5w-30 in my E30 BMW... cloud of smoke

[JHZR2]

Hi,

as some might recall in my post a month or two back in the maintenance and repairs section, my 91 E30 BMW 318i developed a coolant leak to overboard, through the headgasket.

I had it repaired, no problem. The shop put Agip 5w-30 in it. I noted that they put in oil that was too light, and they offered to change it on the spot, but I figured they were going to do it in 1000 miles when I bring it back to be re-torqued, and it was a good chance to run auto-rx.

I use the car to commute, and am very light on the throttle, plus my commute is only 8 miles, barely enough to heat the oil up, so I figured it was OK.

Tonight I was out running errands, and had to use the throttle. I didnt floor it, but I was at about 2/3 throttle, and about 3500-4000 RPM. I noted in my rearview something that I had never seen before... a cloud!

Now, my only possible reason for a cloud seems to me to be because Im running oil that is too light, and is vaporiing/buring. THis never happened with 5w-40 (40-50wt being specced for the 1,8L M42 engine).

But that said, is this an indication that the oil is just plain too light, and should be changed out even sooner rather than later? I have about 500 miles left before I have to take it in to be retorqued... Should I bite the bullet and do an oil change ASAP? Or should I just drive it gently as usual, avoid highway driving and acceleration, and call it OK?

Thanks!

JMH

 

[Fatboymoe]

Maybe you just throttled up enough to burn of the residual oil and coolant out of the exhaust system. I wouldn't do anything drastic until you you do several full throttle runs after coming up to temp. to verify it is a real problem. It might be a one time thing and if it happens more than once in 2 or 3 tries, then look for something else. Something to try.

 

[mechtech2]

Fat Boy has a very good point.
It can take a while for all the crud to burn out of the pipe.
It gets scary after a head job because it takes so long that you think you did something wrong.
I would check you oil and coolant levels, of course.

 

[windnsea00]

A 30 weight oil would have no effect on smoking...it was just probably some carbon buildup that blew out and maybe junk that built up in the muffler, etc. If it's was a white cloud then they didn't do a very good headgasket job

 

[Carmudgeon]

Did your mechanic use factory head bolts?

The factory bolts are torque-to-yield. They are one-time use items and shouldn't be re-used. There is neither a need nor reason to retorque new bolts.

M42 engines of that vintage are notorious for coolant leakage from a failed coolant passage "profile" gasket. It isn't part of the head gasket per se, but requires the head to be removed to repair, and thus a new head gasket.

What color is the smoke cloud? Dark or light?

While those engines like a thicker oil, running a 30wt shouldn't cause any problems, esp. like what you describe.

Unless the fault was truly a failed head gasket, or a cracked head, there shouldn't be any coolant intrusion into the combusion chambers. The typical profile gasket failure only resulted in an external leak.

I suspect that the shop may have botched the job, or there may have been more damage than originally suspected.

 

[JHZR2]

Interesting information, thanks for all of the replies!

If Im loosing any fluid, it is at such a small rate that it is unnoticable from studying the levels... granted Ive only gone 500 miles or so since all were changed.

I am familiar with the profile gasket, and that is what I originally figured this overboard leak was. In the end, the shop I took it to found that it was the head gasket (I was suprised), and changed both the head and profile gaskets. The cost was about the same as when I had the BMW dealer do the profile gasket about 4 years ago as PM.

The leak, as best as I could tell, was somewhere on the front-right side of the block.

The shop said that the head was slightly warped, and thus they sent it for machining. I know that the car never overheated on my watch, and even when the coolant leaked out, we caught it in town, and kept it filled up fully so we could drive it to the shop. Now, that said, the engine was having some combustion-related heat issues, as due to it not having an EGR, I would always just barely squeek by and pass my NOx test. So there might have been hot spots or thermal gradients through the head anyway...

I have no idea why they want to re-torque the head bolts, given what you said. I can't imagine that even if they re-used the old ones (which I doubt), that they would NEED to re-torque them, given they did it right the first time. I am hoping that it is just an issue of them wanting to make sure 100% that the job is correct, in order to gain a satisfed customer (Im new in town).

