My Spyder is taking an age to warm up (5 miles or so for the gauge to move) so I’m going to fit a new thermostat as a precaution. Couple of questions - what’s the general preference between the original location and a remote fitment (QED or the Elise Parts kit)?

Also are there any tips concerning bleeding air from the system after fitting?

Thanks.

Never used to have that issue, it always was a little slower than my everyday Peugeot at warming up as seen on the gauge, but heat came out of heater pretty quickly which suggested it was warming up ok.
Have you checked the sender unit as I regularly cleaned all these to check good bonding... especially the oil pressure sensor. At some time you will find the GTM fuel gauge fun... If it says full, it is, if it says empty, kit is and when driving if it says anything else it means you have fuel! Apparently they all do it!

There's a lot of 'exposed' pipework under the car running front to back and so more surface area to lose heat also more thermal capacity due to more liquid than a front engine front rad type car.

If the systems is working ok you'll find heat coming out the blowers way before the temp gauge starts to climb. This heat should occur minutes after starting off - depending on ambient temps and how hard you're working the engine of course.

Sounds to me like what you're experiencing is perfectly normal.

However I fitted a PRT after a HGF, given that it's recommended by folks on the net and (Land)Rover themselves eventually fitted them as standard.

Unless you intend to renew the coolant I would clamp off the rad hoses at the front and the heater hoses at the rear while you do the work to keep fluid in the rad and the heater matrix. The latter being the place where air can be hard to shift.

Assuming you dump the whole system to renew it http://www.sidewinderforge.co.uk/netlib ... mlb20.html In addition if you have probs with the heater not getting hot first, you can clamp the bleed heater hose and open the bleed to force fluid/any air thru the matrix and out the bleed using pressure bottle method.

Great, thanks. Don’t suppose there’s a schematic of the cooling/heater system in existence? Where would you clamp the radiator & heater hoses?

Although it may not sound like it, I’m pretty mechanically capable, just more used to rebuilding British Motorcycles.

https://www.yumpu.com/en/document/view/ ... ild-manual

All your answers...possibly!
Cheers Phil

I did a basic schematic of the cooling system on my Libra. It should be on here somewhere. I will have a look.

The advantage was it heated up quickly and put the thermostat in a better position.

[Libra Plumbing by Roger Hammond, on Flickr][/img]

There has been loads of debate on thermostats and thermal shock on all kinds of K series related forums from MGF to Elise to freelanders etc.
Some advocate drilling a 3mm hole in the standard thermostat (which would slow down warm up), some even suggest removing the stat altogether which IMHO is a bad choice. Remote stats (either QED type or PRT) are arguably a good idea but there is a cost involved and require revised plumbing. Only really an issue when the stat opens and allows a sudden surge of cold water from the rad into the (by then) hot engine. Obviously linked with the HG failure worries.

I've recently had issues with heater flow from when I changed to a later MGTF plumbing arrangement from when I installed my 160 which I've now sorted by simplifying the bypass route. The bypass set up on the TF system is fairly big bore (16mm) and not thermostat controlled and the pipes contain a fair amount of coolant so warming up all that water takes time. Also the heater flow is another bypass loop so again, adds time to the overall warm up.

I would say 5 miles isn't excessive for the temp gauge to start moving and about the same time you will start to get heat from the heater.

My own opinion is that as long as you don't thrash it until after the stat has opened the thermal shock isn't a problem and in theory the warm up is quicker with the standard stat location (which is the reason MG Rover designed it that way). I've left my stat where it was, undrilled. I have simplified the bypass arrangements though and if you have the later MEMS3 160 (which IIRC Spyder 9 does have) and the coolant plumbing still has the TF arrangement then I would consider simplifying that.

The reasons I did the above.

Reduce thermal shock by moving the thermostat.
Heater warms up quickly and becomes the only bypass
Reduces the amount of pipework and water in the system
Easy to bleed

This way the engine warms up very quickly. I also fitted a Laminova oil cooler into the circuit after the thermostat. This means the water/oil temps stay very similar. During warm up the water warms the oil.

With this set up I never had any issues even on track days when the air temp was 28 degrees.

I used the thermostat housing from Elise parts. Radiator was the triple core Loughborough rad.

Clamp the rad hoses as they emerge from the tunnel just after the long tunnel ally pipes. Clamp the heater hose return just before it enters the metal wiggly pipework over top of gearbox and the heater outflow where it exits the top corner of the engine block.

The standard stat pipe layout as per GTM (the cylinder head overflow to header tank hose not shown)


My current layout Using PRT

Thanks for all of this info, it’s given me a real insight into the cooling system and potential for improvement/simplification.

Hi guys (assuming people still come to the forum!) When I swapped in a replacement engine just over a year ago it came with the PRT stat already plumbed in so a simple matter of connecting the two big pipes to the two big pipes under the car and the two small pipes to the heater pipes under the car. As far as I can tell the plumbing is identical to Sidewinder's drawing in this thread. However it behaves bizzarely. On most runs it is running cool. possibly a little too cool (around 80 degrees) I can live with that. The problem is that when I'm just idling or just pootling along slowly in traffic it overheats. While it is overheating there is no flow through the heater matrix either. It seems that the pressure spring is opening fine so as long as the water pump is spinning reasonably quickly I get flow through the radiator (and heater) but I'm thinking the wax stat isn't opening at all so when there is minimal pump pressure it just circulates coolant around the bypass and the engine quickly overheats. I tried fitting a new PRT stat and it has made no difference. Yesterday I was stuck in traffic on the M5 and it overheated so badly it vented through the cap but all the time no heat was coming out of the heater. If I leave it idling on the drive I can feel the hoses around the bypass loop get hot but the no flow goes to the radiator unless I rev it. The engine was a crate engine first used in 2007 and I'm told the timing belt and water pump were replaced in 2019 so should be fine.

Any thoughts? I'm thinking of going back to the original stat set up as I never had any problems with that!

Sounds to me like an airlock in the heater matrix. When i had airlocks in the matrix the heater would go cold at idle but at speed you'd get warmth thru.

I'd understand that as a reason for the heater not working well at idle but would that explain no flow through the main radiator at idle/low speed?

If there is air in one place could be some trapped in rad too? Deffo no leaks anywhere? What PRT do you have as there are various different temps and strengths of pressure springs.