Coolant Temperature Sensor

[whipmawhopma]

I decided to change the coolant sensor and bought, as per bible, part no.Lucas SNB802. Problem is, the new one doesn't nip tight when being screwed in, it just keeps going round. I thought I had somehow stripped the thread, although I was very gentle. When the engine was started there is a leak around the base of the sensor. I have put the old one back in and this one nips up tight as expected.

Have I bought a dud part or even the wrong part?

[Robert Lees]

Going to do mine at weekend, will let U know if same. I have ordered same part.

[whipmawhopma]

Please do, I'll await your experience.

[Chimaeraman]

Changed mine a couple of weeks ago - used Intermotor part 55128 which is quoted as option to the Lucas part - no problem with fitting.

[Robert Lees]

I started to undo mine on Sunday but stupidly tried it whilst car still warm. As I un screwed it I did notice like a stringy thread coming out with the sensor, I wondered if it was sealant or ???. As the car was hot coolant started to shower out so I stopped .try again Saturday, with cold engine!

[carsy]

If its bottoming out surely it must be the wrong part.

Is this not what you want.

http://www.ebay.co.uk/itm/ETC8496-Land-Rover-Disco...

[whipmawhopma]

carsy said:

If its bottoming out surely it must be the wrong part.

Is this not what you want.

http://www.ebay.co.uk/itm/ETC8496-Land-Rover-Disco...

Just this minute ordered following a bit of research showed the one you mention. Although this is supposed to be an equivalent to the SNB802, but cheap enough to try again anyway so fingers crossed.

Cheers

[debaron]

Fitting with a little PTFE (plumbers) tape might be prudent to allow for possible tolerance differences.

It is well known that some of the intermotor pattern parts are crap when it comes to matching up to the originals however in the case of the CTS I've not heard any bad things!!

If it is to try and cure rough running, get the airflow meter checked out but for christ sake don't get the intermotor pattern part (usually on ebay) for that - they truly are terrible!!

[Robert Lees]

Hi changed mine this morning Lucas part, it doesn't seem to tighten up as the original but then used washer from original part with new sensor and fits ok. Started car left running 10 mins no coolant loss,gave it a good 10-15 minutes blast, checked all dry. The sensor that came out was brown compared to the golden new one so def worth changing for £10

[whipmawhopma]

Changed my sensor all now works except.....it now wants to run at 100degC with the fan almost always on....Any ideas?

[MADMAX2]

whipmawhopma said:

Changed my sensor all now works except.....it now wants to run at 100degC with the fan almost always on....Any ideas?

let the car cool down and bleed the system... add more coolant if necessary then start her up and go for a hoon.... should be ok if not you have a problem!

[s3c chris]

Apologies for resurrecting this thread!

I've just tried to change the CTS sensor on my car with a genuine Lucas one. Same result as the OP, it will not tighten up and spins round. The one removed was an FAE part with the brass nut and this tightens no problem. I had exactly the same problem last time I changed it but couldn't get an FAE one this time.
Has anyone else had this problem? Lucas parts these days seem to be very bad quality wise....
I'm tempted to get one from POWERS as they are made by Bosch but a lot dearer. I guess you DO get what you pay for!
Regards Chris.

[jojackson4]

Has it got a plastic nut?

[s3c chris]

The ones that "spin" round seem to be those with the plastic nut. The FAE one is a brass nut.
When I changed it last year,I had exactly the same thing happen.It is almost as if the thread is too small or the pitch is wrong. I'm having nightmares now about helicoils........
Regards Chris.

[jojackson4]

It's the st plastic nut spinning on the thread remove it and put it in the bin and replace with a brass
Nut one
If it's spun its shaged as the wires are twised together

And yes I have had one of the plastic ones
That's £14 I will never see again

[Sardonicus]

The only one you will ever need and FAE are an OE quality item Ebay number 301434586462

[s3c chris]

Thanks for the replies.
It isn't the plastic part turning round, that is fine.
It feels like the thread in the manifold is stripped yet the FAE one tightens perfectly! I will get another sensor with the brass nut but am still puzzled..... I'm only changing it due to the misfire on start up that a new stepper has failed to cure.
Regards Chris.

[s3c chris]

Apologies to everyone!
I had a closer look at the Lucas CTS and you were right.
It was the plastic part spinning round on the brass body. I took the sensor apart and there are only two very small slots on the body that secure the plastic "nut" to it. I think even hand tightening would cause problems.
New FAE part fitted and no problems, thanks for the link.
Unfortunatrely the rich mixture on cold starting has not been cured.....
Regards Chris.