How hot should it run

[Iansparky]

HI all I am new to E type ownership having not long bought a series1 4.2, its a beautiful car incedible to drive and I am really pleased with it, I have noticed that after a run of about 20 mins when I shut it down the bonnet is way too hot to touch also there seems to be a lot of heat radiating from the engine bay, the temperature gauge sits at around 70 degrees while driving and its not boiling over but it does seem very hot. Is this normal or do I have a problem. Many thanks Ian

[cactusman]

70 degrees while driving sounds ok so long as the gauge is correct. On a hot day the bonnet will be hot, especially on the exhaust side...

[Heuer]

Has the car been fitted with tubular exhaust manifolds rather than the Factory cast manifolds? The tubes radiate a lot of heat and can blister paint on the frames and the bonnet. They also cause a torque dip reducing performance.

[Iansparky]

Hi, the car is standard spec, cast manifolds, I think temp gauge is reading about 10 degrees under as I tested it in a bowl of hot water with a cooking thermometer in, I am maybe over thinking things but it does seem really hot, the cam covers and the inlet manifold are too hot to touch and so is the bonnet.

[cactusman]

See if you can borrow an IR temp gun gauge and see what the temps really are. The exhaust side will be too hot.to touch after a.drive..

[mgcjag]

Yes the bonnets get very hot...too hot to touch....just parked outside on a day like today in the sun it will be too hot to touch.....also there is no insulation under the bonnet so getting hot is normal....your engine will be running 70+c depending on thermostat....this is too hot to touch for any prolonged period....if the car is running OK then I don't think you have a problem....Steve

[DWW]

always good to have to hand a temperature gun, so cheap too.

https://www.amazon.co.uk/Thermometer-No ... 215&sr=8-5

[Iansparky]

Thanks for the advice, I did actually buy an IR temp gun today, will give it a go

[mgcjag]

A heat Gun is ok if you know what your actually looking at....iv never had one used one or thought I needed one...Steve

[mtnjag]

IR temp gauge will not give you an accurate temp on the shiny cam covers.
In fact they are not so accurate and will give you relative differences in surface temp but not coolant temp.

[DWW]

Can always open the header tank and try take the temperature of the coolant, I did experiment with boiling water in a kettle and got an accurate reading of 100 deg C at boiling. You are right though about trying to read off the engine surfaces, never accurate.

[paydase]

I would not advise opening the header tank when it's hot, risks of boiling water projections!
To have a rather accurate reading of hot surfaces with an IR gun, you better shoot on a black textured surface, e.g. the engine block, avoiding exhausts proximity.
Shooting on the black rad itself (look at the differences between top and bottom) also works, as well as close to the big hoses (inlet and outlet).
With many shootings, you get a rather good idea of the temperatures.

[RICHOT]

Hi Guys,

I always open the bonnet after a run to let the engine compartment cool down - if this is away from home (ie the local pub!) it does draw quite a level of interest!!

regards,

Richard

[DWW]

"I would not advise opening the header tank when it's hot"

I was suggesting opening the header tank prior to starting the engine and only then start and let it reach its operating temperature.

[mtnjag]

Full operating temp won’t be reached before it overflows if you have the correct amount of coolant in the engine and cap off.

[DWW]

I beg to differ

[mgcjag]

Yes and no.......with standard coolant your system is under pressure at normal operating temp....with waterless coolant it isnt.....Steve

[malcolm]

I'm a bit worried about the OP's statement that his bonnet gets "way too hot to touch"
As everyone said above, it is a big hot old lump under the bonnet, but I must say that my bonnet doesn't get that hot. And I've got stainless steel pipes from the block down, so gets hotter than cast ones?

[paydase]

I agree with Malcolm.
After a drive, my bonnet is also more warm than hot.
No issues to put hands on it although the engine and cooling circuit hav reached "hot" temperatures.

[cactusman]

My bonnet gets warm but not too hot to touch...at least it did prior to the engine rebuild...standard engine with standard cast exhaust manifolds as per factory...