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Sat May 08, 2021 12:00 pm

Hello,

Rewiring the whole bus (1970 Transporter). Main harnesses are all done, and now I'm getting ready for the add-ons. Previous owner installed an oil temperature gauge, but I'm wondering if this is worth having, or if there's a more useful gauge I could/should put there. Sending unit for this gauge is currently screwed into the oil drain plate.

Thanks,
Larry

Sat May 08, 2021 12:04 pm

Since I installed a cylinder head temp gauge I rarely look at the oil temp.
I won't say it's useless, but if I had just one, it would be CHT.

Sat May 08, 2021 12:24 pm

I personally think VW should have fitted an oil temp gauge as standard and it would have saved a lot of engines. All watercooled cars have a temp gauge and strictly speaking vw’s are oil cooled.

I have them on my stock 1200 bug and the 2110 stroker in my bus, occasionally glance at them like I do the fuel gauge. Just my opinion, I accept others may well disagree.

Sat May 08, 2021 12:35 pm

I have a tach, oil pressure,oil temp, and CHT. Some folks will chime in and say "you will be paranoid and watch them all the time". Not so with me. I glance at them like I glance at my mirrors.

Sat May 08, 2021 1:31 pm

Depends on just where the sender is located. Personally (and assuming that all of your tinwork is good) on a Type 1 engine I would prefer to have an oil pressure gauge.

Sat May 08, 2021 2:31 pm

I'm in the "Gauges are good" camp.

Oil temp is a good one to have.

To me the goal should be: Tach, oil pressure, oil temp, cyl head temp.

.

Sat May 08, 2021 7:31 pm

I have oil pressure, oil temp, voltage, and a tach. That’s just 3 wires to run front to back. The voltmeter can just use a wire from the front. Oil pressure should be high on the list.

Sun May 09, 2021 9:51 am

aeromech wrote: I have oil pressure, oil temp, voltage, and a tach. That’s just 3 wires to run front to back. The voltmeter can just use a wire from the front. Oil pressure should be high on the list.

Quite handy to just buy a 20' trailer light wiring harness and use those 4 wires to run to the front of the bus in a 3/8" wiring loom.

Sun May 09, 2021 10:10 am

Great idea on the trailer wiring. I used to own boats though and can tell you that some of that ribbon is poor quality and the insulation went to hell on me quickly so buy the good stuff

Sun May 09, 2021 10:33 am

lsilverman11 wrote: Hello,

Rewiring the whole bus (1970 Transporter). Main harnesses are all done, and now I'm getting ready for the add-ons. Previous owner installed an oil temperature gauge, but I'm wondering if this is worth having, or if there's a more useful gauge I could/should put there. Sending unit for this gauge is currently screwed into the oil drain plate.

Thanks,
Larry

I would definately say keep the oil-temperature gauge and add a few others for company. The following was what I had in the early-1990s, but I have some more to complement these in a revised dashboard layout.

'How To' & 'Handy Hints' > Retro-fitting supplementary gauges

http://forums.kombiclub.com/showthread.php?t=19396

Sun May 09, 2021 11:25 am

I think oil temp is a very good gauge to have.

However you need to understand what the "NORMAL" oil temperature range is....in order to not have paranoia issues.

With conventional oil....anything under 212* is a little too cool to keep moisture out of the oil. Over 275* for any length of time does damage to the ability of the oil to lubricate and keep film strength. So in a heavily loaded, highway driving vehicle in hot weather....225*F to 250*F....is normal.....and this is conventional oil. YOu can add about 25*F to those temps with synthetic.

There will be low spots and high spots with wind and hills. A lot of web info says 260* peak is fine...but bear in mind you may have temp gauge accuracy issues.

Driving long distance in an ACVW at 50 to 70 mph...and quick glance at the oil temp gauge as long as its below 250....should not cause a second thought.

It is also stated that oil temp gauges are only good for "trending". Thats true too! If every 5-7 minutes on a long highway trip....you sweep your eys over the gauge and its between 225 and 250...no big deal. If the last to times its been pegged at 250.....still no big deal. If one of these times on flat level ground its now at 260.....well...thats a trend. Oil temp is not dropping its rising. Slow down a little....and take a look more often.

