So sounds like fan switch/relay/fuse might be faulty (or the temperature stays low). And the temp sender for the dash gauge is faulty!
Your thermostat condition you can get an idea on operation, start up from cold, let it sit and idle, the dash gauge should rise fairly quickly to 12 oclock (~2min or so), if it takes longer (~10min or so) the thermostat is not doing it's job. If as in your
case the you do not trust the gauge, the coolant lines circulating around the motor will worm up quick to the touch (check the pump suction line next to the left hand head), once this is warm, the coolant tubes to the front (radiator) should still be cold.
If they seem to warm slowly at the same rate as the pump suction line the thermostat is not working
The safest way to check is with a temperature gun (keep your hands away from the motor!), the pump suction line should be approaching 80deg before the pipes to the front start to warm up.
On the running issues, as Hart mentioned, could be AFM
See factory fix on Phil's site
Volkswagen syncro, scroll to part number 025 906 302
It is available after market from some US vendors, or there is a home fix
Vanagon Intermittent Syndrome by Harald
Just as a place to start looking
Also on the temperature guard, the T3 has three modes of telling you there are issues! One is the dash gauge (sender in thermostat) getting high, two the fan coming on very frequently (switch in radiator), three the ECU makes the light start blinking (temp2
sender in thermostat). So there is fail safe built into the system (three independent systems). Unlikely you would have all three fail at once, but if one or two are faulty and not noticed/fixed then your left with no safe guard.
Have a look here
Temperature Gauge & LED in Vanagons | Gowesty
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Volkswagen
syncro
Always use genuine VW G11 or G12+ coolant with distilled or demineralised water to stop corrosion.
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Preview by Yahoo
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---In Syncro_T3_Australia@yahoogroups.com, <jackthebearau@...> wrote :
Thanks Scott, I found the fan runs on both speeds by bridging the terminals in the plug at the temp switch on the
radiator. Found the relay I think but haven't been able to test it yet. Could be the relay is not working or the temp sender is not working. Could also be that the thermostat is stuck open or not there so never getting hot enough??
Temperature gauge is seemingly unaffected by unplugging at the sender on the thermostat housing. If I ground the
wire the gauge pointer goes up to hot. So I think the gauge and sender are working but there is power getting to the gauge from somewhere else, will check earths.
More problems now, lost power and stopped in the middle of a busy intersection in peak hour traffic on way home
last night. :( Was idling very fast on way home for some reason?? Got help to push it onto the median strip, tried to get it going again to no avail so left it and walked 4 kms home. Went back 3 hours later and it started straight up and drove home. Started
to miss and lose power just before home and needed momentum to get into driveway, missing badly but didn't die. Fired straight up this morning but idling high again. Coil??
From: "Scott Pitcher spbconsulting@... [Syncro_T3_Australia]" <Syncro_T3_Australia@yahoogroups.com>
To: Syncro_T3_Australia@yahoogroups.com
Sent: Monday, 26 September 2016, 13:48
Subject: Re: [Syncro_T3_Australia] Re: Temperature Gauge
Neil,
Check your fan relay is working and if the fuse is all ok on the fan.
The fuse is in the glove box and the relay should be next to the radiator (I think).
Best of luck.
Cheers,
Scott
Thanks for the replies guys. That is very helpful information. Now I have a good idea of what is supposed to happen and a good idea of where to start looking, thanks again,
Neil.
Neil,
I have a scooby motor in my syncro so I really cant compare but it actually operates the same as normal - starts at cold and the little red light flashes for a couple of seconds and goes out and then sits just shy of the red LED unless working hard and then
it rise just above the red dot and the fan comes on.
My 2wd caravelle is a bit stranger but it starts out normally at cold level with the red flashing light which goes out after a few seconds then it climbs to just past the red LED and moves slightly further towards hot when working hard and the fan comes on.
I think my radiator is partially clogged and hence the higher reading and I have a low temp thermostat to go in with my new radiator as soon as my new front radiator hoses arrive from Van Cafe.
There are many factors that affect their cooling performance.
Cheers,
Skot
On 26/09/2016 8:56 AM,
cathrich1@... [Syncro_T3_Australia] wrote:
I agree, the light operation sounds normal (it indicates when the water level in the header tank drops).
Normal for the temp gauge on the dash is slowly rising from cold to half way mark then hovering around that. Once past half way the fan normally kicks in.
If your system is otherwise good, on cooler days the fan would not kick in unless your at standstill for a little while, so one test would be go for a drive (bring it up to operating temp) then park for a ~3min. If the fan has not kicked in I'd be guessing
something is not right and a little worried to let it heat up further if the gauge reading is also out.
The temp gauge on the dash is an isolated system, the sender is on the front side of the thermostat (front/left of the motor) and has a single wire to it. Not sure which would cause your fault, sender, wiring or gauge itself though.
The fan is controlled by the switch in the radiator itself, about half way up the RHS (front) of the radiator. If the fan is not kicking in, it can be a number of things, the switch is faulty, the relay or fuse is blown (mounted above/in front of the fuse
panel (need to remove whole fuse panel to get to it, it's up under the dash). Both should be simple checks.
Hopefully it it not that the coolant level in the radiator is below the switch!!! (re-bleed radiator, should be no air coming out of bleed screw)
Could also be the fan motor itself
Richard
---In
Syncro_T3_Australia@yahoogroups.com,
mailto:me@... wrote :
Hey Neil,
Does sound like something wrong, though can't offer any further advice.
My red led flashes when turning on the ignition then stops once starting the engine. Temp needle starts at the bottom of the gauge and slowly rises to just below the led, and hovers around there, below the led, depending on driving down or up a hill etc.
When hot (e.g. city traffic, particularly on hot days) the needle rises above the led, the fan kicks in, then the needle drops and fan stops. On cooler days when moving then no fan required. During winter unless stuck in bumper to bumper I don't hear the
fan much, during summer I hear it more frequently. As far as I know my system is currently functioning as designed.
Good luck, Sam
---In
Syncro_T3_Australia@yahoogroups.com,
mailto:jackthebearau@... wrote :
Since buying my Syncro the temperature gauge has always read just above half way even when cold on turning on the ignition and when hot only moves about another pointer width or just past the red led on the gauge. I don't think this is normal and suspect the
gauge isn't indicating correctly. Would this be most likely a faulty sender? The red led flashes on turning the ignition on and goes out on starting the engine. I am guessing this is correct? Is the led an over heat warning light? Also, I haven't heard
the cooling fan come on for a very long time, would this be normal in city traffic? It did come on a couple of times when I first got the vehicle but has not come on since. Do these vehicles keep their cool without need for the fan most of the time? Thanks
for any advice,
Neil.
