vacuum pump

[lisalotus]

Having sorted out the brakes, the vacuum pump has decided to have a dizzy fit now

Should the vacuum pump be coming on every 10 secs??????????, I know its supposed to come on when first starting the engine, but then isn,t it supposed to switch itself off???????????. Have tested the pump as in removed pipe and put finger on end, and it comes on then switches off, so thats okay, so I,m thinking there has to be a leak somewhere in the system, does anybody have any ideas on how to find leak, cos it looks like spagghetti junction in engine bay, pipes going off in all directions . Or could it be something else?????????????????. Or should it come on every 10 secs, cos thinking about it it must come periodically to keep the system vacuumed, just not sure how often????????????

[tinywillyuk]

Hi Lisa,

Mine does the same and I'm told this is normal, and in five years its done it since day 1!

It runs for approx half a second every few seconds, presumably to maintain an optimum vacuum. If you have a leak - which I've had - it never stops until you turn off the ignition.

SuperDave is the vac pump expert though and may correct us!

Simon

94 S4

[lisalotus]

Hi Simon, I see you have a s4 as well, seems they all have the same quirky little personalities, either that or the mechanics that put together the s4,s were all on drugs .Think I,ve solved the problem, its the epv selanoid, so we,ve disconnected it, being as we no longer have a epv valve, its seems to be a reasonable assumption that we dont need the selanoid, correct me if I,m wrong somebody please.!!!!!!!!!!!!!!

[x6gas]

You've got a vaccum leak somewhere...

The pump does cut in and out to maintain vacuum, but shouldn't be coming on that frequently.

It is worth tracking the leak down and fixing it - it's pretty easy to do - as the pump is not meant to run that frequently and will fail eventually.

[lisalotus]

sorted I think , we,ve bypassed the epv selanoid, but kept it connected to the ecu so, I dont have engine fault light on, vacuum pump now quiet. fingers crossed that it stays that way . thanks for all the help guys.