New turbo fitted but still the noise remains.

[Turbo Lag FTW]

Just had a turbo replacement done today after purchasing a refurbed unit from essex turbos which I have to say was a great service and a very good package according to the garage that fitted it. Car has ooommmph now and has power delivery that is smooth and strong.

But, my problem now is that the noise which I was led to believe was the turbo is not the turbo, infact you can now tell the noise comes from the rear of the engine (AEB). The noise itself is a rattle and occurs when the revs drop, when revving, the noise is totally different and sounds like metal grinding but is only audible when you have the bonnet up. I was advised that it is more than likely the chain tensioner and chain making the noise. I really cant believe Ive just spent shed loads on a turbo and look to have to spend more than I did on the turbo to resolve this problem.

So what should I do guys, up and coming months restrict any kind of big spending and with the noise being there for a fair few months while thinking it was turbo, I drove the car fairly carefully. So as you see its a bit of a dilemma.
SO Is it a must to do and what kinda costs are involved?
Advice much appreciated as usual guys...

 

[NHN]

At what revs does it start to rattle, not sure if the chain has the same as my previous 8L S3 with the hydraulic tensioner for chain, maybe this is the issue its not putting tension on the chain?? Heard of this before tbh.

 

[Turbo Lag FTW]

I dont know what type of tensioner is used tbh, I was hoping some of the more experienced guys on here could tell me. According to the guy that replaced my turbo he told me audi had a fault early on with these engines due to the chain tensioner failing, I just hope it doesnt get that serious and would like some sound advice that can make me take a decision on what to do.

 

[aragorn]

The engines suffer from gunge buildup inside from bad oil changes. This gunk blocks the pickup screen on the tensioner and it stops tensioning.

Chain goes slack and it starts rattling.

Could try throwing a 50/50 derv/oil flush at it and see if that helps. If not then its new tensioner time.

 

[Turbo Lag FTW]

Will have to give it a shot perhaps, worst thing is ive just had it filled with new oil too with the change.

 

[aragorn]

could always pop the rocker cover and see if the pad on the tensioner is visibly worn?

 

[Broken Byzan]

Thats a good idea.

The screen in the bottom of the tesioner housing itself clogs up causing most of the problems. But once its off you just as well stick a new one in. Yours is non VVT so much cheaper than most under £100 from the stealer and 7/10 DIY job

 

[AndyCollins]

Don't rule out the turbo. I had the common lift-off rattle on the 99.5 1.8T I had a couple of years ago. As I lifted of the accelerator there was a metallic rattle while the revs dropped back down to idle. Took it to a reputable Audi specialist who confirmed the diagnosis and fitted a reconditioned turbo for approximately £1400 iirc. Imagine how sick I felt when the first time I started it up I heard the exact same noise immediately. Went straight back to the garage who then started telling me it must be something else. after much debate they agreed to remove the reconditioned turbo and found that it had the same wastegate rattle as the original one. They then returned this to their supplier who replaced it, and then fitted the replacement to my car, which solve the problem immediately.

To summarise, don't ignore the original diagnosis!

 

[aragorn]

Is this rattle fixable DIY then? or is it recon turbo time.

Ours rattles on overrun all the way down to idle and its ****** annoying. Makes the car sound knackered. Cant really afford replacing an otherwise perfectly good turbo though.

 

[AndyCollins]

There are differing opinions on what can cause the rattle. Originally I believed it was the wastegate actuator that had gone, which was allowing the wastegate to rattle about as it wasn't being held in place. You can't get these alone from Audi as they will sell you a whole turbo. I believe Forge do an adjustable one that could be used as a replacement. However, on removal the garage showed me that it was infact the internals of the wastegate that were loose, which required a new turbo. I had put up with the rattle for almost a year, but eventually decided to get it done as I couldn't stand it any longer. also, who knows what damage would have been done if the wastegate had broken up completely?

 

[Lee Goodall]

This might be some help too..

http://www.audi-sport.net/vb/showthread.php?t=77665

 

[Turbo Lag FTW]

I dont mind giving it a go changing the tensioner/screen and flushing, its just the way the guy put it to me at the garage. Commenting on how its best done with timing belt and to be honest thats only 20k old, and to clarify I know its deffo not the reconditioned turbo (essex turbo also give you the test results of the turbo on the balancing machine which I thought was cool) Anyway the noise is clear as day coming from the back area of the engine, the old turbo did produce some noise with the actuator being worse for wear and that caused me to overlook the back of the engine.

So what part would I be asking for at the stealers? and its roughly £90 which is good news at this time of year.