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korfmach
Samba Member
Joined: February 28, 2014
Posts: 247
Location: Fort Collins, CO
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 Posted: Mon Apr 06, 2020 2:19 pm Post subject: Re: Temp Gauge testing at home |
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The adjusters are on the back of the coolant gauge. You'll have to remove the gauge from the tach, but you don't have to take the needle off. Just remove the three nuts on the back of the tach housing that hold the coolant gauge, and remove the two little screws on the face of the tach. That will give you enough room to take the coolant gauge out.
The adjusters are visible through two holes in the back of the coolant gauge. There are little teeth that you can manipulate with a small screwdriver. One is a low-end adjustment, the other is a high-end adjustment. There is some interaction between the two adjustments so it takes several iterations of low/high resistance in the circuit to get it right.
_________________
1989 Westy
2016 Golf TSI
Gone, but not forgotten:
1974 Dorper Baywindow, "The Bleeding Trout"
1998 Jetta TDI, "Trixie"
1987 GTI, "Heike"
1974 Thing, "The Luftwaffel"
1974 Ghia
1966 Ghia |
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SyncroChrick
Samba Member
Joined: January 10, 2005
Posts: 1010
Location: San Francisco, CA
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| Posted: Mon Apr 06, 2020 6:25 pm Post subject: Re: Temp Gauge testing at home |
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All right finally some good progress. Today I received a second set of resistors - the same exact ones Mark recommended.
I put three together to get 67 ohms and this is the result:
As I suspected, my gauge is totally off. I am not sure what was incorrect with the first set of resistors I got, but now I have final confirmation.
I took the cluster apart and will look for these 2 dials. |
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SyncroChrick
Samba Member
Joined: January 10, 2005
Posts: 1010
Location: San Francisco, CA
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| Posted: Mon Apr 06, 2020 7:07 pm Post subject: Re: Temp Gauge testing at home |
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| korfmach wrote: |
The adjusters are on the back of the coolant gauge. You'll have to remove the gauge from the tach, but you don't have to take the needle off. Just remove the three nuts on the back of the tach housing that hold the coolant gauge, and remove the two little screws on the face of the tach. That will give you enough room to take the coolant gauge out.
The adjusters are visible through two holes in the back of the coolant gauge. There are little teeth that you can manipulate with a small screwdriver. One is a low-end adjustment, the other is a high-end adjustment. There is some interaction between the two adjustments so it takes several iterations of low/high resistance in the circuit to get it right. |
Thanks. I took it appart and here are what I assumed the two holes with teeth to make the adjustment.
I really wish I had a sense on which direction to go with these before putting it all back together to test.
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korfmach
Samba Member
Joined: February 28, 2014
Posts: 247
Location: Fort Collins, CO
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| Posted: Tue Apr 07, 2020 12:13 pm Post subject: Re: Temp Gauge testing at home |
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| dbeierl wrote: |
| You can calibrate it -- there are zero and span levers at the back. They interact so it takes two or three passes. You need 35 and 265 ohm resistors to give bottom line and top line on the gauge. |
dbeierl, I re-read your post..I think I've got it figured out. Top and bottom lines correspond to cal dots, 35 and 265 ohms respectively.
_________________
1989 Westy
2016 Golf TSI
Gone, but not forgotten:
1974 Dorper Baywindow, "The Bleeding Trout"
1998 Jetta TDI, "Trixie"
1987 GTI, "Heike"
1974 Thing, "The Luftwaffel"
1974 Ghia
1966 Ghia |
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SyncroChrick
Samba Member
Joined: January 10, 2005
Posts: 1010
Location: San Francisco, CA
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| Posted: Tue Apr 07, 2020 8:02 pm Post subject: Re: Temp Gauge testing at home |
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I started playing with the adjustment. I am not entirely sure if the two adjustments are connected or not, but I was able to move one and take the needle lower.
At 100Ohms resistance, the needle is below the flashing light. At 67ohrms, it's a bit above.
So I am getting closer, but I am not there yet. I suspect they may also be something wrong with the gauge itself. The needle does not move up gently, but instead jumps for the first seconds before it reaches a stable point.
In any case, I feel like I am getting closer I took the van again for a longer drive today, and went up to 65 mph!
Still have a gazillion things to do on it, but it's getting better everyday. |
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Vapor
Samba Member
Joined: July 01, 2020
Posts: 6
Location: CA
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| Posted: Wed Jul 01, 2020 2:18 pm Post subject: Re: Temp Gauge testing at home |
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| SyncroChrick wrote: |
I started playing with the adjustment. I am not entirely sure if the two adjustments are connected or not, but I was able to move one and take the needle lower.
