Glow plugs

[nb maggie]

While sorting out an elactrical fault I noticed that the glwo plus go off when cranking, is this a good or bad idea ?

[Sir Nibble]

They would normally be on when cranking. Did you recieve those brushes ok?

[nb maggie]

They would normally be on when cranking. Did you recieve those brushes ok?

 

Yes thanks. I have updated the thread on the starter with the outcome.

[John Orentas]

It can be done either way, there was a thread a couple of weeks ago one of the Vetus range, the 'heat' position was an extreme left key position so it was most likely that the heating went off when cranking. I would prefer the use of a separate button which will give you the option of heating and cranking simultaneously in very cold conditions.

 

Some Volvo lorry engines with automatic timed starting leave the heaters on for quite a while even after the engine has started, they say to cut down emissions.

[Keeping Up]

It can be done either way, there was a thread a couple of weeks ago one of the Vetus range, the 'heat' position was an extreme left key position so it was most likely that the heating went off when cranking. I would prefer the use of a separate button which will give you the option of heating and cranking simultaneously in very cold conditions.

 

Some Volvo lorry engines with automatic timed starting leave the heaters on for quite a while even after the engine has started, they say to cut down emissions.

On my Perkins the key turns to the left for heating and to the right for starting, so they must be off. The heating position is labelled '12 seconds maximum' but I don't know if that's to protect the plugs or to avoid draining the battery.

 

If it's to protect the plugs, and they would burn out after 13 seconds, I suppose it could be bad for them if you cranked the engine over for 15 seconds - or even for 5 seconds immediately after heating.

 

Or if it's to avoid draining the battery, I suppose it's true that you want as much battery power as possible available when cranking so maybe switching off the plugs would be good.

 

I don't know I'm just guessing

 

Allan

[John Orentas]

Allan.

 

It is really to conserve the life of the heaters, they would be unlikely to burn out but life would be shortened, of course you can give them another 12 seconds if it fails to start. I think it was probably your engine I was thinking about. If the engine is troublesome you can always add a 'heat' button so that you can heat and crank at the same time.

 

Also it is as well to check that all heaters are functioning from time to time.

Edited January 25, 2006 by John Orentas

[DHutch]

In the diesal cars ive seen (my mums had three, and my dad one) the heater comes on for a predetermined time (5secs max) with the key in the "run" possition, then goes off, and which point you hold the key to "start" and crank it over.

 

And towards the end of the montego's life, when it was cold, you used to have to turn the key back a notch, and then onto "run" again to get a 2nd or 3rd heat before it would start.

- Later on it was found 3of the four plugs had gone, so that may not having been the wise.

- Or it may have been why it needed 2/3 heats, we'll never know. (nor care?)

 

 

Daniel

[Noah]

My Kubota is a pig to start when really cold. Heating is done by turning the key to extreme left for 20 seconds before cranking. If I delay cranking for just a second, the glowplugs cool down and starting is more diffucult so I'm going to try John's idea of adding a heater button so that I can keep the plugs glowing until the engine fires.

 

The plugs test OK in situ but I'm going to remove them for cleaning and for a visual check. Judging by the original engine paint, they have not been disturbed in its 15 year life. I'm a little concerned because I've seen glowplugs on a tractor shear off if heavily coked-up. If the worst happens, does this mean a head off job or is it possible to carefully drill out the plug tip and carbon?

 

Noah

[bottle]

My Kubota is a pig to start when really cold. Heating is done by turning the key to extreme left for 20 seconds before cranking. If I delay cranking for just a second, the glowplugs cool down and starting is more diffucult so I'm going to try John's idea of adding a heater button so that I can keep the plugs glowing until the engine fires.

 

The plugs test OK in situ but I'm going to remove them for cleaning and for a visual check. Judging by the original engine paint, they have not been disturbed in its 15 year life. I'm a little concerned because I've seen glowplugs on a tractor shear off if heavily coked-up. If the worst happens, does this mean a head off job or is it possible to carefully drill out the plug tip and carbon?

 

Noah

 

Noah

 

Just a little tip that you may already know (this also applies to any bolt or nut that you wish to loosen), clean around it then tighten it. Not overly.

 

This clears the thread so that it does not drag in the muck and so make it seize.

[John Orentas]

Hi Noah.

 

I have just replaced a faulty plug on my friends Kubota, the engine has been a pig to start from new, even now one cylinder (of three) misfires for a minute or two but always kicks in.

 

The dud one unusually shorted to earth making a real mess of the wiring, the builder hadn't fused the circuit, we also had problem finding a replacement and ended up with one for a Perkins. The heaters are on a 'stiff thread' a box spanner I think 11mm is the best tool, ours came out quite easilly.

 

As you say the apertures can be cleaned out with a drill (trial and error for size) but hold it in a tap wrench or similar. One of those jobs, I anticipated a couple of hours it took ten minutes.

[Supermalc]

With diesel cars, the heaters are on a timer, but the light is on a separate timer. Turn the ignition on, watch the light go out, and then listen, and in a short while you will probably hear the click of the solenoid. Also the light will most likely stay on longer when cold, or a frosty day than hot.

 

My first old worn out van required several heats, even with a warm engine. On a cold day it was like me, it did't start. By the time you'd heated it several times, the battery was so low it would not turn the engine over fast enough to start. I didn't buy a worn out diesel if I had to rely on it starting.

