Need Crazy Ideas: Wastegate actuator broken: Turbo Confusion

[freestyler]

So... I thought I knew how a turbo works, but apparently I'm really confused on it. Also, I'm in need of some ideas.

The Story:
During the removal and blanking of the EGR valve I noticed that the waste-gate actuator near the exhaust end of the turbo was broken. It's not missing the cotter pin, rather the cylinder/pin that is pressed into the exhaust actuator arm is sheared off.

The Confusion:
I know that I have been driving like this for quite some time... months, possibly close to a year, my side exhaust note has been different. There has been no noticeable change in power or fuel efficiency, or deathly-engine-doom from too much boost. All of which I find odd given how I understand turbos.

It's my *understanding* that this broken actuator means I have too much boost into the engine from the turbo. I've driven like this for a long time, hard at times, and I would assume that I should've blown something up in the engine by now. Could it be that when this fails, it fails safely? As in I'm NOT over boosting? Why is there no change in power either way?

The Solution?
The obvious way of fixing this is to remove the turbo and replace this waste-gate actuator arm with one that has a pin in it. Something that involves a lot of my time (OK) or nearly too much money (Not-so-OK). I would like come up with another idea if possible. Good, Bad or Ugly does not matter. Crazy and untested ideas are good too!

My first idea is to drill out the arm and get a free-floating bolt to connect the two. Next is to weld a new pin on.


For reference; I edited the picture below that was originally EricN's from this thread.

[freestyler]

Given the near zero change in power and mileage, I should add that doing nothing is a perfectly good option... assuming that I'm not running a real risk of destroying my engine.

EDIT: I did experience a power loss after all. It was about 10-15% overall.

[Luna-Sea]

Hey,
Do you have a boost gauge installed?
I would also guess you have not messed with
you boost pressure eh?
Under pure postulative reasoning I would guess
that you don't really ever boost high enough to
open the gate.
Also there is a pop off valve on the intake (round disc looking thing)
that should save you if for some reason the boost spiked severely.

You can grab decent cheap boost gauges at Canadian tire/princess auto/harbor freight ect.
Easy install,tells you whats going on in turboland and yes is a cool gauge.

In the big scheme of things I would want the exhaust gate functioning properly.

You have probably noticed a bit more pep since the EGR block plates eh?

Right On!

[Mephisto]

The wastegate actuator holds the wastegate closed, so if the actuator is not attached to the flapper it will be open all the time, so you are making little to no boost rather than overboosting.

[Luna-Sea]

Hey,
Could it be snapped at the shaft and seized/suck closed or partway?
I would think it would be a bit of a gutless imp and quite noticeable
if it were not getting any boost eh?

Let us know what you find and find a boost gauge!

Good Luck

[Mephisto]

Sorry for not suggesting fixes last time, my brain has been a little swollen for the past few weeks thanks to a mishap on my dirtbike. I seem to rely on that for any of my recent moments of brain flatulence. Both of your suggestions are perfect solutions to fixing this issue, the bolt and two nuts being the easier of the two if you don't have access to a welder. To answer Luna-seas suggestion, it's very unlikely that the flapper would be stuck closed and with the wastegate open all the time you'ld have to really rev it up and sustain your RPMs for a while to make any boost(even then you might not make any). A boost gauge would tell you what's goin on for sure. All you'ld have to worry about driving in this condition would be EGTs getting up there, but since you shouldn't be reaching the boost enrichment point you shouldn't be blowing excessive black smoke or anything (black smoke for extended periods leads to really high EGTs) so your engine is relatively safe. I do suggest you fix it rather soon, it'll make your van much nicer to drive and probable keep the EGTs down a bit.

[tonydca]

Hey,
Also there is a pop off valve on the intake (round disc looking thing)
that should save you if for some reason the boost spiked severely.

You can grab decent cheap boost gauges at Canadian tire/princess auto/harbor freight ect.
Easy install,tells you whats going on in turboland and yes is a cool gauge.

Right On!

X2. My wastegate actuator was in need of lubrication after I first got my van, and the overpressure poppet valve LunaSea mentioned was openning in lieu of the wastegate.

It makes a noticeable *Hiss* when it goes off, and IRCC it blows off only about 1 psi above where my wastegate actuator triggers when working.

And the $25 Princess Auto boost gauge is definitely $$$ well spent. If I ease up a bit on the throttle to keep the boost even 1 psi below normal max (where the wastegate opens) I easily get 10-15% better mileage.

[freestyler]

Still waiting on getting the wastegate fixed... I may have a millwright friend that will help me out if I get him enough beer. Ideas are:

1 - Drill out the actuator and replace the broken pressed fit pin,
2 - Mechanically Clamp the popoff valve arm to the actuator
3 - Weld the bastards together
4 - Continue to do nothing.

