My SDL lost all power and is sitting in a restaurant parking lot - Page 2 - PeachParts Mercedes-Benz Forum

kerry · #16 11-14-2012, 10:12 PM

Is the turbo spinning and otherwise functioning?

vstech · #17 11-14-2012, 10:13 PM

... check your air filter...

qwerty · #18 11-14-2012, 10:19 PM

Quote:

Originally Posted by vstech

... check your air filter...

For sure. Maybe some critters have been storing food for the winter in your air cleaner housing.

MercFan · #19 11-14-2012, 10:21 PM

Quote:

Originally Posted by kerry

Is the turbo spinning and otherwise functioning?

I don't know... it's so dang noisy that it's hard to hear it running. It sounds completely different when I pull a vacuum on the EGR - it quiets down instantly. I would need to pull a vacuum and THEN rev it up to see if I can hear the turbo spinning.... will check that tomorrow and report back. It also seems to be spitting droplets of oil - they land on my valve cover and after a while I can see the particles buildup.

@VSTECH & qwerty - I pulled the filter out - didn't see anything unusual in there. It runs the same with or without the filter in place. Makes no difference.

kerry · #20 11-14-2012, 10:28 PM

I'd just pull the air inlet to the turbo with the engine off and see if you can spin it with your fingers.

MercFan · #21 11-14-2012, 10:50 PM

Quote:

Originally Posted by kerry

I'd just pull the air inlet to the turbo with the engine off and see if you can spin it with your fingers.

I will do that. Main question: why would ALL of the exhaust be directed out into the intake (through the cross over)? I though that exhaust gases are mixed in gradually when the engine is working at higher RPMs not at idle speeds?! How do I test my EGR valve to make sure it's operational? I wish I could just block the thing with a plate (temporarily, of course..

)

kerry · #22 11-14-2012, 10:54 PM

Because the turbo is jammed up or broken and the exhaust can't get thru?

vstech · #23 11-15-2012, 06:02 AM

Quote:

Originally Posted by MercFan

I will do that. Main question: why would ALL of the exhaust be directed out into the intake (through the cross over)? I though that exhaust gases are mixed in gradually when the engine is working at higher RPMs not at idle speeds?! How do I test my EGR valve to make sure it's operational? I wish I could just block the thing with a plate (temporarily, of course..

)

ALL exhaust goes through the turbo unless the wastegate is open. otherwise the turbo could not build pressure.
ALL intake goes through the turbo. the fact that connecting the turbo to the intake kills the car shows there is no airflow through it. remove the intake snorkle to the turbo and check for obstructions on both ends. perhaps someone worked on the car, and it sucked in a rag?

MercFan · #24 11-15-2012, 09:42 AM

Quote:

Originally Posted by vstech

ALL exhaust goes through the turbo unless the wastegate is open. otherwise the turbo could not build pressure.
ALL intake goes through the turbo. the fact that connecting the turbo to the intake kills the car shows there is no airflow through it. remove the intake snorkle to the turbo and check for obstructions on both ends. perhaps someone worked on the car, and it sucked in a rag?

Thx - in that case: if the Turbo were seized, then the only thing that was feeding into the intake (via crossover) would be the exhaust gases - and that of course is not enough oxygen to make the diesel run... that may explain it. I'll check the turbo this afternoon and report back.

vstech · #25 11-15-2012, 12:51 PM

exhaust goes out the exhaust pipe through the exhaust compressor housing. intake goes through the intake housing... the two housings do not mix the gasses...

vstech · #26 11-15-2012, 12:58 PM

if the turbo is TOTALLY AND COMPLETELY SEIZED, it will still pass plenty of air to allow the motor to start.

the only place exhaust and intake mix is the EGR.

El ZORO · #27 11-15-2012, 01:16 PM

Sounds like two things are going on, exhaust gases from the exhaust manifold through the EGR into the intake and something is restricting ambient air from entering the turbo compressor.

Unbolt and inspect the EGR, could be janned broken spring, faulty control vacuum signal causing it to open.

For the ambiant air source you need to check the air filter inlet, the air filter, the air filter hosing outlet, the MAF flap/door, the snorkle tub between the MAF outlet and the turbo compressor inlet, and the compressor itself.

The only part that is likely to cause a complete air blockage is the MAF flap/door as it can seal the entire passage. But something like a lost rag or a mouse nest in exactly the right place could almost do the same thing. A completely clogged air filter could also but it would seem unlikely that it could happen over a very short period of time.

MercFan · #28 11-15-2012, 02:59 PM

Gracias, Sr. Zoro - I don't know where the MAF is (or even that my car had one) - thought it was a gas engine thing, but I plan on inspecting the entire air passage way all the way from the inlet to the compressor, and include the compressor rudimentary check later today. Good stuff - thx everybody.

Quote:

Originally Posted by El ZORO

Sounds like two things are going on, exhaust gases from the exhaust manifold through the EGR into the intake and something is restricting ambient air from entering the turbo compressor.

Unbolt and inspect the EGR, could be janned broken spring, faulty control vacuum signal causing it to open.

For the ambiant air source you need to check the air filter inlet, the air filter, the air filter hosing outlet, the MAF flap/door, the snorkle tub between the MAF outlet and the turbo compressor inlet, and the compressor itself.

The only part that is likely to cause a complete air blockage is the MAF flap/door as it can seal the entire passage. But something like a lost rag or a mouse nest in exactly the right place could almost do the same thing. A completely clogged air filter could also but it would seem unlikely that it could happen over a very short period of time.

rosenfe · #29 11-15-2012, 03:11 PM

i had this problem,turned out to be the catalytic converter,sdls have one .no way to know unless you remove it.if its clogged,car will not run and lots of smoke down at turbo toward rear of car

qwerty · #30 11-15-2012, 03:50 PM

Quote:

Originally Posted by rosenfe

i had this problem,turned out to be the catalytic converter..

That would get my vote as a top possibility.