Is there a way to test glow plug heating probe?

[VolvoRob38]

Hi all,

Just bought some Bosch glow plugs off ebay for my C30 1.6d 2009 after having a broken tip removed after about 18 months. I have double checked them for continuity just in case I've been sold crap, but all OK....

But was wondering if there was a way to test the heating probe, so actually seeing it glow, before I bother to fit these?? Simply fitting them in the wiring loom and starting the engine doesn't work as I assume they need to be fitted/earthed against the engine block.

Also, running tests with Vida says that the glow plugs are causing a Reduced Engine Performance message to pop up every time I start the engine, so assuming these are all OK, once installed, will the dash message disapear or will I have to use the software to Cancel All messages to clear it?

TIA

[Lancee]

First thing, don't buy glowplugs from Ebay? Don't run an increased risk of another snapped plug or other problem due to a counterfeit item or items?
Others will chime in regarding testing, ground to block/attach 12v battery etc.

[VolvoRob38]

Thanks... To be honest the ones that snappered were the original Beru's so I dont have a lot of faith in any glow plugs... in any diesel. Hopefully these are genuine and last.

If I connect them to the wireing loom, do I need to earth all of them or can I get away with just connecting one to the block, to test?

Thanks

[GrahamBrown1]

I would simply use a spare car battery or similar, ground the plug and apply power to it. It will glow in seconds. I wouldn’t be fitting to the car to test externally. Be extremely careful and allow to cool for a long time afterwards. They get seriously hot extremely quickly. I assume you just want to see them glow for purposes of yes they work. You won’t need them powered up for long.

[VolvoRob38]

Originally Posted by GrahamBrown1

I would simply use a spare car battery or similar, ground the plug and apply power to it. It will glow in seconds. I wouldn’t be fitting to the car to test externally. Be extremely careful and allow to cool for a long time afterwards. They get seriously hot extremely quickly. I assume you just want to see them glow for purposes of yes they work. You won’t need them powered up for long.

Thats exactly it, I simply just want to see them working before fitting, just so I can rule that out if the Reduced Engine Performance message decides to persist.

Unfortunately I dont have a spare battery. Could I use the existing car battery and test them one at a time using jump leads (seems a bit brutal lol) by earthing the black lead on the engine block, or even the negative battery terminal, and clamping the glow plug in the jaws... and then using the red positive lead from the battery and just touch the glow plug to see it glow. Quick on and off?

[dingov70]

Morning , according to Bosch site , correct glowplugs are rated for 11 volts . So using jump leads very briefly should be ok to check they glow . A good plug should begin to glow very quickly and when you put them down ,a mke sure the surace is heat resistant .
Froma long time in the job view , I would not buy from Ebay due to fake products ( not Ebays fault ) . I have found NGK , Bosch Beru all to be quality products

[VolvoRob38]

Originally Posted by dingov70

Morning , according to Bosch site , correct glowplugs are rated for 11 volts . So using jump leads very briefly should be ok to check they glow . A good plug should begin to glow very quickly and when you put them down ,a mke sure the surace is heat resistant .
Froma long time in the job view , I would not buy from Ebay due to fake products ( not Ebays fault ) . I have found NGK , Bosch Beru all to be quality products

Excellent... thanks mate

[Simmy]

there are some genuine volvo dealers that run ebay sales you need to look carefully at the seller and where they are located

[Baffler]

As a guide you can test the resistance of your existing glow plugs, in situ, with a multimeter set Ohms (Ω) and compare each of their values. It think the average glow plug value is ~0.9Ω so anything outside of this is an indication that particular plug is failing. The multimeter will also have it's own resistance of ~0.3Ω so allow for that e.g. ~1.2Ω for each plug.

[Kev0607]

Originally Posted by VolvoRob38

Hi all,

Just bought some Bosch glow plugs off ebay for my C30 1.6d 2009 after having a broken tip removed after about 18 months. I have double checked them for continuity just in case I've been sold crap, but all OK....

But was wondering if there was a way to test the heating probe, so actually seeing it glow, before I bother to fit these?? Simply fitting them in the wiring loom and starting the engine doesn't work as I assume they need to be fitted/earthed against the engine block.

Also, running tests with Vida says that the glow plugs are causing a Reduced Engine Performance message to pop up every time I start the engine, so assuming these are all OK, once installed, will the dash message disapear or will I have to use the software to Cancel All messages to clear it?

TIA

This video might help.

You don't need to see them glow. All you need is a multimeter to measure the resistance. This video shows how to test with the plugs not fitted on the car.

+ YouTube Video

If you want to test glow plugs that are already on the car, you can do this without removing them. This video shows that.

+ YouTube Video