92 Cabby - high oil temp

[CajunSpike]

I finally found the short that was blowing the horn fuse. The kid had wired in an accessory light but didn't tape up with hot wire...poof it went with the vibration of the car when it grounded.

Next question. This 92 auto cabby, seems to run pretty high oil temps. he said it gets to 130c at times. From looking at my other two manual cars, that does seem excessive. coolant temps don't seem to rise correspondingly though.

Any ideas why oil is getting so hot? or apparently so because of the oil temp gauge?

we'll try fresh oil and filter and monitor it.

[tolusina]

Um, Cajun, you've got enough cars you work on, I think you are ready to shop this page or similar..........
https://www.google.com/search?source...5l5j1j7-1l7l0.

With one of those, you'll be able to measure and KNOW temperatures of things like engine oil and coolant at various places (like both sides of the thermostat, right at the rad fan switch), A/C vent and line temps (hint, lowest A/C vent temps are with the HVAC fan on it's lowest speed) (hint 2, heater vent temps are real close to engine coolant temps), brakes, refrigerator and freezer, hot side tap water, kid's ears, summer sidewalks and shade, lots of stuffs.

The most accurate non-contact infrared pyrometers allow for emissivity adjustments, though it's often tedious to adjust to various subjects. Admittedly, I may well be a bit out of touch with technological advances in the field, emissivity adjustments may now be fully automatic

[lshee778]

Mine gauge reads high when the headlights are on (I'm assuming a bad sensor or grounding issue). Check what yours reads without the headlights on. I was worried mine was running hot but I realized that the gauge reading goes up a lot when the headlights are on. Cabby-Info says they should operate between 100 and 120. I'm sure you are already aware of all this though.

[CajunSpike]

I agree 120 is a little warm..but i get concerned when the kid reports it getting up to 130c...which is the point of this post.

Will ask him if that happens with day or night driving, lights or not. good suggestion.

[kamzcab86]

Mine gauge reads high when the headlights are on (I'm assuming a bad sensor or grounding issue). Check what yours reads without the headlights on. I was worried mine was running hot but I realized that the gauge reading goes up a lot when the headlights are on.

Mine did the exact same thing thanks to VW's wiring wisdom; issue disappeared after relaying the headlights.

I agree 120 is a little warm..but i get concerned when the kid reports it getting up to 130c...which is the point of this post.

Will ask him if that happens with day or night driving, lights or not. good suggestion.

120 is normal, especially in the warmer climates; 130 is high. Verify if accessories are running; if they're not, I'd then verify what the real oil temp is (i.e. use a real gauge, not the VDO in the car). It's possible the gauge sender is going bad, and/or the wiring in between is faulty.

[CajunSpike]

Not that it makes much diff, but this car does have the headlights relayed. did that last year.

ok and just to check...the sender for the oil temp gauge is screwed into the top of the oil filter flange on a digi?

[tolusina]

.....ok and just to check...the sender for the oil temp gauge is screwed into the top of the oil filter flange on a digi?

Yup, the little one with the carpet tack head looking connector.

[CajunSpike]

Thank you sir's and ma'ams.

I have another sender on a parts block.

so plan is....

oil/filter...watch it.
still hot, swap out sender..watch it.
I think I have another temp gauge too..just in case.

[kamzcab86]

You could also add another (and better) ground to the console gauges (Brian's idea).

[briano1234]

I too had the 130 degree oil on my blue cabby, and the green one when tooling down the highway.
Both are automatics, and I never saw it above 120 on my manual. The first times I saw this behavior I was mortified.. Turned off the a/c and it lowered, but it still was a puzzlement.

Both cars are rocking the 36mm oil pumps, and one had the 4-2-1 dual down pipe where as the other is stock still. Both had all new senders....

What troubled me was that the 90's cabs, VW took off the Oil temp stabilizer, I suppose they thought it didn't need it, I seriously thought about installing one but I wasn't happy with tying my oils temperature to the radiator...

I thought it was normal for these auto's but there had to be a better way.
I finally got the temp down by installing a external oil cooler.
With the installation of the external coolers, I find that my Idle pressure increased, and tooling down the highway with the a/c on and top down, I could never get the oil above 110.



Soooooooooo how did I install it?
http://www.toplessrabbit.com/forums/...hp?f=27&t=1892

[CajunSpike]

I vaguely remember, on that 91 jetta i just scrapped....that i THOUGHT I saw one of those oil cooler kits on it.

Any other possible sources to pick up the cooler assembly from other vw models..or still being sold new?

I also THINK that 99 cabrio I have has an oil cooler on it....have to check.

[87CabrioSK]

Mine has an oil cooler as well, never gets above 110 and it takes a lot of driving on a hot day to get there.
Came with me car, but I believe certain Volvo's have the same setup.

[kamzcab86]

I also THINK that 99 cabrio I have has an oil cooler on it....have to check.

