I really hope that's all it is. I honestly cannot think what else it could be. When I get home tomorrow night, I'll rotate the intake cam angle sensor 180* out, reset the ECU and see what happens. If that doesn't fix it, then I'll have to start tearing it down piece by piece and see if I can find what went wrong.

 

Update:

Well, I opened up the intake cam angle sensor cover and decided to take off the pane thing, rotate 180* and see if I could have done that. Well, FYI, the pane thing can only go on truly one way. When I tried to rotate it 180*, it caught on the little tabs, but it won't fully seat. When I rotated it back 180*, it naturally seated all the way flush with the cam. This confirms my notion that the little white paint on the time is indeed indicative of TDC (aligned with the cam dowel).

So unfortunately I'm back where I started... When I was driving it, I did datalog a lot. Would these logs possibly yield some information? Like, does it report where the cam angle actually is and then I can compare that to where it should be and see what is wrong? Or does the ECU only report where it thinks the cam is?

I'm starting to seriously consider just taking this to a shop and having them diagnose it... just makes me feel like all my work was for nothing...

Anyone else have any ideas?

 

Update 2:

So I finally called up my good friend who is a Master Technician at the local Mercedes dealership to get his opinion on the situation. After coming over last night, hearing my description of the problem and checking over my car, he thinks it may be one of two things.
1) My timing is off
2) I've bent some valves ()

So tonight he is bringing over his timing light and his compression tester to check out both possibilities. Let's pray all the cylinder's compression is within spec. I really don't want to remove the head and get it machined! Timing would be much easier to resolve!

Standby for more details as we try to track this down

 

timing is of. I got a buck on it, sounds to familiar.

 

I'm thinking more and more that this is what must be. When I get home tonight, I will be removing the accessory belt and the motor mount, dropping the engine and removing the lower timing cover in preparation for fixing timing. Power of positive thinking!

 

Can you take a few pics of the cam angle sensors index points at tdc? Also the above seems a bit excessive to correct timing, why dont you just put the crank at tdc and see if the cam gears are lined up? I just fixed my timing two days ago, exhaust cam was off one tooth just used the tensioner tool slipped off the belt and got her lined up again.

 

Okay, anticipating a possible massive timing change (like if the oil pump sprocket or balance shaft sprockets were off) I removed the accessory belt, water pump pulley, idler pulley, tensioner, passenger side engine mount and upper timing cover. Here is what everything looks like @ TDC....















So now what...

 

The adjustable cam gear has the exhaust cam slightly retarded, but nothing along the lines with bending valves I would think. I have seen timing off by a tooth or two with still no issues. Are you sure you installed the cams correctly? Did you degree the cams in or just throw the adjustable cam gear on there with the cam and then the belt? The timing light will tell you what the true timing of the motor is, but to me it looks okay to begin with there. The Crank is at TDC as well as the MIVEC and the exhaust cam is less than a tooth retarded. Nothing terribly wrong so far.

See what the compression test reveals...

 

+1 on the timing light... most auto parts stores rent them fairly cheap

 

My friend (Master Tech with Mercedes) is bringing over his timing light tonight to see for sure. I purposely retarded the exhaust cam 1* to add more overlap, hence the installation of an adjustable cam gear. And the cams can only be installed one way - with the dowel pin up. If I tried to install the cams into any other rotational orientation, I wouldn't be able to get the dowel pin into the cam gear (as the photo shows for the exhaust cam gear). So I know the cams are installed, at least rotational, correct. I'm just waiting now to see what the timing light shows and the compression test...

 

Well I'll be damned, the cam sensor is indexed correctly and the timing looks to be dead on to me. It has to be something to do with the cam install though because she was not having issues prior to the install, correct? Timing light may help but with the issues your having I think it would be obvious and the timing is not off imo. Let us know what your buddy says and we'll take it from there Good luck!

 

I'm going to pull off the valve cover tomorrow after I get home from work and see what that shows me. Hopefully that will yield some more information.

Update:

So my friend came over tonight and the first thing we did was run the timing light. It showed that everything was pretty much advanced the same amount per my timing maps (9* at first, then 7* when I flashed back to what the car was before I installed the cams). So nothing there. Next we checked compression. Cylinders 1 - 3 all read about 135, so we didn't bother testing 4 since it was only 2 or 3 that could have had bent valves. So the good news is I don't have to remove the head - the bad news is I'm right back where I started.

At this point I've decided to just re-install the stock cams and see what happens. The car ran fine before I did all this work, and since the timing is lined up and there is no way that an new O2 housing could cause this, it leaves only the cams. So I'll swap them out and run the car. If it runs well, then obviously something is messed up from these cams and I'll be having a chat with the guy I bought them from... stay tuned.

 

OK, I don't have the Mivec on my car but here are a few thoughts:

the first part of you original description:
"I would push the gas pedal all the way down and the car would just sit there, hovering around 400 - 500 RPMs. When I take it out of gear and rev it, it revs up fine to redline."

1. It kind of sounds a lot like a massive boost leak somewhere, like when a hose pops off or the BOV malfunctions etc., did you remove the BOV for the install or anything? Are you sure it's back in properly if you did?

2. The next part is what leads me to wonder about the BOV malfunctioning (working then not working, etc...)
specifically:
"Then all of sudden it starts building boost like crazy (~20 PSI at 2500 RPMs) and I have to let off the gas to avoid massive boost spikes."

... because with just a simple boost leak, you couldn't really build boost, especially under load.

BUT on the other hand, you had to swap the 02 sensor to the new housing, so is there any chance that sensor was damaged or not hooked up? (edit: never mind on that, I guess that would have thrown a code)

I'm guessing that you checked all of the hoses and wires that you unplugged to get the valve cover off ...(?)

Also, are you sure that the waste gate actuator arm is properly hooked up and not getting stuck on the 02 sensor cable or something?

Anyway, just a few things I'd look at, not knowing exactly all the things that you might have already checked while you were standing there looking at the engine saying wtf ???, etc...

good luck, waiting to see what you find out.

 

I have a boost leeak once. The pipe popped loose on the intercooler.

 

Is it a used cams?