[supra_toy]

Just tonight I get into the car and notice a rhythmic ticking noise. Tick tick …. Tick tick…. Tick tick…. About a 3-4 second interval in-between each set of ticks fairly regular. So I pull off the road and turn off the car hoping it will go away. I turn the car back on and it is still there. I then leave the car on and try to find the noise with my ear. It seems to be coming from above the break pedal area. Here is a strange thing about it which makes me think its something electrical. I turned off the car and then turn it to the on position…tick tick…tick tick….tick tick….tick…then it stops. Just one tick instead of the pair of ticks and it stopped ticking. So I start the car back up and the rhythmic ticking comes back on again.

Anyone have a idea what it is?

Thanks

Will

 

[supraz]

I occassionally hear the same thing. It seems to be related to the heater/temperature control.

I just assumed that there was a vacuum valve that was cycling.

It doesn't seem to hurt anything, and I wasn't going to pull the dash to find it.

Dale

 

[supra_toy]

I've herd of the temp control thing but I dont think thats it. The noise seems to be comeing from above the pedal area but lower than the stearing wheel. It may not be hurting anything but it is annoying...

Any one else? Please? (I'm sure this will drive me insane if i dont fix it....)

will

 

[MK2Racer]

Mine did that, slide the temp selector back and forth and see what happens. That fixed mine.

 

[supra_toy]

ok so I just went out to the car and started her up. The clicking noise was gone. The climate control was all the way to the left (cold) Upon sliding it to the right (all the way) the clicking noise returned (grrrr). while fiddeling with it i noticed that if I jiggled it at the right end of the slide I got a whole mess of ticking noises (now not seemeily at any specific interval and very fast). So obvously this has something to do with the climate control.

I vaugly remember replacing the heater core in my last supra (super PITA!) and remember seeing a sort of actuatuaor back ther in the general are where this noise is comeing from.... Could this be the problem? How do I fix this?

I'm certain that I will go insane if I don't fix this.

thanks

will

 

[MkIISuperSupra]

Will,

Just curious, is your AC system up and running and fully charged and your solar sensor in good shape and working?

I have about decided in my own mind that there is a connection there.

Leslie

 

[SkoonMA67]

You have a bad DVV valve behind the radio. Its a double vacuum valve that could be leaking in anyone of a dozen spots. Good luck finding a good one at a wrecker, you're going to have to get all of them you can and build a good one from parts.

Its more than likely a bad coil or pintle seal causing vacuum leak.

Aaron

 

[Dave A.]

The "tick-tick" that you're hearing is coming from the DVV (Dual Vacuum Valve). See if this makes any sense and I'll try not to write a short book in the process:
The DVV controls the position of the power servo stem by applying and bleeding off vacuum from the power servo diaphragm. The setting of the temp. control lever establishes the baseline position of the blend door on the interior air box outlet which is mechanically connected to the power servo stem. The DVV is switched On, applying vacuum to the power servo diaphragm, and then switched Off once the correct position of the blend door is established. The problem occurs when a vacuum leak allows vacuum to be bled off of the power servo diaphragm. The vacuum leak allows the power servo stem to move slowly to the left after the DVV is switched Off, which in turn causes the A/C amp to turn on the DVV once again in an attempt to re-establish the proper position of the power servo stem, which it does, but only temporarily due to the vacuum leak. :roll:
The DVV contains two very small vacuum valves that are operated by two very small solenoids, all internal to the DVV. One valve is used to control the supply of vacuum to the power servo diaphragm while the other controls the amount of vacuum bleed off from the power servo diaphragm. Am I making any sense yet? :lol: Check for any vacuum leaks in the DVV/power servo section of the auto A/C system. You may have a leaky vacuum hose, a leaky power servo diaphragm, or a leaky bleed valve in the DVV (which is what I've found in the past). Try swapping out the DVV and see if that cures the cycling problem. I've seen one case where the DVV bleed valve was to blame. The valves are a needle and seat type arrangement that resemble a scaled down version of the needle and seat in the float bowl of a carburetor (only the needle tip is hard plastic instead of butyl rubber or Neoprene in the DVV). :? Repairing the crummy valve needles and seats in the DVV has proven to be a less than enjoyable experience for me, and I highly recommend replacement of the DVV with a new one instead! IOW, don't attempt to disassemble the DVV unless you have steady hands, nerves of steel, and much patience to deal with the several tiny springs and steel check balls that lurk inside. Chuck the DVV and buy a new one!
The reason the "tick-tick" stopped cycling and ended with a single tick is because your engine wasn't running and thus no continual vacuum supply to the DVV. The more erratic ticking sound that you're hearing when you move the temp. lever to the far right is due to poor contact in the temp. lever potentiometer. Giving the potentiometer a shot of contact cleaner should improve or even cure that problem. The contacts tarnish over time and make poor contact which drives the A/C amp and the DVV crazy.
HTH!!

 

[Dave A.]

Also, the reason that you don't hear any clicking with the temp. lever in the far left position is because initially no vacuum is applied to the power servo at that setting (servo stem at full cool position with no vacuum applied to the diaphragm).

 

[supraz]

Dave A.
Looking at page AC-15/16 of the Repair manual, it looks like the stereo has to come out in order to check/replace the DVV. Is that correct?

Is the DVV still available from Toyota new?

