quick update:

I had a leak from the coolant level sensor on the RMW Expansion Tank So I ordered a new sensor (only found one at VC). Anyway got that installed and ran another pressure test. There's still a small slow leak somewhere! I brought it to 16PSI and it would take about 3 minutes to move down to 15PSI. So there seems to be a small leak but no fluid coming out of anywhere I can see.

I took a trip up to the mountain about 1.5hr drive and 4k ft elevation rise. The heater blew hot the entire time but on arrival the overflow tank was full. Not seemingly pushing any out or if any it wasn't obvious. Drive back home and same thing, overflow full and this time a little more was pushed out. After cooling down here in town it sucked back in about 1/4 of the overflow tank. About the amount it would from max to min although now still 3/4 full.

So I seem to have an insidious leak pulling air into the cooling system only apparent in long drives into elevation. I'm wondering if there is a leak in the air intake manifold?!?! Can air leak into the cooling system from the intake manifold? Could there be a leak that take air in but coolant doesn't leak out?

I tested with a combustion tester a couple of weeks ago and it cleared, so apparently no combustion fumes getting into the system, or they are seemingly not detectable from in town driving.

Any thoughts?

Thanks!

Also anyone know a good, honest mechanic in Portland OR? I'd like someone who is knowledgable about the subaru's and enough of the vanagon not to balk at this! Any references welcome!

[wesitarz]

Have you tried replacing the pressure cap? A long hard drive in the mountains and coolant pushing out the overflow is an ominous sign of a headgasket leak to me. With a small leak maybe you have to rev the crap out of it to get it to show.
Maybe test compression and leakdown to rule out headgasket leak?

Edit: Check heaters for leaks/coolant smell. I recall the rear heater seems to be notorious for leaks.