Thermostat

skymera

Brutal Honesty
I'm guessing my car's thermostat is seized open or totally non existent.

Car takes 15miles or more to get any sort of heat out the blowers (Temp needle rarely reaches half way).
Putting the blowers on hot causes the temp needle to drop all the way to the bottom of the gauge rather quickly.
Symptoms of a faulty thermostat?

Eyeing up this one to replace it
http://www.ebay.co.uk/itm/Thermostat-87C-for-Nissan-Micra-92-00-/380498359079?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model:Micra|Plat_Gen:K11&hash=item5897783327

Or from EuroCarParts for £8 or £10.44 something...

Never done one of these before so any tips would be great such as airbleeds and such

Thanks!
 

frank

Club Member
just 3 x 10mm bolts holding the housing on skymera, a bit of sealer on refitting, and top the coolant up then run it round the block for the coolant level to settle :)
 
OP
OP
skymera

skymera

Brutal Honesty
Thought as much. I'll head to my local Motor Parts Direct tomorow and pick a thermostat up. Got a bit of bathroom sealant kicking about somewhere also..
 

Belly93

to turbo or new lump :/ hmmm
I'm guessing my car's thermostat is seized open or totally non existent.

Car takes 15miles or more to get any sort of heat out the blowers (Temp needle rarely reaches half way).
Putting the blowers on hot causes the temp needle to drop all the way to the bottom of the gauge rather quickly.
Symptoms of a faulty thermostat?

Eyeing up this one to replace it
http://www.ebay.co.uk/itm/Thermostat-87C-for-Nissan-Micra-92-00-/380498359079?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model:Micra|Plat_Gen:K11&hash=item5897783327

Or from EuroCarParts for £8 or £10.44 something...

Never done one of these before so any tips would be great such as airbleeds and such

Thanks!
andrew pages or npa not cheaper if theres any local?
 
I fitted a new radiator and thermostat last weekend to my K11, just using sealer it pissed out and yes both faces were spotlessly clean I had to re-do it using one of the supplied gaskets...perfect.
 
OP
OP
skymera

skymera

Brutal Honesty
andrew pages or npa not cheaper if theres any local?
Nothing really local. MPD do a thermostat with gaskets for £12.44 which seems like the one to get!

I fitted a new radiator and thermostat last weekend to my K11, just using sealer it pissed out and yes both faces were spotlessly clean I had to re-do it using one of the supplied gaskets...perfect.
Thanks for the heads up
 

Belly93

to turbo or new lump :/ hmmm
Nothing really local. MPD do a thermostat with gaskets for £12.44 which seems like the one to get!


Thanks for the heads up
no bother just a suggestion cos i got npa, andrew page and euro local to me :)
 
OP
OP
skymera

skymera

Brutal Honesty
Got a thermostat and gaskets and none of them fit!! Grrr

Sent from my GT-I9100 using Forum Runner
 
OP
OP
skymera

skymera

Brutal Honesty
Took it for a spin and it overheated within a mile. Am I right in thinking the thermostat only fits one way?
Was it air?

Sent from my GT-I9100 using Forum Runner
 
OP
OP
skymera

skymera

Brutal Honesty
Good, that is how I had it originally, but thinking in my head about how coolant flows seemed like it should the other way like above.

Run it for a while with rad cap off, I have heating now, loads of air bubbles come up and I topped the coolant up. Broke my expansion tank plastic too...might just take a hammer to it.

Gotta run it to town in a bit (6miles all round) going to keep an eye on temps!

Temp gauge got 3/4 up before I turned engine off, no risk on damage is there? It wasn't and never got into the red!
 

pollyp

Club Member
m8 the wax end of the thermostat has to be exposed to the constant flow of coolant from the engine block in order to do its job in maintaining a maximum temp.

the pump forces the coolant through the engine block jackets, up through the head, out to the thermostat housing (while the thermostat is still cold, the valve to the rad is closed), through a short bypass hose to the metal return pipe and back to the pump.

so cos the bypass hose provides a stream of coolant across the housing thats where the thermostat wax end should be pointed, inwards towards the thermostat housing as shown in the service manual.

by fitting it the wrong way you've actually blocked off the wax (that operates the valve) from the stream so its no surprise you've caused it to overheat.

btw always good practice to test and verify the suspected part is faulty before spending & replacing em
 
OP
OP
skymera

skymera

Brutal Honesty
it should read 1/2 way up within 2 miles
That was a lot of stop/start.

I'm very impatient, I just want to drive it to the scrappy now. :mad:

Going to work now, 15miles back road and 15miles of M4 on the way home. I'll keep an eye.
 

pollyp

Club Member
i suggest:
  • test thermostat only opens fully in boiling water and shuts once its below 82c
  • test the temp gauge sensor (single terminal) is between 570-1175ohms when in a cup of 82c water
  • test the ecu coolant sensor (double terminal) is bout 0.25k ohms when in a cup of 90c water
  • test the gauge needle is fully down when the sensor wire is unplugged (0v) and reaches fully hot when you short the wire to Gnd
the temp gauge motor has a max/min point and the needle is loose fitted on its axis so it can actually be nudged up/down.
to calibrate the gauge, preferably should use a consult to see what the coolant temp is according to the ecu (provided the coolant sensors within spec). when the ecu says 82c, nudge the needle till it sits middle of the gauge
 
OP
OP
skymera

skymera

Brutal Honesty
Not heating up at all now. I guess the Stat has moved when struggling to line up the housing allowing coolant to pass all the time.