 

Many people try when the light goes out. How many do you hear grinding away on the starter. If they simply switched on and off a time or two, most engines, even worn ones will start almost instantly.

[Keeping Up]

As you say the apertures can be cleaned out with a drill (trial and error for size) but hold it in a tap wrench or similar. One of those jobs, I anticipated a couple of hours it took ten minutes.

Are the heaters in 'blind' holes so that the muck collects in the bottom of the hole, or do they project right through the cylinder head so that it falls inside?

Edited January 26, 2006 by Keeping Up

[John Orentas]

Are the heaters in 'blind' holes so that the muck collects in the bottom of the hole, or do they project right through the cylinder head so that it falls inside?

 

 

The heater holes go through into the combustion chambers, just clean out a little deeper than the lengths of the heaters, any carbon that falls through into the engine will be blown out as soon as the engine fires up.

[Noah]

I'll put getting the plugs out on my to-do list (which never seems to get any shorter) as well as fitting an inline fuse. If one plug is suspect I'll replace all four, only about 20 quid.

 

Noah

[Bones]

I'll put getting the plugs out on my to-do list (which never seems to get any shorter) as well as fitting an inline fuse. If one plug is suspect I'll replace all four, only about 20 quid.

 

Noah

 

hey Noah - you're back. Hows it going?

[John Orentas]

I'll put getting the plugs out on my to-do list (which never seems to get any shorter) as well as fitting an inline fuse. If one plug is suspect I'll replace all four, only about 20 quid.

 

 

 

Noah

 

Check the price before you commit yourself I don't know why that Kubota was different but they cost £30 each and weren't even the right ones. It was the entire engine electrical system that was unfused.

[hnb2907]

While sorting out an elactrical fault I noticed that the glwo plus go off when cranking, is this a good or bad idea ?

 

My Shire 800 only energises the plugs during cranking, and on a cold day it can take a lonnnng time on the starter to get it running... Had thought about wiring them through a relay and changing the keyswitch so that they can be pre-heated.

 

 

Chris.

[Noah]

30 quid EACH! I'll check each one carefully then, John. I was assuming that I could obtain aftermarket glowplugs cheaper than original Kubota. I'll also be looking for an engine fuse because I've never noticed one (typical electrician!)

 

Noah

[Keeping Up]

30 quid EACH! I'll check each one carefully then, John. I was assuming that I could obtain aftermarket glowplugs cheaper than original Kubota. I'll also be looking for an engine fuse because I've never noticed one (typical electrician!)

 

Noah

I've often wondered how much current they should take (and therefore what the fuse should be)

[John Orentas]

I've often wondered how much current they should take (and therefore what the fuse should be)

 

 

Easiest way to test them is to disconect all but one and see if it registers on the ammeter, do all in turn. The sort of thing that either work or they don't. They can take 8 amps or more each so including other things you need a big fuse.

[Keeping Up]

Easiest way to test them is to disconect all but one and see if it registers on the ammeter, do all in turn. The sort of thing that either work or they don't. They can take 8 amps or more each so including other things you need a big fuse.

Thanks John. That's the test I'd been planning to do, but wasn't quite sure if it was OK as my meter goes up to 10A and has an internal 30A fuse that I didn't want to blow. So I think I'll try it and see, might explain why it's been more difficult to start this winter than in porevious years.

[DHutch]

I should be able to handle 8A then.

- But you can always replace the fuse... (ive gone thought a few in my meter)

 

 

Daniel

[Keeping Up]

I should be able to handle 8A then.

- But you can always replace the fuse... (ive gone thought a few in my meter)

Daniel

Checked them this morning. They each take 13 Amps at first, dropping to 10 Amps as they warm up so they didn't blow the fuse, and my cheap digital meter seemed happy enough to read 13 Amps - all the other ranges go up to 1999 so I assume the 10Amp limit is just a thermal one and something would have cooked if I'd kept it at 13 Amps for a long time.

 

Or at least 3 of them do. The other one doesn't do anything at all - so the difficult starting is explained, now all I've got to do is change out the dead one.

 

Hooray, now I know that all 4 should settle at 40 amps, I can check if all are working by just reading the domestic panel ammeter while holding a temporary wire to them from the domestic supply .

 

Allan

[John Orentas]

Hi Allan.

 

I had in mind simply observing the ammeter on your boat if you have one fitted, you would of course need to separate them to check individually but you seem to have sorted the problem. Simply testing each one on continuity is as good a method as any. My horror story of the price is a bit an exception I think, the engine I was working on is a bit of an odd-ball most people mentioned a price of less than £9 each for common types.

[Keeping Up]

Hi Allan.

 

I had in mind simply observing the ammeter on your boat if you have one fitted, you would of course need to separate them to check individually but you seem to have sorted the problem. Simply testing each one on continuity is as good a method as any. My horror story of the price is a bit an exception I think, the engine I was working on is a bit of an odd-ball most people mentioned a price of less than £9 each for common types.

Just a couple of snags - the ammeter is in the domestic circuit only, and the four plugs are connected together not by a flexible wire but instead by a rigid metal bar that screws to all 4. So the only way was to disconnect the lot and test them individually with a meter.

 

Anyway, all is now tested; I think the new one may be pricy (there's a place on eBay selling them at £21 for example). Still, I can take my time over it, it fires up on 3 OK after a bit of steady churning and the fourth kicks in fairly quickly.