At 100Ohms resistance, the needle is below the flashing light. At 67ohrms, it's a bit above.
So I am getting closer, but I am not there yet. I suspect they may also be something wrong with the gauge itself. The needle does not move up gently, but instead jumps for the first seconds before it reaches a stable point.
In any case, I feel like I am getting closer I took the van again for a longer drive today, and went up to 65 mph!
Still have a gazillion things to do on it, but it's getting better everyday. |
@SyncroChrick did you find a solution?
Long time lurker on thesamba.com, going back to 2015 when I was first seriously interested in buying one but prices were pretty high on good examples.
Lurked more and more and finally found an '87 2wd Westy with factory AC (not sure if it works as previous owner never used it) at a reasonable price, purchased back in May 2020 with 217,000 miles. It has some issues which reflected the negotiations with selling price like torn CV boots, unsure if any of the kitchen works (stove, sink), stubborn transmission going into 1st gear, cosmetic paint, etc but nothing major from what I could tell on the test drive as engine power was OK, no smoke from the tail pipe and recent service records. Happiest of all that rust was at a bare minimum.
Onto the nitty gritty of my most serious problem that arose just after getting the van to run clean enough to pass California smog.
I'm somewhat familiar with working on cars but this is my first VW and first car old enough to replicate my age minus 5yrs  after doing many days of research on theSamba for similar issues to what's listed here and my problem, this is my first post here seeking help and guidance after exhausting nearly all avenues.
History: van is an '87 equipped with factory rear ac that is unknown if it works. Miles 217,000 when initially purchased in May 2020. No hot temp gauge issues until recently (219,000mi) which arose with troubles in getting the van to pass smog. It was dirty at idle for California standards but clean at the higher 2500rpm idle rpm test.
Items fixed prior to passing smog:
1. Cracks in exhaust were repaired. It had a bad one on the passenger side rear exhaust manifold near at the 90 degree bend by the head, near rear of the car, the pipe was cracked halfway around. Second crack on the other side of the passenger head at the 90 degree bend out of the head (towards the front) that was 1/3 all the way around, and much smaller cracks near the collectors further down the exhaust system. All fixed and sealed.
It appears the previous owner drove on these cracks for at least 10,000+ miles declining multiple shop recommendations for repair/replacement. I noticed the passenger side head has oil weeping/very slow leak at the rubber gasket near the block. Driver side head is bone dry but noticed some type of RTV sealant on drivers side but little to none on the leaking passenger side.
2. Cleaned K&N air filter
3. Ran Guaranteed to pass emissions cleaner bottle in gas tank
4. Ran Amsoil deep cleaning additive in the gas tank after a full tank of guaranteed to pass cleaner. (total 2 tanks of full gas with each tank that had a bottle of cleaner per tank)
5. Seafoam high mileage motor treatment through the throttle body to clean up the top end
6. Changed oil to Castrol GTX 20w50 + WIX oil filter
7. Checked timing using the 3,000 rpm method. Initial was 39, set to factory 35 degrees.
Prior to adjusting the timing, the engine got 20-22mpg fuel mileage and I thought it drove OK but with a peaky power band. Post timing adjustment, gas mileage dropped to 16-18mpg but power was smoother and felt like better throttle response and better drive ability at lower rpms without a loss of power at the top end. I drive slow, don't Rev out the engine and keep the rpms in the "green zone" traveling 55-60mph on the highway and don't consider driving the van hard. That's why I'm confused with the reduced gas mileage and the hotter water temps after the timing adjustment.
The previous owner bought this Westy from TDI motors with 198,000 miles. TDI replaced the heads with new AMC heads, new distributor cap, distributor rotor, wire set, spark plugs, thermostat, housing, sensors, pressure and overfill bottles, blue cap, fill sensor, cold temp sensor and Guage sensor.
Prior to the 7 items performed above, the water temp needle on the gauge cluster was rock solid at just below the red led. Engine warmed up quickly from a cold start and ran fine with the needle not moving past the red led driving at all speeds, even in stop/go traffic and idling. I never heard the radiator fan turn on.
It wasn't till after the above smog "remedies" that problems started to arise with at first, the temp needle moving up 3/4 during driving up Hwy 330 to Big Bear at half throttle at cool ambient temps. Once at the campsite in Big Bear, just idling, the water temp needle would climb past 3/4 towards the top white line and I'd hear the loud fan turn on. Never once did the low speed or middle speed fan kick on. Temps would stay high on the needle and the high speed fan would fluctuate on and off with the needle never going higher than that.
