Frost warning light

[anonymous-user]

I know we're not having the best of summers....but the yellow/red ice warning light in he centre of the dash is flickering on intermittently pretty much at all temps/all speeds...more when cold or at low speeds. Also getting a dead rev counter on immediate start-up, but that works fine after a minute or two.

Any ideas on the cold weather warning light?? Is it linked to rev counter in any way??

Thanks in advance....
S

[ukkid35]

Hi Steve, you could try cleaning the earth connections that we were looking at last week, and any others you can find as well. That might be the cause of the sleepy tacho. As for the Frost Warning, let me know how you fix that as mine was on permanently.

[Tanguero]

Probably a corroded wire on the sensor. It is just inside the lower front opening and tends to get wet and cruddy.

[anonymous-user]

Tanguero said:

Probably a corroded wire on the sensor. It is just inside the lower front opening and tends to get wet and cruddy.

Thanks mate, will have a hunt around the front...I guess you mean the large centre section under the main air intake/number plate....more likely to be dead flies than rain...only been brave enough to go in rain once so far!!

[V8 GRF]

djstevec said:

I know we're not having the best of summers....but the yellow/red ice warning light in he centre of the dash is flickering on intermittently pretty much at all temps/all speeds...more when cold or at low speeds. Also getting a dead rev counter on immediate start-up, but that works fine after a minute or two.

Any ideas on the cold weather warning light?? Is it linked to rev counter in any way??

Thanks in advance....
S

The two are unconnected. If a frost sensor light is on it means the thermistor has corroded away and/or failed. either replace the sensor or just cut it off and twist the bare wires together to put the light out. You'll find it just hanging in the nearside (passenger) side of the car.

[anonymous-user]

V8 GRF said:

The two are unconnected. If a frost sensor light is on it means the thermistor has corroded away and/or failed. either replace the sensor or just cut it off and twist the bare wires together to put the light out. You'll find it just hanging in the nearside (passenger) side of the car.

I shall go looking for dangling bits round the front end tonight....

[Tanguero]

djstevec said:

Tanguero said:

Probably a corroded wire on the sensor. It is just inside the lower front opening and tends to get wet and cruddy.

Thanks mate, will have a hunt around the front...I guess you mean the large centre section under the main air intake/number plate....more likely to be dead flies than rain...only been brave enough to go in rain once so far!!

Yes - mine was cable-tied to one of the horn brackets in that section below the numberplate. I had to take the numberplate off to get my hand in.

[robsco]

Tanguero, is the sensor for the rev counter and fuel gauge located in a similar place? Mine, like the OP's, can take up to five minutes to get going in a morning. More of an inconvenience than a serious issue, but it might be worth having a clean up in there.

[Tanguero]

The crank position sensor which the ECU uses to generate the rev counter signal is at the back of the engine block by the bellhousing on the drivers side. If its dud, the car isn't likely to be running so I think it unlikely that would have anything to do with your rev counter being slow to start working.

The fuel tank sender is on the top of the fuel tank in the boot so not in the same area either.

I would be checking the connections to the instrument panel rather than suspecting the signal to the rev counter. You could check for a signal directly but would really need an oscilloscope to do so.

[anonymous-user]

Hmmm....like a cold maybe something is spreading...

On a quick run out tonight, the rear screen heater and AC were on without my pressing of any button at all...and took an age to turn off the rear screen heater...frost/ice warning light still flickering green/amber/red too.

Anyone have any ideas??

Thanks in advance,
S

[BCA]

Just seen this... I suspect is is all linked. Have a look at the big fuse first.

IIRC the rear screen heater cannot be turned off once it is on, it'll go off when you switch off or when it is fully heated? Or atleast that is how I remember it?

[robsco]

The rear heated screen stays on for 6 minutes, and can't be turned off.

[anonymous-user]

robsco said:

The rear heated screen stays on for 6 minutes, and can't be turned off.

The things you learn....didn't see that in the manual...or having a Stevie Wonder moment.

Can I ask opinions to if the following oil pressure prob is also related to big fuse or oil pressure relief spring (or both)....

Started her up fine on Thursday eve for a quick run out, got out of garage fine, literally 10m down the road pressure went to zero and oil light on. Brown trouser time. Pulled over and engine off immediately.

Got her back into the garage and checked all round, no leaks, no obvious signs of any failure, oil level as it was before start-up. Started her up again after 5 mins or so and this time all fine, pressure back up to 47/48psi. Left her running to warm up a little and again all fine. Thought Id take her for her run out as all looked ok.....naturally I was driving more looking at the gauge than the road!!

Took her on my usual 25-30miles or so evening run out, didnt push hard at all, except for one occasion when heading back home and a little more confident that the pressure was stable, went upto 60-65psi when pushing on, all good.

But got to set of traffic lights near home and pressure went to zero again and oil light on, pulled over asap at minimum revs, switched off and again looked all round, underneath and again all looked fine.

