Technical Turbo pipe sucking flat - Lots of noise - No power

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Technical Turbo pipe sucking flat - Lots of noise - No power

Niven

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Hi all,

Yesterday the power on my Bravo 100 TD SX dropped dramatically and the engine makes a really deep noise where the whistle of the turbo once used to kick in.

I've just had a look at lunch and the thick rubber pipe (excuse my total lack of technical knowledge) coming from the turbo to the engine is sucking flat above 1800 rpm. This corresponds to the loud noise (I'm assuming the engine is suffocating).

Is this a simple case of replacing the worn out pipe or is something more sinister occuring?

Thanks for any advice.
 
If it's under vacuum - and it looks like it's under heavy vacuum, you turbine is not spooling up, or spinning up, and that leads to engine trying to pull air in and choking as it doesn't get enough. Turbo might be seized, how long it was from your last oil and filter change? Maybe it seized from lack of lubrication. In every way, dont drive it that way, have a garage look at it.
 
Very true. I agree. But essence here is - his turbine is probably seized or not spooling up for any other reason.
 
Thanks everybody,

I've taken it into the garage today to get them to look at replacing the Turbo. I will let you know how I get on.

Cheers
 
More troubles :(
I've had the Turbo replaced and a new turbo related problem has crept in.
The 'garage' (My Dad *cough*) has taken a look and thinks part of the Turbo isn't functioning,

I will do my best to explain but we don't know what it is called, so bear with me. There is a small pipe that connects to valve unit that pulls a bar and opens something on the turbo (actuator?). The bar can be seen through the heat shield over the Turbo. This bar is not moving at all when the engine is revved.

While driving along beyond 2000rpm there is a whining noise instead of the usual whistle. The Turbo isn't kicking in and the car is once again down on power. It was working for a good 4 hours after changing the Turbo so I can say for sure that the power difference is quite high.

He is at a loss and doesn't have a clue what to try but is going to try and get a new MAF sensor on the off-chance it is that.

The car has already cost me it's value in repairs and I'm really regretting buying it now. It's a lovely car to drive but it won't stop falling to bits :(

I really hope you know what I'm trying to explain and can offer any help at all before I end up replacing every last part on the car lol :)

Thanks all
 
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I haven't got a clue where that is :S
I've looked through the bravo manual posted on this forum elsewhere but can't find a mention. Any hints/clues? :)
 
think you may have also had a post on the bravo guide but anyway..

that part you are referring to is the wastegate actuator, and is fed by a small pipe from the compressor side of the turbo, which opens the wastegate when the boost pressure gets near 1 bar. so if this is not opening, you'll have too much boost, but not a lack of power. On the other hand, if its stuck open, the wastegate will constantly be open, and you'll have no boost and lack of power, and possibly some noise. you wont see it opening just by revving the engine, the engine would have to be under full load to obtain enough boost to open it.
you could use an air supply regulated to about 1 bar off a compressor to test it, by applying pressure to the small pipe. Or move the lever by hand, making sure it is stroking fully and you can hear the wastegate snap shut.

Is the intake hose collapsing again ? Were oil and air filters changed ?

Other than that, make sure the turbo oil feed and return pipes are ok, and that you have sufficient oil pressure. also the oil temperature is important, so make sure the oil cooler and thermostat is operating

Also check the EGR valve, disconnect and block off if necessary to be sure.

the MAF is unlikely to be the cause, it (AFAIK) only controls the EGR on the TD100 and wont stop the turbo spooling. once they fail, they fail, and you mention it was going ok after replacing turbo. Its likely there is an oil supply problem, if the same problem has returned..

you ideally need a boost gauge to see what the turbo is producing when on the road. It should produce about 1 bar when you floor it in 4th or 5th above 1800 rpm.
 
I'm so sorry about this. I will write up everything that has been checked and give a more detailed description of the noise and the problem.

So far it has been into the garage 3 times without success. I can only go on what they have told me, but I will attempt to list what has been checked so far.

Better description of problem:
  • Large powerloss, lack of acceleration and the car struggles to get above 60 and maxes out at 82mph on a flat bypass.
  • Whining, almost rattling noise above 2000rpm but seems to vanish above 3500rpm
  • Very deep resonating noise when backing off the throttle above 2000/3000rpm which continues right down to below 2000ish.
It was taken in for diagnostics at a place called Lucas sometime last early this week. The garage was told that no faults were found but that they thought it sounded like a blocked exhaust.

