any 84 coolant circulation hacks?

[atomatom]

my van's temps had been great, but now as summer is here, i turned off the rear heater (and front) and now my van seems to be nearly overheating again.

things are fine on the highway, but in stop and go traffic, it hit 120oC the other day. and it isn't even all that warm up here yet. 120 makes me nervous. and i think also puts the system under pressure - i think i smell a bit of coolant when it gets like that; or perhaps a cooked rodent in the heater box...

it seems to me that cutting off the heating loop on an 84 (the early first try of the waterbox) causes some serious circulation issues. i'm going to put some kind of bypass back there so that there is always some small amount of coolant flowing through the pipes without it going through the heater cores; basically a tee connector to keep the loop flowing.

anyway, i'm throwing this out there in case anyone has any similar experience with the early cooling systems.

fwiw, the rad is pretty new, it is a new decent water pump, hoses are on the right ends of the radiator (i s'pose i should triple check that).

edit: the radiator fan does comes on. the switch is the correct one.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[Paulbeard]

Are you verifying temps with an IR gun, making sure the radiator is getting uniformly hot? No fan when you get to 120°C? That's 248°F…pretty hot. What does the dash gauge look like?
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Currently -> Frida: 87 Tizian Red (mostly) Vanagon GL Westfalia w/ 2.0L ABA conversion
Formerly -> Steward of a 73 Super Beetle (Beater) and 67 Beetle 1300 (Little Max) both names by POs

[Ahwahnee]

IMO you shouldn't have to modify the system if all is working as designed. I drive my 84 in Tucson with temps well into the 100s w/o any issue.

I did replace the radiator 7 years ago -- is yours the original?

Edit - Okay, I see the rad is 'fairly new' so maybe no help there.

[atomatom]

the fan comes on as expected, temps have been verified (but i'll do that again), and the rad is from 2012.

the stop and go traffic that makes it get hot. i know that using an aftermarket gauge means i've got too much information. i still have no answer to the question of what 'too hot' means for a vanagon. maybe 120oC is fine. but this was city driving, granted at rush hour, and not a mountain overpass.

before i go modifying, i'll drain the coolant to see if i find any blockages. it has the original steel pipes, perhaps those are getting funky on the inside.

if 120oC is indeed to hot, then it seems to point to some restriction. the annoying thing is that all winter/spring, with rear heater on, temps were be perfect around 87-90oC. i realise heater cores are extra 'radiators' working to dispel heat, and ones that don't obey the thermostat.

i know that the thermostat opens around 87, then is only fully open at around 100, so there will always be some lag in temps. i guess checking/replacing the thermostat would be the other obvious. thing to check.

anyway, i suppose i'm glad to have something to diagnose on my van. it has been running so well aside from this. i've heard many van owners talk about turning on the heat to cool their vans down. i get it, but that really sucks in the summer.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[beach_creature]

Does your radiator fan come on?
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84 Westy
1.9TD AAZ
5spd manual with Locking Peloquin TBD

[atomatom]

yes, the rad fan works. i've read that the temp difference between front-back can easily be 10-20oC due to lag.

i suppose i should check the system for air. if there are any leaks in or out, i presume that might create some kind of air pockets in the up and down plumbing on it's way to the radiator.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[Ahwahnee]

One thing I did change was to add a manual switch for the radiator fan.

The thermo-switch works fine but I can do something it cannot - I can anticipate the need for the fan,

If I can see that I am in slow & go traffic on a hot day I may switch the fan on before the coolant temp gets hot enough to trip the thermo-switch.

Same thing if I am starting up Mt Lemmon - why wait for the radiator to need the help?

I used a VW fog light switch as it fits in an empty dash spot and is 2-position letting me choose from 2 fan speeds when I use it.

[atomatom]

thanks ahwahnee! that makes a lot of sense. i mean, sure we'd rather it all be automatic, but that sounds a lot more comfortable that blasting the heat when it is hot out - which is neither automatic or comfortable.

i also have a tencent oil cooler, and while i did not spring for the one with the fan, i have thought that i might add one. if i do it on the cheap, i would just wire it to be on all the time (since the oil cooler has a theromstat).

to be honest, the main thing that has stopped me on the oil cooler fan is wondering what direction to send the fan in as the cooler is mounted at the bottom of the side vents. blow hot air up? but would that fight the air flow coming down when at speed? or blow it into the engine compartment.

anyway, i'll go check the basics too. a mechanic said he found the lining from a coolant bottle in there (this was before i replaced my rad), and the main system should probably perform better so i'll see if i can fix it.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[Marcq]

[atomatom]

[Marcq]

[Wildthings]

If you turn on the coolant flow through the rear heater does the engine run cooler?

Not sure how you could do so, but maybe you have the flow through the radiator reversed or some other glitch in how the hoses are hooked up?

[atomatom]

[jlrftype7]

[Ahwahnee]

All connections were made just to the lower drivers side of the radiator/condenser... but specifics (even if I could recall them) might be of limited use as I have a late-Vanagon radiator fan on an early (84) Vanagon.

It was really just a matter of staring at the leads, finding the two I wanted to control (override) with the switch and confirming with a multimeter.

[tencentlife]

[atomatom]

hmm - well. if i am reading the coolant flow diagram correctly, it may just be that the bloody hoses are on backwards. :< i shall remove the spare tire just to confirm the front is not switched too (which would negate the crappy plumbing job)

edit: the hose on top should be the return, and connected to the right pipe to the radiator. but in my van these are backwards

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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[atomatom]

ok, strike that. i think my hoses are correct as is. and the bloody bentley diagram is wrong (or to be generous misleading)

from https://www.gowesty.com/schematic-details.php?id=54

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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[MarkWard]

Unlike most conventional radiator setups, the vanagon coolant flow is backwards. Coolant flows in the bottom and out the top of the radiator. What complicates it is both hose fittings are at the bottom of the radiator.

To be honest, off hand, I cant tell you which hose fitting is which without looking at it. Sorry.
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