1995 Esprit S4s - smoking....

[Karim]

Hi all, I could really use some help...I haven't started my 1995 Esprit S4s for 6 months due to a never ending renovation (don't get me started on that....lol!).  I had some time today to tend to it and replaced the spark plug wires, topped off the fluids (oil and coolant) and after about 5 min at idle, it started smoking.  Any ideas on root cause?

Also, while replacing the spark plug wires, I noticed two hoses unconnected to anything....!  Not sure if this is how they always were or have they become disconnected recently.  I didn't see any fluid leaking from either hose while the car was idling for 5 min.  I've attached some photos of the two hoses - any thoughts on what these hoses are for would be greatly appreciated.  

Thanks in advance for your help

-Karim (S4s owner since '98, San Diego, CA)

[Chillidoggy]

Top photo looks like a vacuum hose to me. I’d check the vacuum diagram schematic first - there should be one on the inside of your tailgate.

[tomcattom]

Where was the smoke coming from, exhaust or engine bay?

[tomcattom]

That last picture looks like the turbo actuator hose given it appears to be originating from one of the solenoids.

[Karim]

13 hours ago, tomcattom said:

Where was the smoke coming from, exhaust or engine bay?

It was coming from the engine bay (left-hand side). White smoke that smelled of a strong burning odor. Not sure if it's oil burning or coolant.

14 hours ago, Chillidoggy said:

Top photo looks like a vacuum hose to me. I’d check the vacuum diagram schematic first - there should be one on the inside of your tailgate.

Good point. Will do. Thanks!

13 hours ago, tomcattom said:

That last picture looks like the turbo actuator hose given it appears to be originating from one of the solenoids.

Hmmm... could that also be why I am not getting full boost pressure?  What should this turbo actuator hose be connected to?

[tomcattom]

If it's from the bay it's probably suffering the same thing as mine while it's been stood up. The cam covers or carriers are leaking oil down onto the exhaust manifold which the burns off as the engine warms up.

As for the turbo actuator solenoid, one side should connect to the wastegate actuator capsule the othe side to the compressor outlet on the tturbo the diagram on the underside of the deck lid should show it. If this isn't connected properly the it will cause the car to run on actuator pressure only.

[Karim]

On 24/12/2020 at 14:59, tomcattom said:

If it's from the bay it's probably suffering the same thing as mine while it's been stood up. The cam covers or carriers are leaking oil down onto the exhaust manifold which the burns off as the engine warms up.

As for the turbo actuator solenoid, one side should connect to the wastegate actuator capsule the othe side to the compressor outlet on the tturbo the diagram on the underside of the deck lid should show it. If this isn't connected properly the it will cause the car to run on actuator pressure only.

Agree on the likelihood that's cam covers or valve cover (or both) are likely the culprit for the white smoke as oil drips onto the  exhaust manifold as it heats up.

For the turbo actuator solenoid - ok, a couple of things:

1. You were spot on that the last picture shows the turbo actuator hose and it originates from the turbo actuator solenoid shown on the vacuum routing diagram on the engine cover lid. 

2. According to the S4s shop manual and the engine cover lid vacuum routing diagram, the  bottom of the turbo actuator solenoid should be routed to the turbo/waste gate actuator.  And the top of the turbo actuator solenoid should be routed to the compressor outlet on the turbo.  HOWEVER, for whatever reason, my turbo actuator solenoid is not connected to anything at all AND it looks to me like the turbo/waste gate actuator is connected directly to the compressor outlet on the turbo, completely bypassing the turbo actuator solenoid.  Is this possible? And what is the effect of bypassing the turbo actuator solenoid

[Barrykearley]

By looping out the solenoid @Karim I believe it stops the delivery of the overboost via the ecu. You will simply get stock boost that the turbo actuator is set to deliver.

[Karim]

On 25/12/2020 at 22:56, Barrykearley said:

By looping out the solenoid @Karim I believe it stops the delivery of the overboost via the ecu. You will simply get stock boost that the turbo actuator is set to deliver.

Got it! Makes sense. Thank you!

[cammmy]

You have to ask why that was done though, It's quite possible that solenoid is faulty. You do want it working though as the wastegate spring will probably be something like 7psi. Normally the solenoid bleeds the signal to the wastegate so that it will run at the max boost in the tune, which could be 12-14psi. Then there's the overboost, which is a temporary increase Above that normal max.