Overheating 83 w/ Subaru conversion and Out of ideas

[wesitarz]

It's not a Nissens rad with a plastic bleed screw like this black one is it?

[t3 kopf]

If you are running your heater lines back to your thermostat from the heater with no loop, then the coolant is being cooled by the heater core and not giving the thermostat the proper feedback. Your thermostat thinks the engine is too cool for it to open. You need either tom sheils thermostat housing or you need to loop the heater hoses to a couple "t"s close to the engine.
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'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[furrylittleotter]

It's not your radiator.

The cooling system is way oversized.

You need to have a bypass system in place.

Coolant HAS to circulate constantly for the suby thermostat to function.


If you want help here you need to accurately describe the bypass you have in place.

You also MUST feel the pipes going to the radiator to see if the system is working. Post results here.

You need to keep a stock suby thermostat in place.

You must bleed every time stem is opened.

You can do this be removing radiator breed screw, drive from cold start around block until it is hit, it may even come out some. That is ok.

Park.

Next day, fill at bleeder screw, replace screw. Drive. Feel pipes.
If both get hot and it runs correct temp, you are good.

If not, let cool, repeat above.

Neil2

[Howesight]

[wesitarz]

Did my 02 2.5L conversion in 2003. Used VW blue G-11 coolant and added a bottle of Redline WaterWetter. VW gauge needle always read to the top of the LED light using a 33 ohm resistor.
Last year finally got around to changing my coolant (yikes - 12 years). The bleeder bolt on the rad was frozen and I stripped it. Decided to replace the 18 year old rad with a Nissens aluminum rad and added a VDO temp sender in the hot rad line just off the coolant manifold. I do a lot of city short trips and at first thought the temps were OK 180-190 (190 being next mark on VDO gauge),but then noticed temps climbing to next mark (212 measured) and beyond when at low rpm stop and go traffic or idle.VW gauge only moves up slightly. Bled the crap out of it.Changed the t'stat even though the old one tested OK. No change. Hmmm.I wondered if my waterpump was bad,since I didn't change my coolant regularly and the van doesn't get driven for several months a year for the past 10 years. I pulled the WP expecting to see a stamped impeller model all rusted up,but found a cast impeller WP with slight rust on the impeller and OK bearings. Replaced it with a new cast impeller WP. Still no change with the low rpm temps. I could control the temps by keeping the revs up, opening the heater up or turning on the low speed fan using the A/C switch (no working A/C in my carat). Before pulling the rad and trying to flush it, I decided to put in another bottle of Redline WaterWetter and after a couple of driving cycles I am happy to say the temps have stabilized at 180-190 on the VDO gauge at low rpm around town. This product does produce an oily film on the coolant not to be confused with leaking headgaskets - my HC color test was negative).So if you've tried everything else, here's a new idea.

[timichango]

Haven't read the whole thread, but... have the coolant reservoir pressure cap tested? We were having some erratic temp issues on a road trip in 2014 on a previously ultra-stable subie conversion, and after much handwringing and testing and an epic thread on here, and other random crap, that's what it turned out to be.
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Vroomhilde-San: Our 1991 Silver Vanagon Westy automatic + Subie EJ25

[tjet]

I'm not a Subaru expert, but how's the ignition timing? Most engines will overheat if the timing is too far retarded, or if the timing advance system fails to work.

[leadbettr]

New rad will be here today.

http://www.gowesty.com/product-details.php?id=2380
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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

[DLJ]

I had the exact same symtoms that you describe. And I do have a new radiator.
Then I did the procedure that "furrylittlecritter" outlines above and now I run perfect temps. I know the procedure is tedious but it worked for me.

[leadbettr]

while I'm waiting for the new rad, water wetter?

Is it something I should look into?
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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

[wesitarz]

Well Waterwetter helped mine a bit. Then I changed the blue pressure cap with another one I had and tightened all my clamps. That helped as it seems to be more intermittent now only see a rise in temp at the engine with my VDO gauge after it has reached operating temps, stop & turn engine off for a few minutes to do something,then start off again. Temp comes down more rapidly now. It's not enough to trigger the rad fan (new switch installed + GW air diverters) Have a new pressure cap on order. Maybe it's just the way my new Nissens rad works. I can manually turn on the rad fan with my A/C switch (no working A/C)

88 Wolfsburg Carat auto with 02 Subaru 2.5L

[t3 kopf]

I still don't see anything saying that the heater is bypassed. If you haven't done this, you're wasting your time.
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'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[kikitee]

My rad fan would not come on, over heat, found that power came from a set of contacts on the ign switch, has 3 sets of contacts, also power the wipers and head lights and a couple dif systems, replace the contact block, bottom of key switch, things work again! every thing else was telling the fan to come on, bet if theres no power? KIKITEE
Keep the Rubber Side Down.

[J Charlton]

Many folks have problems with the Subaru cooling. Most stem from the fact that the vanagon cooling system is very oversized for the Subaru engine.
A slight digression into physics - if a wbx powered van gets 15 mpg at 60mph and a subaru powered van gets 22mpg where does the eneregy not being used to propel the wbx powered van go? Its wasted in HEAT. The vanagon cooling system is properly sized for the relatively inefficient wbx engine but very much oversized for the efficient (relatively) Suby engine.
The guru of Subaru/Vanagon cooling is Tom Shiels - yeah he's the guru of harnesses too - but Tom KNOWS cooling. He made the thermostat bypass so that hot coolant directly from the engine would always be flowing onto the thermostat and the thermostat would therefore always be reacting to engine temp coolant, not from overcooled coolant returning from the rad. Diesel powered vanagons also have a hot coolant route to the thermostat.
I suggest that you look carefully at Tom's version 4 or 5 coolant layout. Either produces uniform temperatures with a Suburu conversion.
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NAHT hightop availability May 18 2023 -
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[tlbranth]

And where might I find said kit?
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Terry

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

[furrylittleotter]

[dobryan]

[tlbranth]

Thanks Dave.
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Terry

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