Oil consumption after CCV replacement

[Dave1027]

I built this setup to see what crankcase vacuum I was running with 02Pilot's mod. I bought a cheap $5 oil cap off ebay, drilled a hole through it and connected my vacuum gauge.

When I first started the car the vacuum was only about 1 in/hg but it gradually climbed and leveled off at 7 in/hg. I had my wife hit the throttle but the 7 in/hg did not deviate. This amount of vacuum is more than I expected it to be but I don't think it's harmful. The engine is running well.

[bmwdirtracer]

I just wanted to point out the interesting correlation between your new vacuum reading, and the vacuum reading I got in my post #249 above......the vacuum reading with which I confirmed a failed ccv system, on the car with massive oil smoke.

Certainly, I realize that one is the very antithesis of the other: the guys in this thread are using that "excessive" vacuum to CORRECT oil consumption -- and yet the same amount of vacuum in a stock car CAUSED the huge consumption......

All very weird. I absolutely believe all the evidence presented in this thread; it's well researched, and well documented, and well supported. But I'd sure like to be able to wrap my head around how this massive vacuum is a sure sign of ccv failure in an oil-smoking stock car, but a cure for excessive oil consumption in engines modified as detailed herein.

[02Pilot]

Chris, the variable in the mod is that it introduces full vacuum from the intake plenum, i.e., behind the throttle plate, albeit in a controlled way via a small orifice and small diameter hose, which act to limit the speed of change. Thus, a modded engine will eventually allow a properly sealed crankcase to be pulled down to the same vacuum as the intake plenum, but slowly. In an unmodded engine with a failed diaphragm, the vacuum source being applied to the crankcase is the same, but it is doing it through the large diameter CCV hose, so it happens abruptly, violently, as you experienced. I suspect this will have the additional affect of increasing consumption in a poorly sealed engine by overwhelming the capacity of the oil separator to deal with the increased volume of fumes, or worse, if the upper hose from the valve cover to the CCV is plugged, by pulling a large volume of oil directly from the pan.

[MarcoZandrini]

chris, the variable in the mod is that it introduces full vacuum from the intake plenum, i.e., behind the throttle plate, albeit in a controlled way via a small orifice and small diameter hose, which act to limit the speed of change. Thus, a modded engine will eventually allow a properly sealed crankcase to be pulled down to the same vacuum as the intake plenum, but slowly. In an unmodded engine with a failed diaphragm, the vacuum source being applied to the crankcase is the same, but it is doing it through the large diameter ccv hose, so it happens abruptly, violently, as you experienced. I suspect this will have the additional affect of increasing consumption in a poorly sealed engine by overwhelming the capacity of the oil separator to deal with the increased volume of fumes, or worse, if the upper hose from the valve cover to the ccv is plugged, by pulling a large volume of oil directly from the pan.

qed

[Dave1027]

Saw this document posted at another forum:
http://forum.e46fanatics.com/attachm...2&d=1428903978

It says normal crankcase vacuum is 10 to 15 mbar (works out to about 1/3 in/hg of vacuum). That's only a tiny amount. I'm surprised there's enough vacuum to cover the blow by.

[bluebottle]

THANK YOU ALL VERY MUCH.

E39 525i manual 84000miles in Devon England.

Had all the same symptoms as you, 1 litre (pint) of 5W 40 LL04 engine oil disappearing every 1000 miles of generally gentle driving, but no sign of smoke. Changed CCV and pipes last year and it made the problem worse. It seems I also have the original oil dipstick with concentric tube which is clear, but it's not cheap to replace with the improved part

The more forums I read, the more I realise that excessive oil consumption in M54 engines is a common but complex problem. My other E39 is a 1998 156,000 mile 523i M52 and not pampered like my 525i but in three years has never lost any oil!

Many people dismiss this problem as normal, but I suspect it's just lazy mechanics. 15% of total oil capacity consumed every 1000 miles or less is not acceptable!! Even BMW themselves dismiss it as 'within tolerance'. I'm also starting to suspect that BMW have a very badly designed crankcase ventilation system as it is the opposite to all other manufacturers..

Last weekend, I made a simple manometer (less than £10). Checked cam cover bolts (cover gasket was changed last year) and spark plugs (Spark plugs quite black and oily after 18 months and 6000miles).Pipe from CCV to dipstick-tube was clean and dry. Started cold engine : manometer level reading was +/-80 mm(160mm).

