Curious Temp Gauge Readings.....

[Saint.V8]

Evening chaps and chapettes,

2003 4.4 Vogue LPG.....

Noticed this morning after about 19-20 miles the Temp gauge starting creeping up from the usual 12o'clock position to the 3/4 mark - then about 3 seconds later went back down to usual...!!

On the way home this evening, same thing happened about 3-4 times - after 3-5 seconds back down to normal again....

No rhyme nor reason - doesn't happen at any specific time, up hills fine, down hills, fine, waiting at lights fine, fast driving fine, slow crawling fine....then all of sudden at no specfic time it creeps up then down again a few seconds later!!

There is a whiff of coolant in the air when you open the bonnet, but no wet marks.

Did notice a tiny damp patch under the front valance (if facing the car on the left hand side - just under the front spoiler) the other morning but nothing since.

Any clues??

 

[wammers]

Are you losing any Ant? Sometimes hard to find if it's slight weep as the lost coolant dries on the hot engine.

 

[Saint.V8]

Hi Tony...

Topped up by about half a litre 5 weeks ago, then just over litre at the weekend.

Checked this afternoon once it had cooled down and the level is where it was at the weekend (the L322 uses a floating stick level).

 

[aerofabrique]

as it's not been a particularly hot today you cant blame it on that?

Perhaps she's running lean and got a temperature?

Air locks, but if it's self bleeding can't see it being that
Sticky thermostat?
Temperamental fan?
Something blocking the grill?

But I know you've already thought of those things and checked

I suspect a leaky hose/fixing allowing the pressure to escape. When the temp works down from 3/4 does the fan work in overtime?
Also since you had it have you got your spanner and hammer out and changed and flushed the coolant?

 

[Saint.V8]

Hi Aero...

Those were exactly my thoughts too - the L322 usues an electronic thermostat, which is known to be a 'consumable' item.

Not sure if when it creeps up if the fan starts working harder as it runs so queitly I can't hear it - and on the way home I parked in a car park in Chobham Common and let it run at around 2000rpm for ten minutes to try and get it to rise with the bonnet up so I could see if the viscous and auxillary fan were running overtime, but the temp never moved....

My suspision is the Electronic Thermostat opening and closing....

I haven't changed the coolant, no - that requires a screwdriver...!!!

 

[dogsbody]

Hi Aero...

Those were exactly my thoughts too - the L322 usues an electronic thermostat, which is known to be a 'consumable' item.

Not sure if when it creeps up if the fan starts working harder as it runs so queitly I can't hear it - and on the way home I parked in a car park in Chobham Common and let it run at around 2000rpm for ten minutes to try and get it to rise with the bonnet up so I could see if the viscous and auxillary fan were running overtime, but the temp never moved....

My suspision is the Electronic Thermostat opening and closing....

I haven't changed the coolant, no - that requires a screwdriver...!!!

This has got to be one of the worst excuses for a bit of dogging that I've ever heard.

 

[wammers]

Hi Tony...

Topped up by about half a litre 5 weeks ago, then just over litre at the weekend.

Checked this afternoon once it had cooled down and the level is where it was at the weekend (the L322 uses a floating stick level).

You must have a slight weep then, but losing that much should not cause temp gauge to fluctuate. Has it got leccy fans? Dicky fan switch could cause that i suppose.

 

[aerofabrique]

I haven't changed the coolant, no - that requires a screwdriver...!!!

Make sure you aim for the clips with that weapon... you may also need a license to operate one of those...

If it's electronically controlled it probably point even more so to that given the speed the coolant temperature drops back to normal. If the halfway is 90 deg c the 3/4 would be probably near or over boiling sending some sort of emergency signal to the stat (and fan etc) to provide max cooling?

It's odd it only happens under load though as it didnt happen when parked up. Having said that the pumps probably not pushing it around enough to recreate the fault. As Wammers said its possible there is a small leak somewhere that might be falling on a hot block. But even that should leave a pink or green residue, like on my driver footwell

Don't rule out (and equally assume) a faulty gauge to!

