Pictorial DIY for an M54 spark plug replacement on a 2002 BMW 525i E39 with 95K miles

I realize my terminology was vague and subjective, but I didn't really have any way to quantify it. However, I think the subsequent posts by Fudman and rdl have clarified it pretty well. Plus, judging by your description of what you did for illustrative purposes, that's not the issue. What kind of gas mileage are you getting? (Not to incite another controversy.) Has it dropped noticeably since you've had the problem?

Nice action shot of brake cleaner spraying, by the way.

Bluebee, I just had another thought. You might need to replace your gas cap to solve this. Here's an interesting article from Popular Mechanics that might explain why. Pertinent quote:

As car manufacturers started to understand emissions better, the number of vacuum lines diminished—but that didn't last long. The EPA started to require that leaking gasoline fumes be reduced to virtually zero, and the EVAP system on every current car is controlled largely by—you guessed it—engine vacuum. When the car is turned off, the system captures fuel vapor in a charcoal canister, then parses the vapors back to the running engine through—you guessed it again—a network of vacuum hoses.

The mouse-chewed hose is apparently, as stated, not a 'drain' hose but a 'return hose' (aka "top hose") for the CCV.

Here is a picture (the front of the engine is to the right) from here:
- M54 CCV top hose



Another picture showing the return hose & location of the CCV is also there:
- ICV, CCV, Vanos or all three?!



Realoem lists it as #7, "Return pipe" (PN: 11617504536, $33.87):



BTW, I don't have oil consumption, smoky exhaust, oil sludge, or, to my knowledge, excessive vacuum (?).

But, I do have a vacuum leak (obviously, from the codes); and there 'is' weird damage to the ccv insulation.

Tomorrow, I'll take a more accurate picture of the vacuum and I'll look for a balloon if I can find one lying around to try cn90's trick:
- E39 (1997 - 2003) > Cute little trick to diagnose blocked CCV

Originally Posted by Fudman

You should have 3"-6" of vacuum pressure, as measured by a manometer, at the oil fill cap or the dipstick tube

I googled for the manometer and found this reference ...
- How to test CCV?

Which suggests this particular manometer:
- Dwyer Slack-Tube Manometer, BMW tool part number 99000001410 (aka BMW PN: 99 00 0 001 410).

The complete kit (including oil-filler-cap-interface) is apparently available from DDM Tuning:
- Genuine OEM BMW Part # 99000001410 C/C VENT VAL TOOL $196.63


But, just the manometer (without the BMW interface components) is available on the net:


There is apparently a service bulletin on how to use it to test the CCV:

refer to service information bulletin number 04 08 98 for further information regarding the slack tube manometer tool ... With all electrical consumers and the air conditioning switched off and engine at operating temperature the reading should indicate from 3.0 - 6.0 inches of water at idle ... A higher than normal crankcase vacuum will cause the crankshaft seals to leak outside air into the crankcase during engine operation. A whistling or howling noise is usually heard coming from the seal areas (front or rear) at idle when this occurs

Regarding the whistling noise, I'll check tomorrow since I didn't realize I should look for that. Here, are symptoms of a bad CCV according to:
- Crankcase Ventilation System Check For 1994-2007 BMW Engines (1) (2) (3) (4)
[Note: These separate references all have the same text so I ordered them in best to worst presentation format.]

A properly functioning pressure control valve is designed to maintain a slight vacuum (approx. 10-15 mbar) in the crankcase ... A malfunctioning crankcase ventilation valve may cause the following complaints:

• Engine runs rough
• Whistling noise from the crankcase ventilation valve
• Check Engine Light on
  • possible DM faults stored
  • misfire all cylinders
  • oxygen sensor/mixture faults,
  • etc.

I searched for how to test the CCV, and went back 5 pages into the Bimmerfest record. There was no thread specifically titled as a CCV test page, so, I'll open one up so that we can explore this topic well enough for others to follow easily in our footsteps.

EDIT: Here is the thread opened up:
- How to test the BMW E39 pressure-controlled crankcase ventilation system (CCV)?

Originally Posted by bobdmac

the EVAP system on every current car is controlled largely by—you guessed it—engine vacuum

Uh oh. I see the problem you're intimating.

