Overheating- help!

[WindyMiller]

Before I explain what the problem is I need to point out that i am not the most technically gifted se7ener you'll ever meet. So please don't shoot me down in flames for such a simple question.

My 1.8k roadsport is overheating, the fan is not kicking in. On closer inspection the top of the rad is hot, while the bottom all the way back to the "submarine" junction is cold. I hope this is something simple like a thermostat or waterpump.

Anyone had this happen or could give some advice before I start messing about too much.

Andy

[New Barbie]

It may well just be an airlock in the system and nothing broken at all.

 

Bleed it first to see if that cures it. Warm the car up and open the heater if you have one (heaters are for girls btw 😬) Raise the front of the car on a jack, undo the bleed screw on top of the rad. Make sure the header tank is full then run the engine until water comes out of the bleed screw. Do that up and top up the header tank if needed.

 

Now see if you are getting a hotter flow of coolant from the rad.

 

 

 

 

 

 

[alicat]

Windy

 

What makes you think it's overheating?

 

Don't rely on the temp gauge. If the top of the rad is hot and the bottom cold then the rad is doing what it is supposed to do

 

If the fan is not kicking in and it is asumed that the switch for the fan is OK then the gauge looks favorite. Does the fan run if you short the terminals on the sensor (does the 1.8 have the sensor or is it from the ECU?)

 

 

 

 

[alicat]

I see someone has advised to bleed the rad ❗

 

My fan did not cut in, and bleeding the rad cured it. I would add that even after sorting out, the gauge still says it is running hot. I am not losing coolant and the fan takes several minutes to cut in even on the hottest of days, but the guage still says it's running hot.

 

Tony

 

 

[New Barbie]

My 1.6kSS runs too hot for my liking. I have the Stack display and the temp runs up to the high 90s very quickly in traffic. In traffic at Le Mans I got Stack warnings for high water temp at up to 104c. I've just checked the car over in prep for Lydden and I've tried a bottle of Water Wetter I had lying around in the coolant to see if it makes any difference. I don't believe the claims but it'll be interesting next time I'm in traffic, albeit with the weather being cooler now.

 

 

[WindyMiller]

Thanks for that gents, I'll try all of this and get back to you. And so gentle with me. I was sure from the general feel on the site that I wouldn't be ridiculed, but it is good to know that IMHO this site and se7en owners are the "Good Guys".

Cheers

Andy

[JP]

I've had this...

1) Bleed rad, then maybe

2) Change coolant to comma coldstream if not already - this made a big difference to the stability of water temp in traffic on mine.

3) Change gauge sender +/- fan switch - all of which are cheap.

 

As an aside, if the rad is old enough and the bottom of the rad is STONE cold it may be a disintegrated core in the rad - I had this on a K series metro and a change of rad did wonders. It was a very old and knackered rad.

[Shaun_E]

Count,

I have same problem - 1.6k SS and Stack display (aftermarket fitment) - and the temperature reaches high 90's very easily and also can get over 100 when stationary.This was over the summer and now the weather is cooler I get lower temps at speed but same symptoms when in traffic. Fan cuts in at somewhere around the 88deg that I have seen posted as the correct cut-in temp.

I wondered whether this is just a fault with either the calibration of the stack or the sender it is using. I would be interested in the results of using water-wetter and also if anyone else has any ideas as to what is causing these symptoms. I am doing the Llandow trackday so would like to solve the issue before then.

Shaun

 

Yellow SL

[Peter Carmichael]

Shaun and Count, This is absolutely correct behaviour. The thermostat doesn't nominally open until 88 degrees. The thermostat is only fully open at 100 degrees. The standard gauges lie horribly when they suggest the engine is running at 80.

[Shaun_E]

Peter,

Thanks - put my mind at rest.

Shaun

 

Yellow SL

[Peter Carmichael]

One other thought. Do you have the sender in the water rail above the headers or in a submarine tube in the bypass hose 🤔 If above the headers it can read very hot and some heat shileding may cure this.

[I.Mupferit]

Count,

Unbelievably, the 'Water Wetter' does seem to work. Like you, I was sceptical and, like yours, my car was getting very hot at Le Mans this year especially stuck in that horrendous jam before Gace on the way back before we turned round. In fact, I was behind you a lot of the time leading up to that jam but bottled out at 120+ ❗ .

Anyhow, I tried the WW and, amazingly, it does reduce the temperatures when sitting in traffic. I know Alex Wong also uses it to good effect.

I think I'm just getting more cynical the older I get but, like Viagra, some things do actually do what they say on the label (so I am told)

 

Brent

 

[Simos]

Windy,

did you really think you'd be burned for asking a question, and is that really the feel you get from the site ?

 

If so then I think the rest of us need a bit or burning !

 

Simon.

 

(Sharper than a thorn eh!)

[WindyMiller]

All this is useful!

As I said in the second post, I didn't expect to be toasted for my ignorance. I just wanted to set the tone as to my ability.

Going to try to sort it this evening, cheers all.

Andy 😬

[Simos]

Oh yes, just read the first :-)

 

Additionally there are several threads on overheating in the archives if you do a search as well as discussion on water wetter etc

[Geoff Dixon]

Following upgrade to approx 195bhp in my 1.6 K series engine also running hotter.

Have changed thermostat to 78 degrees as recommended on earlier blat chat posting with approx 5 to 10 degrees reduction in running temparature as per Caterham temp guage.

[New Barbie]

Geoff,

 

the reason your particular engine runs hotter is the tendency for it to be bouncing off the limiter on the wrong side of the road 😬 - the Le Mans blats being my evidence of this - bloody thing goes well enough but coupled with some Islamic overtaking -

 

 

[puremalt]

I've 'accidentally' run a xflow for five miles with only 2 pints of water in the rad. It only got very hot as opposed to incandescant. Tough as old boots! And the fan brought the temp back inside four minutes.

 

Dave Robertson