Why does only one gauge fog up? - Page 2

mthomas58 · 09-22-2009, 01:05 PM

Quote:

Originally Posted by Sunroof

Sorry, I am with John on this one.........."normal". Some quirky things about the 911 must remain!

If I had to advertise my 911, it would have as part of the description, "fogged left instrument" as factory specified..............

OK, normal it is. I do know for a fact that my windshield seal leaks.....In heary rainstorms I do get some ocassional drips on my left ankle....maybe not normal but I'm living with it.

Thanks guys!

proffighter · proffighter's Garage

LOL, same on my 930, I only have to drive out of the garage into a foggy day, that's it

marcsalleras · 09-23-2009, 05:19 AM

I have a 86 3.2 also and ive been getting fog also in the oil pressure, oil temp, and tachometer........I live in atlanta also ............hmmmm

marcsalleras · 09-23-2009, 05:21 AM

Can anyone say foggy gauge government conspiracy? hahah

bkreigsr · 05:56 AM

anyone had any luck by sending the gauges out to Palo Alto or Hollywood to be resealed?
I bought a few replacement gauges and was going to send my oem's out for rehab.

not a problem on my 73 (115,000 miles), but pops up on my 77 all the time (102,000)

Bill K

Phoenix-MN · 09-23-2009, 08:26 AM

Just to add another twist to the saga,

I have a 914 resto that I put a full 911 dash into and the the car has not seen the "outdoor light of day" yet and little lone even been wet.

911 Dash

The gas/oil gauge fogs up after starting the engine and running a while. None of the other gauges do this.

Is it possible that the gauge movement coils have some moisture in them and when running they slightly warm up and release the moisture?

sballard · 09-23-2009, 09:04 AM

My car does this as well.

Here's my guess. The air inside the gauge is roughly the same humidity as the ambient air. As the engine warms up, the air pasing through the heating ducts behind the left side of the dash heats up, which starts to heat up the left side gauge. When this happens, the glass face is the coolest part of the gauge and the moisture from the air inside the gauge condenses there. The left side is more prone to this because the left side of the dash is closest to the heat ducts. The guage is nearly (but not quite) air-tight and the air is stagnant inside so it take a long time to equilibrate with the outside air.

Just a thought....

911boost · 911boost's Garage

My 964T does this as well. Its my fuel gauge. I took it all apart, as it was on the inside. After carefully prying the ring apart and removing it, I discovered that it is actually the glass de-laminating in between.

kmhemi · 09-23-2009, 11:20 AM

My SC is kept inside an air conditioned garage and its heated in the winter. The car does not get driven in the rain and I ca not remember the car getting wet in the last five years. I have never taken it to a high pressure wash. I took it out last week and one of my gauges fogged. I figured it was becasue it was nice an cool inside then I took it out in the heat.

proffighter · proffighter's Garage

Quote:

Originally Posted by sballard

My car does this as well.

Here's my guess. The air inside the gauge is roughly the same humidity as the ambient air. As the engine warms up, the air pasing through the heating ducts behind the left side of the dash heats up, which starts to heat up the left side gauge. When this happens, the glass face is the coolest part of the gauge and the moisture from the air inside the gauge condenses there. The left side is more prone to this because the left side of the dash is closest to the heat ducts. The guage is nearly (but not quite) air-tight and the air is stagnant inside so it take a long time to equilibrate with the outside air.

Just a thought....

Nice theory, but I do not have heat exchangers and no heating at all, so it seems not to be the reason for our foggy gauges. Further, because my car is without any carpet, bitumen and other dampening and sealing, but full of holes like a swiss cheese (I know what I'm talking about as Swiss), there is probably the same humidity in the trunk area like outside...

slw911SC · 09-23-2009, 12:43 PM

Aw, just fog it and live with it! Happy autumn everyone!

sballard · 09-23-2009, 05:54 PM

proffighter-

Yeah, I agree. I just pulled the gauge and looked behind it and there isn't a heating duct anywhere near it, so I am officially stupid. I knew I should have looked before I posted.

It is funny that my car has been on stands in the garage for a year and the gauge is STILL fogged up!

jsaucedo · 10-20-2012, 06:37 AM

Quote:

Originally Posted by mca

At some point water found its way around the gauge.

When I first got my SC the same thing happened. Water was getting past my windshield seal and running under the dash. Two of my gauges were fogging.

I replaced the seal then pulled both gauges out and used a hair dryer to get rid of the moisture. In all likelihood you won't be able to "see" moisture in the guage ... but if it is fogging ... then the moister is there.

Hey there,

I have the same issue on my '81 SC. How did you remove the gauges? Do you think it's worth it?

Thanks!
James

jclotz · jclotz's Garage

I put a small desiccant pack (the kind that comes in a pill bottle) inside my gauges and it fixed the problem.

steve911T · 10-20-2012, 06:59 AM

Add mine to the list. 89 3.2 is never driven in the rain but sits in a garage that is cooler or warmer depending on the weather. I believe it is the humidity causing the condensation. Only the far left gauge fogs and that is one of the three that was sent out and rebuilt by one of the speedo rebuild companies. My guess is that the seal is leaking and moisture (humidity)is getting in. I can live with it, at least it is not the tach or speedo. Steve

wolds · wolds's Garage

My oil pressure gauge has done the same thing I discovered that when it occurred that it was the only gauge in the dash that was warm probably the defrost duct heating it cold dense air plus warm air equals condensation if we all have the same gauge doing it and it hasn't been raining that's my guess

Windsor4273 · Windsor4273's Garage

Add my 79sc to the list... Along with smoke on startup, moderate heat in winter etc...

DRACO A5OG · DRACO A5OG's Garage

Fellas, foggy gauges is not normal.

The culprits:

Loose Wiper Nozzles
Loose Wipers
Clogged or dislodged fresh air intake scoop or drain
Windshield Seal

I had issues with a drip on my passenger side, drove me crazy. I was detailing my car and noticed my nozzles and wipers were loose. sealed nozzles and tighened the wipers. Tested no more leaks. The one night I decided to work on my AC. I went in for dinner and turned my garage light off and left the hand light on. To my amazement I saw pin hole lights coming from my trunk into the cab area under the dash. Sealed all pin holes. No more leaks

j

moneymanager · 10-20-2012, 02:40 PM

Don't any of you have the anti-fog pump? Mine, I thought they all were, is mounted just behind the brake fluid reservoir on my 74. Tiny rubber lines are routed to each gauge. If these rot, or are carelessly knocked off, or even eaten by rodents you will have no end of trouble. Lose one line and get one foggy gauge. McMaster in LA sells the rubber tubing, N.H. Speedometer and others can rebuild the very tiny pumps.

wasserkuhl · wasserkuhl's Garage

Mine did this as well.

I got some 'rockwool' house insulation and packed it behind the instruments.

Doesn't do it anymore.