I hope and assume that adding the modification pipe will negate the need to purchase the new dipstick tube.

I removed air filter, ducting and MAF as well as DISA and loosened conduit wiring harness box by disconnecting some plugs. I plugged the new pipe into one of the small rear nipples on the manifold and fed the pipe toward the CCV before cutting it to length. I would recommend a 4.0mm pipe as the 5.0mm (3/16") pipe is not tight on the nipples. Because of this, I cable-tied the pipe to the conduit box bracket to prevent it coming off the CCV.

Started engine: seemed normal. Connected manometer to see the vacuum swiftly rise from +/-70mm (140mm) to +/-200mm(400mm) and removed oil cap before I had coloured water sucked into my crankcase!
A vast increase in vacuum. I went for a four mile test drive (engine not too hot so did not exceed 4000rpm). Everything felt fine and perhaps even better than before. When I arrived back home and turned off ignition I was greeted with a yellow oil warning lamp. Oil topped up and I will keep checking oil level and pipes over the next few months. My drive to work and back today included town, country lanes and motorway (all in 9 miles each way!); car felt smoother, more responsive and already computer is reading an improvement in economy 31 MPG rather than 29MPG.

Promise to update post with significant news.

Thank you all again.

Lee

[02Pilot]

Glad it seems to be working for you. I do strongly recommend that you replace the dipstick guide tube (or modify it by removing the inner portion below the CCV drain, but that requires welding). If it clogs, you are inviting problems that could appear quite suddenly. I'm sure many are running this mod without changing the guide tube, and probably haven't encountered issues, but the old design is so clog-prone I wouldn't feel comfortable with it in there.

[bluebottle]

Thanks O2Pilot; I'll find a friend with a welder.

[Dave1027]

Can't you simply drill some holes in the outer tube just below the o-ring? Wouldn't that eliminate the possibility of sucking oil?

[02Pilot]

Can't you simply drill some holes in the outer tube just below the o-ring? Wouldn't that eliminate the possibility of sucking oil?

In theory, but the drain path from the CCV would still be pretty convoluted. I prefer the straight shot from the drain into the main tube and thus the pan that cutting out the inner sleeve provides.

[dirtup]

02, new to this forum but got linked here from e46fanatics. Have read this entire thread and the similar one at e46.

Current BMW is a 330i Sport manual bought new, build date 2-2-02. And yes, I had a '70 2002 back in the day that blew a lot of oil past the valve stem seals above 4000 rpm. In between were a couple of e30s, an e28, and an e34. None used oil, even though three were DD/track cars.

The e46 began using oil almost from delivery. First clue was oil light at 28k. I had even had the dealer do a first OS at 4k. Finally replaced CCV at 95k, including dipstick tube. This was NOT the cold-weather version, but it was the complete kit. Recently replaced vcg and ofhg; now there are no leaks, but consumption is up to about a quart every 200 miles. At cold start [well, 65 degrees] the oil fill hole pulls a paper shop towel down about 3/16". I have no vacuum gauge.

When I checked at back of intake manifold to see where to place the hose to CCV, I found the two small nipples already had hoses attached. The more outboard nipple has no cap, but a small wire will only penetrate about 1/2". Does this situation match anyone else's experience?

To verify suspicions, I will visit the local indy import shop and have a smoke test done. Since the MAF, air box, and cabin filter venturi are already off, is there any sense replacing them before smoke test? I also hope to be able to talk the indy into performing the water injection trick to see if it might remove enough carbon to help.

All advice appreciated,

dirtup

[02Pilot]

Not familiar with the E46Fanatics thread, but a smoke test is a good idea just on general principle. Can you trace the hoses that you've got hooked up to the back of the intake? My E39 had vacuum caps on both nipples, so I can't help you on that, but if nothing else you could simply T into the smaller line.

[bmwdirtracer]

Nothing goes to the cabin filter from the intake system.

I'd hesitate to ask anyone to perform the water injection, if he's not old school and really good. It is entirely possible to hydrolock an engine this way, and that's forever. That said, I got a case of fine German beer from a customer last week, for making his car run better than he ever remembered.