Is it possible the high altitude of Big Bear (7k ft) caused this problem? After that camping trip, the van would run warm according to the coolant gauge and has progressively gotten worse, even driving on the Freeway at 55-60mph, light load, and the needle sits just above the red led.
Parts I've replaced and services I've performed. Bled the cooling system via front end jacked up then back end jacked up. Replaced the thermostat. Previous was an 80, replaced it with a Meyle 80. Replaced the cold thermosensor with a Meyle unit.
No coolant lost as both pressure bottle was full and overfill bottle full before all these problems and afterwards. Barely any air came out of the radiator bleed screw.
Tested the resistor behind the driver headlight, it checked out OK, jumping it with 12v power I was able to get the fan to operate at low, medium, and high speeds.
When turning on the ac, it appears either the low or medium speed fan turns on but only the high speed fan turns on by itself as the coolant temp needle climbs to towards the top line of the coolant temp gauge. The medium and low speed fan does not turn on by itself.
The blue cap passes the blowing on it and breathing in test (trumpet sound and blocked when you try to breathe in)
I've jumped the harness for the coolant temp sender and the gauge moves all the way to the top, indicating the harness and wiring to the cluster are good.
Using an IR gun on the pipes, tstat housing, radiator, it appears the area of the radiator where the fan switch is located shows the coolest temps, like 135f whereas other parts of the radiator are at the normal temps. Why would the high speed fan turn on then? Does this indicate a clogged radiator?
Temps at tstat housing are in line with normal from what others have stated here but don't reflect the needle on the gauge which shows high. The piping coming into the tstat housing from the radiator is coolest and reflects the temp measured at the lower driver side of the radiator.
One thing I noticed that appears new is the flashing led when starting up the engine for a couple seconds. Either that is new since the high temp needle reading problems or I just started to notice it and it's always been there. I don't remember it flashing before I started having these high temp reading problems.
Parts I have not replaced as I'm getting frustrated with this and don't want to just throw parts at it randomly
1. Blue cap (passed the blowhard tests) and is relatively new
2. Coolant gauge thermosensor located below radiator return at tstat
3. Water pump (it's working but maybe not well enough?)
4. Radiator (definitely not original as it looks relatively new)
5. Fan thermosensor switch (definitely not original as it looks relatively new)
6. Any of the relays in dash
Any and all help would be massively appreciated. Since I bought the Westy, I'm finding myself driving it as a daily driver since it's much more fun than anything else I've owned. Yes, all modern vehicles ranging from a 2018 Ford Focus RS, 2010 Toyota FJ Cruiser, 2001 Honda S2000, and a couple sport bike motorcycles are left collecting dust since I'm enjoying the Westy the most but this recent warm operating temp condition is keeping me driving it :/ |
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Vapor
Samba Member
Joined: July 01, 2020
Posts: 6
Location: CA
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| Posted: Tue Jul 07, 2020 3:58 pm Post subject: Re: Temp Gauge testing at home |
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Update: the coolant temp gauge is working now after removing the 43 relay in position 3 of the fuse panel under the lower left side of the dash and jumping - 31and S terminals. It appears the original 43 relay is bad. New one on order. The coolant level gauge wasn't working either however the temp gauge was getting power and ground at the harness connection to the sensor in the thermostat housing. The coolant level sensor is not getting power. Maybe that will change with a new relay? 🤞🏽
Last edited by Vapor on Wed Jul 08, 2020 4:49 pm; edited 1 time in total |
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Vapor
Samba Member
Joined: July 01, 2020
Posts: 6
Location: CA
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| Posted: Wed Jul 08, 2020 1:19 pm Post subject: Re: Temp Gauge testing at home |
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| Another update. Replaced relay 43 with the latest 43 relay. Coolant level works. Coolant temp gauge doesn't work. If I jump the terminals with the relay out, the coolant gauge works. What gives?!?! |
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crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9935
Location: Orbiting San Diego
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| Posted: Wed Jul 08, 2020 1:57 pm Post subject: Re: Temp Gauge testing at home |
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Jump which terminals?
What exactly does "works" mean?
Mark |
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Vapor
Samba Member
Joined: July 01, 2020
Posts: 6
Location: CA
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| Posted: Wed Jul 08, 2020 4:48 pm Post subject: Re: Temp Gauge testing at home |
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| crazyvwvanman wrote: |
Jump which terminals?
What exactly does "works" mean?
