Engine running cool

[ButtonIt]

My engine is running very cool when on the open road. I had a new radiator fitted last year (haven't driven it much since). The guage is constantly reading 60 degrees when driving on the motorway or any kind of open road. In traffic or at a standstill the temperature will creep up like normal, the fans will cut in and it will hold in the middle between 80 and 90 I think. But as soon as I start moving again it slowly drops back down to 60.

The heat coming through the heater drops too. In fact on the very cold drive up to my girlfriends house on Friday night it was actually cold in the cockpit, even with the heater on full hot.

Is it just because my new radiator is too efficient? Will running it that cool have any detrimental effect on the engine?

Many thanks,
Chris

[gruffalo]

Thermostat is stuck open, it is worth getting it changed quickly as the oil will also be on the cool side so basically you are driving on a cold engine most of the time.

Not terrible but not good for the old girl.

[threespins]

You probably have an airlock.
My gauge reads the same as yours, but always plenty of heat coming from the heater.

[phazed]

They have a tendancy to run cool in winter as they are overcooled by the conditions.

You can get a winter thermostat that may improve things slightly or you blank off half the front of the radiator, (a la taxi drivers!).

It shouldn't overheat while moving. By comparison, even on a hot summers track day, I have never seen the temp gauge over 80 degrees, it only rises when stationary in traffic!

[SILICONEKID340HP]

Its normal whatyou are experiencing,Have you thought about covering half of the radiator ?

[ChimpofDarkness]

I ran a rad blind in the winter when I first bought my Chimaera.

This was for two reasons.

1. My temp gauge showed the car to be running very cool on cold days (50 degrees or less on a run)

2. My heater wasn't particularly effective on those colder winter days

Both the over cooling symptoms were much worse when travelling a speed for sustained periods.

Both issues clearly pointed to over cooling, right?

Well the rad blind helped a lot but it was always going to be a compromise between a hot heater on the move & getting close to overheating in town.

I tuned it to give the best heater performance at speed yet safe running temperatures in town, but it definitely a crude compromise.

I don't use the rad blind any more because the truth is the over cooling turned out to be a combination of two things:

1. My heater got much much more effective after Rob Robertson fitted a new cam

Clearly this was nothing to do with cam as such, but a consequence of Rob bleeding the cooling system properly when he put everything back together.

There must have always been a pocket of air in the system, bleeding it properly improved the heater performance from hardly adequate on a cold day to very effective.

2. At this point I was nice & toasty warm yet surprised to see the TVR temp gauge was still only displaying 55 degrees at best on a cold day over 60mph.

So I did the Range Rover temp sender mod and the gauge now follows the correct coolant temperatures shown on my Canems ECU software.

At speed on a cold day the temp gauge shows 80-85 degrees and the heater is great with no need for that rad blind.

So it wasn't really over cooling as such, its just the TVR gauge & sender combo was misleading me and the air trapped in the cooling system meant the heater was ineffectual.

The two symptoms conspired together to convince me it was over cooling, but in truth I was being misled.

I don't use my rad blind any more.

Before you resort to the rad blind my advice is do the Range Rover sender mod and bleed every last bit of air out of the cooling system to get your heater working at its best.

After that you should see the whole set up TVR designed works very well indeed.

[ButtonIt]

C-O-D, your posts are always very useful and explanatory. Thank you!!

[N8CYL]

ButtonIt said:

C-O-D, your posts are always very useful and explanatory. Thank you!!

+1

[Quietlybonkers]

Been for a drive late this afternoon. 20 miles open road, temp in car cool but ok, engine temp showing as 50-65. Five to ten minutes in town traffic, engine temp up to 85. Stopped for twenty minutes, reversed the route with engine and car both toasty and warm.

I will bleed the heating system at my next visit to my TVR guy (let's call him Mat), when we are also upgrading the plugs to Iridium 6s and the plug leads to new ones. I will talk to Mat about the RR temp mod - some hints as to what it is and from whence it cometh would help. I seem to remember GasMunkey saying it is a resistor from Maplins?

Thanks to COD for all the advice.

[ChimpofDarkness]

Cheers boys,

TBH I probably should get some work done instead of typing away on PH.

But glad to hear my work avoiding ramblings help someone all the same.

In this case I bet the Range Rover sender mod will have the gauge reading correctly, & a damn good bleed of the cooling system will have the heater working nicely.

Worked for me


RR sender mod here:

http://www.pistonheads.com/gassing/topic.asp?t=118...


And some good bleeding tips from Cider Andy here:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[v8 racing]

gruffalo said:

Thermostat is stuck open, it is worth getting it changed quickly as the oil will also be on the cool side so basically you are driving on a cold engine most of the time.

Not terrible but not good for the old girl.

Dito, the stat is there to control temperature, regardless if the car is moving or not, (the stat doesnt know how fast you are traveling) if the engine runs below the stat opening temp then it is stuck open

[Taraka30]

Guys - apologies for my lack of understanding but I see the same 'cool running' symptom on my temp gauge and just wanted to understand whether there are any consequences? I've just read through all of the linked threads (very informative) but it seems like the only issue is an incorrectly low temp gauge reading on cold days. Am I missing something and should I be more concerned, especially as I'll be putting some cod driving miles on mine over Christmas...?

Thanks in advance!
Taraka30