Engine coolant temperature

[stephen low]

After my first engine run up I'm puzzled by why my thermo fan didn't kick in and have done a bit of research.

A bit of checking to re-aquaint what I'd set up and I've a 91C thermostat but have sourced (wrongly) a 92 - 87C thermofan sensor. An 82C thermostat would probably be better for this thermofan sensor particularly as practically I measured the thermofan sensor opening at 88C and closing at 83C on the stove tonight.

But it got me thinking as to what operating temperature range is considerd appropriate for these engines. Mine is a 2002 EFI Windsor (AUII)

Have seen advice suggesting engine operation at around 93C is desirable.

Keen to hear if a 93C target is about right else what suggested operating range I should be considering.

I've still to decide whether to get a sensor bung welded next to the lower radiator outlet over the current location next to the inlet hose.

But I'll start this exercise from what the suggested temperature range should be first.

Keen for feedback guys.

Cheers

Steve

[dhs.buckley]

My thermos kick in about 185f or 85c deg on a 1996 mustang ho 5.0 litre.
On my old xh 1998 5.0litre they kicked in at about 91 deg, but by then on a 40 deg day it was to late and had to switch the aircon off to cool it down.

[sambo]

Slowy, why don't you let the ECU control the thermos? Also avoids having to install another sensor and additional wiring to the radiator. Factory thermostat, factory software, done.

[stephen low]

Thanks for that.

Sort of matches my thinking for the moment as a simple replacement of the current thermostat from a 91C - 195F jobbie back to the suggested 82C - 180F would tend to match better with the thermofan sensor cut in and out points.

Just not sure though whether 82C is a tad cold.

What's the consensus guys on operating temperatures?

Slo

[sambo]

I know the Chev Gen 3/4 engines run hotter (90+ deg) for emissions compliance. Have you tried calling Repco or somewhere like that to find out what temp the factory replacement thermostat operates at?

[sambo]

Slowy, good info here: AU thermostats

[dhs.buckley]

my father was recommened to drill a hole in his thermostat, 1998 falcon to stop the shock load from the original thermostat,apparently this was causing the plastic header tanks to fail early, sudden burst of hot water at 91 deg, never replaced the radiator again after that.

[deano59]

on our race cars I always drill a 8 mm hole into the thermostat we find on our engines it helps with bleeding all the air out of them

[stephen low]

Think I am seeing advice backing up the 91C operating temperature using say the TT2000-195 thermostat. This is what I have in mine.

Clearly then my thermo fan sensor needs to operate somewhat above this minimum. I am not going to go for rewiring into the ECU, even if possible, as I've wiring already set to the thermo sensor for fan operation based on whatever sensor I use.

The temp gauge is reading off the bypass pipe sensor which is the standard location and this is also talking to the ECU I believe for other engine management.

So I need to look at a thermo fan sensor operating at an open temp of say 100C with shut down at 95C perhaps.

This theoretically gives me a min max range between 91 and 100C.

However as also mentioned my sensor is located at the inlet rather than outlet side of the radiator so am not sure how this might change my fan sensor opening temp decision.

A new thermo sensor is more pricey than a thermostat but I'd rather have the engine running at an appropriate temperature than worry over a few dollars.

Anyone see any failing in my logic above?

Cheers

[stephen low]

Talked with Don and his recommendation is to go back to the 180F - 82C thermostat.

That suits me fine as this is nicely below my current thermo fan sensor operating range kicking in as tested at 88C and off again at 83C.

My replacement water pump arrived last night so I just need to work on removing the old one and replacing it in the next few days.

Plus buy and switch over thermostats and I can have another run up to see what happens.

After that I will leave it to a practical operation as I don't want to go glazing the bores from too much low rev and no load use.

Thanks all for the feedback anyway.

[Rog246]

Stephen, it is probably more important to have your oil temp within 5-10 of your water temp than overall water temperature-theoretically the hotter an engine runs the more efficient it becomes. ( I think the bloke who came up with that idea wasn't into his engines all that much too !!)