SAD issues

[Richie-Van-GTi 74 2 Cars]

How well does the SAD close off? Mine still passes a lot of air but the plate looks closed inside when hot. Literally can wind the throttle bypass full closed and throttle stop fully back and it idles at 1100. Pulled the pipe off the sad and there is a stack of air going through it.

[Tom Fenton 1,562]

It should shut so it passes next to nothing. Clamp the hose going to or from it and see what the idle speed does. When working properly and you clamp the hose, there should be no change in the engine speed (assuming fully warm). 

[Leslie green 126]

I noticed mine was the same  throttle screw fully closed and butterfly closed and still 1100 rpm , will need to check once I get mot over. 

[Thijs_Rallye 89 4 Cars]

If there is no change to the idle RPM after clamping the hose as Tom suggested, check for air leaks at injectors / seal surface of intake manifold and most importantly all oil breather and fillers hoses.

[Richie-Van-GTi 74 2 Cars]

On 4/4/2025 at 8:49 AM, Tom Fenton said:

It should shut so it passes next to nothing. Clamp the hose going to or from it and see what the idle speed does. When working properly and you clamp the hose, there should be no change in the engine speed (assuming fully warm). 

Half hour of heater on and heated the housing to scalding and I can still blow through it easily, no split pipes etc. it is reduced from fully open but certainly not a struggle by any means. Tried adjusting it both ways and no difference, knackered???

6 hours ago, Thijs_Rallye said:

If there is no change to the idle RPM after clamping the hose as Tom suggested, check for air leaks at injectors / seal surface of intake manifold and most importantly all oil breather and fillers hoses.

No difference when blocking hoses either but can't find any splits etc, seems like the oil breather just passes through the cap and gauze to the elbow on the other side if the throttle body though, normal??

[Thijs_Rallye 89 4 Cars]

There is a breather hose that runs from the top of the valve cover to the T at the bottom of the oil filler hose, oil filler hose should also be free of splits and are often hard to see without removing them imo. Then there is a breather hose that runs from the bottom of the engine block to the side of the oil filler "pot" or however it is called. Another item often overlooked is the bolt that bolts the oil filler pot to the intake manifold. A pin hole is enough to throw off your idle so look closely.

[Richie-Van-GTi 74 2 Cars]

16 hours ago, Thijs_Rallye said:

There is a breather hose that runs from the top of the valve cover to the T at the bottom of the oil filler hose, oil filler hose should also be free of splits and are often hard to see without removing them imo. Then there is a breather hose that runs from the bottom of the engine block to the side of the oil filler "pot" or however it is called. Another item often overlooked is the bolt that bolts the oil filler pot to the intake manifold. A pin hole is enough to throw off your idle so look closely.

All hoses etc are fine, there is no air leaks, the issue is the SAD lets a lot of air through when closed.

[Telf 232 2 Cars]

Buy a new one! They don't really let anything through when closed.

[bacardincoke 42 1 Cars]

Was going to start a topic of my own, however this recent one leapt out at me and has some elements in common / save repetition.

 

1989 1.9 - has run perfectly for a number of years, though mileage is minimal these days (about 300 in the past 2 x years).

 

Serviced regardless / turned over regularly etc.

 

Getting it ready for this year and noticed the cold idle now rises to around 1900 rpm (previously it'd be a max of 1450 rpm).

 

It'll remain there for several minutes, then progressively drop down over course of about 5 minutes to a rock steady 950 rpm.

 

Squeezing the inlet / outlet pipes (while still warming up) to the SAD will cause the revs to drop to point of almost stalling.

 

SAD out today.

 

The open 'pie slice' is there at cold (size / shape matches what others seem have on working SADs).

 

12v through the element on it's own will cause the opening to close, but it can be in excess of 10 minutes (it's the very last tiny glimmer of a hole takes forever to finally shut).

 

Supplement the 12v with heat from a gun and not surprisingly it'll close in much quicker, but hard to quantify as the combination is hard to keep consistent.

 

The last little bit also closes much more quickly when 12v + heat gun.

 

Washed through the SAD with brake cleaner / small amount of plusgas afterwards to re-lubricate the moving window and it's made a difference, though nothing dramatic.

 

At the moment I'm going to tentatively assume the SAD is working correctly, what's stopping me being more confident is I've SAD's from MK1 Golfs on Kjet (called something else in VW circles) and they are confirmed working.

 

They take 2 mins 30 secs to close on 12v only (and consistently).

 

I understand they're completely different things, and there may well be such a wide variation between them, can someone confirm 10 plus minutes for the 205 one is to be expected?

 

When I was looking into this, I notice the pipe from the SAD outlet to the underside of the intake manifold gets 'sucked in' (for about 10cm of its length at the manifold end near the built in kink and not else where), when cold starting... it's like theres a vacuum?

 

It was a new BBM one (4 years old now)

 

Tun the car off and the pipe flexes back out to it's normal shape... when it's 'sucked in' it doesn't appear to influence any thing, air can still pass though presumably at a reduced rate. If I squeeze the 'sucked in' pipe while cold starting the revs will drop to near stalling.

 

If it weren't for the fact the car now out of the blue idles to 1900rpm before dropping to a warm idle, when before it was 1450rpm nothing has changed... runs like a dream as it always has.

 

Did the CO a few days ago and its 1.6.

 

I haven't put the SAD back in yet (issue may be resolved, hopefully) but it's a pig of a job and I didn't want to do it, to then be told there was something else I could have done while it was out!

 

Bit of a ramble, apologies...

 

 

 

 

 

 

 

 

 

 

 

 

[Leslie green 126]

On 4/9/2025 at 1:36 PM, Telf said:

Buy a new one! They don't really let anything through when closed.

Remaufactured sad valve is 360 with a well known supplier which seems a bit pricey,  same as an afm refurb !. I have found you can buy a kit to repair the quadrant but it won't fix a faulty heater .

[bacardincoke 42 1 Cars]

Cheers... found this just now, so if correct further supports the SAD seems to be working.

 

Don't want to go off at a tangent, one for another time, but it had crossed my mind before if it would be possible to make up a 205 SAD from say a MK1 Golf one (or vice versa / or any other), using one of those kits plus the still working bits from which ever?

 

 

 

 

 

 

 

 

 

Edited 20 hours ago by bacardincoke

[bacardincoke 42 1 Cars]

Meant to say the SAD is Bosch  0 280 140 182 (Peugeot equivalent 0345.37) for the 128hp 1.9 1987 onwards, so correct to the car / engine.

 

It's date marked October 1998, so not all that old (car's done small miles from then to now).

 

 

[Leslie green 126]

Seems yours is OK electrically and just not closing fully , maybe a new disc and spring will sort it , it's worth a go at 35 quid . There are 3 part numbers can't see there being much difference as one repair kit fits all 3.im not sure what actually goes wrong inside yet maybe it gets gummed up and jams .

Edited 20 hours ago by Leslie green