Troubleshooting oil temperature gauge

[Nick B.]

It is well known, that one should not change to many things at one time, as there will be no clue to what has gone wrong afterwards. However, that is what I just did.

 

I used to have a problem of the oil getting very very hot when driving spirited on 10CR. The water temp was largely unaffected, but I do have a wide herald type radiator in the spitfire.

After the car had been laid up for appr. 3 years, I decided to do something about it. And I had several things done:

New exhaust,  Carbs were overhauled - it appeared that I had a intake of false air from flanges between inlet manifold and carb housing. This was corrected. 

Ignition were replaced with a NOS

Oilcooler (with thermostat) were fitted.

 

So it appears my troubles are gone, as the oiltemp does not budge. And this to an extent were I doubt the gauge is working. It remains at the furhest left position (70). Now, would this be:

1: The oilcooler does its stuff?

2: The oil cooler does its stuff and was never needed as I ran hoot due to the carbs being lean?

3: Oil temp feeler or gauge is defective?

 

And if 3: how do I test this?

 

On the bright side : car drives superbly, and I am ready for 10CR in a few weeks time.

Cheers

Nick

 

[Escadrille Ecosse]

39 minutes ago, Nick B. said:

It is well known, that one should not change to many things at one time, as there will be no clue to what has gone wrong afterwards. However, that is what I just did.

We all get that....

But good getting the other stuff done anyway and if the car runs nicely then you can bask in the satisfied glow.

As long as you have a thermostat in the system it'll look after itself even if not strictly needed.

However 70 degrees is a perhaps a tiny bit low but depends where the reading is being taken and the 2" automotive gauges are not exactly International Committee for Weights and Measures reference standard so could be a good bit warmer.

Oil temp is easy to check if you have a IR thermometer. Dead cheap on ebay and good enough for the job. I got one for checking the temperature for compostite moulding but have found it invaluable.

Run the car and measure the temp on the inlet and outlet side of the cooler and do the same at the point where you are measureing the oil temp.

The problem with instrumentation is the more you have the more there can be to worry about . Often it is actually OK or at least manageable.

Saturn V pogo for example

 

[JohnD]

Various checks come to mind.

1/ multimeter on the guage wiring.   Do the volts change?  If so but no gauge response, faulty gauge.

2/ M meter on the sensor, in a water bath on the stove.   You'll only get to 100C - you could use an oil bath for hotter, but!  Not certain but probably resistance should drop as heat increases ("negative temp coefficient").   If not, faulty sensor.

3/ there'd a dandy sump oil temp gauge, made for VWs that doubles as a dip stick.   

4/ invest in an infrared thermometer 'gun'.   Look at the temp in the hose to the oil cooler.   If it never gets hot, faulty thermostat.

Good luck!

John

[Nick B.]

Thanks for the replies.

The temp sensor is in the sump, so should be independant of the cooler.

I gues I need to find a multimeter. I have not used one in ages, and seem to have lost the one I was gifted a decade ago. Bit (much?) of a baffoon  when it comes to electrickery. Usually ends up being electrocuted. 

If I survive the multimeter testing, and produces no good explanation, then on to the infrered :-)

Must admit I have been contemplating just getting rid of the gauge and hope for the best. I have already gotten rid of the oilpressure gauge as it was an eternal source of worry. 

Cheers

Nick

[JohnD]

What was the problem with the oil pressure gauge?     I've had my own problems (see Post-Thruxton Post Mortem - Page 5 - General TrackDay and Race Prep - Sideways Technologies (sideways-technologies.co.uk)) but I would no more drive without one than a fuel tank gauge.

John

 

[Nick B.]

10 minutes ago, JohnD said:

What was the problem with the oil pressure gauge?     I've had my own problems (see Post-Thruxton Post Mortem - Page 5 - General TrackDay and Race Prep - Sideways Technologies (sideways-technologies.co.uk)) but I would no more drive without one than a fuel tank gauge.

John

 

Well, the problems were twofold - psychological and mechanical.

Psychology: I kept looking at the thing worrying about what appeared to be low pressure when running on extended trips. Especially coming to a stop - red lights for instance - looking at alarmingly low pressure. I changed oilpump, rummaged around the engine,changed the oilpressure relief valve and increased idle speed. All sorts of things, and all due to  a low pressure which I would never see if I just relyed on the green light. So all in all, a more pleasant ride after the gauge was decommisioned. Perhaps I am killing my engine, but will be doing this with a smile instead of worrying about why I am killing my engine.

Mechanical: The plastictube to the gauge splitted. Replacing the tube as to hard to bother, as I would have to remove the rubbergrommet in the firewall, where the hole was really to tight for the new plastictube with the broncefiting to pass through. (yes, I am a lazy sod).

