Classic Coolant Sensor

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
R

redrenger89

New Member
Posts
567
Hi Guys,

Still have starting problems.
I have been told the coolant sensor could be the problem, mine looked as though it has leaked up into the plug ( Green gunge )

Hot it reads approx 300 ohms Still hot so I will have to wait for it to cool before I can read it cold

If you unplug it hot or cold the engine cuts out, but I have been told to remove it to test whether it is faulty or not.

How do I tell when it cuts out if I remove it hot, and it wont start plugged in or removed from cold ?

Oh boy.
 
well if the coolant level is low it should flash on the dash and annoy the arse outta ya when ya driving
 
Now it's dark I can see the radiator symbol is flashing.
Still warm so she started first try
Topped up the tank, don't rember seeing the light on before but I am now parked on a slope so maybe that could be why

This fault is so annoying, drive 200 miles without a problem, wait overnight and she will crank and crank before she will start, then be fine all day.
Next day same problem.

Thank's for your help I will see what happens tomorrow
 
The one in the cylinder head, second one in from front.

When she does start and disconnect plug she dies straight away, this happens when she is hot or cold
 
oh i meant the coolant expansion tank but if its pinging up on the dash youve got coolent probs any way
 
I had not noticed the low water level before today , but she is on a steep hill at present so she may be a little low and the the fact she is down to the back and side shows, since I topped her up the light went out.

Disconnecting the coolant sensor on the block just stops the engine dead.
 
About the CTS in general:

When starting the car cold the resistance of this sensor should be high - up to 5-10 kOhms (depending on the ambient temp). The car should start when cold with the connector disconnected (resistance infinite) - not when warm though since then the resistance should be low 200-400 Ohms and not infinite.

You can test the cold starting by just disconnecting the plug and putting a 5 to 10 kOhm resistor between the connector pins (or try without it). The car should start and run fine until the engine warms up.

If you suspect problems at the hot end of the readings (jammed at cold end - giving resistance readings at KOhms rather than couple of hundred Ohms) you can try by disconnecting the connector and putting a jumper wire between the connector pins (no resistance) - should fire up when hot and run more or less correct. However, cold start would be hard.

From the description from this thread I would change the CTS without any hesitation. It's cheap as said somewhere above.
 
:) Thank you all very much for your input :)

As you are no doubt aware by my comments I am not very clued up on car repairs, but I try.

Relaced the sensor as advised.

Replaced the rotor arm as I found out it was not genuine, worried about the dizzy cap now. ( Both purchased as genuine from ebay )

Removed and cleaned MAF and input to plenum chamber with carb cleaner. ( quid from the pound shop ) Loads of brown gunge came out.

Removed and cleaned the cold start injector, also covered in brown gunge.

Saved the coolant and topped her up.

A few cranks and she fired, took her out for a run and she seems fine.

I will try again when she has stood all night.

Special thank you to TimoV for a brilliant description of how the sensor and cold start injector works.

Regards Fred
 
I take it you have a 3.5 EFI? As you have a cold start injector. Most times it's just a case of TLC for the car as people before you may have neglected it for a while.
DOnt know if it's true but after a few starts and stops and runs too and fro, your ECU will start to listen better to the sensors etc. Mines seemed to get better after a few outings.
If you havn't yet, try cleaning out the crankcase breather also, or maybe even get some new pipes for it to the plenum chamber. I also done this and it made a bit of difference to the starting and running.

Happy driving;)
 
Thank's DC

Yes it's a late 1989 3.5 EFI with some parts used from the 1990 build so it confuses LR parts when I say no it's not that one.

I think the last owner had a repair only if required approach, so regular services have not been carried out fully. Plenty of electrical faults when I first got it, most have now been sorted and I am down to this starting problem. Good idea to change the hoses, I think she is overdue for a bit of TLC and have the oil and filter ready as soon as this problem is sorted.

Cheers Fred
 
I've just got intot his malarky since last september but it's amazing how much info you pick up if your prepared to do the searching, places like this and a few other forums i'm on are invaluable and save ye a fortune on garage bills.
;)
 
It's a love hate relationship with mine, when she runs we are all luvy dovey, but when she plays up it's big hammer time and I have to compose myself and then something comes over me and I have to do anything to fix her and get out there and drive.
I think she must give somesort of drug induced fumes or something
 
You must log in or register to reply here.

Similar threads

K
L322 not starting
Replies
2
Views
572
backinblack
backinblack
P
Sport Coolant not circulating
Replies
11
Views
1K
pllaw
P
JT_spark
P38 DSE Auto intermittent lack of power after vehicle has been hot
Replies
8
Views
1K
brianp38dse
brianp38dse
R
Discovery 2 heater issue
Replies
1
Views
739
sierrafery
sierrafery
R
86 Range Rover Classic Poor idle
Replies
4
Views
673
Ratae
R
Back
Top