No Boost - No leaks, No codes

[Jocko 22]

Hi fellow Smart Fixers

 

Here is the deal. A few weeks ago my Smart (160k) starts making a high pitch whistling sound. Like a boost leak. I think - It sounds like the Intercooler has sprung a leak. I had repaired the holes in the old IC with JB Weld. The car works well but makes this crazy whistle sound.

Bonus! I find an intact (not holed) intercooler on Kijiji. On the weekend I switch out the IC. Everything looks hunky dory. I have power in the beginning but the whistle is still there. A few days later and all at once- no power.  The motor won't rev past 3k

 

So I figure...

1. the hose from the EGR to the turbo  - It happened to me before so I reinstall the pipe. - Same deal

2. EGR is stuck - I remove and check it. I had put a blocker plate last year - Nope slides perfectly

3. intake pressure sensor mounted near the dipstick - Nope

4. intake pressure sensor mounted on the intercooler - Nope in tight.

5. limp home mode. - disconnect the battery for 10 minutes - Still no power

6. leaky waste gate pressure hose (the short one that goes from the turbo high side barb to the actuator head) - Looks good

7. Struck waste gate - Lubed and loosen but seemed OK. I lengthened the arm to see if it was not sitting well - Nope

8, Crappy new IC - I changed out the IC and put back the old one which was OK BTW. Checked all the hoses and fittings. - Same crap.

This leaves me with

9. bad turbo - I was wondering if it wasn't the whistling sound wasn't it giving up the ghost before I lost power

 

What do you guys think? Are there any checks I missed? Anyone have one kicking around? Should I get it rebuilt? It's kind of a pricey part to change out just to see if that's it.

 

Ideas?  Thanks - I'm in Montreal.

[Jocko 22]

Yeah I was kinda thinking along your train of though and was thinking electrical. I seem to have seen this in a thread somewhere before but its the usual suspects - the EGR valve or the waste gate.

Even with a holed IC it still revved to 4k so it's not an boost leak. Maybe a sensor somewhere that I'm unaware of? I can hear the turbo spin and I get good acceleration up until it starts to build boost or 3k which ever comes first which made me think it was a boost leak and why I changed out the IC again but now I would rule it out.

 

The car ran fine. I got out of the car to run a errand (20 min) got back in and started driving - no boost. Usually you restart the car and the boost comes back but not this time. Its out for good.

 

I have a scanner but it didn't throw a code. No CEL. Nada! It just won't rev, Even with no load. in neutral - floored I only get 3k.

Sounds like safe mode but I did the disconnect the battery thing and nothing changed.

 

Another weird thing happened the other day but it may be unrelated.  I'm still driving the car but using the paddles because it won't rev high enough to shift in automatic. I usually leave it in auto.  All at once the actuator gets all fuddled and I get the 3 bars of death. First time in this car. So I don't panic (much) and I shut off the car, wait 10 secs and restart. Transmission is OK.

 

Alright that's weird! Almost like it didn't have enough electrical power. I'm going to look at the actuator tomorrow but would a battery on it's way out cause this type of problem? I'll check the alternator too while I'm at it.

 

It's almost like the fuel pump isn't getting enough power or creating enough pressure. I rewired the fuel pump directly to the power via a fuse in the fuse box rather than do the relay when the pin went out on the SAM this winter. Could the fuel pump be starved by a bad fuel filter? The air filter is really dirty but I did the same test with the filter removed and still 3k.

 

I checked the ground wires and they're OK. I could throw the battery on the charger but its summer and the car is used regularly so I doubt its the battery.

 

Thanks for the input, I'm gonna keep looking why it won't rev.  It sounds and feels like limp home mode or safe mode

[Jocko 22]

UPDATE!

So I got back under the car today.

I undid the intake to the turbo to check the impeller and for piece of mind. Started the car and the turbo sucks air no problem and sounds good. = It's NOT the turbo.

 

Took off the actuator only to find it's a sealed unit. I open the boot to clean and check as much as I could. Sprayed some white grease as Tolsen recommends and buttoned it back up. The connector is intact and clean. The transmission wires ditto. I'm anal about loose wires so I tend to tie wrap everything so it's tight and doesn't rub or chafe. These motors shake a lot and wreck havoc on the wires and hoses if they rub.

