Temperature Regulator

I have a 1093cc Golf - 1983 - all standard, been off the road for about 2 years. Put back on road last month - running 'ok' now  

However, decided to take some temps. in the air cleaner/filter whilst starting from cold and went on a 10 min run.  (we had suspicion of carb/choke icing  a few months back) - I was surprised to see air intake temp stabilised @ 64C

Ambient was about 9c - reached a max of 76c in traffic, on the open road @70 MPH dropped to 54 C  (I do mean C ! )

I've checked thermostat in 'elbow' and closes at about 25c (not quite fully - very slight gap ) and seems to operate as expected. (** edited 12/3/07 - it isn't 100% correct - see later)

However I'm unsure how the 'temperature regulator' (the orange unit about 1" long with the 2 small pipes)  functions in the air cleaner itself (ie what temp. does it change ? and does it (or should it )  stop vacuum from operating on the flap completely ? (ie no 'hot' air needed under load after a certain temp threshold?). The manuals don't go into detail.

In a nutshell - how can I prove it's working or not ?
Sucking on it doesn't pass through the vacuum thru  (at room temp 20c), therefore in theory it shouldn't be lifting the 'hot air flap up.

I noticed there's a very small hole (about .2 mm) in the top of it
- this was blocked. To put back on and try again

However I thought I would post this first  and also , where do I get a new one !



Thanks

Interesting stuff PeteRBorough,

How did you measure the temperature in the air filter ?

As for the 'temperature regulator' - did you try sucking on both pipes indiviually as there may be a one-way valve.

I haven't looked at this for a while and my son has my 1.1 at the minute - when you suck on the pipe from the elbow (to simulate the vacuum) and the flap moves what would that do - allow warm air into the filter OR allow cooler air into the filter please ?

What I think happens is that when the engine is cold the thermostat in the elbow is open to allow warm(ish) air from the manifold pipe and the temperature regulator is also open allowing the vacuum to move the flap to close off the cooler air from the end of the elbow.

As the engine (and air) warms up the thermostat closes off the warm air manifold pipe and the temperature regulator also closes, removing the vacuum and allowing the flap to move and allow the cooler air to flow from the end of the elbow.

My Haynes gives a figure of 20C for the thermostat in the elbow to close but no figure for the temperature regulator - presumably it operates around the same temperature  :dontknow: as they work in conjunction with each other. So no vacuum at 20C may be about right - i.e. thermostat closed and flap open.

Let me know.

Andy

The hole in mine was blocked up, as were the vaccuum tubes. Cleaning them out did make a lot smoother from cold. GSF list a "Temp Sensor in Air Filter" part no 18206 for 1.1/1.3, ?21 sounds a lot though.

Cheers

Andy

Apologies for delay in reply. Thanks for all info - what fun these cars are ….

Firstly - Vacuum causes flap to rise ie lets warmer air in from manifold

Secondly - I use a digital multimeter with thermocouple lead - cost about ?8 -  5 years ago. A UniTrend Cheapo … (Mine was a UT20C)  does the job and used it for electrical work during that time. I see one similar on Maplin @ about ?16 (Code N73CG-DMM) and states 'leads' included.

Also - for your info - the crankcase breather is circa 22c  (at tickover) as you know also comes into air cleaner - so mine was getting lots of 'manifold' warm/hot air.



Re. my problem - I'll post some photos - perhaps help others also.


I'm 100% sure both components have failed. (still proving this)

My reasoning is - the flap does not fully close (leaves about 15 degree open @ 30c - should be shut by then , do you agree ? - that's 10c over) - there's is some movement on thermostat which is odd ? -  as I would have thought it would have simply failed . I've not tried higher than 30c yet to see what movement there is.
This would explain the very higher temps I was getting (circa 60c)


However (I just read other reply from Mark - thanks) - having cleaned
both pipes (and the pin hole) - - all were blocked and re-assembled and re run I've now getting more interesting readings… (not correct though)

Went out tonight 7pm - ambient about 5c.

Took reading in elbow @ same place - rose to 16c - went for very short run (about 1 mile) as just re-tuned - set up plugs / points etc .. rose to 21 c and dropped to 18c - came back in drive and as fan cut in rose to 35c  (I was happy with this - as under bonnet temp with no air movement - air would be going into the 'cool' inlet. Agree ?   Ran the best it's ever run..

So problem solved or so I thought..

Took it out across city and thought I might as well see what the temp's are like (about 4c ambient now) with a 'proper' journey

Engine was still warm - so reading was already 22c - then as I made my way through the city (about 30mph max) the reading steadily fell and fell
down to 1c .. and the engine went lumpy.  Eased off and temp came up a little , engine didn't stall (I assume the carb/jets must by icing ? Agree ?)  

Got it home - had a look - and the warm air pipe had disappeared !
- trip over same route in other car - found pipe in road - it had been run over !   lol lol ….

So returned fixed pipe and out for another test - temps held at about 8c
and car run fine. However not happy - at this suggests it's getting some warm air  yet no vacuum ? I couldn't get the air temp above 8c

My theory is the vacuum (temp regulator) is not working at the right temp range- yet appeared to be working 'ok' from cold. Still a few tests to do

Looks like a replacement part(s) will be needed (Markwon suggests ?21 maybe for the temp reg - that's more than I paid for the car ! (I was given it))

Thanks


Gordon from Peterborough

Photos of Air Cleaner and Temp Regulator
and schematic (to be updated)

http://locost.bonhomie.biz/vwgolfmk1.htm


Gordon

Finished tests -    Both from cold

During day (ambient 14c) - Air Filter temp  range 31c to 39c
Evening run (ambient 7c) - Air Filter temp range 28c to 35c

Max. was 42c momentarily when stopped in traffic

Flap is NOT closing completely although seems cleaning the pipes and pin hole on Temp regulator is allowing the vacuum NOT to function (correctly when warm) as I'm getting nothing like > 60C now.

Vacuum does operate from cold on valve fine  - although can't ascertain the exact temp it closes / opens valve (unless it's progressive) - as there's slight movement on flap (5 degrees at most) even when warm. (ie circa 30c).
 

Car runs a little 'lumpy' - more than I would have liked …. (@ 30mph in 4th) since tune up when warmed up - going lean ? especially noticeable when lifting off.

That's something else to 'tweat' maybe.. .. The Idle spot on @ 950 rpm pretty steady within 25rpm , Dwell 47 , CO 1% , + timing spot on.    
Runs great above 40mph



Gordon

Gordon,

Interesting measurements/observations - need to have a think  :dontknow:

What carburettor do you have - standard Solex/Pierberg ?

Andy

Andy …

Yes - standard Solex 31 / Pic 7 - (mine is a 1.1 June 1983 model)

History : -  I had loads of rust in tank for previous owner. (he had run rusty filler neck for >  18 months and basically gave up on car)

So I replaced filler neck immed/ cleaned tank (magnet option is 100% fine) then inline filter replace twice and carb clean once.

May change plug leads -  :dontknow:  as these look like the original ones (24 yrs old). Could be a weaker spark on a cylinder ? Still using points (dist cap/rotor arm /points/plugs/condenser all new - coil poss. original).



Thanks for your help .. much appreciated .


Car is set up 100% (ie to the best of my ability with the meters/settings etc ) - however doesn't run <40mph as well as I would like :?




Gordon