Coolant level sensor woes and the traffic hell-hole we call Lima

[blackglasspirate]

TLDR below this paragraph.

Well, yesterday started off pretty normal. Woke up at 13,000ft in the clean mountain air of the Cordillera Blanca and started our 6 hour drive to Lima to spend a day or two before heading farther south. The drive was nice, we were making good time, and all was well until we hit the massive urban sprawl of Lima. I've gotten pretty good at driving like a South American, so the traffic and driving was fairly normal, although my wife still screams and yells at people every time we cut it close. We exit the panam to go through town towards the ocean and get stuck at a horrible stoplight that just takes forever. I am usually overly cautious about coolant issues so I had the front and rear heaters blowing hot air so as to keep the temp down. The temp needle was just in the middle but rather safe than sorry, right? Well, we get to the front of the line to turn and are stuck at the red light when the bus driver I just cut off gets out of the bus and tells me I'm leaking coolant. Great. I pull over to the side and immediately knew what happened. The coolant level sensor blew clean out of the tank, leaving the threads in there and spewing all of my coolant onto the road. Traffic was only going to get worse so it was either try to go the 14km to where we were going to camp, or wait until traffic hopefully died down at 9-10pm. We decided to go for it and I'm pretty sure I lost a few years of my life due to that stress. I put our drinking water in the coolant tank, cracked the pressure cap on the tank, and stuffed a sock into the now empty sensor hole. I heard Lima traffic was bad, but it's 1000000 times worse when you're worried about overheating and cant turn on any of the streets that Google is telling you to. If I drove like a madman before, this was some next level shit. Three hours of maddening driving later and uttering more curse words than I have in the past 5 months in South America, we made it to where we were going and walked to the closest brewery to get some liquid relaxation. Now I have to go searching for this part.

That was story time, now onto the real purpose of this post:
Yesterday marked the third time in the 11+ years I've owned the van where the coolant level sensor blew out of the tank, and two of those times have been in the last 2 months here in South America. The last time it happened made sense - a belt broke so pressure/temp built up and it shot out. This time though I was just sitting in traffic, the coolant temp was normal, and there didn't seem to be any reason that there would be enough pressure to blow out the sensor. Granted, we did just drive from 13,000ft to sea level, but we had done that before without issue. Anyone have any idea why pressure keeps building up enough to blow the sensor clean out?
The only thing I could think of was that the cap on the tank isn't releasing pressure like it's supposed to to the tank behind the license plate. As far as I know, that's the only pressure relief in the system, but the cap was replaced two years ago when I replaced the engine. Any ideas on what could be wrong?

It's really stupid because it's a tiny part, but it's still hard to get down here and without it I am stuck. I do have a friend who has a shipment from Gowesty coming here in the next two weeks so at the very least I'll get a replacement then but if this keeps happening I'll end up shit out of luck somewhere eventually. I am also going to try to find a few replacements locally just in case...
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[[email protected]]

Your friend could send you the tank by rocky mountain westy not cheap but you would not have to worry

[Gauche1968]

Sorry about your troubles. Yes, I drove in Peru once (not Lima) and I swear it took five years off my life, although my biggest fear was an encounter with the Policia de Transito.

Are you sure your radiator and fan are functional?
_________________
1984 Vanagon GL
1984 Vanagon Westy

[blackglasspirate]

[danfromsyr]

these are not solutions but maybe ideas to help.

I've had a plan to install a T-fitting in the heater hose (anywhere in coolant system) and run a small capillary line to a small (low) 0-15psi pressure gauge..

you can adapt in a different cars coolant bottle, but I'd likely go with an all aluminum one for your remote travels. else one of those spheres that VW used in MK-III jettas.
_________________

[thatbaldwinlife]

Agreed on the Rocky Mountain tank. I have one and it is bullet proof.
_________________
1987 Westy
Insta: @Thatbaldwinlife
Vanagon Adventure and DIY videos:
That Baldwin Life YouTube Channel

[blackglasspirate]

Thanks for the input, guys. Unfortunately, I was limited to small parts on this order because it's a friend whose wife is carrying stuff back on a plane ride to Lima. And I also missed the cutoff for ordering. I actually already ordered the temp sensor before it blew out again to have as a spare.

