Auto-Rx - smoke on over-run

[Shannow]

Bought my 20 plus year old Beemer a couple months ago.

Straight away changed the oil. Delvac MX, and Auto-Rx. Techron in the fuel.

Driven about 400 miles...pretty hard so far.

Has started blowing increasingly voluminous clouds of blue smoke on over-run in third gear between 60 and 80 MPH.

Didn't puff when I bought it.

20 plus year old vehicle of indeterminate maintenance history and I paid $1300 including spares, so I don't really care if I have to do up the spare head with new seals (and bigger valves, and maybe some valve springs).

Anyone got any experience on top end leaks and Auto-Rx ?

Is the smoke going to die down on the rinse phase ?

Don't take this as a poke at Auto-Rx...just an observation on a quite second hand vehicle.

 

[Craig in Canada]

I don't think this is uncommon with BMWs. Have you checked your PCV system? It's possible that during ARX you've achieved better ring seal therefore higher compression (and higher vacuum off throttle.

C

 

[Hammer]

I assume you mean close to or into redline on the tach when you say "over-run?" Ring seal is pretty critical at high revs, and I am thinking that A-RX has started cleaning them but they are not fully clean so you now have rings that are not sealing properly. Just do the complete A-RX cycle and see what happens.

Hammer

 

[Rick20]

On a twenty year old vehicle I would be running it more gingerly. Over reving and old beauty makes no sense to me. I agree with checking out the crankcase ventilation for proper operation. Running a motor hard and over reving possibly floating the valves are two different things.

It may be top end deposits passing by partially cleaned up, or weak valve stem seals. My guess is that the smoking will subside in the rinse phase. Does the unit smoke blue on cold starts?

 

[Craig in Canada]

He said "over run" not "over rev".

Generally, to me, this means when you snap the throttle shut at high RPM, generally after WOT. This creates a very high vacuum and tends to slurp oil through anywhere it can - faulty PCV, weak valve guide seals etc...

 

[Gary Allan]

Shannow:

We do need a Oz primer for nomenclature here.

If it's as Craig here describes, I've only experienced this in my old (brand new at the time) 320i when the dealer overfilled the crankcase. Winding it up apparently whipped enough oil to have the high vacuum state suck it through the rings. Then again, my BMW didn't have a traditional crankcase vent system. If you pulled the dipstick ..the engine stalled. That is, the crankcase appeared to be under full manifold vacuum.

Sweat it out and see if it passes.

 

[Shannow]

Gary and Craig,
you are correct.

The PCV is a 2" pipe from cam cover to manifold. Opening the oil cap (to check for blowby when I was buying it) caused the engine to stall.

It's backing off from full throttle in third (about 1500 RPM off redline) that does it most...gives interesting insight into the vehicle's aerodynamics.

No smoke on start, not at full throttle, just over-run after a bit of a push.

Not heaps worried, just interested that it's increased over the last 600km.

 

[sprintman]

Valve guide seals. Will you run the minimum 4,000kms this time?

 

[Gary Allan]

Quote:

---

It's backing off from full throttle in third (about 1500 RPM off redline) that does it most...gives interesting insight into the vehicle's aerodynamics.

---

Well, I imagine it could be some valve seal thing ..but it may just be that the rings are showing some transitional leakage as they de-coke. Blow-by may increase and instead of bleeding in with the normal intake charge (while under WOT), saturates it with oil rich vapor as you slam the vacuum to it at high rpm.

 

[Shannow]

Prolly stem seals, or rings as suggested.

Gives me some neat insight into the rear aerodynamics of the car if I time the on/off throttle and a decent hill.

As stated...not worried in the least really.

And if I've got to get my hands dirty at some stage, I can justify "tinkering" with it at the same time.

 

[Craig in Canada]

Yeah, I'd see the treatment through with the new extended interval and see where you end up. In all likelihood ARX will do nothing but help when all is said and done.

PLease post again with your observations...

 

[e36'n]

I've had a huge amount of increase in blowby since I started my auto-rx treatment. First started to get bad during the cleaning phase, didn't note the exact kms into it though.

I'm 1500 kms into the rinse phase and am praying the rings will some how re-seat themselves, but not counting on it. Currently running Rotella 10w30 CJ-4 and shearing the heck out of it as well.

 

[Oilgal]

This thread totally answers my stupid question about oil consumption in my ARX thread. I am about 700 miles into my first clean phase. I haven't noticed any smoke. But my PCV system has definitely been sucking oil. I have though purposely been taking it to redline and letting off, to suck the ARX through the valve guide seals and rings, because I want the ARX to do it's thing there.

I think your BMW is going to be fine Shannow.

 

[Shannow]

2200km into it, and decided to try a full throttle to 120km/h 1st through 3rd, full off throttle down a hill (120km/h down to 100km/h), and snap accelerate back to full throttle...same as the first post really.

Appeared to be much less smoke (didn't cloud up the rear window).

Could have been prevailing wind direction, so will try it again sometime this week (if I need to buy tomatoes).

 

[Oilgal]

Have you noticed an increase in fuel economy?

I am 2400 miles into my clean phase and preparing to do the OC. I got another 2 mpg on my last tank, and that was nearly all in town driving. Just wondering if you have similar results. I am glad your ring seal has apparently improved.

 

[Frank]

The reason for the change in mileage for the cleaning phase increase from 1500 miles up to 2500 miles is to maximize the effectiveness of the cleaning phase.

The product formulation has not changed. Users with heavily sludged motors should take note to change out the oil filter at 1250 miles during this phase. The other hidden benefit is that the host oil during the cleaning phase is run for an extra 1000 miles, which provides for greater economy.



Used oil analysis was the primary consideration for extending the cleaning phase. Wear metals remained amazingly low over 2500 miles of cleaning. The host oil, with the cleaning dose of ARX, remained healthy and fully serviceable. The folks at ARX always put safely clean a priority in providing instructions. Group III oils such as Pennsoil Platinum provide great cleaning and rinse performance, for those that feel the need to run a more durable oil in the cleaning and rinse phase, when compared to a dirt cheap dino oil.

 

[Oilgal]

Originally Posted By: Frank
The reason for the change in mileage for the cleaning phase increase from 1500 miles up to 2500 miles is


That is all very food to know, and your product is unquestionably nothing short of terrific.

I think you skimmed again though Frank, and you noticed the word increased used a few times in this thread. The word was never used regarding your newly increased mileage instructions however. I sincerely do admire your zeal and dedication though, and ARX remains my favorite product for very good reason.

 

[Shannow]

Originally Posted By: Oilgal
Have you noticed an increase in fuel economy?


a workmate told me that I don't drive the beemer for economy.

It's atrocious...but fun.

 

[Oilgal]

I know what you mean. Recently though, I began to notice that despite my driving style, a tank of gas was lasting noticeably longer, and so I began calculating mileage at fill-up again. I was very pleasantly surprised at the numbers.

 

[Shannow]

Last day of work, I did a business card UOA on it.

The little green pen marks are the entire spread of the droplet when held up to the light.