Dogtag114

How bad do the trims need to be to need to take action?

I’m running +6 on Bank 1 and +15 on Bank 2

Xavier Smith II

It is fluctuating between 95-34-0 and Intake: 9-8.7-4.8-4.5 it will sustain these values. I think I have bad injectors.

ML63 AMG

Def intake manifold leak. Peter is correct. The upper composite portion tends to crack overtime (after so many heat cycles). Bottom is magnesium usually less prone unless corrosion occurs for some other reason)

Xavier Smith II

Coolant temperature is low but when I changed spark plugs, Cylinder 2 and basically all of passengers were white, but mainly cylinder 2 I'm thinking I might have a coolant block somewhere or my thermostat is broken. I read an engine oil temp 197 and coolant between 177-188. If in bumper to bumper traffic oil temps rise to 224 but comeback to 210-202, coolant rises to 197-202. I think my radiator fan is shot and potentially thermostat.


One more thing to note, my exterior temp is off by 35 degrees at times.

BLKROKT

Coolant and oil temp behavior sound totally normal

Exterior temp is an entirely different sensor, it’s stuck in your drivers side grill. Not relevant.

Xavier Smith II

After spark plug replace my my trims are back to normal. But I will still end up replacing the IM +Injectors to be 100% sure. The noise is my Coolant or windshield wiper reservoir (whatever the big oval shaped tank on the passenger side is) rattling against the body of the car. The picture attached is from Bank 1 Bank 2s plugs were very worn. Seems like they were original to the car. I have seen service history for the car. And it’s seen service A and B on time with HBs

hachiroku

lol thanks for that info...just checked mine...its hovering around 4.8-5.4 and i have an idle misfire here and there caused by it. figured it was a leaky/cracked intake manifold but now i know for sure.

Dogtag114

My intake pressure is 4.2

if this is so bad, why is there no code being thrown? Not even one pending

hachiroku

i don't think a reading of 4.2 is bad...but for my car...i do have a random misfire at idle and have had it for a while now. i have over time replaced with new plugs, coils, and injectors for other reasons. last item would be an air leak.

what are folks doing who have issues with intake manifolds failing? buying new one? JB Weld?

Jasonoff

What is your definition of "bad" here? You are loosing pressure in your IM, but not enough for the ECU's corrections to trigger a "malfunction" scenario.

Having unmetered/unfiltered air entering the combustion process is bad no matter how little.

If it should be 8.5, then 4.2 is bad.

Dogtag114

can someone share a real specification for this?

This is a few thousand dollar repair if I recall. I have no codes and no real issues. At times it feels “lungy” between 1-2k when under very light throttle... otherwise the can feels perfect.

BLKROKT

I don’t have the spec. I have this discussion here to go by.

https://mbworld.org/forums/c63-amg-w...ml#post7425366

Take it for whatever it’s worth.

Here’s what I had:
SAE.MAP inHg = intake manifold absolute pressure = 8.3 to 10 (dead on 8.6)

Maybe it’s not the same reading

Jasonoff

What if it's just a $5 vacuum hose?

Dogtag114

[QUOTE=BLKROKT;7972323]I don’t have the spec. I have this discussion here to go by.

Well now, Xavier's screen was in psi so I changed my units of measure to match his ...

By your spec:
8.3 Hg = 4.08 psi min
10 Hg = 4.91 psi max

So perhaps that is not it.

hachiroku

a standard range for tuning idle for standalones is 19-22 inHg which converts to 9.3-10.8 psi. generally speaking, the same should be said for any engine and computer combo that utilizes an intake manifold. the higher the compression the engine, the higher the vacuum.

8.3-10 psi would equate to 16.9-20.34 inHg

BLKROKT

Yeah but I measured in inHg

hachiroku

ok so we're all within range. I still feel I have a leak though for to my idle missing

Jasonoff

Didn't NASA miss landing on a planet once because of incorrect unit conversion?

Xavier Smith II

I just spent $950 on a intake manifold for nothing



Oh well

It will probably go sooner rather than later.

Dogtag114

Happens all the time. I'm burdened with being a Mechanical Engineer, so its usually my first question.

I was in a company that got bought by P&G, We used M for thousands and MM for Millions (Roman). They used M for Million and k for thousand. Yeah some big mistakes were made.

deadlyvt

Come to Canada where we half adopted metric ( engineering and socially) but then kept standard for the actual building and use of things. You are constantly converting things

hachiroku

supposedly this is the only item that fails in the intake manifold. from the dealer it isn't available separately, but luckily the aftermarket has caught up.

https://rebuildmastertech.com/merced...it-1561400801/

Dogtag114

How difficult of a DIY is this for a novice skill level?

Xavier Smith II

Do you have vacuum diagram for this engine?

Dogtag114

My issue was diagnosed today to be the cam shift position sensor and adjuster... well see if that does it. Pressures were all fine.