The other issue....is where the oil temp gauge is reading the temp. Where should it be placed? Where should you read it?

I have my own opinion. I think the oil temp should be read right out of the oil cooler where it enters main gallery to feed bearings. However reading it there is difficult.
The next best is the pickup tube. the pickup tube. In my personal opinion....no other locations are important whatsoever.

Either you want to know what the oil temp is at the bearings after the cooler....or...barring that... the next best thing is to know what its temp is as its sucked into the pump...keeping in mind that the pump will add a few degrees of temperature and oil cooler will remove about 15 degrees on average.

If the oil you are reading at the intake pipe is over the max running temp of 250.....and probably much over 240.....you know you have a problem...because teh pump will add to it and the cooler can only remove so much heat.

Looking for that difference is the only thing the oil temp gauge is for....and why I think its good to have. Ray

Sun May 09, 2021 12:16 pm

Yes, the bearing in temp is exactly what’s important. Reading that isn’t practical in a wet sump engine. Dry sumps like turbine engines have can be read easily because you have external pipes running all over the place

Sun May 09, 2021 7:49 pm

aeromech wrote: Yes, the bearing in temp is exactly what’s important. Reading that isn’t practical in a wet sump engine. Dry sumps like turbine engines have can be read easily because you have external pipes running all over the place

Well....there is a way to read the temp coming out of the oil cooler if one were of the mind to do something a little different.

It would entail cutting a small...maybe 1/2" hole in the sheet metal to access one of the two NPT pipe plugs that plug the in and out galleries on the oil cooler mount.

It would be nothing to make a bulkhead style fitting for a 6" long, bendable thermocouple probe...out of a bolt. The tip can protrude just enough to touch the oil coming out of the cooler port and not block anything. The rest of the 4" of probe can be bent out of the way and screwed or strapped down.

A 6" long J type one with a 1/8" diameter probe made of stainless steel is $23.78 from Mcmaster carr. Ray

Sun May 09, 2021 8:00 pm

Like most things regarding mods, anything is possible given enough time and money. Want to install a 500 hp V8 into a bus? I’ve seen it done.

Mon May 10, 2021 5:47 am

There’s a reason early Porsches 356 & others included an oil temp gauge.
I’ve added one on my 78 Westy along with oil pressure. Helps me determine correct oil viscosity for various seasons in No WI. 10 psi per 1000 rpm minimum. Thinking of adding cylinder head temp as well, it’s on the list.

Mon May 10, 2021 6:37 am

To pick up oil temp at the cooler I use a T3 oil cooler, it has a threaded bung in the base for your temp sensor.

Mon May 10, 2021 10:18 am

Jeff Geisen wrote: To pick up oil temp at the cooler I use a T3 oil cooler, it has a threaded bung in the base for your temp sensor.

Thats probabpy a good solution for the 1970 he has. It should be type 1 based.

Just so no one mistakes my earlier commet....my solution was for a,type 4. The type 3 cooler solution will not work for that. Sorry to muddy the waters.

But if you wanted.....you could probably do it the same way on a type 1 based engine if you have to. Ray

Mon May 10, 2021 10:27 am

I always put the sender in a fitting on the outlet from a full flow pump cover where possible

Mon May 10, 2021 1:07 pm

raygreenwood wrote: I think oil temp is a very good gauge to have.

However you need to understand what the "NORMAL" oil temperature range is....in order to not have paranoia issues.

With conventional oil....anything under 212* is a little too cool to keep moisture out of the oil. Over 275* for any length of time does damage to the ability of the oil to lubricate and keep film strength. So in a heavily loaded, highway driving vehicle in hot weather....225*F to 250*F....is normal.....and this is conventional oil. YOu can add about 25*F to those temps with synthetic.

There will be low spots and high spots with wind and hills. A lot of web info says 260* peak is fine...but bear in mind you may have temp gauge accuracy issues.

Driving long distance in an ACVW at 50 to 70 mph...and quick glance at the oil temp gauge as long as its below 250....should not cause a second thought.

Great info not Ray! Is this a rule of thumb for all ACVW, T1 and T4, or just T4?

Mon May 10, 2021 2:36 pm

whatever you do don't but VDO gauges. they are the most inaccurate fucking junk out there anymore.