505 Turbo - won't exceed 2750-3000 RPM

[trymes]

Ok, so my apologies for posting 500 replies to this thread, but I have some time to kill and I'm spitballing this stuff. From the pictures in the thread above, it looks like one of the actuator bolts may be accessible from below the car, while the other is accessible from above, perhaps after you have removed the pipe connecting the outlet and the intercooler, and maybe the exhaust heat shield.

Are there any tricks to removing these two items?

[Bean]

You're in the right place of you want a good place to validate / justify crazy Peugeot thoughts!

Cracked head and / or broken piston lands are definitely possibilities if the car was abused, but the functional overboost is a very good thing.  A much better test is to connect those wires though - disconnecting them and "testing" ensures and overboost without cut...  

Cracked head presents by pressurizing the cooling system.  Bubbles in the coolant reservoir is a sure sign the head is cracked.  Broken ring lands you'd definitely know about!

Rebuilt actuator is nice since it's a bolt on - but I can't say for certain how accessible it will be.  Most suggest supporting the motor and removing the passenger side motor mount to get access to the turbo for removal - doing the same might be useful for doing the actuator.

Rabin

 

 

[bill]

You have to pull the exhaust manifold. It is very close, but the clearance just not there. It is heartbreaking. I would have the exhaust manifold checked and straightened up at a machine shop while you are at it.

[trymes]

1 hour ago, bill said:

You have to pull the exhaust manifold. It is very close, but the clearance just not there. It is heartbreaking. I would have the exhaust manifold checked and straightened up at a machine shop while you are at it.

Not even with four universal joints on the socket?!

I wish it weren't so. Once I have the turbo in hand, what is the torque setting for the bolts? Any special precautions or tips?

 

How about checking the wastegate to make sure it isn't stuck? Just disconnect the rod and throw some channnel-loks on it? How much force should be required to move it?

I'll be able to get my hands back on the car on Friday if all goes to plan. 

Tom

[bill]

All I am saying is that you cannot simply remove and replace that actuator.  It is the deception from hell, trust me.  My friend insisted even after I told him what George Nunez  had posted..  To say the least, it harshed our buzz.  But we got it, eventually.

[Bean]

Might be better to check for lateral turbo play in the shaft as well - just in case it's time for a rebuild.

Wastegate should flop around easily once the actuator arm is removed - it's just a flap door.

Did you check for bubbles in coolant reservoir?

Rabin

 

[trymes]

Thanks for that clarification, Bill. I was looking for that detail, though I am not looking forward to the task.However, in the spirit of eternal optimism, I will ask some more questions below to confirm that.

Rabin: Is there a way to check the lateral play without removing the turbo from the car? By lateral play, you mean fore and aft when it is in the car, right?

Also, an update, as I finally got my hands on the car again today. My car seems to have the wastegate on the right  that you can see in this photo from this thread.

What this means is that the bolts for the actuator are in the middle and towards the bottom of the turbo, not in the middle and towards the top. Here are three photos showing the bolts from the rear and from underneath. Call me crazy, but the top bolt on the actuator it looks relatively easy to remove, and it seems that I could remove the oil return line from the bottom of the turbo and access that bolt, then replace the actuator, replace the oil return (with a new gasket), and Robert is your father's brother. This leads to more than one question:

1. Is the actuator I have the same as others have encountered?
2. Is there any reason why removing the turbo oil return would be inadvisable? I presume that will have to come off if I remove the turbo, anyway, so what's the harm in trying?
3. I presume that the wastegate itself has a spring on it, so it shouldn't flop around. Am I wrong about that? Still, though, it ought to move reasonably easily, no?
4. Once I give up on the dream of not removing the turbo, what is the easiest way to get it out? I pulled the heat shield from the manifold and if the manifold is going to have to come out, anyway, then pulling it from the top sure looks easier than pulling it from below, even with a lift. Can anyone confirm?

Many thanks,

Tom

 

 

[trymes]

Oh, I also removed the actuator rod and moved the wastegate around. It moves freely, but the actuator has a significant amount of spring pressure. For anyone searching the archives, remove the clip and the rod before trying to confirm that the wastegate is not seized. 

I also did my best to reach into the inlet of the turbo and I did not feel any movement other than spinning (nothing fore and aft nor any wobbling).

[Bean]

Hi Tom,

I'm back home now so I'll take a closer look on the motor I have on a stand to get a better idea of removing the actuator in situ - and take some pictures.

If I have a chance I'll see if I can confirm removal with turbo in place.

As for checking for play, need to remove the air box to turbo hose, then reach in the compressor and check for axial (in - out), and lateral (side to side) play.  There should be a little of each (+\- 1/32" ish), but if it's excessive you'll know it.

Rabin

[trymes]

Another update: I picked up an actuator from Brian Holm yesterday that was classified as "rebuilt". Brian had remarked that it didn't have evidence of having been opened to replace the rubber, but it looks obvious to me that what was done was to remove the bracket from the old actuator and drill it to accept the universal actuators with two threaded studs on them (as I pondered earlier in this thread). The good news here is that I am pretty certain that this modification will make it far simpler to replace in the future. Time will tell.

