glow plugs BWM 320d

gp2

the onboard diagnostics showed three of my 4 glow plugs are faulty, although it's no trouble to start the car when the temp's dipping to zero. Anybody knows 40x3=120's a fair price to change them and can i simply leave those until I got the sign of the problem. Thanks!

colino

I would get a second opinion on the diagnostics. Unusual to have the four fail at once and that looks like a cabling or other component fault.

EssexExile

The diagnostics wouldn't flag up that they need changing after a certain passage of time would they?

gp2

thanks for the opinion, does that mean it's a possible false alarm or something eles's going on but no need to do anything since there's no real problem

Inner_Zone

There was an article in Car Mechanics recently apparently BMW coil packs have expiry dates programmed / printed on them don't know if glow plugs are similar.

colino

Diagnostics really are a combination of the machine plus the operator. While it is quite conceivable that, either through age or contamination, all four fell off their perch at the same time, the glow control unit and wiring have to be checked too.
Incidentally IZ, what age of BMW coil packs allegedly had built-in obsolescence? Although it may be tempting fate, I've had a lot of BMWs through my hands and I've yet to have to change an oem coil.

Inner_Zone

colino wrote: »

Diagnostics really are a combination of the machine plus the operator. While it is quite conceivable that, either through age or contamination, all four fell off their perch at the same time, the glow control unit and wiring have to be checked too.
Incidentally IZ, what age of BMW coil packs allegedly had built-in obsolescence? Although it may be tempting fate, I've had a lot of BMWs through my hands and I've yet to have to change an oem coil.

I can't remember will need to look out the issue of CM.

forgotmyname

Most modern diesels will start without the glowplugs in some extreme cold conditions.
But it puts extra strain on the engine. Its much better to have working ones.

Get the fault diagnosed properly. If they read the code then want to change them instantly i wouldnt trust them.

I was picking someone up at a garage and asked the guy how much to check my glowplugs. We cant check them he says. Just replace them.

Avoid garages like that.

Retrogamer

I've been driving about with 1 faulty glow plug now for the best part of 6 months (EML on)
No issues so far but it's on the to do list.

If i was showing 3 out i'd get them changed. It means it'll take the engine longer to warm up properly and will use a little more fuel.

captainawsome

Glow plug control unit fails (relay) and shows 4 glow plugs at fault. Replace control unit along with all 4 plugs. Their operation cannot be guaranteed after not working for X amount of time, carbon build up etc etc.

Also 'Testing' aglow plug is tricky. The only thing you can do is measure the resistance of it but obviously this varies with temp, so while it may be in spec when cold may be out at running temp or vice versa, or anywhere in the temp range in between.

forgotmyname

Testing them properly is almost impossible but a quick test to see if they
are actually working is easy. Either a resistance test or test how much
power it pulls.

That will just show its not broken. The carbon build up could be shielding the plug from the fuel entering.
Only taking them out will show that.

A clamp meter showed it pulling 30 amps instead of the 40 expected, showed i had one down.

They could have done that and got some work/money from me. Instead i did it myself.