What's this tic-toc from behind the dash?

I have an '02 Passat wagon, 1.8T and AT.

A few weeks ago I noticed a muted "tic-toc" sound coming from behind the dash, repeating at an interval of about 5 seconds or so.

I noticed it first on driving down the alley and navigating the local streets. After a few minutes and on the freeway, I'd only hear the sound when the engine was under load, not when coasting or idling at a stop. After about 20 minutes or so, it would stop altogether, although on longer drives it will start up again for a few minutes and stop again.

There are no starting or driveability issues and gas mileage is as expected for the temperature.

Any idea what I'm hearing?

Reply to
Bert Hyman
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Not sure what you're hearing as it is most difficult to describe a sounds, but I get a "tick tock" sound in my 09 Jetta when the wipers are on in delay mode. I swear it winds up a timer of some sort ... lol... strange thing, but consistently there when I'm using the wipers. And no correlation between the frequency of wiper delay and the tick/tock sound, but always present when they're on.

Wes

Reply to
Willy

Do you lose the clock settings? How good is your battery and charging system?

Reply to
dave AKA vwdoc1

Are you asking me or "Willy"?

My battery's fine, as is the clock.

Reply to
Bert Hyman

Whoever the OP is! ;-)

Trying to see if the cluster loses power or ground which might reset the clock and might cause the tic-toc sound. I have heard ticking before from some Passats if a fuse has blown affecting the instrument cluster. Or maybe even if the battery is old or charging system is not normal.

Reply to
dave AKA vwdoc1

One random thought - my wife who is a very good driver but almost oblivious to what her car (2001 Saab 9-5 wagon) is telling her at that moment once complained about such a tic-toc to me. A REMARKABLE event that she should notice at all.

Turned out to be her rear-wiper delay as Willy suggested. But the center-nut on her wipers had come loose so there was no corresponding movement of the wiper to alert her.

Non-latching relays will also tic or toc if the voltage they see is intermittent or too low - as dave suggests. And if your car is equipped with DRL and auto-dimmers on the headlights, that will do it during the day if the lights are accidentally left ON and on HIGH BEAM

- which will give no overt evidence to the driver other than the blue indicator on the dash - easily overlooked by day.

Peter Wieck Melrose Park, PA

Reply to
pfjw

Based on the perceived behavior, constant during initial warmup, then only under load, then stopping altogether, makes me think it's some emissions-related device doing something.

It didn't do it at all today. Maybe the few days of 50+F temperatures has the car feeling better.

Reply to
Bert Hyman

Another random thought: the headlight circuit has a short, and that's the circuit breaker breaking and resetting. I know it seems that somebody would notice an additional symptom in that case.

Also, weren't the voltage regulators in the dash some mechanical device at some point? What frequency did they operate at?

Reply to
Tom's VR6

Nope, everything is great with mine - 09 Jetta TDI... but do get the ticking "winding" sound from somewhere in the dash when the wipers are on "delay" setting.

Wes

Reply to
Willy

Well, in the case of my 09 TDI, let me try to better describe what I hear. This is a consistent occurrence, and everything seems to be working normally.

When the wipers are on, in delayed mode, I hear a sound that goes something like this... "tick, followed by what I would best describe as a very hard to hear but what sounds like electric sparking for about 5 seconds, then a tock"... You know the sounds you hear if you touch to wires together... that arcing sound. Or another way to describe it would be, if you were able to continuously wind up a clock until it's fully wound, it sounds like that. So it's tick, then winding / sparking, then tock. I actually timed it one day, and don't remember the exact intervals, but they were consistent, and there seems to be no correlation with whether the wipers are on a long or short delay.

And then there's the ticking that occurs in cold weather when you're idling and what I believe to be the electric accessory heater kicking on and off... but doesn't do that often once you're moving. Must be because of the lower RPM'S.... that's another sound all together.

Maybe my ears are just too good! LOL

Wes

Reply to
Willy

Did it briefly today after the temps were in the upper 20sF last night and mid 30sF daytime, so maybe it is something temperature related.

Reply to
Bert Hyman

My 09 definitely has an aux heater. I've tried to pin down at what temp it starts operating (assuming a cold start) but haven't quiet got that figured out as yet. You can hear something, I assume a relay that controls voltage, that goes through an infrequent on off cycle, especially when idling at a light. You will notice this is not longer evident once the temps warm up.

And interestingly, you'll also notice your mileage jumping significantly. It's been in the 60's here today and I averaged 49.1 mpg on a 300 mile drive today... one of my best days. Had a lot of 55 mph roads today so that's what did it. But had it been 20 degrees cooler I would have been mid 40's at best.

Wes

Reply to
Willy

A thought....................... Does this vehicle have electronic climate control? Could it be the vents/flaps moving automatically?

Reply to
dave AKA vwdoc1

No, manual controls. Actually would loved to had auto as all my cars in the last 20 years have, however, the TDI is not available with this option.

Wes

Reply to
Willy

My 2003 TDI Jetta did the tick tock the other day. I thought I was hearing things. I listened hard while driving and I heard no strange voices, just the tick tock kind of like a turn signal sound but faster. I had just used the turn signal but using it again it sounded normal. I turned off the fan. Since I was driving I could not concentrate on the noise. It went away. I found it mildly amusing as there was this recent discussion here. No electric climate control.

Reply to
Jim Behning

Bret I wonder if you are hearing noise from something under the hood rubbing against he firewall. The Passat has a compartment for the battery next to the firewall. Have your mechanic remove the cover and make sure everything is tight and and rattling around. The Passat also has an auxiliary vacuum pump on the left front side of the engine compartment, it is located under a plastic cover under behind the headlamp. It kicks on and off, have your mechanic check this. Hope this helps. Mike

Reply to
mdsimon

Press the recycle air button and see if the noise happens. I have seen the electronic actuators for the recycle air door go bad and make noise. On some vw models this door will close on it's own to prevent exahust from getting inside the car. Mike

Reply to
mdsimon

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