[trymes]

Two steps forward, one step back, but lots of learning today:

1. Remove two 16mm bolts from engine mount base.
2. Remove two 13mm bolts connecting rubber engine mount to aluminum bracket on the engine.
3. Remove the 16mm nut holding the engine mount to the base.
4. Jack up the engine until you can twist the mount and base out of the car.
5. Remove two 6mm hex bolts from turbo oil return (the ones pointing downwards) and loosen the clamps on the oil return hose.
6. Remove three 13mm bolts from engine mount bracket. The turbo oil return will come with it.
7. You can now access the bolts for the actuator and remove/replace it.

It took me some trial and error to reach this procedure, but once you know what to do, it's pretty easy.

Unfortunately, the actuator that Brian had was for a much lower pressure, and the thread on the rod is different, so I was not able to install it (maybe it's for a diesel?). I did bolt the modified bracket back in place, hoping that I can source a more suitable actuator and install it without going to such lengths as I did today. Even if I have to do it all again,I'd wager that the first time took at least twice as long as the second time will.

Nobody seems to have a recommendation for a source for an actuator, but I have found these:

• MambaTek
• Merkur Depot
• ATP Turbo

The second link has a video showing drilling out the spot welds on the OEM bracket and drilling mounting holes. None of these is cheap, and there are more economical options out there, but the first is actually a piston-type, with replaceable o-rings (I think), instead of a diaphragm. Other than cost, my main concern is the size, as if they're too big, they won't fit.

Any thoughts out there?

Tom

[Goce]

Tom, the cheapest way will be to go to a junkyard and pull one there will fit and as is and mechanical part you can test it with a small bicycle pump, i personally drive a turbo diesel with over million kilometers on the turbocharger so the original style wastegates are very reliable and usually outlast the turbo's bearings.

[trymes]

Thanks, Goce, I'm sure that you're right. 

Having said that, Peugeots in junkyards here are likely to be nearly non-existent. I'm sure that I could locate one through the community, but I'm not sure I'd want to invest at least two hours of my time into procuring a part with 30 year-old rubber. I'd feel really dumb if it were to fail relatively soon, so I'd say that a new unit would be cheap insurance.

[Bean]

I agree that using a new actuator is the best course of action as it's role is far too important to trust old parts with.

My only advice is to make sure the actuator opens at the correct 9 psi ideally.  (N9TEA cars run 12 with the ecu controlled boost).   These cars don't really like running higher than stock without more injector and some other ecu trickery using stock components, but even that is steeped in danger.

If you want to pursue additional power it really should be done with a proper standalone system and good tuning.

Rabin

[trymes]

Thanks, Rabin. 9 psi? Here I was aiming for 12, as I thought that was stock, and I have no interest in pushing this car until I have confirmation that it doesn't have other, hidden issues. Also, I know I don't have a N9TEA, but how would I recognize one if I did?

I have reached out to the two vendors of the new actuators, but they only do e-mail contact, no telephone. I think that one (Mamba) is in Taiwan and the other (Merkur Driver) is a part-time vendor. Based on the 9 PSI number, though, it sounds like the Merkur piece will likely be set too high.

What are your thoughts on this image and which of the listed springs would be the best place to start (I have already ordered a cheap vacuum/boost gauge for testing and to confirm reality matches expectations? My guess is green.

[SRDT]

Your actuator is for a lower pressure? The N9TEA control the boost with a solenoid so maybe it's just a N9TEA actuator.

That means that the actuator is set for a lower pressure and the ECU (a Bosch EZK ignition in this case) use the solenoid as a bleeding valve to keep the wastegate closed until the set pressure is reached.

[trymes]

Maybe? It is for a FAR lower pressure. I hooked a bike pump up to it and it began to open almost instantly. I'd wager 1-3 PSI?

The thread on the rod was different, too, so I don't know if that rules anything in or out.

How can I tell which engine I have? Is it a model year or model name thing?

[Bean]

N9TEA cars are 88+ Turbo S cars - turbo was slightly bigger with .48 exhaust housing A/R, bigger injectors, and a boost solenoid in the signal line.  Very likely the same actuator since the solenoid controls when the actuator sees boost.

Sedans saw 12 psi, wagons were detuned to 9 psi.

Rabin

[trymes]

Thanks for that. So, my '86 sedan should be running 9 psi once everything is sorted?

[Goce]

Tom i've went thru my turbo collection and seen that VW TDI turbos run bolted on wastegate actuators, if you have the original bracket you can drill the old one and bolt on TDI one.

[trymes]

Just to add more details for anyone searching the archives in the future: I found a link to a "rebuilt" actuator on eBay here. It is being offered by seller dubarr, who has a bunch of 505 items, it seems. Is that anyone known around here?

I asked a question about how they are rebuilt, as there doesn't appear to be any evidence that the canister was opened in the photos, so I'm curious what was done.

EDIT: Seller has responded that the item is rebuilt by GB Remanufacturing.

[Bean]

Jesse is a known supplier of parts - I've bought a few NOS items from him over the years with no issues.

Can't speak to the rebuild part, it looks NOS...

Did you test the one from Brian?

Rabin

[trymes]

Ah, the saga continues, but in a positive direction. To answer your question, Rabin, the unit from Brian did not fit the OEM turnbuckle, and it opened at a VERY low PSI, meaning I would likely never have built any boost. It did, however, donate its bracket to the effort, which I installed while I had everything apart.

Since then, I ordered up the Mamba actuator, as it looked like it would fit, seemed well-designed, and I found it for somewhat less money on eBay (from the manufacturer). It arrived the other day, and I got in into the car with minimal fuss, and the car is actually driving (mostly) normally! Instead of bucking and kicking when the tachometer hits 3,000 RPM, it continues on nicely, with quite a bit of power. It did feel pretty strong, and on the way home I noticed that it would overboost and cut fuel if I put my foot in it at highway speed in fourth gear (automatic transmission).

I knew that there would be some trial and error with the adjustable actuator, so I had already ordered up a combination vacuum/boost gauge. I wanted to make sure that I hadn't pre-loaded the actuator too much, and that it wasn't running with too much boost. To this end, I temporarily plumbed it in so I could see exactly what is going on. The stock gauge works, but seems more of an approximation than a true reading, there are no numbers, it moves slowly, and it does not peg to the red when in overboost, so I'm not certain how accurate it is. My plan is to use it to get things dialed in and then put it in the tool chest for future use if ever needed. Before I did this, I reduced the pre-load on the actuator for good measure.

After teeing the gauge into the system, I went for a drive, and the gauge reads a steady vacuum at idle, and spools into the boost side steadily as the RPMs increase. Right around the 3,000 RPM range, you can hear the turbo really start to spool up in earnest, and the boost gauge would spike upwards to around 13-14 PSI, and then drop quickly to around 6 PSI. This is independent of the transmission shifting: the boost builds rapidly to 13-14, then drops quickly to a steady 6-7 PSI. On the highway, it will still overboost if I hit the throttle at speed (65-70 MPH) just enough that the transmission doesn't kick down into 3rd gear. The gauge shows a steady, quick build up in boost right up to 14-15PSI and the fuel is cut off. If I really mat the pedal and force the transmission to kickdown, it does not overboost, it jumps a bit and settles into the 6-7PSI.

After this test, I was confused, but I figured I would reduce the pre-load even more, just for the purposes of experimentation. The result was a reduction in both of the numbers above, but still the same behavior. Now it is spiking to 11-12 PSI and running at 5-6 PSI steady after that. It will still overboost on the highway in 4th gear.

I'm at a loss to explain this behavior, but my first guess would be to swap springs in the actuator to a softer spring, and see what happens. Perhaps a softer spring combined with more pre-load will result in more stable behavior? I'm grasping at straws at this point, but who knows, maybe it's worth a try, and with the modified mounting bracket, the actuator isn't all that difficult to remove.

Is anyone here able to provide some insight on what is causing these two behaviors, and what "Normal" would look like? It's not too late to order up the eBay actuator from Jesse, but that seems silly.

[Bean]

Where are you getting your boost signal from for the turbo?  Where did you tee the gauge into?

I tried using manifold pressure for the wg signal once, and it did what you describe. It would only work properly with boost signal from the compressor housing.  Gauge should tee off the intake manifold ports.  I'd also recommend replacing the boost signal hoses (vacuum hoses to wg) with quality lines.  I used fuel line and spring clamps on each end.  (Fuel line is reinforced so it doesn't flex, and that gives crisp boost response).    I've used silicone vacuum hoses but wasn't a fan - found it very weak when removing old lines and it teared easily.)  I've also used pneumatic signal line on race cars - worked great and had very crisp / accurate boost response.

Definitely want to figure those boost spikes out asap though.

Btw - does your Mamba actuator have a single port?  

Rabin

[trymes]

The actuator signal comes directly from the turbo compressor, itself. It's just a 8" hose or so, wrapped around the intake accordion hose and back into the actuator. The gauge is teed into the line that goes from the intake manifold to the MAF sensor under the air filter.

I used fuel line with nylon reinforcement, so I don't think that's the issue. Mamba has been helpful with support, but the time difference generally means I get a response the next morning at 3:45AM. I need to confirm that the rod is exiting the actuator without being shoved to one side, plus open the actuator and confirm sufficient lubricant on the piston. I'd say that the diaphragm type would be a better fit, despite the need to periodically replace diaphragms (every 20-30 years?). Lastly, yes, the actuator is a single-port pressure actuator.

The spikes are weird, and it's almost like the actuator won't move unless you really shock it, or something, so I will take it out and inspect it and the installation. I'll figure it out.

Tom

PS: The newfound oil leaks are what's really annoying me right now. She's marking her territory even worse than my British cars!