I do not suspect any coolant intrusion into the cc's. As I said before, when it happened, we noted a puddle under the car. The exhaust was clear as normal. WHen I drive it post-repair, the exhaust is clear, as normal.

It is only in this situation, where I was relatively heavy on the throttle, at night, with headlights not far behind, that I could see this puff of smoke, which subsided as soon as I let off of the throttle. Color? I could not say... but I will say that it looked very similar to when I floor or nearly floor the throttle on my 83 MB 300D turbodiesel, and it does a fuel dump and emits a cloud of diesel smoke. So, Id venture to guess that it is a dark greyish to black color, given that analog, FWIW. Apples to oranges, perhaps.

I suppose it is worth also mentioning that I have been driving it light, in the interest of fuel economy and the fact that I have lighter than spec oil in there... Now, my manual states that if, for example, one has been sitting in traffic for an extended period, that the engine should be revved higher than normal under load, and left that way for some time so that the engine can 'breathe' and clear out... so all of this may just come to my engine 'breathing'.

Thanks again for all the insight!

JMH

 

[Rickey]

Hmmmm a properly functioning catalytic converter "should" eat a lot of smoke or so it is widely rumoured. Now if the cat were at less than top shelf: a buildup of deposits could have occured which may have resulted in the smoke that was observed. IMHO the real test (solution) is to put a proper spec oil in it followed by some "spirited" driving to see if it clears up. In years past high performance engines were known to "load up" when driven gently for extended periods. Blowing out the carbon while assisted by high octaine fuel was the prescribed remedy. In your case I wouldn't reccomend specification RPM or loading with thinner than spec oil in the engine. Just my 2cents worth. Good luck Rickey.

 

[Titan]

I've never owned a BMW, but the people that I know personally, that have, they've all had some sort of engine work done. Always head-gasket related. And they seem to have to have the head warpage addressed. Are these engines that fragile, or, have I just seen an unusual number of people with failures?

 

[JHZR2]

quote:

---

Originally posted by Titan:
I've never owned a BMW, but the people that I know personally, that have, they've all had some sort of engine work done. Always head-gasket related. And they seem to have to have the head warpage addressed. Are these engines that fragile, or, have I just seen an unusual number of people with failures?

---

It seems that lots of cars have headgasket issues... my BMW hs 106k miles on it. RUns like new and returns fuel economy in excess of the EPA spec. Whether the materials they use are perpetuall improper or what, I cannot say. Obviously it doesnt get the anger and upset that, say a GM intake manifold gasket brings.

Maybe its because most BMW drivers (at least those that OWN their BMWs and keep them past 3yr/36k) think of their cars as more than just an appliance??? I dont seem to hear a lot of complaining.

I just dont know... perhaps others will chime in regarding BMW gasket materials and longevity...

JMH

 

[TooSlick]

Black smoke - engine is running too rich under load, or you're driving a diesel

Blue Smoke - Oil burning

White Smoke - coolant/water burning


Hopefully you're not color blind...

TS

 

[JHZR2]

It was in the dark and I only saw it because headlights were piercing through the cloud (which was not a thick or heavy cloud, BTW).

I might try to induce said cloud in the daytime to see what I get...

Thanks!

JMH

 

[Drew99GT]

If it was me, I'd take it back ASAP. After 500 miles, you shouldn't be seeing any smoke at all! Something ain't right IMO.

 

[windnsea00]

quote:

---

Originally posted by Titan:
I've never owned a BMW, but the people that I know personally, that have, they've all had some sort of engine work done. Always head-gasket related. And they seem to have to have the head warpage addressed. Are these engines that fragile, or, have I just seen an unusual number of people with failures?

---

Most engine issues I ever hear about with BMW's are coolant related due to the fact their radiators/water pumps were known to fail earlier in the 90's 3er's/5er's. So it was more a lack of preventative maintenance than anything as BMW engines are some of the most stout built engines around, specifically their bottom ends are built very strong. Granted these engines have to be built well as they are expected to be able to run near redline for extended periods of time throughout their lifetime on the Autobahn.

