Turbo problem (assume)

[mas]

In the past I found the 05 cdi would go into limp mode if I drove high rpm with a cold engine. Reset and all would go back to normal.

Yesterday, highway speed, 6 gear, 100km/hr and the car starts to slow down, give it more gas until I am flat on the floor hovering top end at a 100 but  slight rises and she would slow down to mid 80's (still flat to the floor), 5th bring it back up to 100  (3500rpm) back into 6th.  I am leaning to a turbo issue but at slower speeds I can hear the whine of the turbo.  I have not popped the hood yet but what can I expect to find?

[MikeT]

Sounds like limp mode. Run a diagnostic on the OBDII.

[Willys]

I agree with limp mode.....it should go away after the sam cycles but it will always come back if your waste gate isn't set up correctly. IMHO, the waste gate needs to be set so the boost pressure never goes much above 16 psi or you risk always having this happen. Do you have a way to see your boost while driving such as a ScanGageII  ???   IF you can afford to get one buy one......they may go on sale for black friday or christmas  Boxing day etc etc. They are excellent for a smart car and it's issues so to speak. You can also watch your fuel consumption rates as you drive in real time to get the best litres per hundred kms driven.  Along with being a scanner.  Ask anyone who has one if they are worth the money I bet 99% will say it is.
Once you can watch your boost as you drive then you can adjust correctly the rod locking nuts for the waste gate and thus be able to set it correctly under full acceleration as you need to be able to do.

 

[Nigel]

I agree with Mike.  Sounds like limp mode and we need to know why.  It’s unlikely wastegate adjustment unless someone has already been messing with it.  
 

Nigel

[mas]

The previous limp mode would never allow me to go above 3000rpm, under this condition I can wind it up to red line.  No CEL then again I have not plugged in my obd2 either.

[Willys]

Have you cleaned your EGR at all...?

 

[Xen0]

I have the same issue on my 06 Cabrio when I don't lube the wastegate arm at the poppet valve every few months.  The valve tends to either not close all the way, or stick slightly on opening.  Then it'll set a non-CEL overboost code on acceleration (usually ~2700rpm).  I usually remove the rear to gain better access and I use a 15mm wrench that fits on the bracket to the valve.  Open and close the valve with the wrench and lube with good penetrating oil.  If it does happen, you can turn the car off for around 30 seconds (until you hear the relay click from the SAM under the dash), start up and drive with full power again until next time it sticks.

 

A 3000rpm limp would be EGR most likely, follow any of the methods here to rid yourself of that curse.  I used a blocking plate and an emulator myself, your smart will thank you for it!

 

 

Edited December 4, 2024 by Xen0

[mas]

I feels like limp mode but I can hit 4000rpm, maybe it is my sensitivity but as I accelerate, I feel/hear air escaping ever so lightly behind me, I checked that out with my neighbour but did not find anything.  My previous limp mode was limited to exactly 3000, so I am leaning toward Xen0 above. Checked OBDII yesterday, nothing. I did however find a new oil patch (size of a couple of loonies) at the end of the suspension arms joined at the center (right behind the bumper) it looks like the oil is traveling down the sloped arm all the way down to the left near the corner bumper..  Looking at the oil source today.  the 05 gets parked on Saturday for the winter. 

I have not swapped out/blanked the EGR, on the todo list.....

[MikeT]

I had something like this with my first smart, a 2005. The car would lose power but still rev to 4400 RPM. The cause was a faulty clutch actuator, which was slurring clutch engagement and to save the clutch disc from excessive wear, the car would cut power and torque do this other version of limp mode. Actuator changed under warranty back in 2006, problem never recurred in the next 230K km.