 

[aerofabrique]

...when it creeps up .....starts working harder... and on the way home I parked in a car park in Chobham Common .... for ten minutes to try and get it to rise...

My suspision is the ...tat opening and closing....

I haven't changed ...that requires a screw..!!!

Completely missed that one! Sorry

 

[wammers]

To find such a leak you will need engine cold, so you don't burn your hands. A static test rig, a torch and mirror. Oh and unless you stumble across it immediately, the most important thing of all, lots of patience.

 

[wammers]

There are some dogging car parks around here were it rises straight away, or so i am told.

 

[Datatek]

There are some dogging car parks around here were it rises straight away, or so i am told.

Voice of experience:behindsofa:

 

[Datatek]

Sooo reliable these L322's, where's Hippo?

 

[wammers]

Voice of experience:behindsofa:

I wish.

 

[Saint.V8]

Took the opportunity to get underneath and have a poke around.

I attach some photos....

As can be seen a little wet patch on the Radiator

A pool of water on the under tray

And a very bad picture taken of the underside of the radiator.

Don't think, as others have put, that the leak is causing the odd rise in temperature - I am still thinking ECT (Electronically Controlled Thermostat) could be the culprit, or even if there is a leak, maybe the pressure changes are causing a fluctuation in temp readings!!

Just to continue the theme of the thread - the girlfriend came home to find me flat on my back, legs in the air with my face buried in some thing wet and smelly!!

 

[Saint.V8]

Thinking the Cause of the odd rise and fall may be due to the Electronic Thermostat...

Here is the legend that is Storey Wilson demonstrating the removal process....

Range Rover MKIII - Replace Electric Thermostat - YouTube

Now gonna research what the ECT actually does..!!

 

[aerofabrique]

Don't think, as others have put, that the leak is causing the odd rise in temperature - I am still thinking ECT (Electronically Controlled Thermostat) could be the culprit, or even if there is a leak, maybe the pressure changes are causing a fluctuation in temp readings!!!

I think thats probably it... from the pic unless you have an overflow pipe the wet patch shouldn't be there...possibly something you need to pay some attention to in the near future. Might be worth doing as draining the coolant and refilling you'd know you have the correct mix of antifreeze and water. Too much of one or the other and it won't be as effective as some coolants have the additives to break down the surface tension of the water.

Not too long ago I had a burst rad hose but the temp gauge never moved even with the decrease in pressure. It just pis*ed every where and the pump pulled whatever it could from the expansion tank to keep the temp at 12. However when the thermostat (mechanical) failed when I first got it the guage was all over the place cool then hot cool then boiling then nothing etc...so yeah ECT etc etc

 

[Saint.V8]

Cheers Aero, those are my thoughts exactly....

I have researched the ECT, and I attach my findings below....

The ECT, which I have been calling it, is in fact an EHT (Electronically Heated Thermostat) It uses a heated element to open and close the stat under different engine conditions and also uses the conventional Wax-Stat principle too.

My theory is that it is opening and closing at odd times, as there is no pattern to when it will start to rise and then drop again...

The replacement price from Island4x4 is in the £46 odd area plus the VAT mans booty so call it £60 for a new one....might be worth a punt!

And yes, replacing the coolant with correct mixture would be a prudent move too...!!! Where do I get a ScrewDriver training course and licence from? or can I operate it under a provisional licence in conjunction with my Hammer/Spanner licence??

 

[Chrisfrain2007]

Unfortunately you can only use the screwdriver after, you pass the hammer and spanner combined test, although you can use it under the influence of tea and biccys under line of sight supervision from a well established screwdriverer!

 

[Saint.V8]

I do have the Combined test on my ticket, also have the Institute of Mechanical Thuggery (IMT) advanced certificate in Hammer use too...

I have the opportunity to use whilst under the influence of Tea and would Custard Creams be suitable or would it need to be some form of Digestive?

My girlfriend can hande a mean Screwdriver in a tall glass with a cocktail umbrella and Orange Slice, if I bribe her enough with shoes and clothes she is willing to sit on the drive with me, does that count as adequate supervision?