Water level light comes on at speed

MoRtYMer · Post by **MoRtYMer** » Fri Mar 13, 2009 6:34 pm

Hi,
I have a new "problem" with the 16v.

The water low level and the stop light comes on when I go past 120kph. If I take the foot of the gas pedal a little it goes off but when I press the pedal again it goes on again.

The water level is ok. And I've done about 40km's at about 160kph and the car doesn't heat up.

Does anyone have any idea of what this could be?

thanuttiscotsman · Post by **thanuttiscotsman** » Fri Mar 13, 2009 10:54 pm

hi, i would start with checking the plug connectors first.

rossco

surjit25 · Post by **surjit25** » Sat Mar 14, 2009 12:25 am

Yr water level is not correct mate, I had this problem once
and by topping up solved it.

Post by **Jezziebx16v** » Sat Mar 14, 2009 2:06 am

MoRtYMer wrote:
The water level is ok.

He said its not that

I had the same thing with more than one of mine, water was allways topped right up, lazy bloke that I am I never worried too much

As Rossco said, check the connectors on the sensors on the expantion bottle, strange that they only do it at speed though

Guess the next thing to check is the sensor itself, cant think what else it would be!

Timmo · Post by **Timmo** » Sat Mar 14, 2009 9:06 am

i seem to recall having mine come on at high revs before, (hard acceleration of a roundabout) but eased off and nailed it again and was okay, like Jezz, i didnt worry too much about it as all the levels were fine!

Post by **Toddman** » Sat Mar 14, 2009 4:50 pm

It isn't anything to worry about but it is nice to fix the issue.

I had the same problem with one of my valvers and apparently it is quite a common fault.
At highish revs the water gets quite agitated and if your water level proble is old and or corroded or dirty they loose the contact which makes the water light com eon.

First step is to remove the proble from the bottom of the water bottle and check/clean it - if this doesn't fix the problem then fit a new probe, they are not very expensive from Citron.

Cheers
Luke

prm · Post by **prm** » Sat Mar 14, 2009 7:03 pm

On one particular 16 valver. had been plagued trying to rectify a very similar problem with the low level water light constantly coming on above 3500-4500rpm. Having the correct water level in the header tank, complete electrical systems tested, changed all related components, system bleed 5-6 times - all with the running temperatures operating normally.

A few pointers that may help solve the problem, but it would appear, in the end, this boiled!! down to the pump cavitating, due to flow restrictions within the radiator and bottom hose, generating static within the coolant.
If you ever remove the water pump and the impellers look like they have been sand blasted, the pump has been cavitating.

You could first try, removing the header tank sensor, cleaning the contacts and checking the cable connection on the block connector. Cable tie the pair of wires as these are inclined to flap around.

Check the block connector and cables on the control unit attached to the side of the rad, which also carries the oil level relay.

Remove and flush the rad, check the condition of the bottom hose. If the rubber is weak about 3-4 inches away from both connecting points, the pump suction will reduce the hose ID as the revs increase. Bleed the system, raise the front of the car as high as possible, fully open the cabin heater valve and run engine to normal temp, then bleed the system again.

Let us know how you get on, as I have only experienced this problem with this car,

Regards

petwar · Post by **petwar** » Mon Mar 16, 2009 4:40 pm

I am having a similar problem with my 16v... But I'm fairly certain it's a matter of air still being trapped somewhere in the cooling system. I recently disconnected the cooling hoses from the oil cooler while locating an oil leek, and ever since then the water level warning light comes on whenever I'm revving beyond 4000rpm. The problem becomes worse when the engine is properly warm...

I checked and replaced the water level sensor and there was no difference. My engine heater broke (not fun during cold Swedish winters) after this problem started, and I'm guessing it's because there was an air pocket surrounding the heater element instead of water. Heater elements break almost in an instant if they aren't submerged in liquid when you plug in the socket (I don't know if you use engine heaters in the U.K.?).

I've tried breathing the cooling system several times but the problem persists, I've even lifted the front wheels 6 feet in the air with the bleeder screws open and the engine running trying to get all the air out, but it didn't make any difference whatsoever.

I don't want to kill the engine so right now I'm driving frustratingly calm... I want to be able to put the pedal to the metal again!

Frenchracingblue · Post by **Frenchracingblue** » Mon Mar 16, 2009 5:12 pm

There's a little box with a multiplug by the OS headlamp, clean up the contacts, it fixes the problem!

petwar · Post by **petwar** » Mon Mar 16, 2009 5:29 pm

Frenchracingblue wrote:There's a little box with a multiplug by the OS headlamp, clean up the contacts, it fixes the problem!

What does OS mean?

Timmo · Post by **Timmo** » Mon Mar 16, 2009 7:46 pm

OS = Off Side

driverside in u.k. passenger side in E.U.

thanuttiscotsman · Post by **thanuttiscotsman** » Mon Mar 16, 2009 8:10 pm

hi there, os means 'off side' which is the right hand side. if your heator is cold after this happened im guessing an airlock is likely to be at or in the heator matrix behind the dash. when you said you had bled the cooling system did you use all the bleeding points? there are 3 different points on these cars if i remember correctly see here ...

also i dont think bouncing off the rpm limit a couple times would do any harm, i have often got trapped air out a system by revving the engine, i guess the higher rpm will create higher water pressure with the pump going faster?

rossco

ollie · Post by **ollie** » Mon Mar 16, 2009 8:44 pm

And mines been doing it too! New sensor off spare car didn't fix it and I couldn't really be arsed chaing all the connectors!! And whats this magic box by the drivers headlamp?

Its stopped recently and anyway it only came on above 70 so it was a usefull fuel economy aid........ isn't this whay we love them?

Ollie

prm · Post by **prm** » Mon Mar 16, 2009 10:00 pm

I never realised this low level water light at high revs was a common problem on 16v’s.

Initially, I thought the header tank level sensor, connected to the relay control box attached to the rad, was interconnected with the oil level probe circuits???

There must be a detectable fault somewhere in the system, as several members have changed individual components and cured the problem.

Will dig out my old electrical drawings and have a run through the level sensor circuit board.

I’ve never owned a P1, are all the electrical components and circuits identical??

Regards

Frenchracingblue · Post by **Frenchracingblue** » Mon Mar 16, 2009 10:24 pm

Hi, cleaning up the connections on that box fixed every BX i ever saw with that symptom. seems to sense rpm more than speed when it is faulty.

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Water level light comes on at speed

Water level light comes on at speed

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