Mk1 V6 Tacho Not Working Oil Light Flashing

[chucks4x4]

I've only posted a few times in the past so feel a bit guilty asking for help now.

 

In the past I've managed to stumble through most problems but this ones got me beat.

 

1998 MK1 V6 4X4 Auto.

 

Yesterday while out in the car I lost tacho read out & oil warning light started flashing. I believe this is because of the way the car monitors the oil pressure light warning system, it watches for the second, high pressure pressure switch closing above 2000rpm (takes signal from tacho).

 

I've put it on our Vagcom & shows no faults, engine or instruments, I can read the engine revs so believe the sensor (if it's got one)/wiring to ECU is OK. I took it to a pal's garage for a second opinion he checked on his Snap-On diagnostics again no faults & he had no ideas of the cause.

 

The engine is still running smoothly, no noises. The oil level is spot on & clean (changed ~3months ago), so I'm confident it's not an oil pressure problem. A couple of times while driving steadily the gear changes have been really snappy so believe this may be linked to tacho/engine load ? monitoring.

 

The car has 98K on it & we've owned it since new.

 

Removed battery left for 15+mins reconnected it, switched ignition on & clocks did full scale sweep, so tacho is capable of functioning.

I don't have the facility to drive the instruments from my diagnostics.

 

Any help/ideas gratefully accepted.

 

All the best everyone for 2013.

:38: Chucks

[chucks4x4]

Well just dropped one of my lads in town, found more symptoms, coming back joining local dual carriageway, car had no kick down & felt as if trans was staying in sports mode/low top gear.

 

Contemplating sensors in trans, earth connections etc.

 

Thinking back to driving an old MK3 Cortina the dash lights used to go out & i'd slap the top of the dash to get them back on, so nothing to lose slapped the dash @ about 1 o'clock position above tacho................

 

Low & behold tacho back on oil light out, all systems ok :38:

 

Should of tried the old techniques first.

 

At least I know where the problem lies, must be a connection on the instrument cluster, so see how long it lasts.

 

:D Chucks

[gregers]

:38: :D at least it gives you something to search for.

hopefully someone with more knowledge on these rockets will be able to give more info for you.

[tamlynne2]

Hi Chucks

 

I think this will be your lucky day. I can tell you with 99% surety that your problem is been caused by water in the auto gearbox ECU. I know this as I had the same problem as you.

 

Cheers

Andrew