Now, I'll leave you in O2pilot's excellent hands....

[dirtup]

Thanks to you guys for quick comeback. After smoke test and injection I'll look at where to tee the line. Asked about cabin venturi box because it covers up a lot of the back of the engine. Of course leaving off the MAF will pop a code, but that's where the h2o goes. Love the car, but this oil business is driving me nuts!

Indy and I are definitely both old school. I'm so old I've forgotten my SCCA number; BMW CCA 93395.

Rusty Ford - BMW CCA instructor 1991-94, SCCA old boy racer and instructor 1994-2004

[02Pilot]

No need to leave the MAF off to feed water in. Do it though the small F-shaped nipple in the intake ducting before the throttle plate, or even through the one on the back of the intake (though given the position this may not distribute the water evenly).

[dirtup]

Our little college town supports a few indy import shops. Indy #1 is young and Mooresville-educated. After a few years in diesel fleet service, he had no problem with the idea of water injection but no direct experience using it on gasoline engines. He lent me a vacuum gauge with fittings and suggested the water mist method for finding vacuum leaks. Connecting his gauge to the nipple at lower rear of intake manifold revealed quite a leak: 12-25 inches as I blipped the throttle in neutral!

So I'm halfway to applying the 02Pilot method for misbehaving CCV's. However, after removing bottom tray, air filter, MAF and the elbow behind it, ps reservoir, and the alternator exciter connector, I still can't see the CCV. What should I pull next?

Indy #2 instantly answered "CCV" when I told him about oil consumption, the make and engine. He does not have a smoke machine for vacuum diagnostics, but that point is now hopefully moot. This is the old-school guy; he's not opposed to water injection [he prefers a spritzer bottle] but doubts it will do much with carbon buildup below the piston crown. He suggested SeaFoam, either a soak through the spark plug hole or into the oil. Since there's less than 200 miles on my BMW Turbo 5w30 oil service, is it OK just to add a can of SeaFoam to the crankcase?

Feeling much better about the old e46,

dirtup

[02Pilot]

Throttle body needs to be removed (move the junction box first), and personally I'd recommend the oil filter housing as well; the gasket for the latter is leaking whether you know it or not, so replace that while you're in there, and removing it gives you much better access for attaching the line from the valve cover. Apply a little WD-40 to the O-rings in the hose ends to make connecting them easier, and make absolutely sure they are fully connected - it's easy to get them halfway and think they're all the way.

[dirtup]

Just replaced ofhg, so will try just loosening j box and pulling t body. Again, this is just [I think] to attach vac line from rear of intake man'd to plugged nipple on ccv. Isn't that what I'm after? ccv was replaced about 20k back, and there's decent vac at oil fill.

Any comments on SeaFoam, either on top of pistons or in crankcase?

tia,

dirtup

[02Pilot]

OK, I missed that you had a new CCV. Yeah, just the junction box and the throttle body is sufficient.

You can do the piston soak - shouldn't hurt. Not going to do much in the oil, at least not for combustion chamber carbon buildup.

[dirtup]

Got to ccv without removing throttle body, which scares me because of the extra hose clamp. Unfortunately, the extra nipple on ccv is a good bit smaller than the one at the back of intake manifold, so one hose will not stay snug on both ends. Last time a vacuum hose end failed - on the inner nipple of the intake "f" - I was able to fashion a fix using copper tubing to connect existing vac hose to some Aeroquip -6 that I hose-clamped to the "f". No way to install a clamp onto ccv nipple unless I remove a whole lot more stuff that I'd rather not. Local NAPA did not have the right hose diameter for ccv end, but maybe some other vendor will.

Meanwhile, is there a chance of compromising the effectiveness of this mod because one nipple is so much bigger than the other?

dirtup

[02Pilot]

Never heard of this before. There should be a nipple on the intake that's exactly the same size as the one on the CCV. Can you look around the back with a mirror and see if you've got one you haven't located?

[dirtup]

There are two smaller hoses: one goes to check valve for air pump, and the other goes to a bracket on lower rear of the block. Can't trace beyond without removing reinforcement plate. Can't find it on Realoem, either. FWIW, build date is 2-2-02 and last 7 are km01066.

