Blown turbo

[zeke]

I blow the turbos last week , while I was on the track trying to pass another RS4 and all of a sudden I no longer had boost at all, the computer doesn’t show any codes, has anybody had this problem before?
I have no boost and the exhaust is clean is doesn’t show the blue smoke that usually have when you blow the turbo.

If I have to change the turbos for new ones, what will be the best turbo to put? Right now I have MTM stage III 458h.p. in my car, with the stock turbos.

Regards

Zeke

[saf]

If it is your Turbo's

If its an MTM stage 3 then youd have bigger turbos.

I guess you mean stage 2.

The best thing to put is some nice stage 2 RS6 turbos, or even stage 1 RS6 turbo. They are straight bolt on. Have it mapped, and you should be seeing 520 - 550 HP with standard RS4 Intercoolers. If you have Front Mount then you should see more.

Thats with the RS6 stage 1 (straight RS6 turbo unmodified). With a stage 2, you would really need the Front Mount Intercooler to see good gains. Then you could see around 620 brake. This is providing youre running an unrestrictive exhaust system with around a twin 2.75 inch exhaust and precats gutted and have some custom turbo intake pipes with larger bore than the RS4 standard ones.

An easier way to get slightly over 500 brake, is to go for K04 RS6 hybrids, which use an RS6 compressor wheel on the cold side. These run more efficiently and are usually quite solid if you find a good turbo builder in your neck of the woods who sell them pre modified as they have to be made up.

Easiest thing is as I said before. Straight bolt on RS6 turbos. Ordered straight from KKK, with waranty. Cant go wrong. you only need someone who can custom map it for you.

If you cant custom map it then I suggest you go for same turbos. Or post your ECU for a gneric map form a tuner that has tuned this spec car before.

For your K04's to go pop, they may have been running high boost. I know of a lot of MTM RS4's that have been perfectly fine running the Stage 2 MTM stuff without problems. From reading your post, it seems like youve had a boost leak that has caused your turbos to pop. If youre not getting the smoke, then it may just be a serious boost leak thats cut you back into limp mode.

Somethign tells me if youre not getting the smoke, its not your turbos.

[Blue_Thunder]

You don't have to have smoke to have fooked turbos. My K04's recently failed. They made a hell of a whining noise and got so bad that on full boost you could here the scraping of the blades on the housing.

I'd take it to a local specialist before jumping to the expensive conclusion that your turbos have definitely gone. Have you checked that your N75 is still working? There may be a leak in one of the vacuum lines. Although saying that, it would probably show up on a Vagcom scan.

[saf]

You can use vag come if you suspect there is a minor boost leak by logging. Its pretty obvious that there is a boost leak somwhere if the turbos are still okay. But I wouldnt be logging right now as you know something is wrong for sure. You dont want to be drivign the car at all in the state its in.

Most of the time you do get the smoke whent he turbos blow, but sometimes you just dont get anything as you have said Blue Thunder. But I think thats rarer. The whining noise means that turbos are on there way out. Saying that the whining noise can last for 2 years , or for 2 days before the turbo decides to pop. I think the whining is just the turbo fins in bad state for one reason or another which cause the fins to touch and make the whining noise.

If I had to bet on it, i wouldnt. Its either a blown hose , or blown turbos. Or combination of a hose popping and the turbo(s) gettign affected as a result depending where the boost leak was.

I didnt think of the N75, that could also be the problem. Even a faulty MAF causing car to go into limp mode.

Either way, get it checked out before you drive the car any further.

[grizz]

Carry out a pressure test first , this will show any pressure loss . If you've had a big loss of boost it will have damaged the turbos if left for some time . .

[neckarsulm]

I thought Stage 3 for RS4 was just downpipes and cats using exisiting turbos?

If its an MTM stage 3 then you'd have bigger turbos.

Stage 2 is just map and exhaust, approx 428bhp.
I'd have thought there'd be some codes showing like negative deviation (actual boost well below requested boost) and management light on, maybe Mexican diagnostics aren't what they are in Europe....come on Zeke, more info please!

[saf]

I thought a stage 2+ was with custom or larger bore downpipes and sports cats / no cats. Thats what its like on the S4. Maybe its different on the RS4.

[dace]

I thought Stage 3 for RS4 was just downpipes and cats using exisiting turbos?

If its an MTM stage 3 then you'd have bigger turbos.

Stage 2 is just map and exhaust, approx 428bhp.
I'd have thought there'd be some codes showing like negative deviation (actual boost well below requested boost) and management light on, maybe Mexican diagnostics aren't what they are in Europe....come on Zeke, more info please!

Stage 3 is as you have stated with existing turbo's. should be around 450 / 460bhp IIRC

[saf]

Cool. So a stage 3 S4 and stage 3 RS4 is about the same power. Maybe a littl eless on an S4. Stage 3 S4's can also have bigger turbo's including hybrids, or RS6 turbos and thus have even more brake than an RS4. Which is why I though a stage 3 RS4 would be one with modified turbo's.

Zeke - In answer to your question, I just remembered that the RS6 turbos isnt a straight fit. The angle of one or both of the turbo's have to be modified to fit the RS4 or even an S4. I think KKK will do this if you tell them its going onto an RS4. (A friend of mine reminded me). If you do this then they are straight bolt on.

[zeke]

Thanks for all the info, I did check the hoses and couldn’t find any leaks ,all of the hoses are ok, then I check the MAF and the reading is ok on the Vagcom and it doesn’t show any engines codes. The check engine light is not on and the turbos doesn’t make any noise at all, is like they are not moving at all. I have a boost gauge install on my car and I have cero boost on the engine, the car hits 90 kph with a lot of trouble and can not go above that speed on a strait line.

Like I said before I want to go to MTM stage IV or V (if a have to change the turbos), because down here in Mexico there is no one that can mapped the computer so the RS6 turbos don´t work for me, that’s why I want a bolt on kit that I can put in with out any problems in other words plug and play. Has anybody tried the MTM stage IV or V, and what is the turbo that MTM is putting in instead of the KO4? or were can I get some heavy duty K04 for the RS4 instead of the OEM?

Saludos amigos

[saf]

Zeke - Check audiworld, theres a guy on there selling hybrid turbos. YOu can go for straight bolt on K04 RS6 hybrids . Basically it is the K04 with RS6 compressor wheel. This runs mroe efficient and will give and hold mroe power to red line. This is what a heavy duty K04 is.

They are expensive but well worht the cash for what you get and the power it delievrs to the RS4 with straight bolt on ease.

All you need is a map.

If you need a map done and an ECU sent out I can reccomend you someone if you send me a PM when and if the time comes.

If you cant find the guy on audi world, let me know and ill look for the link and send it to you.

[docwyte]

Stay far, far away from hybrid turbos, particularly ones from Buehn. They're very unreliable. Considering the amount of work and expense involved labor wise to swap turbos, I'd stick with factory K04's.

[saf]

Is Jacob still around then?

are there any good hybrid turbo builders around.

I think the best to trust is KKK. They make it, they can warranty it.

[neckarsulm]

Anyone know if there should be a fault code if turbos fail?
From my years with VAG COM I would expect it but never come across it on a 2.7T so don't know how these react.

[docwyte]

I think Jacob is still around, but no one on AudiWorld is using him anymore. His failure rate was close to 100% it seemed.

Blouch may be a better hybrid builder, but no one will build one as good as KKK/BW.

Won't necessarily get fault codes with a blown turbo (s).