Overheating 83 w/ Subaru conversion and Out of ideas

[leadbettr]

I think this is less a Subaru issue and more the VW side of the equation.

New Head Gaskets
New Radiator
New cast water pump
New Fan switch
Tested Fan wiring and relay, working.
Fresh Coolent added with a Libbey Bong
New Thermostat (172*)

When it's not overheating it runs like a dream. Before redoing the head gaskets, it idled and the temp needle stayed within the led area of the gauge. The head gaskets job solved a big problem but left a smaller one.
Now the engine idles at a temp gauge reading of just over 3/4, it can be driven but will overheat at the sign of an incline.

I can get it to function without a thermostat and the high fan mode hardwired on but I need to solve this.
Please don't hesitate to ask for more details because I know this is vague. Cheers
_________________
1983 Vanagon L with 1993 Subaru Legacy EJ22
(and Bentley manual)

I'm a owner with pretty good mechanical skills and not the greatest diagnostic skills.

"Do what you can, with what you've got, where you are." -TR

[danfromsyr]

I ask this on every overheating subie thread, so excuse me if it's been asked or gone over before.

How is your cooling system plumbed by/around your Thermostat? do you have a Tom Shiels style bypass loop added?
http://subaruvanagon.com/tom/Thermostat%20housingk.htm

does it overheat/not overheat when you have the front heater core open/on?

the stock Subie system is designed for a constant flow of the heater core loop at the T-stat, but VW shuts down the flow at the core(s) when they are off.
_________________

[syncrodoka]

The Tom Shiels thermostat housing bypass is for cold weather heater issue.

The type of cooling system layout that you have used including a reversed or non reversed coolant manifold should be looked at. There are many different ways to run the cooling system so your specific layout needs to scrutinized.

[geodude]

Two questions:

1. How is your temp gauge wired; does it have the resistor installed to correct the difference between the Subie sender and the VW gauge? Do you have a VW sender installed instead? If no to either of those your temp gauge will read high. Are you sure you are overheating? Have you used an IR thermometer on the outlet manifold to know your actual temp?

2. How is your coolant lines plumbed? If you are not getting proper bypass flow past the thermostat you will overheat. I've also seen overheating issues due to the way the expansion tank was plumbed and the amount of coolant that passed through the tank and back to the engine instead of going through the radiator.
_________________
1988 GL Camper
1991 Multivan — the basket case

[dbose]

I did an SVX swap and used a new rad, water pump and so on, I did not fully tear down the block it had 130k miles on it. I started getting overheating issues two years in, suspected and changed head gaskets after marginal hydrocarbon in coolant test. Still had the problem after that. Did see a lot of sludge in the block when doing the head gaskets. Went back and flushed the new radiator and sure enough it had plugged in the first two years with that block.

Just in case you may have a block with similar mileage and sludge in coolant passages.

Dave

[leadbettr]

danfromsyr: no bypass, cold coolant enters the engine at the bottom of the water pump headed upwards, the heater is stuck on at the moment and has been the whole time since we acquired it.

syncrodoka: the coolant system seemed to be working fine before we started putting miles on it and breached the old head gaskets. It looks like very few modifications were made and the two systems were just hooked up.

geodude: 1. Can't speak to exactly how the gauge is wired but I know there's a resistant issue between the two stock systems. I can say that before any of these major issues started, the engine would warm up to the LED [50/50] on the temp gauge and stay there despite hills or acceleration. So I think it has the needed resistor? 2. I don't see any obvious bypasses and it doesn't have the Tom Shiels thermostat housing bypass. Where would I look for a bypass?

dbose: It is a high mileage engine, but we had recently done a coolant flush before installing the new radiator, hoping that would solve that problem at the time. I'm also watching the coolant for "stuff" as I drain it an refill it every time I work on the system. I haven't seen anything significant.


I really do appreciate all the thoughts and troubleshooting. I really hope we can figure out what this issue is.
I'd like to re note though that the system seemed to work just fine before we blew the aging head gasket allowing exhaust bubbles into the coolant system. Said coolant looked old and very past the due date.
That is the big puzzle here.

Thanks!
_________________
1983 Vanagon L with 1993 Subaru Legacy EJ22
(and Bentley manual)

I'm a owner with pretty good mechanical skills and not the greatest diagnostic skills.