 

So lets forget the turbo, IC, the hoses, the actuator. I checked them all twice

Lets call this is a case of limp home/ safe mode with no codes.

 

WTF am I supposed to do with that?

 

Please don't tell me to go to MB! Anything but that! They're such losers. They can't even do a proper brake job, forget diagnose something like this.

I'll bet money that I go there and they tell me it's the turbo and charge me $3k? This is of course after I just checked it and it works fine. Any takers?

[MikeT 744]

Peace of mind would be better than piece of mind....

 

Too bad your dealers aren't trustworthy - on Vancouver Island they are excellent, if a tad pricy.

[Jocko 22]

OK so what I need now is a list of things that can make the car go limp home/safe mode but won't necessarily throw a code.

 

The Waste gate will do this sometimes but I checked it and it moves freely and it's manual.

 

The EGR may do it. - I'm tempted to unplug the clip and provoke a code to see if by clearing it I can get it back to normal. The piston moves free and the solenoid looks OK. I had put a block plate a while back so it's oily but not crusty.

 

I did notice a bit of oil in the IC and the intake hoses but would a blocked rebreather valve cause a limp home?

 

I'm going to pull off the wheel and check the alternator. It squeeks a bit but who knows at this point so may a well check that.

 

Can anyone think of anything else?

 

Thanks for the support.

[Gee 0]

on my 454, i have that whistle sound too, however i got jumped one time when i had overused battery on radio and it went away. Generally i have a problem i haven't gotten around to understanding. the car shows an engine light the occasionally wont start. if its in a incline too it wont start i have to being it to a flat to get it to start. after moving around in town doing bills it can also also just shut down while moving only to start up in limp home/safe mode. wait 5 to 10 minutes it starts up like it didn't just stop in the middle or a high way. i had it hooked to a scanner but nothing came up even with the engine light showing

i believe it might be the fuel pressure, but on reading your post seems you cleared that, my aproach however was to actually do a replacement of the pump than rewiring 

[Jocko 22]

Check the pins in the SAM. The fuel pump one (11 i think) tends to fry with time. Too many amps on a crappy pin. Why they didn't put a relay is another topic. I could be just a loose connection in the SAM to the fuel pump. I just hot wired mine to the fuse box with a fuse in between. Super easy and it will probably need to be done if that isn't the cause.

[Jocko 22]

I did a turbo leak test with a plastic and rubber deal I made and it holds boost. It's pointing to the EGR. Any one know where I can get an emulator these days?

[stickman007 309]

Do you want me to send you another emulator just to confirm? I should be able to put together a plug and play one for you to save some time on diagnostic?

 

3k limit usually has to do with the EGR, but sometimes it takes a few ignition cycle to clear the codes. If you have a working EGR body, the 180 rotation of the cartridge is the simplest/reliable in the long run. 

[Jocko 22]

Hi Stickman

I honestly have no idea what the hell it is and I didn't have the time to install the emulator. I just figured it might be something to do with the EGR as it seems like a boost leak or a SAM limiter.

BTW I do clean the EGR regularly and the valve moves nicely. I did try to pull ou the valve and flip it around but it wouldn't come out so I just plated it. It was easier than messing up the valve. I could use the puller. LOL

I'm going to try install the emulator you sent me weekend as a new knocking sound seems to be coming from the motor at idle.

Thanks for the support!

[smartdriver 49]

The EGR valve has a variable resistive feedback element which tells the ECU what position the solenoid valve is in.

 

It can wear and bounce causing electronic noise for which Mercedes Benz sold an accessory cable with a high value resistor placed across the resistive element to prevent the ECU from seeing an open circuit.

 

You didn't install the emulator?????

 

 

Edited November 8, 2017 by smartdriver

[Jocko 22]

So installed the emulator and now I get a P0409 error. Not too sure if its the emulator or the order of the pins that I got reversed. i'm still looking into that.