It should (IIRC from perusing the Bentley); my VR6 Jetta has the same dang thing... just blew the seals on it, in fact. My Vanagon has it too. Yes, VW has used the same cooler for 2 decades.

The OEM oil coolers are readily available new (more VW models actually have them than don't, and I highly advise, that if you go this route to NOT put a used cooler on your car), but you'll need a bunch of other OEM parts to go along with it for your Digi Cab. Whole lot easier to just do what Brian did.

[CajunSpike]

I'm just laying it out in my head. Assuming I can get hold of the oil filter 'tank' part, I would prefer the air cooled route. I don't like the mix-water-and-oil idea myself.

[briano1234]

You can buy the sandwich plates for the externals off of ebay, hell you can get the whole kit.

Just do a search on VW Oil cooler sandwich.

[Darter]

If you go with the coolant version, you have two options. My passat had the thinner version that you see on various other older vws. When it failed, I upgraded to the thicker version to provide more cooling circulation:

http://www.amazon.com/028-117-021-L-...sim_sbs_auto_3


These days there's a much cheaper aftermarket version:

http://www.amazon.com/Cooler-0281170.../dp/B002N4GPUA


Here's the thinner style, for reference:

http://www.amazon.com/Volkswagen-Coo...sim_sbs_auto_1


To use the thicker version, you just need the longer center threaded pipe to go with it. Just twist on/off to replace. We also combined that with a taller oil filter for more cooling volume/capacity. I think we got an extra .7L out of the swap.

[CajunSpike]

So today, we put fresh oil and filter on this green monster and took it down the road.
The oil temp pegged all the way out after a run taking it up to 70mph.

Touching the radiator hose from the block to the radiator, it was very hot. Might actually have a cooling issue showing up in the oil temp instead of the radiator temp. Radiator was pretty decently warm also.

Opened the overflow cap and had coolant overflow. With the engine running at idle, there is very little flow in the line coming into the tank. If you rev the motor, then a small stream of fluid moves..but thats it.

Starting to wonder if the thermostat is stuck. I did put a new pump on here when the car was rebuilt.
Radiator fan kicks on as normal.

[vwcrackerjack]

Check out http://cabbyinfo.com

Look under the technical area under gauges. It explains oil gauge and what it means if it pegs all the way how to test it also. There is only supposed to be a small stream of fluid going in the coolant tank. As long as it is flowing and not just a dribble its working. It almost would be the same type of stream as if u squeeze a bottle of dish soap sideways.

[vwcrackerjack]

Www.cabby-info.com

[briano1234]

If you go with the coolant version, you have two options.
My passat had the thinner version that you see on various other older vws.
When it failed, I upgraded to the thicker version to provide more cooling
circulation:

http://www.amazon.com/028-117-021-L-...sim_sbs_auto_3


These days there's a much cheaper aftermarket version:

http://www.amazon.com/Cooler-0281170.../dp/B002N4GPUA


Here's the thinner style, for reference:

http://www.amazon.com/Volkswagen-Coo...sim_sbs_auto_1


To use the thicker version, you just need the longer center threaded pipe to go with it.
Just twist on/off to replace. We also combined that with a taller oil filter for
more cooling volume/capacity. I think we got an extra .7L out of the swap.

Those are a oils stabilizer and not really a cooler. It allows the Oil to get up to temp quicker
and keeps it tied to the Radiator coolant temp. So if your car is over heating, then
your oil will get warmer also. It can allow intermix of a/f to oil if it goes bad the wrong way also.
I don't know if that was one reason the removed it from the 90-93 cabbies but have noticed that
they installed it on the Passants for those model years....

This is one reason I am a advocate for the External Oil Coolers which do cool the
oil by air flow and not Radiator fluid. Then with the advent of installing one of those
on my 93, I would of added that funky 3-way hose as well as 2 more hoses that
I would have to replace or check often.... I follow the rule of KISS, Keep It Stupidly Simple.

Check out http://cabbyinfo.com

Look under the technical area under gauges. It explains oil gauge and what
it means if it pegs all the way how to test it also. There is only supposed
to be a small stream of fluid going in the coolant tank. As long as it is
flowing and not just a dribble its working. It almost would be the same type
of stream as if u squeeze a bottle of dish soap sideways.

Psst I think Cajun is well aware of that site.


Cajun, It could very well be that your t-stat is partially opening, and if you didn't replace it
when you did the pump that would be one suspect. (be sure to drill the weep hole in the lip.)

And on a side note since I have been having cooling flange or radiator issues as of late.
I have found a Turkey Baster to be a useful tool.

I suck the Fluid out of the Res in to a jug.
Then I suck out as much of the fluid as I can, via the CTS sensor. I pop it out, and
use the Turkey Baster to suck the fluid out of there too.
I usually can get 1/2 to 3/4 of a gallon out, and limits the Douching I get
from under the car.