 

Perhaps I am just longing for uncomplicated motoring without having to observe all the gauges. I still have the voltmeter, which reliably informs me that my denso-alternator works perfectly !

 

Cheers

Nick

[JohnD]

Nick, 

Electric oil pressure gauges are available.   Sensor where you want it, a wire to the guage on your dash.   Connecting them no more troublesome than any other through bulkhead wiring job!

I have one I use as a fuel pressure gauge, as I definitely didn't want a pipe that could squirt fuel at 100psi inside the car with me!

Mine is made by "GlowShift".  Eg from Amazon:

 https://www.amazon.co.uk/GlowShift-Tinted-Color-Pressure-Gauge/dp/B007GE2SIA

Edited August 23, 2022 by JohnD

[Nick B.]

28 minutes ago, JohnD said:

Nick, 

Electric oil pressure gauges are available.   Sensor where you want it, a wire to the guage on your dash.   Connecting them no more troublesome than any other through bulkhead wiring job!

I have one I use as a fuel pressure gauge, as I definitely didn't want a pipe that could squirt fuel at 100psi inside the car with me!

Mine is made by "GlowShift".  Eg from Amazon:

 https://www.amazon.co.uk/GlowShift-Tinted-Color-Pressure-Gauge/dp/B007GE2SIA

This could very well be the next step. However, I would probably go with smiths gauges and the sensor bell thingy on the sump. Not that I am a purist, but still. I do share your concern about hot oil delivery in the cabin being a bit suspicious. There is just something appealing about a mechanical gauge .....

 

Cheers

Nick

[Escadrille Ecosse]

1 hour ago, JohnD said:

as I definitely didn't want a pipe that could squirt fuel at 100psi inside the car with me!

Where's your sense of adventure?

It's not so much the pressure, which isn't good I admit, it's more the temperature in my experience. Getting sprayed with hot oil let's you know how folks attacking medieval castles must have felt.

[JohnD]

But I thought that a fart in your general direction was a sufficient deterrent, or was if you were French, your mother was a hamster or your father smelt of elderberries.

Edited August 23, 2022 by JohnD

[Nick Jones]

2 hours ago, Escadrille Ecosse said:

Getting sprayed with hot oil let's you know how folks attacking medieval castles must have felt.

Very true, though even when only moderately warm it does rather spoil your jeans and shoes….

[Escadrille Ecosse]

3 hours ago, JohnD said:

But I thought that a fart in your general direction was a sufficient deterrent, or was if you were French, your mother was a hamster or your father smelt of elderberries.

That's the one

[Hamish]

Can you not just put the oil temp sender in a pot of boiling water and just check it moves to 100 or less ?

I mad the mistake of fitting one ( just because the sump had a hole for one) I now worry about lack of temp. 
I have a cooler without a thermostat 

engine builder hates thermostats his suggestion is to part tape up the oil cooler for the colder months.

and valvoline vr1 mineral is quite robust. 

[Nick B.]

1 hour ago, Hamish said:

Can you not just put the oil temp sender in a pot of boiling water and just check it moves to 100 or less ?

I mad the mistake of fitting one ( just because the sump had a hole for one) I now worry about lack of temp. 
I have a cooler without a thermostat 

engine builder hates thermostats his suggestion is to part tape up the oil cooler for the colder months.

and valvoline vr1 mineral is quite robust. 

Putting the sensor in water is a very good suggestion. My problem is I need to find something to replace the hole for the sensor. Next I would need to remove the gauge. And 10CR being a week and a bit away, I believe the multimeter solution is the way to go. 

I would rather not temper to much with the car just before going on a longer journey . It runs fine for the time being, cold oil or not.

I like the suggestion of taping the cooler up - might be able to trigger the oil into heating ?

 

I will keep you posted.

Cheers

Nick

[michaeljf]

Hello, You could cover it up or make a cover that you can put on or off as the temp. requires IF you don't want to fit a thermostat! regards, Michael.

[Nick B.]

Covering up might work. And it does allready have a thermostat in the oilcooler circuit. But I believe it is the gauge or sensor that has died. 

Prior to the oilcooler being installed, it woked, Then followed by a lay-up and oilcooler, it does not work (or oil is really really cold). 

I believe it is the wiring that has gone awry - it is wireed over the voltage regulator, and something might have gone wrong.

 

Cheers

Nick

Edited August 24, 2022 by Nick B.

[JohnD]

A cork? 

Or else whittle a piece of rubber to block up the hole, while you annoy 'er indoors muck about on the cooker!

[Nick B.]

SOLVED!

 

What was wrong was that the car needed a flogging. Must have been a bad connection somewhere. Going up Stelvio it suddenly came on - and stayed alive. Was a nice 90 degrees when running on A-roads. Going hard uphill moved it to 115. Dropping back to 90 going downhill.