The garage has ran the car with sections of the exhaust disconnected and cleaned out the system. It continues to make the noise even with the CAT removed and apparently the noise is very loud down the exhaust.

The Turbo has been checked as well as possible without replacing it (I really can't afford to buy another). It is spinning beautifully when idle and revving and spins perfect even manually blowing it with air.

The actuator pipe has been checked manually with air and is opening/sliding fine. The pipe is clear right back into the turbo, so it's not blocked or anything (or something hehe).

One other point I can think of, was that my old man said the EGR pipe was disconnected when he checked it today. Lucas must have disconnected it during the tests. I had driven it for a day or two like that and had noticed zero difference in performance/running etc. I haven't tried blocking off the pipe though. How best can I block it off?

I'm incredibly desperate now. the car is bleeding me dry and I would just about cut off my left *** to get it back to normal :(


Oh, sorry... forgot one thing that might be relevant or not.
When the turbo was changed, it started making the noise after an hour or so of driving. This continued all day until it was left for a few hours.
When we went out later to go to the shop, it was 100% PERFECT. I was so happy :)

It ran like this for a full day before it all just went pear-shaped again. The only thing I had done was leave the bonnet on the catch. This might sound really stupid but I popped it up to check if I could hear the noise, forgot to check and left it. It was 100% perfect after this and didn't break again until I closed it after my m8 told me it was up in the carpark.

I know this is 99.99% likely to be a coincidence but it is a really vicious coincidence that has been playing on my mind ever since. I know squat about cars really and things like this really convince me it had something to do with it. I mean, it was literally, bonnet up, perfect car, put bonnet down, instantly borked :S lol anyway, thought I'd add that just in case...


I'm really sorry for all this spam but I'm just hoping a better description will remind someone of a similar problem.

I have a bad sound quality recording of the noise that I will try to upload. I will post the link if I manage to get it uploaded later.

Thanks all, I really appreciate it,
Lee
 
Ok, this is the point where you all think I'm totally barmy and phone the men in white coats.

After finishing the previous post, I was so sick of sicking on my *** doing nothing and feeling hopeless that I decided to go and tinker with a few things so that I could add some detail to the post.

First I checked the intercooler pipe for pressure when revving and it fills out very well indeed. Above 2000/3000 rpm it was hard to squeeze.

I then blocked off the EGR valve (with bluetac of all things) and took it for a test drive. No difference at all.

In frustration, I did something pretty dangerous and popped the bonnet onto the catch and took it for a test, semi-safe in the knowledge that the catch is strong as hell and I would only be going semi-slow :S

Instant power gain, upto the point where it induced wheelspin pulling off in 1st and 'powered' up to 60 up a pretty steep hill.
The whining/rattly noise was reduced by a good 60% at least and it felt a lot more powerful in every gear. It had enough pull to push me back in my seat quite noticably where as before it had about as much power as your average fart.

What the hell could cause such a power gain just from popping the bonnet catch???? please tell me I'm not going totally insane. O_O
 
Ok, first of all, I'm so sorry for spamming the forum but I had to let you know! :D :D :D

I phoned my old man, let him know what I'd tried and he told me to rip off the air intake box.

It goes like a rocket! :D
No noise at all and it shoots up to 4000+rpm in a heartbeat (To the point where I'd better back off on the heavy foot I've become accustomed to using these last few months).

It shot up the hill like a freighttrain (in comparison *cough*)

He is thinking that the bonnet catch spring was maybe crushing the intake box to the point where the car was suffocating.

I have no idea how that could produce so much noise throughout the whole exhaust system but bh I am so happy now that I don't care :D :D

Just thought I'd let you all know. 3 months of garage work and suffering and it turned out to be something so simple :)

I'd like to just thank everybody who has offered advice. I appreciate the time you took to help out very much. Thanks all :)
 
:D

The original turbo had seized a few times, so did need replacing anyway. It was in a right state when we took it out.

Wether this had any bearing on it failing I don't know.

I've had another look since and it looks to me like the sound-proofing ws being sucked into the intake. I will need to find a way of pinning it back before replacing the intake but for now I assume it will be fine with the intake box removed :)

Cheers all.
 
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