I would suggest a new t-stat as well as a flush of the cooling system.
If you open the heater to full hot, and high fan on defrost, do you see a temp
decline?

[CajunSpike]

I had the kid take the car out for a drive after we changed the oil/filter. When they got back he pointed to the oil gauge temp pegged all the way. The hose from radiator to head was VERY hot. Opening the coolant fill cap slowly resulted in excess fluid overflowing. Radiator was warm but not burning hot like the upper radiator hose was. cooling fan kicked on for a short time then went off.
There just didn't seem to be any movement of coolant in the tank while i was watching it. the small pipe liquid just didn't move unless the engine was revved up to a decent rpm. On Etienne #2, there is always a nice stream of fluid moving out of the small pipe hole in the tank.

Didn't try the heater core thing since i wasn't in the car. the coolant temp gauge doesn't show excessively hot..which is a bit of a mystery. At the same time, you can feel the heat radiating off the engine.

I'm leaning to the thermostat/flush as well..and maybe just do the water pump while I'm there
I might also try to get one of those metal thermostat outlets as well.

[twinair]

Seems like a bad water pump

[briano1234]

I had the kid take the car out for a drive after we changed the oil/filter. When they got back he pointed to the oil gauge temp pegged all the way. The hose from radiator to head was VERY hot. Opening the coolant fill cap slowly resulted in excess fluid overflowing. Radiator was warm but not burning hot like the upper radiator hose was. cooling fan kicked on for a short time then went off.
There just didn't seem to be any movement of coolant in the tank while i was watching it. the small pipe liquid just didn't move unless the engine was revved up to a decent rpm. On Etienne #2, there is always a nice stream of fluid moving out of the small pipe hole in the tank.

Didn't try the heater core thing since i wasn't in the car. the coolant temp gauge doesn't show excessively hot..which is a bit of a mystery. At the same time, you can feel the heat radiating off the engine

I'm leaning to the thermostat/flush as well..and maybe just do the water pump while I'm there
I might also try to get one of those metal thermostat outlets as well.

How I change out a water pump on my 93:

The cooling system and the oil system temps are 2 separate things. The coolant flange is were the Radiator Temp Gauge sensor is. It is a little different location than the Oil.
They aren't tied to each other as the Radiator temp is controlled by the fan, and the oil isn't cooled at all on the 90's.

With that said, I don't usually see a 1-to-1 relationship of the OIL-to-RADIATOR temps.
I have had the Water gauge go nuclear when the Oil didn't my thinking was that the running of the heater on full hot would bleed off coolant temps and then by osmosis the oil should calm a wee bit. I mean that even when my 93 was pegging at 130 as I was tooling down the highway, I had to open the heater on full then it still took a bit for it to get down to the 125-120 mark.

It is the nature of the Auto's I think as both of mine would do the same thing. Just be happy that at 130 degree C the oil is at 266F and that is still well below the burn point of the oil.

Get the external oil cooler and add it, you will be happier, your engine too, and you will get a higher pressure at idle.

Replace the t-stat, and flush the cooling system as there is a issue there as even at idle the radiator should push fluid to the res via the itty-bitty hose.

Gee in the oldie days, they didn't worry about oil temps on gauges, I just had a direct feed line to the Oil pressure gauge. Bad thing was that on MG's and A/H's that I drove the oil pump was behind the engine and that you have to pull it to change it.....

[kamzcab86]

Those are a oils stabilizer and not really a cooler. It allows the Oil to get up to temp quicker and keeps it tied to the Radiator coolant temp.

And the radiator coolant temp (84-95°C) is lower than the oil temp (100-120°C)... hence, VW calling it an oil cooler. I do agree, though, that external air coolers are more efficient and less problematic in the long run. However, for all the bad-mouthing the OEM cooler gets, the one on my Cab lasted for over 20 years; the one on my van was still going strong when I replaced it at the age of 20 years (O-ring went bad and hoses leaked; replaced the cooler as preventative maintenance). I'd say that's a pretty good record.

I don't know if that was one reason the removed it from the 90-93 cabbies but have noticed that they installed it on the Passants for those model years....

Except, the 2H over in Europe got the oil cooler. Cost savings seems the more logical reason ("Zee convertible people in zee USA take only short drives to zee beach; they have no Autobahn; leave the cooler off and we'll save DM40 per car!"), but only VW really knows.

[CajunSpike]

Possible solution.

Changed coolant thermostat, no difference in oil temp.

Changed oil temp switch on oil filter housing with one I found on an old block...nothing..dead oil temp gauge.
Took oil temp sensor off working car put on this car...oil temp appears normal after a run down
the street.

On the inverse, took that bad sensor and put it on good running car...oil pressure warning system is going off.

Verdict:

bad oil temp sensor....to be replaced.