 

All in all a succes. Time heals most wounds (unfortunately not big ends)

 

Cheers

Nick

 

 

[Nick Jones]

2 hours ago, Nick B. said:

What was wrong was that the car needed a flogging

 Excellent. Good temperature range too.

Congrats on surviving the 10CR - seems there were some mechanical issues for others

[zetecspit]

20 minutes ago, Nick Jones said:

 Excellent. Good temperature range too.

Congrats on surviving the 10CR - seems there were some mechanical issues for others

The whatsapp group was busy! often stuff that should have been sorted before leaving home. Not to mention one team that had badly worn tyres, replacing teh worst with a brand new spare at teh top of one pass. The other would have still got you 3 points in the UK. Unforgivable......

But it was a really good, if knackering, event. Best bit was the Ibex burger at the top of one of the passes, it was excellent!

[Nick B.]

3 hours ago, zetecspit said:

The whatsapp group was busy! often stuff that should have been sorted before leaving home. Not to mention one team that had badly worn tyres, replacing teh worst with a brand new spare at teh top of one pass. The other would have still got you 3 points in the UK. Unforgivable......

But it was a really good, if knackering, event. Best bit was the Ibex burger at the top of one of the passes, it was excellent!

I would be the wrong one to point fingers at problems which should have been sorted, when I left home without extra points and condensors. In my defense - I have never had a problem with condensors. Still - now there is even more reason to fit the megajolt which have been rummaging round in the desk for more than 10 years.

The event was brilliant as ever. I have just figured out that I covered 4517 KM /2806 miles with a fuel consumption of 309.7 liters which (according to the internet) makes 19.348 UK MPG. Not bad running 1.5 SU with AAA needles.

Cheers

Nick

[zetecspit]

1 hour ago, Nick B. said:

I would be the wrong one to point fingers at problems which should have been sorted, when I left home without extra points and condensors. In my defense - I have never had a problem with condensors. Still - now there is even more reason to fit the megajolt which have been rummaging round in the desk for more than 10 years.

The event was brilliant as ever. I have just figured out that I covered 4517 KM /2806 miles with a fuel consumption of 309.7 liters which (according to the internet) makes 19.348 UK MPG. Not bad running 1.5 SU with AAA needles.

Cheers

Nick

You were fine.... the tyre incident was dreadful though. However, Megajolt is excellent and I would wholeheartedly recommend.

I think you may need to have a look at those needles though! 

[Nick Jones]

1 hour ago, Nick B. said:

The event was brilliant as ever. I have just figured out that I covered 4517 KM /2806 miles with a fuel consumption of 309.7 liters which (according to the internet) makes 19.348 UK MPG. Not bad running 1.5 SU with AAA needles.

19mpg from a Spitfire….. 

Thats PI territory….. and badly setup PI  at that……

But hang on….. actually you need to use a better internet calculator…,

4,517km x 5/8 = 2,823 miles

309.7l/4.54 = 68.22 gallons (imperial)

2823/68.23 = 41.38 mpg

Now that is a lot more acceptable. About right for 1300 Spit driven hard over long distances. 

[zetecspit]

2 minutes ago, Nick Jones said:

41.38 mpg

Now that is a lot more acceptable. About right for 1300 Spit driven hard over long distances. 

Ah, that actually looks very good!

[Nick B.]

11 hours ago, zetecspit said:

You were fine.... the tyre incident was dreadful though. However, Megajolt is excellent and I would wholeheartedly recommend.

I think you may need to have a look at those needles though! 

Thanks - were you driving the yellow spitfire? I think we had a brief chat on densos and waterpumps at Rolduc. It is difficut to put faces and names on these internet aliases :-)

Needles and carbs are a bit strange. The car has tubular sports exhaust and raised compression with 1.5SU on a 1300 engine. I originally ran with AAQ needles, but melted a sparkplug. Then changed to AAA - emergency needles, which is OK, and judging from the plugs not to rich. I will probably do some more testing when I have the megajolt installed. It has really been waiting for to long.

 

11 hours ago, Nick Jones said:

19mpg from a Spitfire….. 

Thats PI territory….. and badly setup PI  at that……

But hang on….. actually you need to use a better internet calculator…,

4,517km x 5/8 = 2,823 miles

309.7l/4.54 = 68.22 gallons (imperial)

2823/68.23 = 41.38 mpg

Now that is a lot more acceptable. About right for 1300 Spit driven hard over long distances. 

Thanks for helping with the math - I apparantly used the wrong internet converter 

It was indeed driven hard - and there was a fair bit of autobahn involved toget back and forth to Denmark. Car seemed happy just around 115-120 KMH/ 70-75 MPH with OD engaged.

Cheers

Nick