TVR 3C - steaming up

[peter wolfe]

Can anyone help?
The 4 small instrument dials on my TVR3C steam up after about 15 miles. The car is not overheating but the dials cloud up after about 15 miles of running. When engine turned off they clear soon after. I have checked the hoses at bulkhead and all seems ok and there is no water loss.

[phillpot]

A classic case of "they all do that Sir! "

[v8s4me]

It’s a unique design feature which tells you there is moisture in the air and so don’t leave the roof at home.

[Stwdv]

Wouldn't be without mine but it does clear after a while

[GadgeS3C]

phillpot said:

A classic case of "they all do that Sir! "

[jwigglesworth]

Yep, mine does exactly the same top up or down.

[SJS357]

GadgeS3C said:

phillpot said:

A classic case of "they all do that Sir! "

Yep even after the rebuild... Still the same. It's character
Concerns me now if it doesn't do it

[steve j]

I had this too, my speedo was particurlarly bad. I drilled a 2.4 mm hole in the case and gave a quick squirt of WD40, bingo no more misting.

[glenrobbo]

I have a silica gel bag stuffed up behind the instrument panel of my S1, seems to get rid of most of the condensation.
I just take it out every two or three months & recharge it in the microwave for 5 mins on full power.

[S2Mike]

Mine too, on really bad occasions I can only see the last 10mm of the speedo needle, but as said already its a design feature built in for amusement.

[mohitos]

Mine too ! Over the weekend and 377 miles it came and went. Came and went. No rhyme not reason to the conditions that triggered it.

[glenrobbo]

It's due to a complex balance of ambient temperature, pressure, humidity and the steam coming off your trousers.

HTH

[Oldred_V8S]

glenrobbo said:

It's due to a complex balance of ambient temperature, pressure, humidity and the steam coming off your trousers.

HTH

Glen

Not all of us have reached an age where we have that problem!

Edited by Oldred_V8S on Thursday 17th April 11:45

[ijbd]

imho there is a hygroscopic material inside the gauges.
Probably the glue or less likely the paint. The bimetals are perhaps glued, rather than soldered.

Bimetal and lightbulbs heat the cases up, the hygroscopic water is driven off, and condenses on the coldest surface, the inside of the glass.
Note the fuel gauge, at low fuel level and with instrument lights off, does not mist up, or less. Closed roof with a warmer interior, also less water condensed on the glass.

When you turn off and on the instrument lights, say as a block wave 5 times for 5 minutes, the contents of the dial will breath. 100% relative humidity at elevated temperature out, then ambient temperature/humidity in.
You can do this in the garage, before driving off. The hotter the glass is during the initial heat up, the less water condenses out, and is driven out of the case instead.

I did not try this, but two minimum size holes drilled high and low in the cases should ventilate. If you feel the glass while driving is warm (10 degC?) to the touch. Eventually it should dry out then.

regards Boudewijn