Mark |
When I place a paper clip jumping [S] and [-31] with relay 43 out, the dash coolant temp gauge is functional. Install the new relay 43, coolant temp gauge goes completely dead/full cold. However with relay 43 in, the coolant level works, when I remove the connecter at the coolant level sensor in the expansion tank, the led light begins to flash. Why does jumping the terminals result in a working temp gauge when having the relay in disables it? |
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crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9935
Location: Orbiting San Diego
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| Posted: Wed Jul 08, 2020 5:33 pm Post subject: Re: Temp Gauge testing at home |
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Again, exactly what does "gauge works" mean?
Starts out reading stone cold, slowly goes higher over several minutes of engine running before stabilizing mid-gauge, never goes higher than 2/3?
Mark |
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Vapor
Samba Member
Joined: July 01, 2020
Posts: 6
Location: CA
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| Posted: Wed Jul 08, 2020 5:55 pm Post subject: Re: Temp Gauge testing at home |
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| crazyvwvanman wrote: |
Again, exactly what does "gauge works" mean?
Starts out reading stone cold, slowly goes higher over several minutes of engine running before stabilizing mid-gauge, never goes higher than 2/3?
Mark |
Thank you for asking about clarification Mark. By working, the gauge slowly moves up to the middle of the LED upon turning the engine on and the coolant warming up. Fluctuations are small as the needle moves slightly above and slightly below the led. I removed the 43 relay and jumped the terminals since knowing the coolant temp is more important than the coolant level. |
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zoti
Samba Member
Joined: December 26, 2007
Posts: 2061
Location: Plano, TX USA
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| Posted: Tue Oct 20, 2020 9:01 am Post subject: Re: Temp Gauge testing at home |
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I did the temp gauge test by grounding the connector at the temp sensor to ground. The needle went up to about half way (where the led light is) and stopped there.
I understand it should shoot all the way to the top.
What should I check for repair? |
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Slimvest
Samba Member
Joined: March 20, 2014
Posts: 431
Location: Portland, OR
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| Posted: Sun Mar 21, 2021 2:37 pm Post subject: Re: Temp Gauge testing at home |
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I wanted to add my gauge's readings for others to reference.
Confirmed 10 volts (9.8 actual) from the temp gauge wire at the thermostat to the cluster.
I think the gauge is functioning as it should, but as has been said, everyone's gauge is different. I have a single connection sensor and no ground wire with the Gowesty aluminum t'stat housing.
100ohm (should be near but not reaching LED)
67ohm (should be over some part of LED)
50ohm (should be 2 needle widths above LED)
33ohm, LED was flashing (should be at last white mark and flashing)
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'87 GL w/ Reimo top |
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derekdrew
Samba Member
Joined: October 14, 2007
Posts: 246
Location: Far Northwest CT
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| Posted: Tue Oct 19, 2021 10:48 am Post subject: Re: Temp Gauge testing at home |
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I don't know if this would add anything, but ETKA says VW changed the coolant temperature gauge in mid-1990 production (!!!) so that 1990 body 030-001 and later use coolant temperature gauge 255 919 511A whereas 1990 body 030 000 and earlier use only 255 919 511. I can't imagine how these two gauges may differ. ETKA doesn't seem to make the same body chassis distinction for the coolant gauge temperature senders that I can see. For someone with multiple late vans, this is very confusing. This thread should help.
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Derek Drew
derekdrew - a t - derekmail - dott - com |
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TomInAlaska
Samba Member
Joined: June 02, 2007
Posts: 386
Location: Anchorage, Ak
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| Posted: Sat Oct 23, 2021 11:27 am Post subject: Re: Temp Gauge testing at home |
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I finally got my hands on some 100ohm resistors and got a chance to do some diagnosticing on my '84. I found that with 200ohm between the sensor wire and ground, the needle moved up to right at the first white tick mark, with 100ohm, it started moving up to just under the LED, then made a few small jerks and then kept moving all the way to the top of the gauge. Same results with the 67ohm (I stopped testing there).
Should I assume that means that my gauge is malfunctioning? A previous owner had installed an aftermarket water temp gauge (in the radio slot no less  ) so that probably means they same to the same conclusion. Could the 43 relay have anything to do with it? Note that the LED which had previously wouldn't stop flashing with the low coolant sensor plugged in (GW's aftermarket sensor) now isn't flashing at all when turning on the ignition. Guess I need to find a replacement gauge.
_________________
'73 Super Beetle (resto-mod/rally look, 1776)
'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight= |
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