When I ran this long-term P0455 CHECK FILLER CAP test, I lost the gas cap!
- Loose gas cap has triggered Service Engine light

Right--it's possible that with your gas cap off, the extreme vacuum from descending a 9% grade with the throttle closed would be enough to suck air in through the evaporative emission system and produce a lean condition that would register a fault code.

Originally Posted by bobdmac

What kind of gas mileage are you getting?

I have no idea! I never check my gas mileage.

Besides, I use the verboten low-octane-rated stuff from Costco (I'm ducking already!)
- Engine fuel, i.e., gasoline & octane (1) & "The Gasoline FAQ" & top-tier gas stations (1)

Next fuel fillup, I'll keep records to test the gas mileage (taking into account sig figs):
- What is the tolerance (i.e., accuracy) of our typical miles per gallon (MPG) calculations (1)

Originally Posted by bobdmac

Nice action shot of brake cleaner spraying, by the way.

Heh heh. Thanks. It's a balancing act, one hand on the SLR up close to my face (so I can't see except through the lens) and the other hand spraying in the 'general direction' to where I 'intended' to point it (while the Brakleen splatters all over the camera lens like in a bad dinosaur movie).

Here's a shot of the Brakleen aimed directly at the 'mouse-chewed' portion of the CCV return pipe which connects on one end to the "intake manifold" and on the other end to the "connecting line" (which itself, connects to the intake manifold and to the CCV).

Note: I think the realoem diagram has this insulated CCV "return pipe" positioned backward. The "return pipe" seems to connect in the rear of the engine (to the right in this picture) to the intake manifold; and it seems to connect in the front of the engine (to the left in this picture) to the CCV "connecting line" (which itself connects to the intake manifold on its upper end, and to the CCV itself on its lower end).



However, detailed debugging of the CCV is probably off topic for a spark plug DIY, I opened a separate thread (after searching for an existing thread of the same topic) specifically for testing the CCV over here:
- How to test the BMW E39 pressure-controlled crankcase ventilation system (CCV)?

BTW, Rajaie apparently said the following regarding testing the CCV vacuum with a plastic baggy:
- E39 (1997 - 2003) > Cute little trick to diagnose blocked CCV system... (see post #4)

"The crankcase vent valve and 4 associate hoses fail and cause a vacuum leak. The valve gets stuck open and the hoses crack. These last 70-120k miles and usually fail 80-90k miles. Here are a couple diagnoses.
At warm idle, place a small plastic freezer storage bag on its side over the oil fill hole. If the bag sits on top or gets slightly sucked in, ~1", the valve is good. If the bag gets significantly sucked in the hole the valve is stuck open and bad. With the engine off and cold, carefully remove the hose at the valve cover front corner. Blow hard into the hole. You should hear oil bubbling in the oil pan. If you don't hear the bubbling the top or bottom hose is likely cracked. The bottom hose often breaks just below the valve connection. There can also be cracks in the other two hoses."

BTW, while researching the CCV, I found an excellent picture of the 'underside' of the mouse-eaten CCV "return pipe" over here:
- CCV Replacement FYI - M54

That photo above sparked my imagination in that I can now come up with a tentative hypothesis of WHAT caused that semi-circular shaped 'mouse-eaten' bite out of the CCV "return pipe" foam insulation.

My hypothesis:
- Someone flipped up the "air distribution piece" much as Jason5driver did here.
- In doing so, they 'pinched' the CCV return pipe between one of those prongs sticking out of the air distribution piece and that circular tube sticking up out of what appears to be the intake manifold.

Does that hypothesis sound potentially reasonable for the cause of a semicircular bite out of the M54 CCV return pipe foam insulation?

Sure does--especially if, in typical BMW fashion, the rubber has oxidized and become friable. It seems to crumble at the slightest provocation.

I was updating the misfire diagnostic thread today with new information:
- General diagnostic procedure for a single or multi-cylinder E39 intermittent misfire?

Where it says:

Swap the spark plug boots between adjacent cylinders

• If the misfire moves, replace the spark plug boot

Now that I've replaced my spark plugs, I have a better idea what is there, and, well, uh, um ... I don't remember 'no spark plug boot.

