Oil Temperature Dipstick

[chad]

This is from a Machine 7 advert for the savemybug one:


"In normal conditions your light will remain off, if the light starts flashing then your engine temperature is getting too hot. If the light comes on solid, then your engine temperature is definitely too hot and you should stop the engine.



So now when you are chugging up a long incline or you are sat in a traffic queue you can actually tell when the oil temperature starts to rise, and before it hits a critical temperature you can do something about it"


Fortunately I haven't had an overheating engine (yet) but understood if you thought it was overheating the course of action was to let it tick over as the fan would be running to help cool it down.

Is this too simplistic a view as by stopping it you may save any or further damage so it depends on the circumstances?

[VW Toast]

I thought a/c engines were designed to run cooler when on tickover/stuck in traffic? for that very reason. If you actually turn the engine off, the heat won't dissipate.

[Zed]

If your actual oil light won't go out with a few revs, switching off seems sensible.
Generally the info you quoted seems a bit daft. Far better to have a temp gauge than this half-arsed lighty thing that seems to provide two levels of worry but no real info to base a decision on. Oil temp gauges are cheap enough and with one of those you can adjust your driving to avoid getting into this situation in the first place. Far better than alarm lights suddenly flashing at an inconvenient moment.

If someone gave me one, I'd bin it.

[Zed]

Apr 20, 2018 8:23:18 GMT VW Toast said:

I thought a/c engines were designed to run cooler when on tickover/stuck in traffic? for that very reason. If you actually turn the engine off, the heat won't dissipate.

Mine relies on it's extra cooler in the breeze and does slowly heat the oil when stuck in traffic, but only because it's so cool in the first place.

[chad]

Thanks guys.

I bought one of these a few years ago and it was for when my wife and eldest son drove it, which turned out to be fairly rare.

I've got a CHT gauge and an oil pressure gauge which I keep an eye on but they're used to modern cars so gauges are alien to them.

I've told them in the past to pull over and let it tick over so will leave it at that, although they'll have no doubt forgotten so will switch it off and then ring me when it starts flashing, assuming that they notice it.

[VW Toast]

The moral or that story is don't let your wife or children drive your camper.

[chad]

I try not to and am basically successful but if I fancy a beer or two and we're just out for the day ....

[Eoin]

Apr 20, 2018 8:28:59 GMT Zed said:

Apr 20, 2018 8:23:18 GMT VW Toast said:

I thought a/c engines were designed to run cooler when on tickover/stuck in traffic? for that very reason. If you actually turn the engine off, the heat won't dissipate.

Mine relies on it's extra cooler in the breeze and does slowly heat the oil when stuck in traffic, but only because it's so cool in the first place.

What does yours run at with the cooler?  I did a decent run down the A15 in mine this morning, bimbling (due to people who drive modern cars slower than my camper) at 50 is and at 80 C with the updated map.  Rose to about 85 C with a steady indicated 60 on a clear stretch.

[Zed]

Once it's warmed up it sits at 85°C however fast or slow I go - in line wax thermostat and 15 row cooler. Temp is measured on it's way to the bearings. It's quite strange having a temp gauge that doesn't move!

[sANDYbAY]

I measure mine with a taco plate in the sump and it takes a good 30 mins before it’s up to temp. I have noticed the ambient temp has a big influence on how hot it runs at. In the winter it’s 80° for hours but does tend to creep up if we’re sat in traffic.
In the summer it runs between 100° to 110° but still steadily creeps up at idle in traffic.
I’ve decided that my cutoff temp will be 120° but (touch wood) I haven’t got there yet.

[Zed]

And this is where comparing oil temps gets a bit meaningless. Yours is measured pre-cooler, mine is measured after.

I'd quite like to know how hot mine gets tbh but as it's still thick and clear after 5,000 miles I assume it hasn't been too hot.

When I worked, I'd find some people's oil as thin as water... once it's been cooked it doesn't go thick again, it's knackered.

Sensible people seem to think 240°F is too hot for the good of the oil and would change it if it happened. By that measure, 120°C (248°F) is way too hot.

Another fing I was reading about was the effect of oil weight on cooling. If it's too thick, even when it's hot it will press the bypass plunger and won't go through the cooler at all. If you have a stock bypass spring and see over 50psi (assuming you have a gauge) and your oil gets too hot and it's XW50, try A 40, or even a 30.

I wish I'd known these things when I built my T1 engine which got too hot cruising at 65mph. Looking back I just lobbed any old oil in it and it was almost certainly 20-50 as the 15-40 I'd used for years had disappeared from the shelves.

[Eoin]

Apr 20, 2018 14:08:04 GMT Zed said:

And this is where comparing oil temps gets a bit meaningless. Yours is measured pre-cooler, mine is measured after.

I'd quite like to know how hot mine gets tbh but as it's still thick and clear after 5,000 miles I assume it hasn't been too hot.

When I worked, I'd find some people's oil as thin as water... once it's been cooked it doesn't go thick again, it's knackered.

Sensible people seem to think 240°F is too hot for the good of the oil and would change it if it happened. By that measure, 120°C (248°F) is way too hot.

Another fing I was reading about was the effect of oil weight on cooling. If it's too thick, even when it's hot it will press the bypass plunger and won't go through the cooler at all. If you have a stock bypass spring and see over 50psi (assuming you have a gauge) and your oil gets too hot and it's XW50, try A 40, or even a 30.

I wish I'd known these things when I built my T1 engine which got too hot cruising at 65mph. Looking back I just lobbed any old oil in it and it was almost certainly 20-50 as the 15-40 I'd used for years had disappeared from the shelves.

I noticed when mine was too rich at cruise it would tend to get hotter and then at a certain point the hot pressure would drop as the oil thinned. The remap seems to have resolved that now someone who actually know what they are doing (i.e. not me) has set up the fuelling.

[Zed]

I use 20-50 in mine because Rob told me to.

It sits bang on pressire, or did before the gauge and/or sender went nutty. Now the sender reads too high (measured ohms) and the gauge doesn't return to zero when I switch off unless I tap it about 20 times.

[Zed]

I think the oil weight/overheating is more of a type-1 engine issue.

[sANDYbAY]

Apr 20, 2018 14:08:04 GMT Zed said:

And this is where comparing oil temps gets a bit meaningless. Yours is measured pre-cooler, mine is measured after.

Sensible people seem to think 240°F is too hot for the good of the oil and would change it if it happened. By that measure, 120°C (248°F) is way too hot.

Does that mean that my self imposed 120° limit is too high?
Also, I’d be the first to admit that I know far more about the intricacies of the oil system in jet engines that I do about the oil system in type 4, but surely the oil in the sump will have been through the cooler first, I can’t see the point of sending oil through the cooler before it goes to the bearings, I’d have thought it would be cooled after it’s been used on its way back to the sump.