Overheating

Post by **Dryad** » Thu Aug 04, 2005 3:06 pm

I have a '68 Minor 1000, and as I've only owned it for 5 months (my first moggie!) I don't know whether it's normal or not; the orange warning light on the left of the speedometer comes on after the engine has been running for about ten minutes. This only started in late Spring, when the weather started to get warmer - coincidence?

My first thought was that the thermostat was sticking, so I went to replace it only to find that it was missing its thermostat anyway. After putting one in (82deg) nothing changed - the light still came on after the same amount of time.

My second thought was that the radiator needed flushing, which I did last night (thoroughly - with radiator flushing liquid!) but still no change.

It's not using up water, and there's no water in the oil or vice-versa.

Also, although not necessarily connected, I replaced the cable operated heater valve with a brand new one (the old one being permanently stuck in the 'on' position), but it seems to make no difference whatsoever, and in this weather the last thing I want is the heater on! And at £20 for the new valve I'm not at all pleased.

Any ideas?

Post by **ColinP** » Thu Aug 04, 2005 3:58 pm

Hi,

I'm quite sure that the orange light is the oil filter warning light.

When did the oil & filter last get changed? It may be just as simple as changing the filter. You can change the filter without draining the engine oil, but that's not really worth doing.

Check the oil with the dipstick (looking for correct quantity and the condition of the oil - should be between the MIN & MAX marks, as well as light brown).

On my '66 1098cc Mogie, the oil pressure warning light is on the right side of the speedo, but I'm not sure if that's the same for all the cars - I think (and an expert will be along soon) to tell us!

If it's the oil pressure warning light, then ther4e's not enough oil pressure. Either the oil is low (see dipstick), or it's too thin (use 20W/50 or 15W/40 - good quality one like Castrol, Duckhams, Miller), or you have worn bearings etc...

Unfortunately all the work with the cooling system doesn't have much influence on the oil system.
(Mind you, it needed doing). Do you still have problems with the heating/cooling? If you do, it will be simpler to start another thread - that way we won't get too confused with the messages.

All the best,

Colin

ps where are you? - (edit your Sig)

Post by **Dryad** » Thu Aug 04, 2005 4:13 pm

It's definitely not the oil light, as that is the orange one on the the right, above the red ignition light and comes on just before I start the engine and goes off a second or so after the engine has started, just as it should. The light I assume to be a temperature warning light slowly comes up from being off, to a dim glow, and then after ten minutes it is bright enough to see easily.

Besides, I changed the oil and filter the day after I bought the car (2600 miles since) and the oil level is nearer the high mark on the dipstick.

One thing I forgot to say in my last post is that the very first thing I did when I noticed the light was to replace the radiator cap, as it was spewing out a little water, but not much. The rubber washer was quite worn. With the new cap it doesn't seem to be doing it any more.

I'm now wondering whether the temperature sender unit is faulty....

(I'm in Norfolk - Norwich to be precise.)

Post by **Pyoor_Kate** » Thu Aug 04, 2005 4:30 pm

As far as I'm aware the mog never had a temperature warning light - but that orange light was used as an oil filter change warning light. Unless someone's added temperature sensor - which is a possibility, there is a hole for it - and used the (often unused) light that was previously the oil filter change light.

If it is the oil filter change light I'd check the oil filter's all seated happily and that nothing unfortunate has happened to it; and if it is I'd suspect that the filter change sensor's nadgered.

Post by **Cam** » Thu Aug 04, 2005 4:35 pm

A '68 Minor should have 2 orange lights, one for low oil pressure and one for a blocked oil filter. As Colin says, check your oil filter. It's possible that it has been assembled incorrectly when refitting.

The Minor does not have a temperature warning light at all so it's nothing to do with your cooling system. Get a handbook for your car and it will tell you in there. If it's an orange light then it's oil or oil filter related!

Of course if could be a dodgy oil pressure sender unit that is going faulty when hot...

If you fill the radiator up to the top then a little water will 'spew' out as the correct level is about 3/4 to an inch below the filler neck.

Unless you have a temperature gauge then you probably don't have a temperature sender! The car did not have one originally but it DID have an oil pressure sender AND an oil filter blocked light.

Post by **Dryad** » Thu Aug 04, 2005 4:42 pm

Ah! This sounds like it makes sense. My Moggie has had a reconditioned engine, and has had the spin-on oil filter mod. There is also a temperature sender plug just below the thermostat housing which has a wire attached, so this is probably what's happened.

I've had several cars in the past with A or A+ series engines (Mini, Marina, Ital, Allegro), so I'm used to seeing the temp plug with a wire attached and thought this was completely normal. Seems that I've just revealed my Newbie-to-Moggies status!

Does this mean I can disregard the orange warning light?! The engine appears to be running absolutely fine.

Thanks!