Heats up in traffic and drops rapidly when moving.

Will remove and test everything Saturday.

Thanks for all the help.

Sent from my GT-I9100 using Forum Runner
 

Belly93

to turbo or new lump :/ hmmm
Good, that is how I had it originally, but thinking in my head about how coolant flows seemed like it should the other way like above.

Run it for a while with rad cap off, I have heating now, loads of air bubbles come up and I topped the coolant up. Broke my expansion tank plastic too...might just take a hammer to it.

Gotta run it to town in a bit (6miles all round) going to keep an eye on temps!

Temp gauge got 3/4 up before I turned engine off, no risk on damage is there? It wasn't and never got into the red!
should be good i had mine right in the red one day to the point it was starting to lock up :oops: lol fingeres crossed it been good since and i just filled it up again and off i went :)
 
OP
OP
skymera

skymera

Brutal Honesty
Does the thermostat fit snugly? This one just sort of rests in place, doesn't slot in anywhere
 
OP
OP
skymera

skymera

Brutal Honesty
Humm, can't remember if this one actually did y'know! Might be a little too big?

It didn't have a gasket for a Micra so it might not actually FIT a Micra? Just what local motor parts gave me.
 

pollyp

Club Member
the thermostats i used to get from local factors were bout £6 but didn't feature a 1-way bleed valve. the genuine one from dealers was just £10 and did feature the little valve which made bleeding abit easier.

the thermostat sits in a recess lip on the housing, you have to scrape off the old gasket yaknow.
if unsure on anything, get a haynes manual to follow and not just assume.
 
OP
OP
skymera

skymera

Brutal Honesty
the thermostats i used to get from local factors were bout £6 but didn't feature a 1-way bleed valve. the genuine one from dealers was just £10 and did feature the little valve which made bleeding abit easier.

the thermostat sits in a recess lip on the housing, you have to scrape off the old gasket yaknow.
if unsure on anything, get a haynes manual to follow and not just assume.
Found a Nissan dealership in Reading, so off I trot tomorrow.

Oh, the previous thermostat was held in with a ton of silicone sealant stuff not a proper gasket >.<
 
OP
OP
skymera

skymera

Brutal Honesty
Well Nissan phoned me back, a genuine thermostat is now £28. Scandalous.

Fair to say this'll be the only genuine part my car receives!

Excuse me whilst I pull my pants back up...:rolleyes:
 
OP
OP
skymera

skymera

Brutal Honesty
Decided to play around again today and do some comparisons.

The thermostat originally was a genuine Nissan thermostat and about 1mm bigger than the one supplied by MPD, it fit snugly in the recess whereas my newer one didn't, it could slide about!

On the Nissan one I noticed one side had some old sealant or something that was rock hard and stopping the valve working. I chipped this all away and the valve could open/close again.
Thoroughly cleaned the surface of the stat itself, housing and the block where housing connects, making sure to remove any old gasket.
It fit like a glove, bolted the housing back together, topped the coolant up and ran the car idle for a few mins.

Heated up a bit fairly quickly idling, and when driving it heated up in just over 2miles to half way on the gauge and didn't budge any further. Heating is nice and warm and temp doesn't drop when heating is on either!

Problem solved I believe, a bodged repair by a previous owner it seemed. Shame I spent £12 on a new stat but grateful I didn't spend £30 at Nissan!

What a palava
 
OP
OP
skymera

skymera

Brutal Honesty
I highly suggest a genuine Nissan thermostat over a pattern part.

It's expensive (£30) in my case but it's guaranteed to fit and has a valve to aid in bleeding
 
I highly suggest a genuine Nissan thermostat over a pattern part.

It's expensive (£30) in my case but it's guaranteed to fit and has a valve to aid in bleeding

does the genuine thermostat come with a gasket then? my needle spends most of its time very low on gauge with blower on, but heats ok
 
OP
OP
skymera

skymera

Brutal Honesty
does the genuine thermostat come with a gasket then? my needle spends most of its time very low on gauge with blower on, but heats ok
From memory, the kit had everything.
I had the same problem as you where the needle drops with the blower open. I had a headache with the cheaper thermostats so I'd recommend a Nissan genuine one.
 
On the same subject I was thinking to chk if stat is alright coz its taking a long time to heat up the engine. And longer for heating to be working. Was just browsing on eurocarparts and found one for £4.99. Dont know if it gonna fit. Will probably ask my mate to find me a used one in working condition later on.
 

pollyp

Club Member
On the same subject I was thinking to chk if stat is alright coz its taking a long time to heat up the engine. And longer for heating to be working. Was just browsing on eurocarparts and found one for £4.99. Dont know if it gonna fit. Will probably ask my mate to find me a used one in working condition later on.
checking the thermostat

 
Top