The coil attached directly to the spark plug, IIRC.

But, maybe the coil was two pieces?

Is it that the bottom half of the coil (see below to the left in the picture), is a removable "spark plug boot"?

As for the unanswered question about the separate "spark plug boot" (aka "spark plug socket"), & bearing in mind that Realoem is sometimes wrong, I opened a separate thread over here:
- Does the M54 coil have a separate spark plug boot (or not)?



I did a retest using the "balloon" method suggested by cn90.
Results appear to be:

• Oil filler cap has slight (about 1/2 inch) suction
  • Also the oil filler tube "gurgles" when I remove the oil filler cap (what does that indicate)?
• Dipstick guide tube has neither vacuum nor pressure
  • Suction seemed barely minimal or even non existent
  • Pressure seemed non existent

Here is a pic, without any enhancements, of the oil filler vacuum test:


And, here's that same test on the dipstick guide tube:


Lastly, here's my attempt at rubber banding a nitrile glove onto the dipstick guide tube (sorry cn90, I didn't have any balloons handy):

Bluebee, have you replaced your gas cap yet?

Originally Posted by bobdmac

Bluebee, have you replaced your gas cap yet?

I'm still LOOKING for the silly thing in my garage!

Just for the record, Mark has noted, from experience, that the Bosch plugs are subject to something called 'blowout', as noted in this thread today:
- did I just drop a cylinder? (Blown plug, please help)

Originally Posted by Mark@EAC

Lots of folks have reported that the bosch plugs back out after being torqued down. Yours probably backed out a few threads and then the compression of the engine pushed it right out taking the threads with it.

For the record, a set of discussions today about the $1,200 savings at 100K miles simply by using 87 AKI over 91 AKI fuel prompted me to look again at my spark plugs shown above for evidence of ping-related damage:
- What factors in cost differences between using regular vs premium fuels on our E39s?

Those original spark plugs above were removed after about 70K miles driven using Costco 87 AKI fuel.

Given those plugs had about 30K miles presumably on 91 AKI with the remainder on 87 AKI Costco fuel ...

Do you see anything negative about those spark plugs that is unusual for 100K miles?

For the record, today a nice set of pictures was posted showing oil in the sparkplug well:
- E39 (1997 - 2003) > Oil in Spark Plug Well

For the crosslink record, apparently in this thread today, there are 'claims' that some spark plugs provide better 'horsepower' than others.
- E39 (1997 - 2003) > Pulstar Pulse Plugs

I'm wary of the chart below, simply because a spark plug merely enables a spark to jump a gap - and that's pretty much it - so how in the world changing that can increase horsepower - is beyond me.

But, here's the chart so that this thread has all the relevent spark plug charts and diagrams ...

Originally Posted by bluebee

For the crosslink record, apparently in this thread today, there are 'claims' that some spark plugs provide better 'horsepower' than others.
- E39 (1997 - 2003) > Pulstar Pulse Plugs

I'm wary of the chart below, simply because a spark plug merely enables a spark to jump a gap - and that's pretty much it - so how in the world changing that can increase horsepower - is beyond me.

But, here's the chart so that this thread has all the relevent spark plug charts and diagrams ...

... stuff deleted ...

It is possilbe that spark plugs might affect power and peak torque. Consider what very high mileage or fouled plugs can do. Even if there is no noticeable misfiring or engine roughness, MPG and emissions can get worse. Alternatively, one plug could provide a better spark, better combustion initiation & therefore more power or torque than other spark plugs.

A commonly accepted statistical technique to compare trial results such as these is ANOVA (analysis of variance.)
An ANOVA of this dataset at 1%, 10% or even at a 25% confidence levels finds that
"F is < Fcrit, therefore we cannot reject the hypothesis of equal means"
for all levels.

Note that the higher the confidence level, the more willing we are to "make a mistake" in saying that there IS a difference between the plugs even if there is not. Commonly used confidence levels are 1%, 5% and 10%. Using 25% implies we are "streching" and are quite willing to "make a mistake" in saying there is a difference between plugs.