Mulled getting the AA out, but started her again after a few minutes and pressure was still zero....as I was so close to home, thought I'd risk limping back on min revs as I wasn't convinced it was an actual oil pressure problem.....( I know I will get lots of replies saying that's exactly what I shouldn't have done) got a couple of hundred metres further down road and pressure jumped back up to normal again and was fine for the 2-3 minutes back home.

Started her up yesterday after checking oil level again, all fine, pressure upto normal 47/48psi on start up, held revs at 1,500 for minute or so to get everything moving and warming and all sounding looking good. No "mayo" on the dipstick or oil in the header tank, so happy(ish) its not a obvious head gasket prob.

I couldn't hear any appreciable increase in noise or any grinding or anything different to a normal cold start up. So I'm thinking either the capillary tube has a problem, or the pressure relief spring has had it/on its way out, or is it maybe related to the other electrical problems above.

I'm going to change the relief spring first and do the big fuse, see if that cures it. And she deff has plenty of oil in her, I check water/oil before any drive (as Im paranoid!) and according to BCA the natural oil level for her should be halfway between halfway and max...and thats exactly where it was on pre-drive check.

The only thing I can think of that I did which didn't feel normal when I took her out on Thursday eve, was when I replaced the dipstick it didn't seat right first time, so took out and put back in, and it just felt a little awkward to get back in....if the dipstick isn't seated right can pressure escape via the dipstick tube?? Looking on the forum over the weekend, most oil pressure issues either revolve around the relief spring or big fuse.

Any further ideas apart from the obvious....?

[C3BER]

The dreaded dip stick.

There must be a hundred answers on oil pressure and dip stick readings. For some reason you can re fill an empty engine on two cars and you will get a different reading on the stick.

I think your low on oil as 40 odd at idle is low when cold. It should be in the 60s then drop into the 40s when hot.

[anonymous-user]

C3BER said:

The dreaded dip stick.

There must be a hundred answers on oil pressure and dip stick readings. For some reason you can re fill an empty engine on two cars and you will get a different reading on the stick.

I think your low on oil as 40 odd at idle is low when cold. It should be in the 60s then drop into the 40s when hot.

Yeah the search function brings up a lot of relief spring/big fuse related issues, so they are going to the first things changed.

The "natural" oil level and pressure from my cerb's previous owner (BCA) are 50psi on cold start up, 40 at hot idle, 60-65 when pushing here....after an oil change due to a re-threading of the sump bolt, the pressure have been a touch lower than that...but she's still consistently giving me those numbers. Oil level should be halfway between halfway and full on the stick...again oil level bang on that...anymore and she spits it out of the breather tank. I agree they all differ from car to car, but mines pretty much where she should be, except those two strange occasions above.

[C3BER]

Should be 60ish on cold start but each one can be different. If it's blowing oil then the spring seems a possible fault. I think I can recall Gaz having one that was snapped but still worked.

[Tanguero]

If both the pressure gauge and the oil light say no pressure then believe them! They work off different sensors so the chance of them both being misleading is small.

Intermittent loss of oil pressure could be pressure relief spring broken, partly clogged capillary, something blocking oil pump pick-up or a slipping woodruff key in the oil pump drive shaft to name just a few. I am sure there will be other suggestions along shortly.

[BCA]

Tanguero said:

If both the pressure gauge and the oil light say no pressure then believe them! They work off different sensors so the chance of them both being misleading is small.

Intermittent loss of oil pressure could be pressure relief spring broken, partly clogged capillary, something blocking oil pump pick-up or a slipping woodruff key in the oil pump drive shaft to name just a few. I am sure there will be other suggestions along shortly.

I didnt realise they were off two different sensors, I thought the dash was just going nuts... in that case, I think it may be time to give APM a call and see what he recommends/ can sort. Hopefully it'll be something small, simple and cheap.

Not yet spoken to Dad about the frost sensor stuff, but I still think it may be big fuse related.

[Tanguero]

The oil warning light is driven by the pressure switch down in the V underneath the rear coil pack, and the gauge is fed by a capillary direct from the engine, so if they both say there is no pressure then switch off sharpish and don't try to run it until the problem is resolved! Running with no oil pressure will kill an engine very quickly indeed!

The big fuse is only in the charging circuit directly between the alternator and battery. If its flaky it seems to affect the rev counter as the battery voltage starts to fail but it definitely won't affect the oil pressure gauge as that is mechanical.

[anonymous-user]

well "big fuse" and pressure relief spring changed. Bit fiddly to get the bolt out/in due to a couple of small copper tubes in the way...pretty sure didnt bugger them up! Just out of interest what are they for?

Did do a visual side by side check and the old spring was perhaps a tiny bit shorter.

Pressure on cold start about 10psi higher at just under 60! Yay! Also sounded a little quieter too on the cold start.