I notice there's a difference in oil temperature measured at the oil cooler
(170°F) and at the oil filter (250°F) and heat exchanger and I am surprised
too.
My guess is the oil filter and heat exchanger are too close to the exhaust
pipe - about 2 inches from the exhaust pipe/elbow to the tip of the oil
filter, and I think this makes a false reading.
The IR gun picks some heat from the exhaust pipe when I point it to the oil
filter.
fyi... in this order : oil filter + Mocal sandwich adapter (about 2" thick)
+ heat exchanger

On Tue, Jul 6, 2021 at 9:32 AM Bruce Todd <beeceetee@gmail.com> wrote:

> Thanks very much Dan for making the effort of running this test /
> experiment with all the details provided.  Curious to hear what other
> comments may follow.  Also curious to know what the temperature of your oil
> actually is given all the various readings.
>
> Bruce
>
> On Tue, Jul 6, 2021 at 8:21 AM Dan N <dn92610@gmail.com> wrote:
>
>> I told Bruce that I will record  the engine temperature on my van for him
>> and send it to him... I am not sure what is relevant. I did as best as I
>> could.
>>
>> Van description.
>> - 1990, Tin Top Syncro.
>> - Rebuilt 2.1 WBX with about 5K miles.
>> - 14" wheels with General Grabber AT2
>> - Vanistan oil cooler with fan.
>> - Home made air scoops on both rear vents.
>> - Small Thule cargo box on the roof.
>> - Engine and radiator were recently pressure washed.
>> - No oil temp. and no oil pressure gauges.
>> - 20W50 Lucas High Zinc oil (not synthetic). Oil level is between 2 marks
>> on the dipstick.
>> - One bottle of Lucas Super Coolant in the coolant system.
>>
>> The drive:
>> - 9 miles one way on 2 lanes country road, 4.5 miles of flat terrain
>> (about 55 mph), 4.5 miles of twisty uphill road (about 40 mph on 3rd gear).
>> Total drive 18 miles.
>> - Temperatures are measured using a Ryobi IR gun after 9 miles out and
>> after 9 miles back. Ambient temperature 90°F.
>> - Driver only, empty van with some tools.
>> - Have AC but not ON.
>> - Some stop and go in traffic in town.
>> - The temp. needle stays on top of the red LED.
>>
>> Temperatures measured at:
>> - Vanistan oil cooler: 170°F
>> - Hose from engine to oil cooler: 195°F
>> - Return hose from oil cooler: 170°F
>> - Oil filter: 250°F
>> - Heat exchanger: 268°F
>> - Thermostat tower: 162°F
>> - Coolant expansion tank: 190°F
>>
>> I am not sure about the accuracy of my measurement but I tried ...  :-)
>> I will re-measured at a specific spot(s) if there's any request.
>>
>> dan
>>
>>
>>
>>
>> On Mon, Jul 5, 2021 at 6:04 PM Bruce Todd <beeceetee@gmail.com> wrote:
>>
>>> A quick update - came home from work and replaced the oil temp sender
>>> with
>>> the proper one - looked at it closely and it even said VDO on it even
>>> though I bought it separately from the VDO gauge.  Removed about 600
>>> millilitres of oil in the process and went for a drive around the City in
>>> after work traffic.
>>>
>>> Now I never got out on the open road so I couldn't really get going to
>>> check on things too much but I can say that around town stopping and
>>> starting in mid afternoon sunny weather I was running about 218 F with
>>> the
>>> first stage of the fan kicking in and out.  Not a lot of consistent air
>>> flow or sustained speed.  Oil pressure at idle was a little higher at 21
>>> psi from 18/19 yesterday - not sure if it had anything to do with
>>> draining
>>> the oil level down which in turn kept things a little cooler.
>>>
>>> So now it seems I am a bit more in the ballpark when it comes to oil temp
>>> and can start dialling things in a bit more to understand the operation
>>> of
>>> my motor.  I think both suggestions made quite a difference.
>>>
>>> Bruce
>>>
>>