Realoem does show the ccv extra nipple as 3.5 mm, which is just a hair bigger than 1/8". Pushed a 1/8 hose onto nipple and then mated it via plastic adapter to the 3/16 hose coming from mystery nipple on rear of intake manifold. No cel's yet, so will just drive, assess exhaust pipe deposits, and check oil consumption. First road trip will probably be to go test drive an e90 335i: BMW : 3-Series Base Sedan 4-Door

dirtup

[bmwdirtracer]

I'd just like to say that a vacuum gauge hooked to the intake manifold will read ~18-20 in/hg at idle, will drop very significantly, likely to 10-12 in/hg when throttle is suddenly opened, and will rise to ~25 briefly when throttle is suddenly shut. This is absolutely normal, and is NOT a way to look for intake leaks. A smoke machine is the only reliable way to find out if you have intake leaks -- or at least to prove that you DON'T have intake leaks.

Furthermore, using a mist bottle of water isn't going to effectively remove deposits. You need a hot engine, and a SHOCK of cool water, not a gentle mist. Seafoam's fine, put it in the fuel tank, where it can also soften the deposits on the back of the valves. Note that I said "soften". To remove the deposits, you need to either use a harsher method, like the water injection, OR drive the car very hard, to redline repeatedly in several gears in a row, many times in a few days. and/or use Jectron, Techron, etc very regularly.

(Sorry to interrupt the proper connection of the vacuum hose; yes, there's a small nipple at the back of the manifold, no clamps necessary anywhere.)

[maxell0405]

One of the best threads on the forum. Thanks to everyone, especially 02 Pilot and the always helpful Dirtracer.

After watching this thread forever, I just got around to trying this mod and can't wait to see if it works for my M54 3 liter. It runs great in every way except oil consumption, and when my cats died at 130k I resolved to give this a try, being convinced that oil burn contributed mightily to their demise. I tried the ATF/Seafoam in the oil method, picking up on the theory that sticky oil rings might be a culprit, but that made no improvement. I have been burning a quart every 1500 - 2000 miles for a long time. No smoke or residue at the tail pipes.

I have the cold weather CCV, which I put in about 4 years ago. This makes this mod a bit more difficult, but fortunately the insulation foam is soft and I cut away some of it with a utility knife to access the nipple on the CCV. I used 3/16ths fuel line, as the parts store did not have any vacuum hose in that diameter. I bought 3 feet and trimmed it to fit. The hose was a bit loose on the nipples, so I zip tied them the best I could. Since this whole thing is vacuum I guess I won't worry too much about them staying connected (?) I accidently removed the large nipple cap at the back of the intake manifold and found that it was dried out and cracked, so I wrapped it in teflon and electical tape and reinstalled. I routed it between the DISA and the throttle and there was plenty of room.

I topped up my oil and will report back about results. It was a fair bit of work, but if I can significantly cut the oil consumption with a two dollar hose I will be well pleased.

[dirtup]

Yep, those are typical vacuum readings, except that here they were coming from a nipple that had no cap on it. That nipple is now connected to ccv via a 3/16 hose to a Dorman 47602 adapter [1/8 to 1/4]. Realoem shows the ccv nipple as 3.5mm, which calculates to .138 inch, nicely covered by some 1/8 hose. So the mod is complete.

This car was a birthday gift to my wife in '02, and it's been her DD ever since. It used to be our #1 trip car until I got a V70 a few years back. Looks like it's time to switch with her and employ extra revs and distance for a while.

As for intake manifold nipples. there are two that have intact hoses on them: one hose goes to a check valve behind the cylinder head on its way to the air pump; the other runs down to a bracket on rear driver's side of the block, and I can't trace beyond without pulling off the reinforcing plate. Realoem gives no hint as to the destination of that hose.

We routinely put Shell Premium in the BMW, having read that Shell, Chevron, and Exxon add Techron at the refinery. The plugs are always clean - originals replaced at 93k along with a fuel filter and coolant flush. Coolant was flushed again at 115k when I also backflushed the heater core while curing a no-heater condition. I probably damaged or dislodged the missing nipple cap when checking temperatures where hoses attach to heater core. That's about when oil consumption really picked up. Now at 117k.

To gauge effectiveness of the mod, I'll not use any additives until after employing the "Italian tune-up" for a week or so. Injecting water in sufficient quantities is an action that's way over my pay grade. Thanks for all the help.