Personally, I think #2 will be the easiest with the least amount of risk.

I'm tossing the boost gauge around still. I haven't looked up how to do it (I'm assuming that it's not *that* time consuming)... in lieu of seeing how it's done, it's really a personal momentum thing on my part that I need fix.

[freestyler]

Hey,
Could it be snapped at the shaft and seized/suck closed or partway?
I would think it would be a bit of a gutless imp and quite noticeable
if it were not getting any boost eh?

Let us know what you find and find a boost gauge!

Good Luck

Thanks for the wishes...

I don't think it is seized. The wastegate actuator moves freely and sounds+feels as if the gate inside the turbo is connected and doing it's thing; There's nothing obvious pointing to what you are suggesting.

I did some looking up on the boost gauge install... seems easy enough. Does anyone have recommendations to a kit/gauge that fits in console that has the altimeter in it?

[Manitoba Delica]

Hope I'm not hijacking this thread, but I've had concerns with my wastegate actuator as well.. The snap ring/cotter has been missing, so at times I've realized it was disconnected.. THis is always accompanied by huge loss of power, and lots more black smoke on acceleration.. I pop it back on, and it works much better.. When I am placing it back on, the actuator arm ( with the pin) seems to move very freely, with no weight or resistance.. The arm that reaches down has no play at all vertically.. Is this correct. I was begining to wonder if that had become seized.. Now I am having more black smoke/power loss despite having the arm connected... THanks for any tips..

MAtthew

[Mephisto]

When you attach the actuator arm to the flapper arm you cannot have a solid connection, the connection must be able to rotate. This means welding the two together or clamping it tight will not work. When the actuator sees the appropriate amount of boost to overcome the spring that holds it shut the actuator arm gets pushed out, this movement opens the wastegate flapper to allow exhaust gasses to flow around the turbo rather than through it, effectively capping the amount of boost made. When the actuator arm moves out, the connection needs to be able to spin to allow the flapper to move, if that connection point cannot spin the wastgate will not open even when the appropriate boost level is reached, this will cause an over boost situation. When you fix this issue you must either weld in a new pin and use a clip of some sort to keep the actuator on the arm or you can drill out a hole for a small bolt and use two stover nuts, one to clamp the bolt tightly to either arm and the other to connect to the remaining arm loosely in order to allow rotation. Use a stover nut (pinched at the top to prevent self loosening) rather than a nylock nut as the temperatures on the turbo will melt the nylon and render the locking aspect useless.

For the second question, If your actuator arm has no vertical movement it is probably still working fine, the spring that is inside takes quite a bit of force to move, you probably just didn't pull hard enough to move it. Since you have noticed that you are beginning to blow black and have power loss even when the actuator is attached to the wastegate the actuator may be weakening thus allowing the flapper to open early, but since you say the actuator arm is so stiff this is unlikely, again I suggest putting a boost gauge on and seeing what is happening. Hard numbers make remote troubleshooting much easier as, no offence, untrained owners often misinterpret things. See if you can measure the wastegate pin and get a clip that will fit, then at least you won't be worried about the actuator falling off again, again troubleshooting is alot easier if things are consistent. Not to mention that should be fixed anyways, lol.

[freestyler]

When you attach the actuator arm to the flapper arm you cannot have a solid connection, the connection must be able to rotate. This means welding the two together or clamping it tight will not work. When the actuator sees the appropriate amount of boost to overcome the spring that holds it shut the actuator arm gets pushed out, this movement opens the wastegate flapper to allow exhaust gasses to flow around the turbo rather than through it, effectively capping the amount of boost made. When the actuator arm moves out, the connection needs to be able to spin to allow the flapper to move, if that connection point cannot spin the wastgate will not open even when the appropriate boost level is reached, this will cause an over boost situation. When you fix this issue you must either weld in a new pin and use a clip of some sort to keep the actuator on the arm or you can drill out a hole for a small bolt and use two stover nuts, one to clamp the bolt tightly to either arm and the other to connect to the remaining arm loosely in order to allow rotation. Use a stover nut (pinched at the top to prevent self loosening) rather than a nylock nut as the temperatures on the turbo will melt the nylon and render the locking aspect useless.

For the second question, If your actuator arm has no vertical movement it is probably still working fine, the spring that is inside takes quite a bit of force to move, you probably just didn't pull hard enough to move it. Since you have noticed that you are beginning to blow black and have power loss even when the actuator is attached to the wastegate the actuator may be weakening thus allowing the flapper to open early, but since you say the actuator arm is so stiff this is unlikely, again I suggest putting a boost gauge on and seeing what is happening. Hard numbers make remote troubleshooting much easier as, no offence, untrained owners often misinterpret things. See if you can measure the wastegate pin and get a clip that will fit, then at least you won't be worried about the actuator falling off again, again troubleshooting is alot easier if things are consistent. Not to mention that should be fixed anyways, lol.

