Thermostat

[Una]

I'm kind of new to diesels.. I see I have a huge selection of thermostat temperatures for this car.. Which one should I get? I think the car came with is too low, because it cruises down the freeway just below 1/4 of the way.. When I'm in stop and go it'll get up to 1/2 way.. I'd imagine I want a thermostat that keeps it at halfway all the time.. Less thermal stress on the headgasket that way. My choices are 71, 80, 87 or 92celsius. I'm guessing 87, 92 seems a bit hot, but maybe it's good for combustion on a diesel? (for the Americans, that's 160, 176, 189, and 197f)

[damac]

My experience thus far. I had the stock one and drilled a small relief hole people suggested, but the car was running cool and all over the place. So much so that I wasn't even getting good heat on the coldest days. Didn't seem right how the car was acting.

Left it in until I placed another order for other parts months ago and got the Thermostat; 87 Degree C and didn't drill a relief hole. I have been running it and summer just hit and in the 100 degree heat and just driving the car normally(no ac), it is now running just a bit hotter than before. Now my new up to temp spot on the gauge is when the marker is just passed the led, before it wouldn't go past the marker just blocking the high end of the led.

I had this idea I was going to run veggy conversion but then sources fell through and I haven't really bothered to change it out. Seems the stock one without a relief hole in it would work just fine for me.

[82vdub]

The instrument cluster gauge isn't a good measure of actual temp. Due to age and wear on the cars, gauges from vehicle to vehicle aren't consistant. What it does is tell the driver how it differs from what "normal" is for that vehicle. As for the Tstat temp, I'd probably shoot for the 189F Tstat. Diesels like warmer temps. Most (if not all) new cars have high Tstat temps these days. The hotter the engine runs the lower the emissions coming out of the tailpipe and it's one way for the manufacturer to lower emissions.

[Una]

While the dash gauge isn't accurate, it does give a good indicator that the temperature is currently inconsistant. Sounds good, I'll go for that thermostat.

[Fatmobile]

Candy thermometer in the coolant resevoir is a good way to check your sensor.

[damac]

Anybody have a link to an affordable temp gauge kit and where to install it?

I bought a harbor freight kit for the basics and found that the lead was too huge to install

[Una]

Thats a good question, I couldn't find a decent place to put the probe for my gauge either.

[vanbcguy]

There are some aftermarket gauges out there that will work with the VW-style senders. You just need to find a gauge that measures on the same scale as them.

[Una]

In that case, you're still using half of the unreliable factory setup.

[vwtyp133]

In that case, you're still using half of the unreliable factory setup.

If you've got the factory gauge in the instrument cluster & sender in the rear of the head, you might want to back it up with a slim digital gauge that's easier to find a 'home' for. One such gauge is the Shindy, with a fair description here http://www.cruisercustomizing.com/detai ... t_ID=57254 OTOH you might find a better price by searching around on Amazon or another "deal" service. No personal experience with that unit, but the size looks readily adaptable. Many aircraft and industrial instrument makers also have small digital offerings, and the prices are widely-varied.

It should be easy to come up with a "T" adapter to fit the sender in beside the factory sender. Have done that on quite a few vehicles factory-equipped with just overheat "idiot light warning (more of an 'invitation to the funeral' for the engine, than an actual warning service). A selector switch and additional matched senders mounted at various locations (lower radiator, upper radiator, oil flow pathway, etc.) allow for some selective temp comparisons to be made under actual road & load conditions... and yet avoid the 'Cessna-envy' look that many aftermarket gauge installations take on.

YMMV

[Quantum TD]

Go with the 87 degree stat. Get a WAHLER one (brass). If you live in a consistently-hot climate, then do the drill-hole trick. If not, then don't. I did it on my car here in Tennessee. It's nice to not see the gauge go up in the summer, but in the winter it sucked.

Also get a new WAHLER temp switch. It's cheap insurance.

[bottleworks]

I have found differences between the temp sending units as cause for the different gauge readings. New vs New and vs orginal senders resulted in all different respective results on the gauge.

[Una]

Yeah, if the gauge were just sitting at a quarter constantly, I'd just chock it up to the gauge, as long as the heater worked.. But it was all over the place until I changed that thermostat and the coolant. It's now just below halfway, and seems to stay there at all times. I'm happy.

[Gutta Perka]

VW orginal part nb:
068121113H for D/TD

In the junkyard I picked the petrol one: VW 056121113D Rabbit. Also 87 Celsius but Slower.
It works fine! As you see 6 figures are the same and exakt the same measures.
Compared to the diesel one it shows a Little-litle bit low when motor is not pressed or "properly used" -:)
Otherwise no differense!

I'll keep it in!

[the man 53]

I put an 87c in mine and had the coldest in it before. I can actually tell the car performs better than it ever did. I have an autometer gauge as well as the factory and both went up. The autometer went up around 15F-20F, but it never goes over 195 no matter how I run it or leave it idle for a long time.

What I did to run both is there is a cast piece coming off of the trans side of the cylinder head. I took it off and put it in a vice, drilled a hole, and tapped it for the autometer sender. IIRC it was 1/8 NPT maybe 1/4 NPT either way it is tapped. I used teflon tape and DID NOT over tighten as I didn't want to see what the cast Al was really made of. It works flawlessly with no leaks. I don't know which way the coolant leaves the head or if both the front and side is leaving, but I am sure it is accurate temp.