"Do what you can, with what you've got, where you are." -TR

[davevickery]

I wonder if you could still have air in the system causing the thermostat not to open. Is the radiator fan coming on when the temp guage moves above the LED.

[leadbettr]

[levi]

Did you get your new stat from a pep boys auto zone kind of place or a dealership.
_________________
One of these days I'm gonna settle down,
but till I do I won't be hangin round.
Going down that long lonesome highway,
gonna see life my way

https://youtu.be/cSrL0BXsO40

[dbose]

I had done the coolant flush as well... A couple times and my fan wouldn't come on either unless I bypassed the fan switch. The fan switch is sensing at the outlet of the rad and since the flow was so low going through the rad it didn't see the high temp until the temp at the engine was already very high. Sounds very similar to my scenario. I tried to listen for flow in the rad pipes and although there was flow it wasn't enough. The day before we left for camping I was ready to cancel and that was when I pulled the rad and used a garden hose and flushed it from both the inlet and outlet back and forth. The tubes are small in the rad and plugged up easily with that sludge from the engine block. If I read your post correct before doing the head gasket everything at one point was functioning properly for a while meaning the plumbing should be correct right?

[davevickery]

[leadbettr]

I made it back home.

I did the trip with no changes except changing the hard wired fan 2, to a fused switch.

So the system is Libby bong filled and no thermostat.
_________________
1983 Vanagon L with 1993 Subaru Legacy EJ22
(and Bentley manual)

I'm a owner with pretty good mechanical skills and not the greatest diagnostic skills.

"Do what you can, with what you've got, where you are." -TR

[leadbettr]

Today I:
Stove-top tested the thermostat [worked fine],
Installed back the thermostat,
Hooked the garden hose up to the cool side of the radiator to back flush it.

Refilled the system and
pressurized the system to 15 psi with a bike pump as an attempt to try another way of getting air out of the system.

Results:

Fan switch [brand new still] never turned on and
the temperature hovered around 50/50 for a good while then started climbing. [This is a new change as last time it hovered around 75/25]


I didn't see any junk flow out during the flush and
the radiator did get pretty warm to the touch. Also,
the heater switch is working again [the metal hook popped of apparently] and its off [switched to cold] to isolate the heater core [and it's possible bubbles]

Is there something I'm glaringly doing wrong?

Cheers
_________________
1983 Vanagon L with 1993 Subaru Legacy EJ22
(and Bentley manual)

I'm a owner with pretty good mechanical skills and not the greatest diagnostic skills.

"Do what you can, with what you've got, where you are." -TR

[VWinVT]

Did you bleed air out of the top of the radiator via the bleed screw? I know it seems obvious, but sometimes it's the little things. I had to do this a few times to mine to get all the air out.
_________________
1981 Westfalia with a 2001 Cabrio ABA

Small wheel turns by the firing rod,
Big wheel turns by the grace of God.
Every time that wheel turns 'round,
You're bound to cover just a little more ground.

[tlbranth]

Whenever I've had an overheating problem such as yours, it's been the radiator. This includes a Bay Window with Mitsubishi engine, a stock Subaru wagon, a Toyota Corona.
The things clog up and have to be rodded out. No amount of flushing worked for me. Since you've done just about everything else, I'd have a radiator shop flow-test the radiator.
_________________
Terry

1991 Westfailure. 2004 Forester 2.5 engine. 4speed Standard transmission.

[wesitarz]

What brand of radiator did you put in?

[leadbettr]

[leadbettr]

Still poking and it's holding super solid at 75/25 on the temp gauge.
Fan is coming on intermittently on high every minute or so.

But it's idling, for the fist time in a long time.


I've been adding and bleeding, adding and bleeding, adding....

I'm feeling like it's really a clogged rad
_________________
1983 Vanagon L with 1993 Subaru Legacy EJ22
(and Bentley manual)

I'm a owner with pretty good mechanical skills and not the greatest diagnostic skills.

"Do what you can, with what you've got, where you are." -TR

[syncrodoka]

[ScottShelley]

I may have missed if but are you using an IR gun to get a good reading on the actual temp.? I my conversion I installed the adjustable resistor, from Gowesty, and adjusted the gauge to where I wanted it based on the temp measured at the engine. If the fan is coming on then coolant is flowing.