In other words, the results reported are quite/very consistent with NO difference between the spark plugs tested for either power or peak torque.

Regards
RDL

Great write-up, wouldn't expect any less from you Blue.

Originally Posted by rdl

It is possilbe that spark plugs might affect power and peak torque.

Along that vein, this thread by an expert in the E46 forums today may be of interest:
- E46 (1999 - 2006) > E3 Spark Plug Experiment = FAIL (pics)

Originally Posted by smolck

I put a set of E3 spark plugs in my car about 20k or 30k miles ago because they were a gift. They did just fine, until last week. My car started missing like a mofo but was not throwing codes. Then one day I finally got a p0101 (MAF code) and I thought "ok, no problem". Changed out the MAF, no improvement. At this point I KNOW it is the plugs but I decided to wait and see what happened. Well today I was on my way to work and the car is in bad shape, won't accelerate and obviously it is running on less than 6 cylinders. Read my codes (yes, while driving) and I got 0304 and 0306.

So I go to the parts store, buy my OEM Bosch plugs, installed them tonight and problem solved. Come to find out many have had issues with them crapping out in the 15k-20k mile range. When I pulled them I realized why, look at the gap on these suckers! The middle electrode is worn WAY down from where it was. I am sure I was blowing the spark out.

MORAL: E3 Spark Plugs suck and so does any product Horsepower TV says is good.

And, in this E46 thread today, Joe, at EAC Tuning, answered the 'boot' question with this picture:

Now that I've replaced my spark plugs, I have a better idea what is there, and, well, uh, um ... I don't remember 'no spark plug boot.

The coil attached directly to the spark plug, IIRC.

But, maybe the coil was two pieces?

Is it that the bottom half of the coil (see below to the left in the picture), is a removable "spark plug boot"?

I am now convinced that Blubee is a machine. No human being can produce this amount of very useful information (with photos) as frequently and detailed as Blubee does. Which leads me to three possible conclusions

1) Blubee fell into a time machine from the distant future and has no way to return home

2) Blubee is an artificial lifeform that escaped from the NSA and seeks to empower humanity

3) Blubee is one smart cookie that has given me the tools needed to maximize my vehicle at the minimum cost.


These could also apply to Fudman and several other participants in this forum.


BTW - I just ordered my NGK (3199) spark plugs from Amazon at $7.20 a plug with free shipping. + $4 in total tax. Thanks to this post installing them should be fairly easy to do. How much money will I save on this vs going to the dealer?

Originally Posted by seemyad

No human being can

Actually, I'm a dog. But anonymity & equality is just what I like about the Internet!



BTW, there is one thing I wholly missed when I did this DIY ... which is WHERE is the M54 engine Schrader valve for the fuel-injection system?

everyone helped by bluebee should send a buck...it might cover the purchase of a newer 5-series

Originally Posted by bagodonuts68

everyone helped by bluebee should send a buck...

Maybe I should start a blog, and charge advertising fees!

BTW, speaking of blogs, here is a related Bavauto blog:
- BMW DIY Video – Spark Plug And Coil Replacement, 4-Valve Engines (V8 and 6-Cylinder) September 8, 2010



Reproduced below, in PDF form, for posterity.

Originally Posted by bluebee

WHERE is the M54 engine Schrader valve for the fuel-injection system?

Thanks to JimLev & RDL in this thread today:
- Where is the M54 fuel line schrader valve (to test lean conditions fuel pressure)?

I was (finally) able to locate the M54 engine fuel system Schrader valve in Realoem (it was hard to find simply because it is unlabeled):


With that information, I was able to easily locate the M54 Schrader valve in my photos above (reproduced below with the fuel supply Schrader valve circled):


RDL even kindly supplied the BMW TIS for testing fuel system pressure; however the suggest using GT1/DIS for testing the fuel pressure:



But I will try to use the Autozone $150 loaner tool:
- Actron Fuel Pump Diagnostic Kit CP9220A


In addition to testing the fuel system, I'll also try to figure out how to do a DIY intake system 'smoke test' to see if/where vacuum is leaking, causing my lean conditions:
- Does the order of the misfire OBDII DTCs diagnostic trouble codes actually matter (1)