Mud-club

Vehicle & Technical => Defender => Topic started by: bombx3 on April 21, 2006, 22:03:14

Title: waste gate
Post by: bombx3 on April 21, 2006, 22:03:14
can anyone tell me should it move when you rev the engine as mine dont move
Title: waste gate
Post by: Budgie on April 22, 2006, 00:05:33
If your talking about standing still & revving the engine then probably not.
I think the engine has to be under load to produce the exhaust pressure to open the waste gate & feed the turbo.

If I'm wrong then someone will let you know.  :wink:
Title: wase
Post by: timberdog on April 22, 2006, 06:44:15
so you have to hang on the bonnet with hood open at 70mph!!...lol

on a serious note i think as above under load?
Title: waste gate
Post by: Sharpshooter on April 22, 2006, 06:58:24
Deffinately under load. :D
Title: waste gate
Post by: Xtremeteam on April 22, 2006, 13:15:59
although on a td5 it can be made to open with no load
Title: waste gate
Post by: rollazuki on April 22, 2006, 20:54:36
the only way to make it open is to increase boost levels on the intake side of the turbo to the point where boost is excessive and the 'gate' opens. This is unlikely to happen when stationary with no load on the motor.. Just check the pipes are all in good order, and  if need be, cycle the wastegate lever by hand with something like a vicegrip/molewrench to check its not siezed. Be carefull, its fairly robust, but damned expensive. If you have a boost gauge fitted, get the car in mebbe 3rd gear and nail the throttle. The boost should rise to perhaps 0.7 bar, then get no higher, as the wastegate should have opened and be dumping exhaust gas. If it keeps rising and gets over 1 bar Id say its siezed closed. If it never gets much more than 0.1-0.2 bar its siezed open.
Title: waste gate
Post by: Porny on April 23, 2006, 09:51:31
As stated, you only get boost under load.

Quote from: "rollazuki"
increase boost levels on the intake side of the turbo to the point where boost is excessive and the 'gate' opens


Sort of....

Boost pressure is the pressure that is in the intake side of the engine.

In simple terms, the air comes through the air intake, into the turbo where is gets compressed and thus pressurises the the intercooler (and pipework) and the inlet manifold.

The actuator simply controls this pressure and when it becomes too high opens the poppet valve on the turbo to allow excess 'boost' pressure to escape.

But this will only happen under load, and not just revved.
This is because the turbo will not be spinning fast enough... if just revved, and not under load it will only have low cylinder pressures, thus the pressure coming out the exhaust ports into the turbo will be low - enough to spin the turbo, but not enough to produce 'boost' pressure.


To test the actuator, as rolazuki stated, with the engine off you should be able to use a set of mole grips to move the actuator arm to check it's not seized.
Other than that you need to connect a boost gauge, and check 'boost' pressure under load.  The best condtion for this is attack a steepish hill in third gear - getting the engine to work. Under full load, the boost will get to the highest level it can - which it won't always quite do under normal driving.

I've attached some pictures of my boost gauge on my old 90.... it is connected as per Land Rover instructions (although there are other ways).


For a 200Tdi (which I think yours is) you should get 0.8 bar (11.6 PSI) although, if you after a bit more power this can 'safely' (i.e. you 'shouldn't have any problems) increase this to 1 bar (or 14.6 PSI) - mine was set to a peak (under the condtions mentioned early) at just over 1 bar.



Ian
SimplePortal 2.3.5 © 2008-2012, SimplePortal