hi guys. yesterday i had my secondary air pump replaced after a large amount of water was found in a pool at the base of the pump. when i picked the car up, the dealership said it was the first they had seen like this and they put it down to someone having driven through deep water at some point in the cars life.

now i had a read on here and a few other forums and it turns out that fault is pretty common on the 1.8t engine. one forum user said:

"typically the pump failure is caused by 2 reasons. 1st being the corrugated plastic hose is split allowing water into the pump. 2nd is a broken vacuum line to the combi valve, this causes the combi valve to allow warm exhaust air back through the cold SAIP where it condenses and fills the pump with water"

now im currently looking through Rob Clubley's site for a few more location images of the combi valve and hosing etc however i thought i would take a few pics of my own whilst inspecting the hosing. and what i found surprised me (images below)

can anyone tell me where this water is coming from i simply cannot afford to have another SAI replaced :(

thanks

Jeeping f**k!!!

Judging by the colour that looks like condensed water from the exhaust manifold. I see it's gone all the way up the secondary air pipework to the air box and collected at the bottom of it!!!

Your panel filter must have been a right mess!!!

I would clean everything out and check the hoses (as you're doing) possibly consider replacing the combi valve or even (bit drastic) remove the whole secondary air system. Filling your airbox with water like that is very very bad!

What the hell! Never seen that before!

That water can't come from the combi valve. If the vacuum line is removed from the combi valve, it will just stay shut. Warm exhaust air is also an understatement! Hot exhaust gases is more accurate, and they would melt the plastic pipe.

I'd say one of the plastic pipes is split, and someones been through a ford. Or the water came from the airbox, and the car has been in some very very deep water! But if that were the case, if fairly sure the turbo would be destroyed too. So my money's on split pipe or pump.

Inspect all the pipe work, and get that airbox cleaned!

Ahh actually..... if the pump fails, and the N112 still opens the combi valve (it really shouldn't though), then the pressure in the exhaust manifold would be greater than the pressure in the pump pipework, and gases would travel in the wrong direction. Being only at cold start, the gases wouldn't be smoking hot, and the gases would be rich in fuel. You'd have to be very unlucky though!

If the pump is now working, you should be fine. If it is that.....

Just a thought but are the rivets on the SAI pump corroded or snapped? water could of got into the system through the cracks there if the car has been driven through a ford or a deep puddle.

thanks for your replies.

chicken eyebrow: i know it is crazy! i couldnt believe it when i opened up the air filter housing - what a mess - panel filter was half brown, half yellow! well put it this way if i cant find the leak or the price of a replacement valve is too much then im afraid i am gonna have to resort to ripping the lot out. in the long run it will be much more cost effective i think - plus if that amount of ****ty water travels up into the airbox at any point again i could be looking at even more bills £££££ :no:

bodge: didnt really think about the heat issue and of course a direct feed from the manifold would surely melt the plastic piping - very good point. the real trouble i have is understanding the way this thing operates? does is draw air from the airbox to the pump and then to the combi valve? its just if that is the case then if you look at pic 2 on the top half of the filter housing the water has almost trickled into the airbox as you can see the rusty markings underneath the hole on the top half of the housing. its almost like the pump was working in reverse. either that or there was just so much water in there it had no where else to go apart from up

tommyj_vrs: well when the old pump was fitted i checked it and the housing looked solid with no leaks etc. it was last serviced in nov 09 meaning that the air filter would have been replaced so has obviously occured since then. so with there being no visible leaks in the old pump this is what is worrying me and making me think it might just haoppen again to the new pump :S

I've had a thought.

There's no way that the water can go that way up the piping normally. Even if there was a split in the pipe, or the pump rivets had failed, the water would be sucked through the pump and blown through the exhaust, not pushed back up through the piping. The pump would have to run in the wrong direction to do that.

I think that the combi valve is sticking open and letting exhaust gases the wrong way through the SAI pump (the pump will have turned off and won't be 'resisting' it ). This will be accelerated by the intake sucking at the top of the pipe, effectively sucking gases from the exhaust back into the intake, along with any moisture in the gas.

Maybe??

I've had a thought.

