Thermostat housing steam

[ambibus]

Hi Every one

Decided to give the van a run out the other day as it had not 'turned a wheel 'since christmas. I was really pleased that it started first time and ran mint.
On returning home and backing into a parking space outside our house the view in the passenger mirror looked like the 'return of father' platform scene in the railway children! . nah it was'nt that bad but when I lifted the engine lid water was coolecting on the stainless heat shield below the red sencor/switch on the thermo housing but I can't see exactly where it is coming from. I've searched Wiki first but can't find an answer, Vans full service history 42k miles. any thoughts?

Ta Paul

[kevtherev]

Engine type?

[ambibus]

oops 1.9 petrol DG 1989 G reg

[kevtherev]

plastic housing then
Could be a few things, the O ring that seals the lid on the stat has gone
The housing "lid" needs a tighten
one of the connecting pipes has sprung a leak at the clip (common)

no panic even if the housing has cracked as they are available again

[ambibus]

Thanks Kev

Yes it is plastic, bolt heads are very crusty though will attempt to tighten them.
will keep you posted
Thanks very much

Paul

[ghost123uk]

Those sensors are sealed into their housings with a rubber 'O' ring, they can develop leaks. Might be that ?

The 'O' rings are a very common fitment on many many VW models and are usually in stock and dead cheap at the dealers. At a VW car dealers spares counter they may not deal in 'commercial' spares, so ask for the ones on a MK1 Golf or MKII Scirocco temperature sensor (mounted on the front middle of the block).

Take care your leak does not introduce air locks into your system. Airlocks are not good on these engines. You don't want to make a little problem into a huge one !

[kevtherev]

good point about the o rings I forget them as my housing a syncro metal type

[ambibus]

thank you both for your replies.

fortunatley the van is 3rd vehicle in our household so I won't need to run it till its fixed, the water does appear to be seeping from around the red sensor.

thanks once again

Paul

[ambibus]

just an update

ordered the O rings from Brick werks and they came yesterday, only a day and a half after I ordered them

Plus 2 'BUS' decals that were removed when I had the van sprayed last year

just need to get my Haynes manual back off a local T25 owner who borrowed it last year for '10 minutes'

lets hope this cures it I'm eager to get on with the interior

Paul

[Ian Hulley]

Could also be the metal clips which secure the sensors in the housing ... they rust (badly ) and if they weaken or break the sensor is loose. Also check for bursts/splits where the bolt guides pass through the plastic ... some smartass made them in mild steel ... GITS.

Ian

[icosahedron]

On mine it was the o-ring between the housing and the cylinder head that was the first to go.

[Graham81]

Mine does this too, im sure its the ring between the housing and the head. Ive not been brave enough to take mine to bits yet as its all a bit crusty round there.

[ambibus]

Hi All

The two o rings i ordered turned out to be to big, the steam was issueing from the bottom s shaped pipe where it 'fastened' onto the thermo housing
accessed by putting hand up from underneath between rear seat bulk head and thermostat housing.
The fella who had borrowed my haynes manual jumped at the chance of fixing it on saturday, we did'nt realise the new o rings were wrong untill the
local auto factors were shut and it was going dark. I was imparting Johns (Ghost123uk) info about the seal being the same as on a Audi or MK1 golf
block temp switch when a neighbour shouted 'Like this one?' whilst holding up a small box!. He had just returned from buying a new sensor and gave
me the seal off it, it fitted perfect. Talk about being jammy. we also replaced the seal that goes around the thermo stat itself, after jacking
the front up to bleed the system everything seems to be ok so far, thanks everyone

[ghost123uk]

I was imparting Johns (Ghost123uk) info about the seal being the same as on a Audi or MK1 golf block temp switch when a neighbour shouted 'Like this one?' whilst holding up a small box!. He had just returned from buying a new sensor and gave me the seal off it, it fitted perfect.

Glad to be of help

[brander]

Only just spotted this and glad to see you've got it sorted. I was just going to add though - I'd resist the temptation to tighten the bolts on the plastic housing. They inserts aren't that robust. I broke one when I was untightening and that created havoc!