Rough idle

[4everRS]

Intake valves look great. Don't forget to scrub the TB with some carb cleaner.

[kday]

So does anyone know what this suction jet pump does? The Bentley doesn't explain it anywhere I can find.

My guess is that it is a vacuum generator for keeping the brakes boosted (ironic, given what happens when it fails) when the manifold pressure is at or above atmospheric. From the pics in this thread it looks like it bleeds off turbo boost pressure from the manifold and routes it to the intake side of the left turbo after the MAF, and that pressure differential powers a venturi pump which draws down the vacuum accumulator etc.

Some earlier turbo cars (Porsche 964 turbo, Audi Ur-S4/S6) use hydraulically boosted brakes to address the problem of powering brakes under sustained turbo boost. That system has its own complications (leaking hydroboost servos, the infamous "bomb" hydraulic pressure accumulator, etc.) and surely the venturi pump is cheaper. But if the venturi pump is not reliable, it would be better to not have it at all -- you might loose brake assist if you're WOT for 30 seconds, but unless you're on the salt flats, when would that happen?

[Brav]

So I got the passenger intercooler/radiator out but the drivers side seems a lot more reluctant. All coolant hoses are off. But I can't get it to lift up off of the upper bracket. Any tips?

[hahnmgh63]

Could just be the grommets are tight & frozen on there. Just keep wiggling it while applying upwards pressure. I lubricated mine with some Silicone grease when I installed my Wagners.

[Brav]

OK thanks. Seems to be an ongoing theme with me and this car.

Does anyone had a scheme for pulling and capping the aux radiators and hoses? I'd like to rip them out.

[hahnmgh63]

http://www.rs6.com/showthread.php/22...with-01E/page4
Steveken was my inspiration for this but for me it was a complete removal as my engine/tranny were out of the car but you can get most of it out and cap the rest. Look at the exploded view carefully of the Aux radiator system and you will be able to figure out where to cap it all. They are just bascially added on to the stock system so you only need to cap them off and don't need to install a bypass (runaround system).

[SteveKen]

The only way to completely remove all the aux rad hoses is to drop the steering rack. The system is capped in two locations. The one is the first hard line off the water pump outlet. The second is off the convoluted fitting near the coolant reservoir.


Also, one thing to note is that the RS6 has an electric boost pump for the brakes. I'd love to understand why they put this in te RS6 and not the S6. Initially I thought it was an automatic transmission thing. Not so, maybe??

The early B5 S4's didn't have them, but the later versions did. I'm wondering if it can be removed and what affect it will have if removed? Any thoughts on this?

[kday]

If there's an electric pump (where is it?) then the jet pump thing must be for something else. Crankcase vent maybe?

Turbo cars spend more time not making vacuum in the intake manifold. Not so much on the RS6 maybe but think about a little 1.3 liter turbo -- you'd be in boost every time you were on the gas.

[hahnmgh63]

The electric pump is right next to the Power steering resevoir. The Aux radiator coolant line that goes by the steering rack could be left and I wouldn't even bother to cap either end. That is #32 in the ETKA pic. I had my engine out so was anal and removed them all, including the other difficult one which is #24 I believe which is buried inside the bottom radiator/condensor assembly which must be dismantled if you want this one out. But then again when I did my KW's, I pulled every DRC pipe out from under the car and scrapped it rather than capping it off. The pipes mentioned are Aluminum pipes so they are not really adding weight or will they become a rust problem if you leave them open or capped.

[SzymekCRX]

kday, yes the SJP is helping to boost braking with the venturi effect

On the other hand I don't have a frickin idea why the designers put it UNDER the manifold and not just hanging around under the hood like in a VW or any other VAG car ! It's not that big :/

[Brav]

Another question - do I need to replace the intake manifold gaskets? they seem ok to reuse. Do I need to apply any special grease?

[mik15]

the guys from the Audi dealer where i took my car for the same problem said they will replace the intake manifold gasket as it is a must, they also said that the MAF's seals should be replaced as well if you take it out, this was mainly because i got an error code from them when they scanned it...the gasket price is about 50$ from what i understood, so i would say change it if you're there...

[Brav]

OK thanks. I already received my MAF seal kit from Apikol

[mik15]

how much was the kit?

[Brav]

59 bucks. including shipping and glue for the seals to help hold them in.

I finally set up a wholesale account (I have an auto dealer license) with local Audi Stealer. Prices are ALMOST as good as Genuine, but I dont pay shipping, and some are in stock for same day service. They said I need 2 o-rings per injector (rail and manifold side), so I will go with 8 since I cant see any leaks from rail. The plastic bit that I show broken is NOT order-able requires new injector. I assume I would be an idiot to reinstall the one with the chipped plastic washer, maybe I can get away with that cracked one. What is the purpose of those?

I guess I should order at least one new injector (Bosch for less than half the price, thanks Hahnmgh. By the way, have you or anyone else used the Bosch injectors yet as a replacement?

I did find it here for 93 bucks.. cheap!
http://www.theautopartsshop.com/fuel...280156167.html

[ben916]

59 bucks. including shipping and glue for the seals to help hold them in.

I finally set up a wholesale account (I have an auto dealer license) with local Audi Stealer. Prices are ALMOST as good as Genuine, but I dont pay shipping, and some are in stock for same day service. They said I need 2 o-rings per injector (rail and manifold side), so I will go with 8 since I cant see any leaks from rail. The plastic bit that I show broken is NOT order-able requires new injector. I assume I would be an idiot to reinstall the one with the chipped plastic washer, maybe I can get away with that cracked one. What is the purpose of those?

I guess I should order at least one new injector (Bosch for less than half the price, thanks Hahnmgh. By the way, have you or anyone else used the Bosch injectors yet as a replacement?

I did find it here for 93 bucks.. cheap!
http://www.theautopartsshop.com/fuel...280156167.html

That is CHEAP for a new injector!!!!

Also is there a link for the Apikol MAF seals?

[Brav]

That is CHEAP for a new injector!!!!

Also is there a link for the Apikol MAF seals?

I searched their site and couldn't find one. So I just emailed them and got a quick response from Doug, payment by paypal and done.

Also, ordered one injector from theautopartsshop.com, came to 112 with 2 day air. Summit was 140 with handling charge and air charge. Hopefully it works out.

[Brav]

Not much update today. I picked up my pump relocation kit to put in, and it seems it doesnt fit.

I think from the pics of the TSB that the dealer gave me with install instructions that its supposed to be for V6. The belt drive, hose locations and other references in the drawings don’t match up at all to what I am looking at. For example, under the intake manifold, the supplied 90% elbow plastic pipe does not fit right with the stock pump location.. it should be a linear coupling (see here where I disconnected). I have to really stretch it to come close to putting it on right.



I got the intercoolers out, just had to push harder. Removed aux radiators, and will cap them off somehow. ICs are soaking, driver side was pretty dirty...




Also on drivers side upper IC hose.. the clamp was barely on evidenced by the indentation. this shows you where it was sitting if it were still installed.. maybe a leak source?


And finally, what are these 3 "rings" or holes that line up on the frame and sub-frame? looks like some bushing should be in there, but both sides are empty...