I went with the diagram and I made an educated guess as to pins 1 and 5 and soldered them in order. Maybe Stickman thinks I know a lot more about electronics than I actually do or the pins are not in order. 

No problem, Still in limp home mode with CEL. Car drives the same. LOL

[Jocko 22]

You can clean the valve with Carb Cleaner with it still in the EGR and it will move freely. This would resolve the code when ever I would get one. Usually it's just the valve that's stuck. Since I plated it I haven't had a code.

I'm getting a code now with the Emulator. The EGR isn't connected.

[Jocko 22]

Quote

The only way to clean the EGR is to pull it out!

If you didn't remove it to clean it, and it is plugged, it will give a fault code. Putting a plate over the port does not cancel the EGR's ability to show a fault.

 

I've been going in circle for months with this.

This is the point. I have NO error codes with the EGR in but the car is still in limp home mode.

The emulator is just cheaper than buying another EGR to test to see if the EGR is causing the limp home mode.

Also why turning the valve doesn't matter because it's plated. It doesn't get dirty because no exhaust is getting in the EGR. The valve moves no problem.

I was hoping it was an fault in the EGR that didn't pop a code but caused a limp home mode.

At least now I have an error code and limp home mode   and the car still drives the same. I'll keep at it and drive it anyway until get the emulator working properly.

[smartdriver 49]

What was your educated guess about the emulator pins?

 

 

 

Edited November 13, 2017 by smartdriver

[Jocko 22]

Here is the emulator installed. I presume the pin 1 is the first wire on the right and the pin 5 is last on the left with the rest just following 2 3 4 with 3 being the grey. The odds are 50/50 I got it right.

[smartdriver 49]

Did you not receive instructions from stickman?

 

Your Pin 1 and Pin 5 are correct.

 

I'm surprised that you didn't take the time to read the previous post thoroughly. By clicking on the stickman007 link you will see a photo with pin numbers that may or may not be the same as the pinouts on your emulator. They are not necessarily 1.2.3.4.5.

 

Perhaps stickman007 can chime in.

 

You can confirm the correct pinouts by comparing the physical circuit to the schematic below.

 

 

 

 

Edited November 16, 2017 by smartdriver

[Jocko 22]

I just got the module. No instructions but yeah I used the diagram you posted and the wire numbers to match. That post BTW is 30 pages LOL but yeah I breezed through it. I guess only Stickman can give us the answer. I just assumed the rest were in order. You did notice almost all the wires are the same color. It makes it all the more challenging. Why 1 grey one? Just to mix it up a bit?

[stickman007 309]

Grey is #4. If the emulator burned out, let me know and I'll send you another one. I thought I sent you the link to this post, but my mistake.

 

There is a slight change on yours. The big 100Ohm resistor is now in the left hand side.

 

Hope this helps.

Edited November 16, 2017 by stickman007

[smartdriver 49]

21 hours ago, Jocko said:

but yeah I used the diagram you posted and the wire numbers to match. 

 

It would appear from stickman007's post that the numbers do not match.

[Jocko 22]

Well there's your problem! 

I'll get around to soldering up the right way on Saturday. I didn't drive the car since I installed it so I'm hoping it's alright.

Thanks guys I'll let you know how I make out.

[tolsen 630]

No control of documentation and change. Possible costly permanent damage to engine control unit. 

[tolsen 630]

EGR valve is a Pierburg design. You already should know, dealer mechanics only replace components hoping for the best. Our type of EGR valve can normally block EGR gas regardless of car manufacturer simply by turning the insert a certain angle so nothing to do with Mercedes.

[Jocko 22]

So its Good News - Bad News

 

Good News is - no damage to the car. I wired the Emulator properly and have no codes. The car starts and runs fine.

 

Bad News is- The car runs the same as before in Limp Home Mode. So I think it's safe to rule out the EGR.

 

Next is to do another boost test to see if I have a leak somewhere. Maybe a weak hose with a pin hole or cut in it somewhere. I had done a quick check once before and didn't find anything. I'll do a more thorough inspection this time and while I'm at it I may spin the valve like recommended or delete the EGR all together.

 

I'll keep you posted.

[smart142 605]

I would recheck the turbo.