Post by **Dryad** » Thu Aug 04, 2005 4:48 pm

Just seen your post, Cam. I replaced the oil pressure sender about 6 weeks ago because the oil pressure light never came on at all. Now it comes on when I turn the ignition on and goes off a second or two after it starts.

Where would the oil filter senser nomally be?

Post by **Cam** » Thu Aug 04, 2005 4:53 pm

Right! We're getting somewhere now! I think (as Kate said) you have the oil filter sensor wire connected to your temperature sender! Disconnect it and the problem should disappear!

The oil filter sensor is part of the oil filter housing so if your car has the spin-on conversion then it won't have one.

Post by **Dryad** » Thu Aug 04, 2005 4:58 pm

Thanks all! I'm very relieved - it's a bit unnerving driving along and seeing a warning light on! I shall remove the wire from the temp sender tonight and stop worrying.

What an excellent forum this is! Thanks!

Post by **bigginger** » Thu Aug 04, 2005 5:01 pm

The one on the left of my speedo was lighting up, ('69) and was cured by filling up the oil - if that's any help...

Post by **rayofleamington** » Thu Aug 04, 2005 5:21 pm

Does this mean I can disregard the orange warning light?! The engine appears to be running absolutely fine.

I would wait until the light is on - then disconect the wire from the temperature sender. If the light goes out, then you 100% know not to wory about it any more.

The 'oil filter blocked' sensor was on the original filter housing. People often go for the spin-on oil filter kit without thinking too deeply.
Personally I'd find an original oil filter housing (with the sensor) and convert it back. The oil filter element isn't hard to work with if you have a very basic mechanical ability.

Post by **Onne** » Thu Aug 04, 2005 9:16 pm

I still think it is a rotter of a job changing the oil on a Minor. It never works first time, down to either badly ftiing rubbers, or dried out ones. It's a good hours work on the mog, where as on the toyota it only takes 15 minutes, most time for the leaking out!

Post by **NZJLY** » Fri Aug 05, 2005 10:37 am

Onne, if you fit a mini oil filter, then you can use a spin on filter. Just make sure that you get the studs that go into the block as they are much shorter than the minor ones.
Dryad, if it is the wire from the temp gauge, then fitting a temp gauge instead of just disconnecting would be wise.

Post by **ColinP** » Fri Aug 05, 2005 10:44 am

I know that we all have different views on oil filters (which is why there are the kits!).

My experience is that the oil change is easy (leave it to drain while I do the plugs/points/rocker clearances.

The filter's quite straightforward - mind you I don't change the sealing rings very often. They seem to last for ages (even though I get a new one each time - anyone need a spare?).

It is woth rotating the filter housing as you tighten the nut - that allows it to seat more easily. Also, don't overtighten it!

Colin

Post by **Cam** » Fri Aug 05, 2005 11:46 am

NZJLY wrote:Dryad, if it is the wire from the temp gauge, then fitting a temp gauge instead of just disconnecting would be wise.

It will be the wire from the oil filter switch that has been used and connected to the temp sender.

If you wish to connect a temp gauge then run a wire from the regulator on the back of the speedo to the gauge, then take a fresh wire from the gauge to the sender unit on the cylinder head. If you don't do this then the temp gauge will not read properly as it won't be getting a regulated feed.

Post by **Dryad** » Fri Aug 05, 2005 12:55 pm

It was definitely the oil filter light which was connected to the temp sender. It stays off now.

Anyone got any ideas why the brand new cable-operated heater valve I bought from DSN Classics doesn't seem to work?

Post by **Cam** » Fri Aug 05, 2005 1:31 pm

You mean it's not shutting the water off to the heater matrix? Have you felt the hoses near the matrix while the car is up to temperature?

If you are convinced that the valve is faulty then contact DSN classics!

Post by **Dryad** » Fri Aug 05, 2005 2:05 pm

Yes, heat is still coming from the outlet of the heater matrix when the control knob is pulled out, just as it does when it's pushed in. I've not felt the hoses yet, but will try it later.

Post by **simmitc** » Fri Aug 05, 2005 2:53 pm

Also double check that the cable (both inner & outer) is attached properly at both the valve and the knob. With the knob puhed in, the lever on the valve should be right out (towards left hand side of car) with the knob pulled out the lever should be hard against the valve body. If the cables is loose or borken then it might not be moving the lever; hence no change in heater setting.

Post by **ColinP** » Fri Aug 05, 2005 3:36 pm

Might also be worth checking whether there is anything preventing the valve from closing (grot in the way).

- I've tried to write this carfully - but I'm having problems so please be gentle...

How far does your knob ... (no, next try)

The heater control pulls out, do you have the full movement there? (Mine's about 4 inches )

Lastly, check out Cam's links to photos and check all the pipework goes where it should... (recon engine swop).

All the best,

Colin