Buggers, I was at CVI today and the consensus was to weld it.... So we did. After I got my turbo back and it was a pretty large difference!! There is such thing as power-loss in this case but I would estimate that it is a +10-15% difference. For some reason I was thinking a 40-60% in my case which didn't add up.

On the way home it was clearly being over-boosted; the pop off valve was going off at 2500 RPM under load (it's not a measure but it's the only number that I can go off of right now). When I got back I decreased/adjusted the boost by doing this: http://www.delica.ca/forum/adjusting-tu ... -1441.html

The pop-off valve is going at ~3900 RPM under load so I put another 1/4 turn loose... I don't go any harder when driving, so I figure I should be covered. --- I'll report back when/if I hear it pop off again.

Also: I'm installing a boost gauge in the next two days (just have to make the time to buy one) and I'll report back on the true PSI and what I've been experiencing.

pre-PS: any suggestions on a boost gauge and size that fits into the pitch/yaw indicator hole would be awesome...

Cheers,

Freestyler

[freestyler]

Working in the rain is not all that fun, but the boost gauge is in and mounted in the dash pod in place of the pitch/yaw. The install wasn't 'easy' but it was very straightforward. It took time to figure out what I did and did not need to pull off the van to make it work. I think I could halve the time I did it in if I were to do it again and only then would it call it easy in the global sense. :P

The results:

- With no load it's boosting to ~ 8-10 psi around the 4000 RPM mark.... boost doesn't kick in until the 2000 RPM mark.
- With load, going up a very steep hill with nearly full throttle, the pop off valve kicks in again at 15-16 psi (is this normal?). I need to do more driving tomorrow and I'll be adjusting the turbo down so that it does not kick in now that I have actual numbers to go off of.

I'll update very soon... any commentary would be great. I'm flying blind for most of this.

Cheers

EDIT: I ended up with an Autometer 2" Boost Gauge: model 3301 which has a range of 0-20psi. ~ $70 w/ tax from Lordco. I installed it in place of the pitch/yaw on the dash pod. I had to drill a hole out the back of the pod for the air line to go in at a better angle and I had to dremel the face place that had the degrees on it in order for it to fit. I painted it black to cover up what was left of the numbers; the plate made a great mount for the backplate that came with the gauge. I figure that the 2"1/16 gauge would work just fine as well.

Oh ya. Bicycle brake cable is very good for fishing the nylon pressure hose up into the dash pod hole.

[jessef]

- With no load it's boosting to ~ 8-10 psi around the 4000 RPM mark.... boost doesn't kick in until the 2000 RPM mark.
- With load, going up a very steep hill with nearly full throttle, the pop off valve kicks in again at 15-16 psi (is this normal?). I need to do more driving tomorrow and I'll be adjusting the turbo down so that it does not kick in now that I have actual numbers to go off of.

Not normal. Too much boost. I would recommend to turn it down ASAP.

8-9 PSI under max load is the recommended/factory setting for boost.

You 'can' go higher, up to 11/12 PSI but it is at your own risk of course.

Turn the boost down. Also one thing to look at, unless you have already, is the fuel screw on the injection pump. If it's turned up too much and your boost is up at 15/16 PSI, you're cooking the engine and can do some serious damage.

[freestyler]

- With no load it's boosting to ~ 8-10 psi around the 4000 RPM mark.... boost doesn't kick in until the 2000 RPM mark.
- With load, going up a very steep hill with nearly full throttle, the pop off valve kicks in again at 15-16 psi (is this normal?). I need to do more driving tomorrow and I'll be adjusting the turbo down so that it does not kick in now that I have actual numbers to go off of.

Not normal. Too much boost. I would recommend to turn it down ASAP.

8-9 PSI under max load is the recommended/factory setting for boost.

You 'can' go higher, up to 11/12 PSI but it is at your own risk of course.

Turn the boost down. Also one thing to look at, unless you have already, is the fuel screw on the injection pump. If it's turned up too much and your boost is up at 15/16 PSI, you're cooking the engine and can do some serious damage.

Thanks for the advice!

The fuel screw was adjusted, but down ~1/10 of turn, from it's original setting around a month ago. I'm guessing that is still OK as I have no measure or reference to what it should be at or what was done previous to the me getting the van 3 years ago. I''m assuming the loosening it (turning it left) leans out the mixture. If you can confirm that I'll dial it down a touch (1/4 turn?) to be extra safe.