Home > Puma (Tdci) > Swapping Glow Plugs |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6298 |
Not got round to testing them yet (a job for the weekend) but I got wondering and did a search but couldn't find anything.
anyone here replaced their glow plugs on a Puma? I understand they can be a pig to get out? - also once the engine is up and running how much effect do they have on the running of the engine (if any)? |
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15th Jan 2016 1:19pm |
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Mash Member Since: 09 Feb 2015 Location: Guernsey Posts: 1674 |
All glow plugs do is preheat the air in the combustion chamber prior to starting, once the light goes out on the dash they have stopped working. 90 wolf - Jasmin http://www.defender2.net/forum/topic39408.html
90 V8 - Maggie http://www.defender2.net/forum/topic42564.html 110 TD5 - Buggsy http://www.defender2.net/forum/topic59029.html 52HG25 lightweight https://www.defender2.net/forum/topic72342.html D3 Hse - Fiona Capri 2l S - Anna Think I might have a problem............ |
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15th Jan 2016 4:26pm |
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scotty38 Member Since: 21 May 2011 Location: Lincolnshire Posts: 571 |
Good lord, what's wrong with it now?
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15th Jan 2016 4:46pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6298 |
smoke and rough on start up. Suspect a dodgy glow plug. Will test them when it stops raining the w/e. |
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15th Jan 2016 6:58pm |
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Retroanaconda Member Since: 04 Jan 2012 Location: Scotland Posts: 2642 |
In a lot of cars the plugs are on for a short while after starting to aid combustion while the cylinder is cold. The light going out is the signal to the driver to start the engine, not the indication that the plugs have shut off.
On mine if you turn the ignition on and just wait the light goes out after a few seconds (where you would normally start it) and then a short while later you can hear the click as the plugs are turned off. |
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15th Jan 2016 10:20pm |
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Supacat Member Since: 16 Oct 2012 Location: West Yorkshire Posts: 11018 |
Not correct. They operate for 3 separate tasks: 1. Cold start 2. After glow 3. DPF active regeneration |
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15th Jan 2016 10:33pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6298 |
Thank you.
What's after glow? Does this aid combustion during normal running. Ie are the plugs assisting all the time? |
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16th Jan 2016 6:22am |
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Cupboard Member Since: 21 Mar 2014 Location: Suffolk Posts: 2971 |
The plugs aren't going all the time, but they run at a reduced voltage for a bit once the engine has started and is still cold.
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16th Jan 2016 9:34am |
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Supacat Member Since: 16 Oct 2012 Location: West Yorkshire Posts: 11018 |
Glow plug facts from the MY12 Workshop manual :
"The glow plugs are a low voltage metallic type that operate at a maximum tip temperature of 1050 °C (1922 °F), achievable within 2 seconds." "The ECM (engine control module) uses the signal from the ECT (engine coolant temperature) sensor to determine the preheat time. The lower the temperature, the longer the preheat time. There is a maximum preheat time of 2.1 seconds at -20 °C (-4 °F) or lower. At temperatures above 20 °C (68 °F) there is no preheat phase." "Once the engine has started, if the engine temperature is less than 70 °C (158 °F) the glow plug system enters an afterglow phase. The after-glow phase lasts for a maximum of 500 seconds, or until the engine temperature reaches 70 °C (158 °F). The tip temperature of the glow plugs is reduced as the engine warms up. The ECM uses a glow plug control map of engine speed against load to determine the optimum tip temperature during the after-glow phase. At high engine loads the after-glow phase is interrupted to protect the glow plugs and improve their durability." or a potentially contradictory statement: "After-glow is designed to function at engine temperatures below 50°C (122°F), below 2,500 rpm and for a maximum of 30 seconds after engine starting." "During the active regeneration process the following ECM controlled events occur: The glow plugs are occasionally activated for up to 40 seconds to provide additional heat to assist in raising the DPF temperature." I believe that the glow plugs active indicator (the amber light in the instrument cluster) only illuminates for the pre-heat function due to the the ignition switch being turned to position II. |
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16th Jan 2016 11:43am |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6298 |
Anyone here them over....i hear lot of horror stories? |
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16th Jan 2016 12:15pm |
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Mash Member Since: 09 Feb 2015 Location: Guernsey Posts: 1674 |
How times have changed, and there was me using my 80's diesel tech knowledge, always glad to learn 90 wolf - Jasmin http://www.defender2.net/forum/topic39408.html
90 V8 - Maggie http://www.defender2.net/forum/topic42564.html 110 TD5 - Buggsy http://www.defender2.net/forum/topic59029.html 52HG25 lightweight https://www.defender2.net/forum/topic72342.html D3 Hse - Fiona Capri 2l S - Anna Think I might have a problem............ |
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16th Jan 2016 12:36pm |
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Supacat Member Since: 16 Oct 2012 Location: West Yorkshire Posts: 11018 |
They certainly have - not necessarily for the better.
I was surprised most by the maximum time they operate on cold start - 2.1 seconds. On some previous vehicles I had to do double doses of 10 seconds to get the old girl to fire up smoothly! |
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16th Jan 2016 2:09pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6298 |
thought I'd just 'pop' out and check the glow plugs, small socket set, multi-meter and 10 minutes should do. F ' in aida - I think I might need to set a day aside in the summer. I'm guessing the only chance of doing that is inlet manifold off? with the chance of snapping a glow plug off I'm wondering if installing a webasto type diesel heater might be easier and do away with the need for glow plugs plus all the other benefits.....and if a plug does snap off could prove cheaper overall? |
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16th Jan 2016 4:09pm |
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Supacat Member Since: 16 Oct 2012 Location: West Yorkshire Posts: 11018 |
Wouldn't it be easier to just use a scan tool and read any diagnostic trouble codes and see if they are associated with the glow plugs?
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17th Jan 2016 10:26am |
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