turbo plumbing

[G588 OEA]

Started the maestro yesterday for the first time since i got it really.
As was stated from the under bonnet picture ,the breather system is a bit hit and miss.Also whilst having a good look, most pipes are perished or in some cases not even going any where.Does any one have a picture or diagrams of the breather system and turbo pipe set up,as the pipe to the acctuator is not even on :eek:
I think this would be a good starting point
Thanks in advance
http://www.maestro.org.uk/forums/showthread.php?p=33674#post33674

[E_T_V]

Ahh yes the first bit of advice is DON'T run the car with the actuator disconnected, as you'll get unregulated boost levels which although will make the car really really fast for a few seconds will quickly cook the engine and turbo.

Your car has obviously been modified somewhat from the pics and I think there is a charge cooler installed.

I can take pics of a standard set up if that is of any use to you.

Basically the big pipe from the turbo goes to the front of the car through in intercooler then back into the carb. (yours also has a charge cooler I think after the intercooler).

Somewhere also will be a smaller diameter pipe that comes from the inlet (at or after the turbo) and should lead to the actuator. This pipe provides boost pressure to the actuator so that the maximum boost level can be controlled by movement of the actuator/wastegate.

The breather from the sump I'm not familiar with really so I'll have to go and look at mine. I think it'll have a valve to regulate pressure in so I'll just have to go find where it is!

There is also a breather from the carb. This leads to a small solonoid on the inner wing?. This solonoid sometimes sticks and causes trouble so don't be suprised if you see it disconnected.

I'll try and take some pics later of my standard setup for you. And if you are around the next time I visit my parents (who live near mold) then I might pop over and see if I can help untangle the mess :D

Cheers

Dan

[G Force]

Hi, you might know this but incase you dont know, you dont have the standard turbo plumbing or breather setup. This could be the work of a complete tuning genious or a misguided attempt to gain more power.

The square box in the pipe between intercooler and plenumn chamber has been added probably as some other form of air cooling, the two green hoses you need to tell us where they are connected to, (I hope it is not engine coolant). The crankcase breather arrangement looks like it may have been just piped to atmosphere, is there a small bottle at the end of the long pipe going from the check valve to the o/s head light area?

The smallest pipe on the check valve should be connected to the hose on the inlet manifold in front of the carb (tell us where this is now connected). Then one large hose goes to the turbo air feed hose just after the air filter box, and the other to the tee peice connecting the oil seperator and oil filler cap. the oil filler cap is usually square on the turbo models.

The rude looking red pipe and blue valve on the plenumn is a dump valve. this has been fitted to control boost pressure now that the wastegate pipe has been removed.

Cheers Gary. :)

[D87 SMW]

The large box in the engine bay with green pipes is a PACE chargecooler kit and is a good upgrade for a car fitted with a standard intercooler aswell. The dump valve does not control the boost, this will still be controlled by the actuator, which will open the wastegate once its preset pressure has been reach. The signal for this comes from the back on the plenum chamber and also shares the same line as the fuel pressure regulator. It is very important that these lines are not leaking. It would be very apparant if you had a problem because boost levels would be through the roof, and the engine could also run lean increasing risk of detonation.

The dump valve cannot regulate boost, it is vacuum actuated and boost pressure would keep it closed firmly under load, so whatever is controlling the boost at the moment, its definatly not the dump valve. In fact, if there is no hose connected to the actuator in anyway, boost will be uncontrolled.

http://i6.photobucket.com/albums/y230/turb9/100_0358.jpg

Here is a picture of a nice tidy engine bay, and shows more clearly the breather pipe set up. The black/red valve above the cam cover should be positioned near the air filter housing. The small bore outlet of the valve goes to the one way breather/vacuum valve mounted on the inlet plenum/brake servo pipe.

The large bore pipe currently disappearing to the drivers side of the car goes to the air filter housing underneath. The remaining outlet goes to near the oil filler cap. On the sump is a breather also, a hose comes off this and a T piece is usually fitted. The hose that comes off this T goes to the filler cap, the other end of the pipe goes to the aforementioned black/red valve near the filter housing.

Advice C/O Gareth (GKAutoWorks).

:spanner:

[metro]

The rude looking red pipe and blue valve on the plenumn is a dump valve. this has been fitted to control boost pressure now that the wastegate pipe has been removed.

How would that work?

[G588 OEA]

Thanks for the quick replys ;)
Right the charge cooler pipes go to a seperate header tank and a front mounted heat exchanger.The original intercooler has been replaced with a bigger one as the original is in the boot,behind the driver side headlight is a tango bottle (apple if that helps) :laugh: .The pipe off the front of the inlet manifold goes to a blank end(blocked off) The acctuater pipe appers to have perished,as a bit is left on the acctuater itself.Before it was neglected apparently the car ran 25psi and ran a 13.4 quarter miles.But as its no tax or test i have not driven it,as the previous owner assures me the turbo is knackered :sad: i dont know???

[E_T_V]

25 PSI!!!! No wonder the turbo is shagged. That is unregulated boost levels at a guess. I think as standard they ran 11psi? (I'd check that figure as I've not delved into the books for ages). If the turbo is shagged you'll soon know about it by the plumes of blue smoke and rapidly emptying sump.

[G Force]

How would that work?

Hi, well if it is a dump valve that works in the way that Steve describes then obviously it could not work and when I looked closer on the picture I think you can just see a vac pipe to the right of the valve. :fim: On the standard Maestro turbo there is a plenumn chamber dump valve that dumps turbo pressure above a certain pressure in the event of a wastgate malfunction in order to protect the engine from what would otherwise be unlimited boost pressure. I genuinely thought you could buy this type of safety dump valve at various pressures as a cheap way of dumping high boost pressures but it seems I am mistaken :o so appologies to the OP if I caused confusion.

Cheers gary :hide: