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  #31  
Old 11-15-2012, 03:54 PM
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sdls have a trap oxidixer plus a catalytic converter.muffler shop can cut cat out and put in staright pipe,you will have lots more power than before ,almost like a new car.
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  #32  
Old 11-15-2012, 04:06 PM
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Zero exhaust would sure indicate something clogged in the exhaust pipe ... clogged cat would sure do it.
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  #33  
Old 11-15-2012, 06:28 PM
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MAF may not be the correct MB nomenclature, but there is a sensor unit that is located just below the air filter housing that incorporates a swinging flap or door. The flap position is measured and I beleive there is a thermo sensor device that measures air flow into the engine.

The fact that it appears your engine is starved for air would point to some severe restriction to it's flow. As has been stated earlier even a completely seized compressor would allow enough air into the engine to keep it running, maybe not enough for any speed or power but it would not stop the engine as you've described when you've had it runninng and tried to insert the crossover pipe. The fact that you where able to alter the EGR state pulling vacuum to it and that changes the running also leads to air startvation as a likely problem.

It hasn't been mentioned but I'll assume that the pipe from the valve cover to the intake snorkel is intact and not restricted? If it is restricted for some reason it would pressurize the crankcase and cause the shut-off solenoid on the IP to close the rack staving fuel and causing the engine to die. This condition can cause all kinds of weird running/dying of the engine, you press the accelerator the engine reves, pressure builds and the engine starts to die. It will return to a poor idle if you let off the accelerator. I notice you mentioned oil spray occuring, when there is a pressurized crankcase oil will spray in fime mist and droplets out from the oil fill cap past its gasket out onto and over the top of the engine and past the gasket around the pipe from the valve cover.
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  #34  
Old 11-15-2012, 08:49 PM
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New information tonight

This is what I did tonight: I've started by removing and dismantling the entire air intake: first the air filter and filter housing (inspecting each). I then proceeded to remove the snorkel and the vent pipe from the top of the valve cover to the rubber snorkel - the darn plastic cap broke into 3 uneven pieces ... and I have purchased this thing brand new about 2 years ago.. There were no restrictions anywhere in any passage ways. Other than some oil spray in the snorkle, MAF and the vent tube, I didn't observe anything unusual.

I then removed and inspected the EGR valve. It too appeared to be in good condition with a strong spring keeping it normally closed. Blowing into it wih my mouth (hehe) it was barely escaping past the closed valve. Pulling a vacuum on it lifted it up and removing the vacuum snapped it closed quite crisply. Works as designed, I believe.

Next, the turbo: first of all, it spins, but it doesn't spin freely to the touch. Not like the turbo in my 617.952 engine I had before. That 617 turbo spun freely with just a gentle touch. The turbo in this 603 turns when you use your finger to turn it but there is just enough resistance that it will not free-spin no matter what you do. Not sure that's normal or not. There was no play in the shaft.

Here is more info. Having removed the entire air input to the turbo, I then re-connected the EGR valve and started up the car. Again, it started on first crank. I then attempted to reconnect the cross-over valve.... and before I even closed the gap completely the car had stalled! Mind you that input to the turbo was completely open - not obstructed in any way. Still, the engine stalled immediately when I put the crossover pipe in place!

Next, I started the car again, and this time, I had the helper rev up the motor, while I observed the turbo (with a little mirror). The turbo did NOT spin even when the helper revved up the car pretty good - in fact it never moved... I had hoped that it would spin when revved up but it didn't... is this normal?! I do hope the Turbo is ok (though there is some oil leaking past the seal for sure).

So, at this point, my theory is that there is an obstruction somewhere in the Exhaust - probably the catalytic converter (as someone else pointed up above). My reasoning: if the Cat is plugged up completely, the only exit path for the exhaust gasses is to overpower and push past the the EGR valve, and escape out the top of the turbo. That's why the sound changes completely when I pull the vacuum and open up the valve - no resistance to overcome, so the sound changes, but it's still the same escape path for the exhaust gasses to travel out of the engine. Once I close the gap with a cross over pipe, the engine stalls because there isn't enough oxygen to keep it running!? I now believe (looking at that picture), that if the gases can't escape downwards through the tail pipe then they won't travel past the turbo blades and therefore the turbo doesn't spin....

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Last edited by MercFan; 11-15-2012 at 09:18 PM.
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  #35  
Old 11-15-2012, 08:54 PM
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Turbo should spin. How easy is it to disconnect the exhaust pipe coming out of the turbo and give it a try. If it runs ok then, the exhaust pipe is obstructed.
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  #36  
Old 11-15-2012, 08:58 PM
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Quote:
Originally Posted by kerry View Post
How easy is it to disconnect the exhaust pipe coming out of the turbo and give it a try. If it runs ok then, the exhaust pipe is obstructed.
Was thinking that too... will be pretty tough, I'm sure (everything else has been) but I'll sure give it a try - would be a good test for sure.
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Last edited by MercFan; 11-15-2012 at 09:23 PM.
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  #37  
Old 11-15-2012, 10:23 PM
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Sorry

Quote:
Originally Posted by MercFan View Post
This is what I did tonight: I've started by removing and dismantling the entire air intake: first the air filter and filter housing (inspecting each). I then proceeded to remove the snorkel and the vent pipe from the top of the valve cover to the rubber snorkel - the darn plastic cap broke into 3 uneven pieces ... and I have purchased this thing brand new about 2 years ago.. There were no restrictions anywhere in any passage ways. Other than some oil spray in the snorkle, MAF and the vent tube, I didn't observe anything unusual.

I then removed and inspected the EGR valve. It too appeared to be in good condition with a strong spring keeping it normally closed. Blowing into it wih my mouth (hehe) it was barely escaping past the closed valve. Pulling a vacuum on it lifted it up and removing the vacuum snapped it closed quite crisply. Works as designed, I believe.

Next, the turbo: first of all, it spins, but it doesn't spin freely to the touch. Not like the turbo in my 617.952 engine I had before. That 617 turbo spun freely with just a gentle touch. The turbo in this 603 turns when you use your finger to turn it but there is just enough resistance that it will not free-spin no matter what you do. Not sure that's normal or not. There was no play in the shaft.

Here is more info. Having removed the entire air input to the turbo, I then re-connected the EGR valve and started up the car. Again, it started on first crank. I then attempted to reconnect the cross-over valve.... and before I even closed the gap completely the car had stalled! Mind you that input to the turbo was completely open - not obstructed in any way. Still, the engine stalled immediately when I put the crossover pipe in place!

Next, I started the car again, and this time, I had the helper rev up the motor, while I observed the turbo (with a little mirror). The turbo did NOT spin even when the helper revved up the car pretty good - in fact it never moved... I had hoped that it would spin when revved up but it didn't... is this normal?! I do hope the Turbo is ok (though there is some oil leaking past the seal for sure).

So, at this point, my theory is that there is an obstruction somewhere in the Exhaust - probably the catalytic converter (as someone else pointed up above). My reasoning: if the Cat is plugged up completely, the only exit path for the exhaust gasses is to overpower and push past the the EGR valve, and escape out the top of the turbo. That's why the sound changes completely when I pull the vacuum and open up the valve - no resistance to overcome, so the sound changes, but it's still the same escape path for the exhaust gasses to travel out of the engine. Once I close the gap with a cross over pipe, the engine stalls because there isn't enough oxygen to keep it running!? I now believe (looking at that picture), that if the gases can't escape downwards through the tail pipe then they won't travel past the turbo blades and therefore the turbo doesn't spin....

You have described a bad turbo.

Disconnect the exhaust down pipe from the turbo, if there is no or minimal change = a dead turbo.


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  #38  
Old 11-15-2012, 10:49 PM
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Quote:
Originally Posted by whunter View Post
You have described a bad turbo. Disconnect the exhaust down pipe from the turbo, if there is no or minimal change = a dead turbo. .
Yes, I will need to try that, but meanwhile, is there any chance that the work I did with the vacuum lines may have affected operation of my turbo? I've read this post here (see post #2) and it mentions vacuum lines... I've closed up some open vac lines and have replaced 2 or 3 old vac lines with factory new lines and some rubber connectors. I do have a vac hose going from the intake manifold to the overboost valve on the firewall. The output is blocked by a golf tee... hehe since the PO had removed the ALDA. Grasping at straws here..
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  #39  
Old 11-15-2012, 11:11 PM
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Exhaust Flow Test - Remove One Bolt

Just to rule out restriction....

You can remove the bolt in the exhaust manifold that sits almost all the way forward on the manifold. It may be a test port or a place to install temps and exhaust restriction. It is seen in your photo in the approximatle forward area of the EGR yet on the manifold.

Yank it and fire it up for your test. I would not run it for long or you'' bake something
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  #40  
Old 11-15-2012, 11:30 PM
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Quote:
Originally Posted by MercFan View Post
My reasoning: if the Cat is plugged up completely, the only exit path for the exhaust gasses is to overpower and push past the the EGR valve, and escape out the top of the turbo. That's why the sound changes completely when I pull the vacuum and open up the valve - no resistance to overcome, so the sound changes, but it's still the same escape path for the exhaust gasses to travel out of the engine. Once I close the gap with a cross over pipe, the engine stalls because there isn't enough oxygen to keep it running!? I now believe (looking at that picture), that if the gases can't escape downwards through the tail pipe then they won't travel past the turbo blades and therefore the turbo doesn't spin....
Now things are coming into focus, I believe.
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  #41  
Old 11-16-2012, 08:53 AM
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Quote:
Originally Posted by 86-300sdl View Post
Just to rule out restriction....

You can remove the bolt in the exhaust manifold that sits almost all the way forward on the manifold. It may be a test port or a place to install temps and exhaust restriction. It is seen in your photo in the approximatle forward area of the EGR yet on the manifold.

Yank it and fire it up for your test. I would not run it for long or you'' bake something
I see the bolt for the test port you're suggesting but I don't understand what the test would be. What would removing it and firing it up tell me?!
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  #42  
Old 11-16-2012, 09:53 AM
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It would release enough pressure on the exhaust for the turbo to spin if the problem is a plugged cat and not a bad turbo.
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  #43  
Old 11-16-2012, 10:19 AM
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Quote:
Originally Posted by kerry View Post
It would release enough pressure on the exhaust for the turbo to spin if the problem is a plugged cat and not a bad turbo.
Hmmm... if he means this bolt in the pic below (green arrow) then I still don't get how this would prove blocked exhaust since this port is BEFORE the turbo. Sure it would relieve the pressure but how would it rule out the blocked exhaust pipe...?!

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  #44  
Old 11-16-2012, 10:25 AM
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Ooops, you're right.
Instead of unbolting the exhaust at the turbo, it might be better to unbolt it in front of the cat because you're going to have to remove the cat anyway if it's plugged.
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  #45  
Old 11-16-2012, 10:58 AM
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Quote:
Originally Posted by kerry View Post
Ooops, you're right.
Instead of unbolting the exhaust at the turbo, it might be better to unbolt it in front of the cat because you're going to have to remove the cat anyway if it's plugged.
Yeah, but the cat is welded onto the exhaust pipe under the car (I checked last night)... so I've got to stick with the original plan to unbolt the exhaust pipe after the turbo (if I can get my gorilla hands in there).
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