Disco 3 (LR3) Glow plugs

Can anyone tell me if it’s ok to leave the old glow plugs in rather than replace them? The engine is a 2.7 diesel with 176 k on the clock. Runs like a new engine, when garaged starts first time, sweet and tight just had belts replaced etc. Thinking about using a controller with the FBH to help warming rather than change plugs, which can cause big problems with the heads. My LR specialist recommends I just leave them as it’s not cost effective to remove heads. Thanks!

The glow plugs are not just for cold start... they have the post-heat operation after the engine was started to reduce carbon deposits... at least ask your ''specialist" to check them in situ cos that's easy, only a multimeter is needed

Glow plugs are used for cold starting, and emission reduction once started. If you pre-heat the engine, then there's no need to replace them. The engine will start if the plugs are duff, but it'll just need cranking more than normal. Large industrial diesel engines don't normally have glow plugs. Then engine is just cranked over until it starts.
YouTube class 37 locomotive cold start, for some really interesting cold cranking to start a heavy diesel.

Yes that's fine it's common practise in the D3 world

Brilliant help from all three of you cheers. I didn’t know that big diesels don’t have glow plugs. It looks like garaging in winter is all I need to do. I will check the plugs supply in situ though. Thanks all

Stradreagh said:

Brilliant help from all three of you cheers. I didn’t know that big diesels don’t have glow plugs. It looks like garaging in winter is all I need to do. I will check the plugs supply in situ though. Thanks all

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If you google Discovery temperature sensor bypass/resisitor, you will find some peope have tried a few tricks to get around duff glow plugs.
1 is to pour hot water on the coolant temp sensor, which is right at the front of the engine , so easy to get at.
2 is to fit a resistor into the coolant temp sensor wiring with a switch for cold starts
3 or do as you suggest, the fbh mod, you need the webasto oval timer, or the controller that is driven off of the D3 third fob button

Big diesels can have glow plugs, if specced for cold conditions

Lynall thanks for this. I did find these fixes on other forums and I’m working on ways to start FBH before engine start. Trouble is at the moment my FBH is not running. Tried fuse so far seems to be getting power. Not looking forward to a full overhaul. Thought I might use the Webasto software to troubleshoot.

Stradreagh said:

Lynall thanks for this. I did find these fixes on other forums and I’m working on ways to start FBH before engine start. Trouble is at the moment my FBH is not running. Tried fuse so far seems to be getting power. Not looking forward to a full overhaul. Thought I might use the Webasto software to troubleshoot.

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If you can clear the fbh codes, I bet it will start.
I bought an icarsoft for my D3, and it cleared the fbh codes, and it has ran just fine for the last 5 years, best 100 quid spent.

Iitc the fbh will start with the engine running, if the external temp is below 7 degc.

Thanks I have seen this on eBay will give it a go. The reason I mentioned the Webasto software is it does the same job for free. You just need a KKL adapter to connect a laptop to the loom. Have you heard any reports about this?

Just checking the icarsoft you have is that the i930? It’s the smaller one around 5 inches by 2 not the larger laptop version which has rubber grips each side?