Wastegate Actuator Stuck Open

[Ian]

An Essex based garage have been in touch to try to resolve the issue of a member's Bongo where the wastegate actuator is stuck open. The glow plug light is flashing and there is a severe loss of pressure & power once the vehicle has warmed up. It is a year 2000 diesel Bongo. The EGR valve has been blanked off, solenoids have been changed, and a brand new ECU wired up. But the fault still remains.

On the garage's behalf I have checked here on the Forum back to 2008 and sent them a summary of the remedies given (wiggling actuator rods, check/change vacuum valves under driver seat, replacement vaccum relay, stripping tubo down and replacing gasket etc). But does anyone else have any suggestions?

[briwy]

At 2000 it could be a fly by wire in which case there are numerous tubes,valves and a vacuum reservoir that are all associated with the turbo. A small leak on one of these or a valve sticking could be the problem.
If I remember correctly there is a tube coming from the front of the engine which carries the vacuum up to all this lot as well.

Does it happen all the time or only when the engine is hot? I had this happen last year and the Bongo went into limp mode. Left overnight and a tank of "proper" fuel rather than cheap supermarket stuff and it never occurred again.

[Ian]

Does it happen all the time or only when the engine is hot?

Only when the engine has been running a while.

[briwy]

That's exactly what happened to us Ian on the way back from the Scottish Bash last year. Fine for about 45mins then limp mode and the actuator was stuck so could be the same problem, crap fuel. Only used branded fuel afterwards and it never happened again.

No sign of coolant overheating but obviously the exhaust gasses must have got too hot and jammed the turbo.

[Northern Bongolow]

as brian has said this turbo suffers from overheat/sticking very easily, the vanes in the turbo run very close to the internals so extra heat can affect them.
julian has made posts saying the same in the past.
if you need to chat to julian and cannot get him ring me ian.

[Northern Bongolow]

have you seen this from julian (the last post).

http://www.igmaynard.co.uk/bongo/forum/ ... 91#p579191

[Ian]

Yes, read it, summarised it (and other posts since 2008) and forwarded to garage.

[topbanana]

As if by coincidence, that's exactly the same fault as mine, 2002 diesel.

Currently at 321, same issue only egr has not been blanked, been there three weeks now and they seem stumped!

No codes either according to them. Interesting to hear the outcome from this owners problem.

Cheers,

[Diplomat]

have you seen this from julian (the last post).

http://www.igmaynard.co.uk/bongo/forum/ ... 91#p579191

I followed that link and read it with interest, especially the grip it with pliers bit. Is it safe to twist it? I have tried in the past to move it back and forth with no luck but stopped short of twisting it, not knowing how it was connected.

My interest was borne of curiosity as, judging from the patina (a nice word for corrosion gleaned from the antiques world) on it, it looks like it has never moved.

Received wisdom suggests that my extremely frugal accelerator use could be the reason why it has never apparently moved, at least during my ownership. I've never sat at the end of a journey and had to think "I'd better let the turbo cool down before I switch off".

Do they really get knackered unless you thrash them?


Frank

[Northern Bongolow]

it should move quite easily frank, the manual gives details as follows.
put in adjustable air supply, remove pipe from bottom end of turbo, (starting low) to a max of 112-121 kpa, (just over 1 bar) actuator rod should move. do not over pressure as it will damage diaphragm.

i wouldnt spin it though as it may be fastened to the diaphragm with a screw/nut, not sure, although it may be a circlip.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[alan]

This sounds the same as our bongo we give up in the end and let her go just couldn't spend any more time or money .
She With Allan now hope he put her back on the road.

[briwy]

have you seen this from julian (the last post).

http://www.igmaynard.co.uk/bongo/forum/ ... 91#p579191

I followed that link and read it with interest, especially the grip it with pliers bit. Is it safe to twist it? I have tried in the past to move it back and forth with no luck but stopped short of twisting it, not knowing how it was connected.

My interest was borne of curiosity as, judging from the patina (a nice word for corrosion gleaned from the antiques world) on it, it looks like it has never moved.

Received wisdom suggests that my extremely frugal accelerator use could be the reason why it has never apparently moved, at least during my ownership. I've never sat at the end of a journey and had to think "I'd better let the turbo cool down before I switch off".

Do they really get knackered unless you thrash them?


Frank

If it hadn't moved you really would have noticed it Frank. Having driven about 170 miles without the turbo coming in I can definitely say you would have been screaming at it and jumping up and down in the seat to make it go faster. Nearly got out to give it a "good thrashing" as per Faulty Towers. They don't need a heavy right foot to get the turbo moving.
Hope everyone gets it sorted.

[Diplomat]

If it hadn't moved you really would have noticed it Frank. Having driven about 170 miles without the turbo coming in I can definitely say you would have been screaming at it and jumping up and down in the seat to make it go faster. Nearly got out to give it a "good thrashing" as per Faulty Towers. They don't need a heavy right foot to get the turbo moving.
Hope everyone gets it sorted.

I don't think there is any doubt that my turbo is working as I have always been satisfied with the Bongo's grunt. Certainly not the lack of power which you describe, which puts my mind at rest on that issue. I just remain to be convinced that I've ever driven it hard enough to open the wastegate. Am I right in believing that the latter action does need some welly (or a pair of pliers)?

Could it become corroded and stuck shut through lack of use? In other words, the opposite condition to being stuck open like the one referred to by Ian. If it does stay shut would a driver who hardly ever goes above 3000 rpm be aware of the fault?


Frank

[teenmal]

If it hadn't moved you really would have noticed it Frank. Having driven about 170 miles without the turbo coming in I can definitely say you would have been screaming at it and jumping up and down in the seat to make it go faster. Nearly got out to give it a "good thrashing" as per Faulty Towers. They don't need a heavy right foot to get the turbo moving.
Hope everyone gets it sorted.

I don't think there is any doubt that my turbo is working as I have always been satisfied with the Bongo's grunt. Certainly not the lack of power which you describe, which puts my mind at rest on that issue. I just remain to be convinced that I've ever driven it hard enough to open the wastegate. Am I right in believing that the latter action does need some welly (or a pair of pliers)?

Could it become corroded and stuck shut through lack of use? In other words, the opposite condition to being stuck open like the one referred to by Ian. If it does stay shut would a driver who hardly ever goes above 3000 rpm be aware of the fault?


Frank

You are correct in your assumption, The waste gate is a Pressure relief (safety)mechanism, it should only Open at a pre determined pressure.

[NathM]

You are correct in your assumption, The waste gate is a Pressure relief (safety)mechanism, it should only Open at a pre determined pressure.

The wastegate on later models works in the opposite way to a normal unit, instead of opening to allow gases to bypass the impeller, these close to restrict flow onto the impeller.


Ian, where in essex is the garage?

Nath