Turbo problems...where does this pipe go?

[noiseman]

Hi all,

Just discovered this forum, good stuff.

Can anyone help me out there please?

I have a 1993 (k) TD (don't know what ps of it is), And have a problem with the turbo.

The engine recently began to make a screeching similar to a slipping fan belt but after looking at it this was not the case so my attention turned to the turbo. The pipe that goes into the diaphram/ rod bit (i assume this is to operate the wastegate) is broken and worse still i can't see anything to connect it to.
Van seems to be a bit down on power but as i only drive the van every week or so i can't really say for sure.

Question is how does this pipe normally connect and to what?
If I leave is disconnected what will happen?, as the wastegate will not be controlled, what are the consequences?.

Any help will be appreciated, have looked in Haynes book but the turbo section is err....vague to say the least.

cheers

[Nighthawk]

A picture would enable a correct answer,

There are 2 diaphram devices in that area, one is indeed the wastegate, the small pipe comes off the compressor side of the turbo and goes onto the wastegate actuator. If it comes off there is nothing to control the boost levels, when it rises too much the fueling will trim down though as a safety feature.

The other diaphram unit is on the throttle housing, it controls a butterfly valve inside the housing. If the pipe comes off here, the engine will suffer poor performance because the air can't get in to the engine.

both are within 6" or so of each other.

[noiseman]

Thanks for the swift reply.

The pipe is from the smaller diameter diaphram, the one with the longer (approx 5-6") actuactor rod and runs front to back, parallel to the exhaust manifold.

If the pipe is off of the compressor as suggested, does this mean too much air is drawn in or will the 'hole' disrupt the turbo's efficiency as the compressor is open to atmosphere?

Would this disconnection be a source of the noise?

I'll try to get some pics at the weekend.

cheers

[stevew]

The pipe is connected to the high pressure side of the compressor. If it's not connected you'll loose turbo pressure at the inlet manifold and hence engine power. The noise you're hearing is the pressurised air escaping.
Steve

[Nighthawk]

Yup, you've lost the connection to the wastegate actuator, the noise is likely to be the high pressure air escaping.
It was held in place by a small spring clip.

[noiseman]

Thanks for the help chaps,

I have found where the pipe should go and have reconnected it.

Noise is a little less now but there is still a bit of a noise, you can almost hear idividual bursts at the speed of the engine rather than continuous.

Ran out of light today, but tommorow I will check the nuts around the flange that is just above where the butterly valve is housed (it is triangular and is secured with 3 studs) as there appears to be signs of fresh oily residue a sure sign of a leak also.
Does anyone know at what pressure the air on the intake side is?
The term 'high pressure' lends itself to something like 50psi +.

I was reading also somewhere else on the forum that leaks the exhaust manifolds can also produce the same noise as described, then again I suppose leaks anywhere be it intake or outlet on a turbo engine can produce excess noise due to high pressiures on both. I think i'll check em all one by one.
Thanks again for the help so far!

[Nighthawk]

yes, leaks on the exhaust manifold gasket and the area around the turbo can make screeching sounds as gasses escape the exhaust system.

The inlet side can do the same, so have a good look round before you start spending ££££

Oil in that area is normal, just wash it away every so often, it gets expensive fixing that issue.

On the HIGH side of the turbo, you'd be looking for a pressure upto around 1.7bar on the diesels, some high performance engines will often go double that figure though.

[stevew]

1.7 bar! Are you sure about that? I feel obliged to just beleieve you since you've been spot on for everythign else!
My Haynes manual says 0.61 to 0.71 bar at full boost.
I have fitted a boost gauge to my van, mainly so I can see if the turbo stops working or starts to fail. It reads up to 1 bar but the waste gate opens at around 0.9bar aand then it sits at 0.8 when cruising on the motorway. I'm not exactly confident about the accuracy of the gauge, it's more for incication, but I have tested it against a different one and it's not too far off.
If it's supposed to run at 1.7bar that could explain the slightly feeble performance I'm getting!
Steve

[madmark]

0.7bar sound best ,rs turbo escorts were only this standard ! steve as a matter of intrest were did you pick up the pipe from to connect the boost gauge????????

[Nighthawk]

Dont forget, boost is measured in Absolute terms, your living and breathing 1bar right now so by the time a turbo increases it you get to 1.7 real quick

[madmark]

sorry mate wasnt doubting your word, so if a guage in a car is 0.7 ie standard rs turbo is that write or is the gauge messhure difrent??????

[noiseman]

Problem sorted.
Checked for loose nuts and not only did I find 2 exhaust manifold nuts so loose they were only finger tight but on the underside of the manifold where you can't see, 2 studs actually missing!

Quick visit to hardware store, 1 length M10 studding and half a dozen nuts.......0.79 Pence, Result..Screeeching gone.

Still have a little whistling when turbo cuts in but will check that out when I have more time. I actually have a spare one about thats in good nick so all is not lost.

Thanks for your help have learnt alot

[MrMPuk]

You might want to replace the stud bar with proper exhaust studs and nuts otherwise you may well have the same problem in a short time!

[Luke]

sorry mate wasnt doubting your word, so if a guage in a car is 0.7 ie standard rs turbo is that write or is the gauge messhure difrent??????

as we are now the atmosphere pressure is 1 bar so if a gauge reads 1 bar when the engine is switched off then it is reading correctly- most gauges will read 0 bar at atmosphere - when the engine is switched off. this is deliberate to make it easier to understand when you are only talking in terms of pressure increase on atmosphere
ie. 0.7 bar is the same as 1.7 bar

confusing tell me about it!!

[100ps_drw_hicube]

Problem sorted.
Checked for loose nuts and not only did I find 2 exhaust manifold nuts so loose they were only finger tight but on the underside of the manifold where you can't see, 2 studs actually missing!

Still have a little whistling when turbo cuts in

i had the same problem with a loose exhaust manifold caused the same problems but as mrmpuk says get some proper studs in there as i temporarily used some ordinary bolts but they all fell out within a few miles the correct ones seem to be a tighter fit

and finally i dont think there is anything wrong with the turbo as all the turbo d.i's we have had have a whistling turbo it seems to be like that on most vans