Either you have spent many an evening working on this problem, or you are a rocket scientist. :idea:

 

[supra_toy]

The AC i Just turned on the other day and it works fine (It could be a little colder but still pretty cold) and the little lenze on the dash pas. side it still their.

I'm convinced it has something to do with the climate controls with the temp slider all the way to the left (cold) it dosent make this clicking sound. and when I slide this slider I can hear the actuator working back there...

Help!

will

 

[Dave A.]

Well, you basically have two options. You can either pull the radio or stand on your head under the dash to get to the DVV. :roll: Although I believe you can just remove the cover under the steering column to get a clear shot at it. I'm not sure if a new DVV is still available or not? They were available about two years ago but I'm not sure about now. It might not hurt to try and do a GP on some new ones if they are still available!!
Rocket Scientist? Nah, just a stickler for detail with a lot of patience! 8)

 

[Dave A.]

I'm convinced it has something to do with the climate controls with the temp slider all the way to the left (cold) it dosent make this clicking sound. and when I slide this slider I can hear the actuator working back there...

Help!

will[/quote]



Yep, you're on the right track! A new DVV and some contact cleaner and your ticking problem should be solved.

 

[supraz]

Dave A.

I'm too embarassed to tell you that I am a service person for what company (not automotive), but as Charlie Brown's father say:

When the car makes a strange sound, turn up the radio

Actually it's driving me crazy too. I'm heading down to Toyota tomorrow to see if that valve is still sold :lol:

 

[supra_toy]

Dave A. you are the MAN! I figure that the DVV you are talking about is the mechanism I saw back their when I last ripped out the dash (to the fire wall!) in my old supra.

Funny thing is I got into the car this afternoon and went off on my way and it was doing it’s clicking thing and I just turned up the stereo and ignored it (the stereo is coming out this weekend by the way poor stock deck and speakers are shot) Well I get into it tonight to come home from the pool hall (~2:00 am) and the clicking is miricusly gone! I figure it will return right after I get the dash put back together after the stereo install… LOL.

Supraz let me know if this DVV is still made would you?

Since I have my left arm in a brace/splint and my finger on that hand don't work so well after my accident I doubt trying to R&R the DVV is going to be a possibility for me.

I wonder how much this DVV is going to cost me?

Is it possible that I might be able to fix this problem with out replacing the DVV and instead just replacing some simple vacuum lines (wishful thinking?)?

Could you tell me where the temp. lever potentiometer is located? (I have the 85 TSRM and chiltons manuals if it’s in their just say so and I look it up and quit bugging you all) Mind you I just a shade tree mechanic type and this terminology is sometimes over my head. Also what it the best way of going about cleaning the contacts?

 

[supraz]

Leaping Lizards!!!!!!!!!

I went to Toyota this morning and they are checking to see if the DVV is still available. They will know in about a week. But full retail is US$375!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!11 :shock: :shock: :shock:

I put in an order for one anyways. Sigh. I am heading to the wreckers right now to get a heater box with vacuum bits. They quoted US$37. Goodness knows, it may be bad too, but you never know.

 

[supraz]

SkoonMA67,
I see thought you were being suprisingly quiet after your comment about finding a good one at the wrecker. But hope springs eternal :lol:

 

[supra_toy]

E f'n gads! $375!!!

Thats outragous!

Thank god the problem has seemed to go away...for now.

will

 

[Marblehead]

Is it possible that I might be able to fix this problem with out replacing the DVV and instead just replacing some simple vacuum lines (wishful thinking?)?
Could you tell me where the temp. lever potentiometer is located? (I have the 85 TSRM and chiltons manuals if it’s in their just say so and I look it up and quit bugging you all) Mind you I just a shade tree mechanic type and this terminology is sometimes over my head. Also what it the best way of going about cleaning the contacts?

Supra_toy,
I don't mean to speak in place of Dave, he is definitely the founding father of locating and repairing this annoyance. His advice has helped many to repair this noise, including me. The temperature potentiometer is the lever which you slide to control the temperature...well, actually, it's what the lever is connected to behind the panel. A small metal box, about 2"Wx0.5Hx0.5D. Within the box are the electrical contacts.

The Supra has an electric temp. controller, many cars of this age would have a mechanical temp. control. Over time, the electrical contacts accumulate dirt and debris providing poor contact between the metals. To clean the potentiometer simply use the extension nozzle of the electrical contact cleaner and spray into the slot on either side of the lever. To make things easier you could remove the face plate surrounding the temperature control panel. Simple: remove the black caps of the levers and three screws from the plate. Removing the plate will allow you to see the potentiometer itself and where/how the lever enters. Give it a few quick sprays, slide the lever back and forth and the internal contacts should be clean.

While I had the dash out I disassembled the potentiometer and replaced the DVV with a new one from Toyota. Voila! No more clock behind my dash! (THANK YOU Dave!!) This was all done just within the last couple months so, yes, the DVV is still available....and NOT at that outlandish price. They were obviously quoting the wrong part. I'll look up the part number and the price in my records tonight. Hell, I might even order another before all of you exstinguish the remaining lot. :lol:

Don't take life too seriously, you won't get out alive.
Scott

 

[supra_toy]

Supra_toy,
.....electrical contact cleaner

What brand and where do I get it?

Thanks Marblehead

will