Waste Gate Valve Operation

[Terranical]

All the posts I have read regarding checking the operation of the waste gate valve on a pre-intercooler T2 TD (1994) suggest that they tend to seize, and to check for this the rod should be moved by gripping with a pair of mole grips. If it moves it's not seized. Well, mine appears to be exactly the opposite i.e. I can move it backwards and forwards very easily with my little finger. The only spring pressure appears to come from the torsion spring on the pivot shaft. Can anyone tell me if this is a cause for concern (the car is going ok, but I get a whining noise from the engine when I am accelerating which dies away after around 3000 rpm, even though I am still accelerating. I feel this is coming from the turbo, and wondered if the waste gate valve could be a contributing factor.

 

[Timbo_1975]

Right, the valve rod connected to the pressure capsule, should be under quite abit of spring tension from the spring inside the capsule pulling it closed. With a pair of grips you should be able to open the valve pushing away from the capsule. Quite abit of force needed.

If yours is flapping about, then either the rod has unwound itself (sometimes possible depending on the capsule) the spring has broken inside (less likely) or the valve head inside the turbo has fallen off (much more likely)

Un hook the rod from the arm by removing the circlip (dont let it ping off out of sight) and check the individual compontents to see where the fault lies.

In all the scenario's, you'll be getting 0 boost pressure and the truck will be driving like a NA 2.7 of about 80hp.

 

[Toolbox]

I can move it backwards and forwards very easily with my little finger. The only spring pressure appears to come from the torsion spring on the pivot shaft.

Are you sure your looking at the correct thing? there is not normaly a spring on the pivot shaft.

 

[zippy656]

sounds like you need


PIC!

 

[rustic]

Re the whining noise, check out the threads on the radiator cooling fan, it is a viscous fan and makes this noise starting from cold and goes away after a 100 yards or so, or maybe over certain revs.
Hope this helps.
Regards,
Rustic

 

[Terranical]

sounds like you need


PIC!

Pic as requested - don't think this is the waste gate valve, in fact, don't have a clue what it is!

 

[Terranical]

Re the whining noise, check out the threads on the radiator cooling fan, it is a viscous fan and makes this noise starting from cold and goes away after a 100 yards or so, or maybe over certain revs.
Hope this helps.
Regards,
Rustic

Thanks for the info Rustic, that sounds about right (noise seems more frequent when temp. is 25 or upwards here in sunny Espana!)

 

[Timbo_1975]

Thats the throttle valve!! Two purposes:

a) To increase volume of EGR around idle speed.
b) Known as a 'doser valve' in french circles- point being to reduce shut-off shudder on a high compression engine when you switch off- should close on ignition off.

 

[Terranical]

Thanks for that, wouldn't have worked that out in a million years! I do get a violent shudder when I switch off, does that mean the throttle valve is u/s?

 

[briggie]

Thanks for that, wouldn't have worked that out in a million years! I do get a violent shudder when I switch off, does that mean the throttle valve is u/s?

i get a violent shudder ( from the engine ) too when i switch off the ignition

 

[Terranical]

i get a violent shudder ( from the engine ) too when i switch off the ignition

Probably nothing to worry about then - cheers Timbo1975 & Briggie

 

[clivvy]

i get a violent shudder ( from the engine ) too when i switch off the ignition

dont most big diesel engine give a violent shudder at shut off? all the ones ive ever driven did....believe it or not, doesnt bother me...!