Either way, I'll see what I can do and try to get more locally. Could it really be the tank that is the problem? If pressure is building up and the only way it's getting released is by blowing the sensor then maybe putting in a metal tank would cause the next weakest part of the system to blow out (blow off or rupture a hose, break another plastic piece in the system, etc).
Not really sure if that's the case, but that's what I'm wondering.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[DanHoug]

the pressure cap should release way before the sensor blows out so you should get a new pressure cap.

after blowing out the first time, there MAY be some thread damage that makes it easier to blow out but those are thick cut threads and the tank must be swelling up like a puffer fish to release the sensor.

get a new cap for sure, then a new tank if it is available to you. the plastic threads on the sensor are a harder plastic than the tank so that should be okay.

-dan

[Farf]

[dobryan]

I have seen many times when folks have put a hole in the cap to run without any pressure because of a coolant leak that the pressure was making worse. Perhaps you can find a rubber bung that fits and put a hole in it to drive gently.
_________________
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

[Jake de Villiers]

I'm wondering if the low atmospheric pressure at that altitude is a contributing factor.

If your sensor was on the small side of 'Good' and the opening on the pressure bottle on the high side I could see the internal pressure overcoming the threads and popping the sensor.

Maybe Rocky Mountain's aluminium tank is the answer.
_________________
'84 Vanagon GL 1.9 WBX
'86 Westy Weekender Poptop/2.5 Subaru/5 Speed Posi/Audi Front Brakes/16 x 7 Mercedes Wheels - answers to 'Dixie'
@jakedevilliersmusic1
http://sites.google.com/site/subyjake/mydixiedarlin%27
www.crescentbeachguitar.com
www.thebassspa.com

[tim_ha]

blackglasspirate, I'm enjoying following your journey and reliving my trip south. I guess that my wife and I got lucky and didn't have the pleasure of experiencing the nightmarish Lima traffic.

I agree with you, it seems like too much pressure is building up even though those sensors/pressure tanks are crap. Maybe you could use the old sensor to try to pressure test your cap. Drill a hole in it and glue a bicycle valve in so that you can hook up a pump and try to confirm whether or not the pressure cap is opening up at the right pressure.

Altitude won't affect this system significantly unless there is a significant amount of air that hasn't been bled out. Even if this was the case, you'd get more pressure going from sea level up to elevation.

If you think that your "day or two" in Lima may extend out to a week or two, it might be worth finding an aluminum fabricator that could weld you up an aluminum expansion tank to your specifications. I vaguely remember reading another panam traveler's blog that found a fantastic 4x4 shop in Lima which helped them out with vehicle issues that they were having. I'll see if I can figure out who that was, or if I am mis-remembering.

!Suerte!
_________________
1986 Syncro Sunroof EJ22
www.subagonsouth.com

[Wildthings]

Yes you can put a hole in the cap so that coolant freely flows between the pressure tank and the overflow tank. Unless it is really hot out that should work well. In desperation you could do this and raise the overflow tank to roof level which would maintain about 2 psi in the cooling system.

With the Rocky Mountain tank you also have the option of running a 4-7 psi pressure cap, which lowers the stresses on the entire cooling system. You might actually be able to have a tank built locally if you can find the right craftsman.

If you are getting a combustion leak it can overwhelm the ability of the cap to release pressure.

This is a fairly new replacement tank off of my 83 1/2. I don't think it saw anything beyond normal pressures and temperatures as the van was just idling in the driveway and the fan had been kicking off and on as expected, but as you can see the plastic began to deform.

And it came very close to costing me an engine when the threads deformed and the cap blow off the tank.

I have been running 4-7 psi caps on several of my older rigs for a decade plus at this point in time and had noticeably few problems with the cooling systems.

[blackglasspirate]

[blackglasspirate]

[Abscate]

I bought my first Vanagon in Lima. There was a bad two car backup onto the I390 on ramp too.
_________________
.ssS!

[crazyvwvanman]

To me that looks more like an over-tightened sensor. The sensor has a o-ring at the top of the threads.
Once you screw it in to the point that the o-ring is fully seated it hurts rather than helps to make it any tighter. If you keep tightening, the corners of the black "nut" hit the tank and then you are stressing the sensor plastic threads needlessly.

Mark

[Jamo7]

[djkeev]

I honestly don't get why people travel to "3rd" World Countries in a Vanagon with known failure prone cooling system plastic parts.........

But then again, I freely admit that I worry a lot about the "What Ifs".......... hence my excessive inventory of spare parts and tools that I carry!

https://www.thesamba.com/vw/forum/viewtopic.php?t=...;start=720


Dave
_________________
Stop Dead Photo Links how to post photos

Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[Farf]