There's no way that the water can go that way up the piping normally. Even if there was a split in the pipe, or the pump rivets had failed, the water would be sucked through the pump and blown through the exhaust, not pushed back up through the piping. The pump would have to run in the wrong direction to do that.

I think that the combi valve is sticking open and letting exhaust gases the wrong way through the SAI pump (the pump will have turned off and won't be 'resisting' it ). This will be accelerated by the intake sucking at the top of the pipe, effectively sucking gases from the exhaust back into the intake, along with any moisture in the gas.

Maybe??

i think this is probably the best explanation. i am just so suprised at how much water there was - surely all of this couldn't come from the exhaust gases?!

could the faulty combi pump explain why the new SAI pump is so freaking noisy? they only fitted it the other day and literally you cant hear a conversation immediately outside the car it is that loud. took a vid this morning and going to post on youtube because it is far from normal.

I reckon you're onto a winner there with that theory.

What I reckon is that the combi valve is stuck open as rk696 says. Now normally, when the cold start procedure is happening you are not revving the engine so the pump is happily sucking air through from the air box and delivering it into the exhaust manifold through the open combi valve (maybe this also explains why it's not a good idea to drive these cars when they're going through the cold start procedure).

When the cold start procedure is finished, the combi valve should close. In your case it isn't closing, so whenever you rev the engine, the suction in the air box is causing exhaust gases to be drawn out through the combi valve, and backwards through the air pump up into your airbox where they cool and condense forming all that water. The gases are going through the pump the wrong way causing the blades to spin the wrong way on the bearing which is what I reckon is causing that noise (does the noise sound really bad when you rev it?) If the combi valve was closing as it should be, it would be a closed system so when you rev the engine during normal driving it would not suck air through from the secondary air system and not spin the pump the wrong way.

Now I think you just need to narrow down whether it's the combi valve itself that is at fault or the N112 which controls it via a vacuum. You could try fitting a t-piece into the hose between the N112 and the combi valve and then fit a vacuum gauge to that and see whether it is reading a vacuum during the first 60-90 seconds of starting the car from cold. If it's not then the N112 is at fault, if it is then I would say it's the combi valve.

<edit> ignore that last bit as if the N112 fails it fails inactive so doesn't provide a vacuum in which case the combi valve would be closed. So either way, it's going to be the combi valve, not the N112.

Edited 22 July, 201015 yr by chicken_eyebrow

chicken eyebrow: thanks for this break down. i just could not get my head round how it works but also what the hell is happening to my system to cause all of this water build up! on another forum one user states the following:

"Combi Valve: Check that it is getting vaccum (there is a tiny vac hose that goes into the back of the valve, it may have come loose or gotten loose over time as the rubber stretched out).

There is also a procedure for checking the combi valve when you remove it from your car, air should only pass through when vaccum is applied to the small nipple at the back.

Trace the vac line from the back of the valve to the solenoid underneath the bracket in front of the intake manifold - check for leaks, etc.

If it's allowing air to pass in both directions regardless of whether or not vaccum is applied, then you do indeed have a bad combi valve, and this could cause the condensation to build up in the pump destroying it over time."

so thats my plan for tonight. also ordered a pipercross panel filter today so gonna clean up the airbox and fit the panel when it arrives.

took a vid this morning of the noise (as promised) and it can be found at the link below. let me know what you think cos personally i think it is a tad loud maybe?!

Sounds a bit like a Harrier doing V.T.O.L. at first

I've heard a pump make noises like that before but that was because the rivets had gone and there was a gap between the two halves of the pump, and as you say, yours is a new one that's just been fitted.

I'm also wondering whether the hoses were connected to the right connections, both on the old pump and on the new one (I assume when the garage fitted the new pump they just connected it the same as the old one). I.e is the hose from the air box connected to the "input" part of the pump (the end of the pump) and the hose from the combi valve connected to the "output" part of the pump (the side of the pump).

Let us know how you get on with checking the combi valve. I've got a feeling it's a bit awkward to get off as you have to disconnect a coolant hose and lose some coolant to reach one of the bolts.

