Low Oil Pressure, High Water Temp And Stop Light On

[TaffyTim 6]

A few weeks ago I had my blown head gasket sorted and while doing so the chap kindly tidied up my electrics a bit.

 

Intermitanatly since the warning light for the above have been staying on while the car is being driven, when they normally go out after a few seconds, but the gauges are showing healthy readings (the oil temp light and gauge doesnt work so this light might be wanting to come on also).

 

When this first started to happen the lights would randomly go off during a drive, but in the last week when they dont go off after start up, they stay on for the whole journey.

 

Ive got an MOT tomorrow, , and dont want this to happen when the mechanic starts the car up.

 

I pressume its a loose connection that needs a bit of WD40 squirted at it but i dont know where to start squirting. Is it the trusty brown multiplug that i should aiming at or somewhere else?

 

Any other thoughs are welcome.

[jackherer 543]

sounds like a wire is shorting to earth somewhere, either the oil pressure warning light or the coolant temp warning light wire. Either sender causes both warning lights and the stop light to come on.

 

BTW there isnt an oil temp warning light, just a gauge.

[TaffyTim 6]

ok, how do i stop this earthing. My electrical skills and knowlage are worse than my mechanical skills.

 

Earthing means its touching something it shouldn't right?

Edited November 9, 2006 by TaffyTim

[jackherer 543]

cars use the metal of the body and engine etc as earth (negative) so the wire could be touching anything really, follow the wires from the brown multiplug to the sensors as this is the most likely section to have broken insulation IMO.

[jackherer 543]

Also a wire could simply have become disconnected and the plug may be touching something..

[TaffyTim 6]

ok, ta will have a look tomorrow.

 

where do i find the sensors to follow the wires from? Sorry to ask but I havent got a haynes for the mi16 engine.

[TaffyTim 6]

OK a search has revealed that the oil pressure warning light is under the inletmanifold and is the smaller of the 2 senders.

 

The water temp warning light sensor is on the water housing and if i read the thread correctly is the left of these 3 sensors.

 

http://www.mdracing.co.uk/images/rebuild/large/pic382.jpg

 

Can some one say where this water housing is located on the engine or ifany of this info is wrong.

 

ta

Tim

[jackherer 543]

the thermostat housing is by the distributor, it has a large hose going to the radiator on it.

 

I cant remember which of those two spade connectors is the warning light, its one of those spades though, and the other one is for the gauge. If you unplug one and touch it to the engine block then look at the dash you will see either the warning light on or the gauge showing maximum so you'll be able to tell which is which.

[vince 0]

and my advice would be to avoid using WD40 to clean elec contacts but proper contact cleaners...

 

WD40 is not design to clean elec plugs but to lubricate parts...

 

vince

[TaffyTim 6]

Thanks jackherer, will tinker with it tomorrow.

 

good point vince, thanks.

[TaffyTim 6]

Earlier i had the engine switched on and found both senders. To work out which one was shorting i disconnected each, one at a time, expecting the warning lights to go off when i had disconnected the offending wire from its sender.

 

This didnt happen. The warning light stayed on throughout my experiment.

 

Im I wrong in thinking that the lights should have gone out? Any other suggestions welcome.

[Richie-Van-GTi 70 2 Cars]

if there was no change in the lights then it suggests the fault lies with the wire itself earthing elsewhere. When you say water light is the one that looks kind of like a pan lid with wavy lines below it? If it is then its the sensor thats plugged into the top of the expansion tank. As for the stop light and dodgy oil prssure try swapping the wires over on the oil pressure sender and oil pressure switch.

[TaffyTim 6]

My shoddy workmanship was at fault for my last reply.

 

I was pulling the pressure gauge wire off its sender not the warning light.

 

Needless to say when the pressure warning light wire was removed from its sender (with engine running) the stop light, low pressure warning light and water temperature warning lights switched themselves off.

 

I traced the wire through the loom under the inlet manifold over the gearbox to the multiplug and couldnt see any obvious earthing. I then traced it from the multiplug round hte back of the dizzy and engine to the bulkhead and still couldnt see any obvious problems.

 

When reconnected the lights come back on so Ive disconnected it. This does mean both the low pressure warning light and water temperature warning light are not in action now (must be linked in some way).

 

Any thoughts on what to do to have it in working order?

[Richie-Van-GTi 70 2 Cars]

which pressure switch did you undo?? If it was oil then read above reply, if it was water then as long as you dont have stupid pressure in the coolant and its been bled correctly and runs at the right temperature Id not worry about it. Mine went dodgy after a blown gasket, it soon sorted itself though.

[TaffyTim 6]

Richie the oil pressure is good and the gauge acts as it should with the type of oil pump i have (almost full on the gauge when cold and 1/3 of the gauge when fully warmed up) and since the HG has been fixed the water expansion bottle is not getting any excess pressure.

 

The wire i disconnected was the wire which goes from the oil pressure waring sender to the multiplug, disconected at the sender under the inlet manifold.

 

As for not worrying about it, i'd rather have things working than not. I know the gauges will tell me the same thing but Id rather have 2 warnings than 1