Why does only one gauge fog up?

mthomas58 · 01:06 PM

Seems like I've read other posts indicating the propensity for only the oil/temp & oil pressure gauge to fog up. Why would this be?

We've had rain in ATL for 7 straight days so it extremely humid...past couple of days the oil pressure gauge has totally fogged up and nada on the others. What gives?

jcsjcs · jcsjcs's Garage

Same problem on mine. It tends to fog up early in the morning after a somewhat cool night.

tomphot · 09-22-2009, 07:34 AM

Mark
Me too - though I haven't been driving in the floods like you.

Talewinds · Talewinds's Garage

WTF? Same here, started just last week in the cooler evenings. And ONLY the oil temp/pressure gauge.
Looks like only Carrera 3.2's on this thread so far....

Gemballa2006 · 09-22-2009, 08:49 AM

Same with my 86 3.2. Was going to just swicth out the gauge but it seems there may be more too it if lots of people are having the same issue

mca · 09-22-2009, 08:50 AM

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.

ossiblue · 09-22-2009, 08:53 AM

Same issue on my 75S and 73.5T. Without any real investigation, I'd guess it has to do with the location of the gauge--directly in line with open area to trunk--and the construction of the gauge itself--possibly more openings to outside atmosphere in the case or more "empty" space inside the case itself allowing for easier condensation. Just a wag, and something to live with during the cooler months.

RNajarian · RNajarian's Garage

Add my '75 S to the list. . . I wonder if replacing the gasket would help

carreraken · carreraken's Garage

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.

Ditto on the windshield leak - had the same problem with foggy gauges which stopped once I fixed the leak.

Sunroof · 09-22-2009, 09:30 AM

In my 1973.5T, 1974 911 and 1979SC the guage has never failed to fog under certain conditions. I attribute the fogging to the location closest to the door and outside conditions. I have never had a failed or faulty guage as a result of the fogging in any of these cars over a span of 30 years.

If it did not "fog" it would not be a 911!!

Bob
73.5T

john walker's workshop · 09-22-2009, 09:44 AM

normal. smoke at start up, normal, g50s rattle, normal, heater could work better, normal, etc. they have quirks.

Looking_for_911 · 09-22-2009, 10:00 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.

Here's a curve ball for you!
My SC did it last week while out on a short hop.
And the car lives indoors, it wasn't raining. I suspected that the cool temps of the basement combined with the rather hot and humid ambient temperature caused it, much like when my camera lenses fog when going outside from inside the house.
I will check for water leaks, though!

sean m · sean m's Garage

Mark,
Mine was doing the same thing. I did a search here and there was a very good thread on how to "carefully" take the glass off, clean the glass, let sit a few days to get humidity out, then carefully put glass back on.

I did it and mine no longer fogs up....

As I remember, you have to use a tiny screw driver to carefully pry open the lip of metal that holds the glass on. I used one of those eye glass screw drivers.

Do a search, I'm sure you'll find it.

SCWDP911 · SCWDP911's Garage

I think 3 or 4 (left to right) of mine will do this on cool mornings, if I have the top down

James Brown · James Brown's Garage

happens in the PNW all the time so I looked into the cause, plenty of moisture outside but none behind the dash. after pulling the gage, I noticed a whole in the firewall leading to the trunk. I left the Gage out and drove around a bit an sure enough, you an feel quite a bit of air coming from the trunk area. So, I figure that moist air, from the trunk, is being blown in/around that gage combining with increased OAT and elevated moisture and most of the time the Gages are cooler than the outside=fog/condensation. I'm working on a deflector for the back of the gage (just some cardboard or plastic) that should help.

mca · 11:07 AM

Quote:

Originally Posted by Looking_for_911

Here's a curve ball for you!
My SC did it last week while out on a short hop.
And the car lives indoors, it wasn't raining. I suspected that the cool temps of the basement combined with the rather hot and humid ambient temperature caused it, much like when my camera lenses fog when going outside from inside the house.
I will check for water leaks, though!

So yours is fogging on the outside of the glass (meaning that you can wipe it with your finder) and not the inside?

The gauges don't have the best seal but they still shouldn't fog on the inside. I suppose it is possible but in 2 1/2 years since I replaced my windshield seal, I haven't had any issues. My car is also stored inside and it is hot and humid down here in Charleston.

cfries · cfries's Garage

Add my 75 to the list. Its stored in the garage and hasnt been in the rain. Took it out last night and the oil/temp gauge fogged right up. Its been doing it for years.

Sunroof · 09-22-2009, 12:46 PM

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..............

Looking_for_911 · 12:50 PM

Quote:

Originally Posted by mca

So yours is fogging on the outside of the glass (meaning that you can wipe it with your finder) and not the inside?

The gauges don't have the best seal but they still shouldn't fog on the inside. I suppose it is possible but in 2 1/2 years since I replaced my windshield seal, I haven't had any issues. My car is also stored inside and it is hot and humid down here in Charleston.

No... When I first saw it I did the finger wipe and was quite dismayed to see it was inside.

But, I did have the fleeting thought that this was a "normal" 911 quirk and wasn't too concerned with it.

I know Charleston's humidity well. Birmingham has the same humidity with none of the Charleston charm!
We're there a couple times a year. Absolutely love it. I'm trying to get the finace' to apply for admittance to the SC bar so we can move there! Sullivan Island is my favorite place. Folly Beach, too. But if I had that mythical boat load of money I'd buy a house on Sullivan in a heart beat.

mca · 09-22-2009, 12:50 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..............

I guess that I would be concerned that water was entering the dash area. Or that rust might form around the windshield if the seal is leaking. This is what I saw when the shop had my glass out.

"normal" no ... "tolerable" probably