indimb

Hi All,

There is a clicking sound coming from this part under the hood. Its a rectangular back box which looks like a large relay or something placed a little ahead of the battery.

The clicking is at its loudest just as I start the car and seems to go away a few minutes later. What part it this and why is it clicking, Thanks

Cheers

Hogger

Is that the ABS module?
Are you seeing any dash lights pop up after start up? Maybe ABS, SRS light?
Our ML320 does that.

indimb

Yes Sir, ABS it is! Thank you.
I think it is called the ABS ECU Control Module placed next to the ABS pump.

No, there are no lights popping up in the dash except for the glow plug sign which comes on ever so often.

Now the question is why is the ABS ECU Control Module making a clicking sound. Is it normal/expected behaviour? If not, what does the clocking sound signify? Thanks

WaveyKat

the ticking sound that comes from that area is normally a bad purge valve. its a little unit next to the ABS module.

ODB

Hi!
This is a control unit of glow candles A 646 153 65 79

indimb

Thanks alot WaveyKat, will have that checked out. The sound is coming from around the ABS module for sure.

indimb

Bingo. This looks identical to my unit and the glow plug light in the dash comes off and on while driving so this seems to be the culprit. Thanks alot ODB!

What does the clicking sound from the glow candle control unit signify? Is it expected behaviour or somethings gone awry, Thanks Again.

ODB

If the spiral icon on your dashboard goes out after ignition and do not lights again, it means that everything is ok. i will try to hear my one to determine this clicking sound.

indimb

Thanks ODB. The spiral icon goes away only to come back sometimes while driving. This happens randomly and the icon keeps disappearing and appearing again.

Im facing another major issue with the radiator fan running very slow even though the coolant temp is around 95 degrees celsius and a/c high pressure is around 225psi. Hope these 2 issues are not related to each other?

Glyn M Ruck

This is what causes the ticking sound on gasoline powered cars. It is the EECS (evapourative Emissions Control System) Purge Valve. Yours is diesel.

ODB

It may be caused by problems with glow candles or control unit. First of all try to check your glows and replace if needed.

indimb

Yes Sir, thank you. In fact, most of the threads I came across were based on this purge valve, which is why I got confused. Thanks for clarifying the same. Mine is diesel indeed and I have the glow candle control unit placed around the same area near the battery and ABS pump.

Blackbradpitt

I am having this same issue. Now the million dollar question. Is it easy enough to replace yourself?

indimb

Glow candle it is, Thanks again.
As per the mechanic, glow candle no.2 needs to be replaced. Hope its an easy DIY?

The mechanic has already given me a disclaimer that the glow candle may break during removal and if that happens, I should forget about my car for a few days

indimb

Hi Blackbradpitt, I dont think you need to replace the control unit to begin with. In my case glow candle no.2 has been found to be faulty and I think the problem should go away once I replace it.

As rightly pointed out by ODB above, you need to get your glow candles checked, there are 4 of them and see if the sound goes away after replacing the faulty glow. Hope this helps.

Glyn M Ruck

Please also note translation issue here.

The term is "glow plug" in English.

Glyn M Ruck

The purge valve is dead simple to replace.

indimb

Thanks for pointing that out Glyn. ODB referred to it as glow candle so I thought thats what its called. I'm just glad to have found out the issue and hope to have it fixed asap, Thanks & Cheers

Blackbradpitt

I'll be honest. I had no idea what a "glow candle" was. The only thing I could think of was maybe it was some type of foreign slang for headlights.

So for a little while there i kept thinking, "what the hell do the headlights have to do with any of this".