Any one know how easy it is to change the glow plugs on the bkd engine?

I think it's fairly easy. Cam cover off though so order a gasket first. No point using the old one. I think it's a 10mm long reach socket just unthread them. What's the issue though?

Its takeing a lot longer to start when the engine is cold. I know theres a fault code for all 4 plugs but I cant remember what it is! :/

All 4 plugs won't be faulty. So its more than likely a wiring problem. The diesels only use the glow plugs below a certain temperature and i don't think it's low enough as yet but i can't remember what the temperature is. Mine is doing the same at the moment. 3 attempts to start from cold and lumpy idle for 10 to 20 seconds before clearing. Injectors or coolant temperature sensor is my thoughts right now.

All 4 plugs won't be faulty. So its more than likely a wiring problem. The diesels only use the glow plugs below a certain temperature and i don't think it's low enough as yet but i can't remember what the temperature is. Mine is doing the same at the moment. 3 attempts to start from cold and lumpy idle for 10 to 20 seconds before clearing. Injectors or coolant temperature sensor is my thoughts right now.

 

mine were...

 

If you have a mulitmeter test them - resistance should be about 3ohms each (max about 5 to 7) between connector pin and engine block.

mine were...

 

If you have a mulitmeter test them - resistance should be about 3ohms each (max about 5 to 7) between connector pin and engine block.

Don't forget to zero your meter leads or take away their resistance. I know the fused leads we use at work are 2.5 ohms 

Edited 9 November, 20169 yr by SuperbTWM

mine were...

If you have a mulitmeter test them - resistance should be about 3ohms each (max about 5 to 7) between connector pin and engine block.

All 4 at the same time? Don't think I've ever heard that before.

The Haynes manual says:

Test battery voltage. Should be at least 11.5 volts. Disconnect wiring plug from coolant temperature sender. This will simulate a cold engine which is a requirement for the glow plug system to work.

Disconnect a plug from most convenient plug and connect voltmeter between wiring and good earth.

Switch on ignition. Battery voltage should be displayed for approx 20 seconds. Voltage will drop to zero when pre to post heating periods end.

If no supply is detected at plug, either glow plug relay is faulty or or wiring. Also check glow plug fuse.

To locate a faulty plug, disconnect battery. Disconnect wiring plug from glow plug terminal. Measure electrical resistance between glow plug terminal and engine earth. Ceramic plugs should have a resistance of no more than 1ohm and metal glow plugs more than a few ohms indicates defective plug.

If a suitable ammeter is available, connect it between glow plug and it's wiring connector, then measure steady state current consumption. ( Initial current surge will be 50% higher ) As a guide, high current consumption ( Or no draw ) indicates a faulty plug.

Final check remove plugs, inspect the stems for signs of damage. Badly burned or charred stem may be an indication of a faulty fuel injector.

Well they probably all went at different times over an extended period but the issue only became notable once all 4 were dead. Three very much so and one borderline judging by the resistances.

Fault codes indicated all 4 were shot and came back after clearing so I checked the resistances and then had them changed. Cleared the fault codes again and all is now spot on.

Well they probably all went at different times over an extended period but the issue only became notable once all 4 were dead. Three very much so and one borderline judging by the resistances.

Fault codes indicated all 4 were shot and came back after clearing so I checked the resistances and then had them changed. Cleared the fault codes again and all is now spot on.

Ok. So any other symptoms other than poor cold start? Any lumpy idles at start up or juddering etc?

Not on the Octavia but previous car I had 3 out 4 fail. Tested using jump leads and battery where only one warmed up.

 

If you are changing them do it with a warm engine as they come out easier and less chance of snapping one.

Ok. So any other symptoms other than poor cold start? Any lumpy idles at start up or juddering etc?

poor cold start (but never failed - just took a few turns), intermittently lumpy idle when cold and smokey when cold (I don't have a DPF)

poor cold start (but never failed - just took a few turns), intermittently lumpy idle when cold and smokey when cold (I don't have a DPF)

Sounds like mine too. Lumpy idle only for a few seconds though. Two or three attempts to start and smokey. I also have no dpf. It could be my glow plugs too.

Lumpy idle and poor starting is an issue related to glow plugs. Sime people say to replace just the faulty one. But for the sake of £50 I would change all four. I had a similar issue with my CR170, changed the glow plugs and now it starts fine everytime.

Edited 10 November, 20169 yr by Ecomatt

Usually a derv will start on a single glow plug, as long as it's not too cold.

Due to this, people don't tend to notice until they are all dead, even if it doesn't happen at the same time.

So do the glow plugs heat up everytime the ignition is turned on? I thought i read they only worked below a certain temp i.e middle of winter temp!

They will always heat up on intial start up no matter what the temp is outside. However it all depends on how warm the engine temp is as to how long they continue to heat during the combustion process. That is to help keep emmissions down.

If you watch the glow plug light it goes off real quick in the summer and will take a few seconds on an icy day. They defo glow up every time the ignition goes on!

They do stay on after the dash light goes off as Ecomatt says to help with lowering emissions until the engine starts to warm up. Probably the reason why they don't last as long nowadays as they are actually being used more.

Well they say you learn something every day although at my age it's more like every other day! Some good info chaps I'm now thinking my glow plugs are going/gone. I'll add it to the list.

NGK have a good video on ewetube. For replacement, They recommend a few drops of 5w30 oil onto the top of the threads area, as the plug is slightly recessed the pool of oil will stay there. Drive the car through several heat cycles for 5 to 7 days to allow the oil to penetrate. Most important next step is to use a torque wrench at 16nm (if I remember the setting correctly), and see if the plug will loosen. Applying more than 16nm could/will snap the plug. I have 1 plug gone bad this morning (air temperature was 6C) and she started but sounded like 3 cyl running. No smoke out the tail pipe. Took about 2 minutes to warm up enough before it idled better. After work, air temperature 14C, it started perfectly and I went straight to the auto parts and bought a set of 4 bosch plugs. I've added the drops of oil to my gplugs to soak in for the next 7 days. I'll do a multimeter ohm reading then before removing the old ones. 352,000kms on my 2011 superb cf/gb model engine 174bhp.