P-ssedrightoff

Well after weeks of guddling, testing injectors, starting and running nicely, was about to book it's m.o.t. .
Let it run for a while, temp guage near up to the red and no fan coming on.
Header tank hot, put a lower temp thermostat in a while back.
I have a lower temp fan temp. switch which I've not wired in but I'm assuming the wiring is
maybe goosed?
Any help appreciated as I'm coming to the end of my tether with this car.

GVK.

If you remove the fan switch wires and bridge them with a bit of wire the fan should run, if it doesn't check for power, might be a fuse gone... can you turn the fan by hand?

P-ssedrightoff

Thanks, fan turns easily by hand, fuses fine, continuity on both wires from fan switch to fan, Dubious bridging anything in case linked to ECU. Will try
12v direct to fan, then thinking new switch and thermostat for all they cost, after that air lock in coolant... or a new loom.
Used to be loads on Ebay but can't see any now.

GVK.

Fan isn't linked to anything else so fine to bridge the fan switch loom

charlie luciano

iTrader: (3)

I had a similar problem with my Cosworth when I first bought it. If you bridge the fan switch with something like a hair pin and the fans blow that tells you that as far as the car is concerned from the switch back the switch and wiring is all operating as it should. It’s a very simple circuit, if the fans don’t blow it more than likely means they are goosed and need replacing.

if the fans blow and everything on the car is ok with wiring and fuses etc I would hazard a guess and say you have got some kind of circulation problem with the coolant getting around the engine and radiator. It was the rad that was blocked on my Cosworth as over time the core inside radiators deteriorates and turns to mush causing blockage, with the greatest respect especially on older cars. Worth looking into, I changed the rad on my Cosworth and bingo everything was fine. Mind you I had to buy new fans too as previous owner had wired them up to run constantly and it didn’t take too long before they burnt out.

best of luck with it I hope you get it sorted

P-ssedrightoff

Thanks Charlie,
Bridged the fan switch today and fan runs no problem.
Radiator was flushed when out of car and checked coolant was clean today
as there was a puddle under the car..alternator fan had punctured the Samco silicone hose so had to drain it all.
Luckily the main radiator hose is the only original I had left so that's on now.
Not refilling till a new thermostat and fan switch arrive.
Doubt very much if I'll bother replacing the Samco thing at a 196 quid +vat.
Was never impressed with the fit and the 3 hoses cobbled together.

studabear

You sound like your car needs a shorter alternator belt to keep the fan on alternator away from the coolant hose.

P-ssedrightoff

Thanks for that, good idea. However new thermostat and fan switch. Fan works fine if I bridge the switch so
must be getting power. Still no fan coming on and let it run as near to the red as I dared.
Also wondered that it would only accept 5 litres of coolant before overflowing the header tank?
Thought I could run in till thermostat opened and top it up, Top hose, swirl pot hot, lower hose cooler.
Now as well as a slight leak from the new sump and gasket, also appears oil coming out of flex section on exhaust.
Can't see it being the valve stem oil seals so knowing my luck... oil seals in turbo?
Rapidly losing patience with, two steps forward, 3 steps back.Wondered if it could be the Grey or Yellow coolant
temp sensors causing the problem.

nigel b

Are you sure you have the correct temperature sensor in the head?
Wrong temperature sensor will make it look like it is running hot when it isnt
if you bridge the wires on the fan switch and the fan comes on check what temperature the fan switch comes on at

P-ssedrightoff

Maybe being thick but if I bridge the wires in the plug to fan switch, fan comes on immediately.
Temp. Sensor in the heads correct and new fan temp.,I assume is standard 88 as opposed to the 83 I removed.

boost monster

By bridging the connector you are by-passing the temperature switch that it plugs into.

P-ssedrightoff

Realised that Boost Monster but can't see how bridging the actual switch would help, even if I
could get near it for the bl--dy swirl pot.
Rapidly beginning to think it's a mega air lock.
Wondering about draining, raising the front of the car and refilling at the top radiator hose.
Probably changed the coolant in this twice and twice in my last RS and never had any problems
before now.
Have a new water pump in the cupboard but the heaters are blowing hot air.
Doing my head in as it's starting and running nicely, just no fan.

boost monster

So bridging the connector confirms the functionality of the fan.
Next for me would be to place the switch in hot water and confirm that the contacts close.
If that works then the switch isn’t coming into contact with hot water, and would need investigating.

P-ssedrightoff

Tanks BM, no visible contacts so would continuity between pins when hot suggest contacts closed.
Next problem, Auxiliary Air Valve, came back after 3 months supposedly sorted. Virtually no voltage to the said.
Ran a new cable from the positive at the fuel pump relay and sorted that.
While ago that seemed fine 1600 revs dropping to 960 after a few minutes..
Started behaving erratically. Stuck in a spare, now starting at 960 and staying there but running fine.
Saw the method of squashing hoses, bit daft as they are hard plastic.
So wondering if the earth wire to it is goosed or can I just put 12v direct to see if any of the 3AAV's
I have function correctly?

boost monster

Correct. No idea about the other stuff.

P-ssedrightoff

Thanks BM. Original thermostat tests fine.
Original fan temp switch dubious.
Have a new lower temp fan switch which tests fine. No coding on wires
so assuming makes no difference how they are attached as long as closing contact.

boost monster

Correct again, doesn’t matter where the wires go.

P-ssedrightoff

The Saga continues. Dropped the end of the engine to replace the water pump, timing belt and put on the vernier pulley.
Swirl Pot bar tight against fuel lines so took it of.. only to find it clogged with soapy stuff.
Just put the engine and box back in and now head off.,as I'm assuming the head gasket has gone.
Be glad to see the back of this thing.
Edit, talking nonsense, was actually the Bailey Breather blocked with stuff like Mayonnaise hence me thinking head gasket???

P-ssedrightoff

Well progress, changed the water pump (nowt wrong with the one I took out) so changed the timing belt as a matter of course.
Did away with the swirl pot and reverted to standard hose set up, stuck in 7,8 litres of plain water as bloody coolant stained all the monoblock.
Leaves me thinking was this just an air lock?
Starts and runs fine, fan kicks in and all seems well
However the new sump and gasket pissing oil when hot. Fix that, m.o.t. and the Love affair will end. Stage 3 head and fully recond short
block can go in the boot for it's new owner,lol.

XR2

You don't want to run your car without coolant. It protects the block AND the head from corrosion, it raises the boiling point of the water and it has a better heat transfer than plain water!

P-ssedrightoff

Thanks but well aware of that. Only a temporary measure to see if the problem was resolved before
wasting more coolant.

P-ssedrightoff

Just a hint for anyone else, checked alternator belt against old ones. 1 cm longer at 810 cm was why the alternator fan chewed the Samco hose. Hard to believe.
Old 80 cm belt on and all fine. Took off swirl pot and reverted to standard set up, took return to header hose off and eventually cleared air lock in coolant system.
Strange as never had this problem with umpteen head changes on both my RS.

Ginge !

mine is linked via relay to car heater motor and something else
Its a yellow relay in engine bay fuse box

GVK.

First i've heard of that.