Edited 22 July, 201015 yr by chicken_eyebrow

Let us know how you get on with checking the combi valve. I've got a feeling it's a bit awkward to get off as you have to disconnect a coolant hose and lose some coolant to reach one of the bolts.

to be honest mate - after reading the guide on rob clubleys site i dont even wanna go near it, but hey needs must i guess! will keep you posted...

thanks again

Keep us posted, I wanna find out what's wrong now lol

As Bodge says, check that the input and output connections on the pump are the right way round too.

UPDATE!!

right then a little update for those interested.

I have taken out the air filter housing and clean it thoroughly. with this i also replaced the air filter with a nice new pipercross foam element. i also took off the plastic hosing from the filter housing to the SAIP and gave that a good clean as it was just dried rusty muck inside. while it was off i tested for leaks by filling it with water and no leaks there. i then took off the smaller hose leading from the SAIP to the combi valve. (now this is where it gets interesting.) as i undid the clips holding the hosing onto the combi valve it ****ed out with water, but real blacky browny (hot/warm) water. so much so that when i ran my finger in and around the combi valve inlet it was more like oil that was on my ifnger rather than water - thats how discoloured it was.

so having also cleaned this hose and checked for leaks i think it is safe to say that it is def the combi valve that is at fault. the SAIP does start when im driving - even half an hour after a cold start it will just randomly start up. so im guessing the solenoid is getting tricked by the faulty combi valve and starting up to help compensate for the loss. either way that combi valve i would say is bust.

good news though, booked in to the dealers on weds of this week and they are replacing the combi valve for me and are going to test the solenoid as well. i know this all seems a little bit expensive compared to removing the entire vac system, but i simply just do not trust myself doing the job - especially installing the resistors etc.

will update again when i get the car back weds nite.

Good news and sounds like it won't be long before it's fixed. I'm guessing it probably drives a bit better now the filter isn't waterlogged?

Good news and sounds like it won't be long before it's fixed. I'm guessing it probably drives a bit better now the filter isn't waterlogged?

ah you're right there. it is just a dream to drive now - so much smoother . just hope it didnt do any long term damage. just need to get rid of the harrier start up noise which should be fixed as of wednesday and then i can get the 007PA on at last. woooooo!

Hope you get it sorted, water in the air system is a bit of a nightmare, hydrolock and all that.

A good reason to have a induction kit! no where for that water to puddle.

Hope you get it sorted, water in the air system is a bit of a nightmare, hydrolock and all that.

A good reason to have a induction kit! no where for that water to puddle.

cheers mate. yeah when the funds are there i think a carbonio will go on it some time in the new year

Just a thought... i think that the water will have come thru the air box and been sucked into the pump etc. a car i am working on now had a similar problem (but tdi and killed airflow meter) the inner wheel arch liner had been broken and the front tyre was just throwing water up straight into the air intake pipe,

maybe the same problem here and maybe the last owner had a new airflow meter and filter fitted etc?

worth a look anyway (and i can prob find you a pump if you want one)

good thinking, wouldn't ever had thought of that..

Worth a shot if the combi valve doesn't work lol

Just a thought... i think that the water will have come thru the air box and been sucked into the pump etc.

hi mate - thanks for the suggestion. the thought had crossed my mind actually but then when i opened up the air filter housing it became apparent that the water was coming from the pump.

if you look at the 2nd pic above you will notice that on the top half of the filter housing (which im holding in the photo) there is brown staining right below the hole which connects to the pump. it looks as if it has just trickled down out of that hole and then pooled at the base of the filter housing. this is what makes me think it is combi valve. but how the hell water got all the way up that pipe to the air box mystifies me :wonder:

will let you guys know how i get on after the dealers tomorrow - fingers crossed

thanks again

ahh the pics didn't load earlier we ahve a slow connection at work.. yes i can see that clearly from that pic. i suppose once there is enough water/condensation in the pump then the exhaust pressure is going to push it up the tube into the airbox..

potenial for a fire there if the valve were to stick open and let super heated exhaust gasses thru it into the plastic pipework too :wonder:

It most have been doing it for a while to be so bad!

Wow what a mess! The damage could have been a lot worse with water going into the airbox

how the hell water got all the way up that pipe to the air box mystifies me :wonder:

every time you revved the engine a lot of the exhaust gases would be going straight down the pipe to the air pump then up the other pipe to the airbox.

I spose it could have reduced performance a bit as well as those gases should have been going out through the turbo