As all you MK4/A3 1.8T owners may know, when you start up your 1.8T's from cold, it seems to make a noise for 30seconds where its automatically warming up, and then goes silent. Well lately, the noise has become really loud, and sounds only what can be descirbed as, "like a belt screeching" But when it cuts out the car is back to normal, and is as silent as a mouse. Anyone else had this problem before? Cheers
I've lost count how many times I've seen this, metioned this to the customer who has then replied "what noise??"
My pump was noisy and after taking it off I found the reason why. 3 of the rivets had broken off so air was leaking out. Drilled the remaining ones out and replaced with bolts and nuts as per the Uk MkIV thread. They are a ridiculous amount of money new, so for the sake of a few quids worth of nuts and bolts and some knuckle scraping its well worth doing it yourself.
Yea i might sort this out myself one day... * Also ive noticed that on some morning the air pump wont start up at all, even when its really cold, which i worring. Would there be any reason for this?
Just a quick revival. Do i need to have this air pump. Its starting to annoy me lately tbh. Can i just disconnect it, or remove it completely? Every day i start my car it comes on, even when hot...
Rip it out and stick some resistors in to fool the ECU into thinking it's still there. It will store a fault for 'incorrect flow' but it won't light up on the dash if you know what I mean. Here's a pretty good write-up on ripping everything unwanted, the SAI removal is also shown: http://forums.vwvortex.com/showthread.php?3111538
It`s only purpose is to help get the Cat up to optimum operating temperature as quickly as possible so helping keep cold start emissions down. Not having one won`t actually do any harm though, so if it`s becoming a problem, get rid.
It'll be some of the rivets that are broken. As I said, 3 of mine were duff, I drilled them all out and replaced with nuts and bolts, it shut it up straight away. It's a bit fiddly, but easy enough.
SAI pump can be removed and cal/d out in a recalibration or a suitable resistor can be subsituted as the pump motor load, similar to tricking airbag controls. As said by Stu it is used to rapidly heat up the under floor catalyst by injecting air in a rich and hot exhaust ( via ignition retard) causing a thermal reaction infront the cat brick. Usually the ECU calibration is set to switch this process one at engine coolant temps of 12-30 deg C.
Cheers for that Toyotec. Been thinking about it, and ive decided i'll replace the nuts and bolts, just incase i decide to sell it in the future. I suppose it will help when its cold to. Will let you guys know how i get on. Cheers!
2.0l GTI non turbo engine SECONDARY AIR PUMP NOISE FIXED Hi Guys I had the same frightening noise from the secondary air pump this morning, starting from cold. Went quiet after 1minute running. Sounds like a mixture of cam belt touching the case/ dry alternator bearings and dry camshaft bearings all happening at once!! but it wasnt any of these in my case. It was the secondary air pump with one of the black plastic air tubes popped off its position causing a leak of pressurised air. I remember last week I had the secondary air pump off, for getting access to the spark plug leads coming from the distributor because getting to them without first removing the sec. air pump is a b....t. I must not have snapped the air feed tube back on to the spigot positively enough. It has `squeeze me` side clips which snap on to the spigot. I popped the plastic tube back on to the compressor and hey presto, noise has gone. There are 2 black plastic air hoses attached to the sec. air pump. This loose one was the smaller diameter one which is on the pressurised side of the pump. Other people have reported noise from their pump because of air leaks due to rivets falling out of the case and leaving an airhole. I can understand this now. While writing about this I had disturbed the air pump hoses initially to get to the distributor to check spark plug leads. I had trouble starting one morning and then reluctantly it would fire then run on 1 cyl almost. Wouldnt idle at all. Strong smell of petrol. It turned out to be a corroded high tension socket on the distributor head, feeding plug 2. I cleaned this out and hey presto all fine.
