Running temperatures

[Nutrunner]

Now, Ive been reading everything and doing everything I can to make my Chim run at sensible temps, Runs at 70 on gauge in the morning going to work on the motorway, sits at 80-85 in traffic and then 70 again on the motorway. Fans cut in at 85 on gauge and wont go off, the temp comes down to 80. This is gauge temp in which i'm sure is out. The thermostat has been replaced by TVR and Rover examples, new water pump, 50% antifreeze. No change at all. Now master of bleedin system. The cabin also reflects the engine temp. i.e cooler in the car when at 70. Toasty at 85.

[JonRB]

Sounds normal for this time of year.

[Nutrunner]

Is the rad in need of replacement or do I have to live with cold winters?

[pbrettle]

Mmm, I have an 94 Chimaera with the older otter switch - on 96, off 92 (I think). I do have a fan override though which I use when pulling up to stationary traffic on the motorway.

However, I have the same experiences. Motorway (above about 55) and it runs at 70. Stop in traffic for more than 10 minutes and it rises to 90. I override the fans and it will stay at 90! Doesnt go down.

In fact I was stuck on the A1 yesterday (and M25) for ages and getting worried. Fan on, and it stays at 90. However, I was stuck for ages and the traffic was a nightmare - probably stuck for around 30 minutes. Temp rising by about 1 degree per 10 minutes - but importantly didnt go down again.

Is this normal? I though I would expect to see the temperature drop when the fans are on - but it seems to just keep it stable.

In the end it was fine as the temperature dropped when i got moving again and didnt get any higher than 93 / 94. But worried just in case I get completely stuck on the '25 or something...

Suggestions? Is this normal? Do I need to do something?

Cheers,

Paul
94 Chimaera 4.0HC

[.mark]

Not sure if it will help you much but here is my experience.
Summer: 85-90 driving, 90-95 queuing.
Winter (well now): 70-80 driving, 85-90 queuing.
Both: Fans cut in around 80, temperature still rises but is always steady never too high. Car is always at a comfortable temperature inside, I just adjust the temperature with the heating system as with other cars no problem, get too hot turn it down to cold then get too cold!!
All in all no problems at all, even queuing to get out of Silverstone this year left engine running for 2 - 2.5 hours temperature never went over 100

Hope that throws some light on the issue! Also hope that Great God The Gaffer (thanks Steve Heath!)smiles kindly on me now I've said all that!

[JonRB]

I'd say that its "fair comment" that the fans seem to stabilise the temperature rather than reduce it. Certainly seems that way on my 500.

[Nutrunner]

Seems were all experiencing similar findings, never overheated but often bit chilli in cab, heaters ok when temp is 80-85. Are the gauges unreliable, how do i test the water temp? 4.0 chimp 1995

[gideonr]

I think I have a problem with either the gauge or the sender unit.
My gauge indicates around 50 (well bottom of the scale) on the open road, which rises to around 70 in traffic, at which point the fans come on. The gauge stays at around 70 until moving again, and it definitely gets warmer inside.
I know somebody with a spare Range Rover 3.5 temperature sender unit which I could try, is likely to be any use?
It's a 1996 4.0HC BTW.

[Nutrunner]

My local land rover specialist knows a lot about the 4.0 litre lump. We tried a new sender (£12) as used on their 3.9 and 4.2 lumps, there are only 2 types available, look at your plug for identification. It made no difference to my car though.

[pbrettle]

Ahah, a quick read of the Steve Heath "bible" confirmed that the water coolant level is critical to maintain. Read instructions, topped up with clean fresh water (dont worry lots of anti-freeze already there) and a quick test.

Now, the running temps are slightly different:

Running in slow town traffic : 75 - 80
High speed running : 70 (ish) - it is cold today
Stationary (10-15 mins) : 90 - 95

Now the fans kick-in automatically and bring the temp down to 90 each time. No problems with the fans constantly running. Left the car to run over this cycle twice and it is fine...

So, one more lesson leant by a newbie TVR owner.

Cheers,

Paul