 

[BennyL]

ok, allow me to chime in on a few issues.

first of all, i also own a BMW 318. mine is an E36 though - 1996 - with the slightly updated M44 engine.

i have to say that my bimmer has been nothing but amazing since i got it. not a single issue. i've got 176,000 KM's on it (approx. 110,000 miles), and it runs so smooth!

JHZR2: i was going to suggest liqui-moly 5W-40 oil for you, as i know of many guys who run that oil in their M42/M44 engines, and love it. it seems that you already know that your car needs a 40 weight oil though, so i'd just suggest checking out liqui-moly.

if you want to know more about your M42, an amazing forum to register at, would be: www.maxbimmer.com/forums

i have been on those forums since i got my bmw, and have found it to be a great resource. the guys are great, and the E30 crowd is vast.

 

[double vanos]

An observation, if I may. There is the very real possibility that the repair shop, after closing the engine up, added coolant, let the car idle while checking for leaks and let it go at that. No fuel injected engine enjoys the stop/start scenario that your car may have been subjected to. The fuel enrichment circuit probably had a field day doing what it's supposed to do - pour enough gas into the engine to keep it running when cold. When you left the shop, chances are your catalytic converter was charged up with raw fuel from all the screwing around in the shop. Then you finally get the car all warmed up and start putting the mojo back on 'ol betsy and she blew out a cloud of unburned hydrocarbons ! This could be what you are seeing. After all that mechanicing work it's probably a good idea to give the car an oil change. How about Syntec 5w50 - it's a thick oil with excellent low temp pumpability. Your car will love it! Then give the car some full blast work and you should be good to go. If you blow the head gasket again, you'll know they reused the old head bolts! A comment on BMW reliability. My '02 330ci has been gem of a car! Have I spent some money on the car? Yes, indeed. After 85k of faithful service I treated the car to front brake pads and rotors, spark plugs and fuel filter, water pump, hoses, radiator, belts, tensioner and idlers, shocks and struts, lower control arms and bushings, new sway bar links, tires and an alignment. It all added up to about $4000 with me doing most of the labor. So what did all this get me? A 5 year old Bimmer with 90k on it that virtually drives as good as, if not better, than new. The engine and manual trannie drivetrain haven't given me the first bit of trouble, as 5k OCI'S took care of the engine and 15k oil changes took care of the trannie and diff. From around 10k miles on, this car has had a steady diet of way too fast driving and frequent excursions into the rev limiter! I plan to take her to at least 300k, if I don't wreck her first (heh heh). Cheers all!


s

 

[mechtech2]

What commonly happens is that coolant enters the exhaust pipe beause of the original problem, or when replacing the head. It can take a loooong time to stop smoking.
I've had this happen bunches of times.

 

[mdv]

BMW "reliability" is usually due to electronic issues. The cooling systems in the M42 and pretty much all E36 and E39 cars were notorious for radiator, water pump and coolant manifold problems. Chances are if a head gasket needed an early replacement on an M50 or M52 motor it was a result of an inattentive owner who let the overheat condition go too far because one of the above items failed. Not saying that was the case here (M42's seem to be a weird engine).

BMW engines in general usually can take a beating for 200k that would make other motors run with their tale between their legs at half that mileage.

 

[mdv]

quote:

---

Originally posted by double vanos:
15k oil changes took care of the trannie and diff.

s

---

Glad to see you do this, most owners of these cars seem unaware or uncaring of any maintenance for these parts. Beautiful car BTW, I still want one, though the new 335 looks interesting

 

[Brons2]

I had an E30, 85 325e. Always used Castrol 20w50 and the car was still going at 300K when I sold it off. The engine was never opened, other than for valve lash adjustments. This is in Austin, Texas mind you. More northern locales would be better with the Xw-40 as mentioned elsewhere in this thread. Regardless, the old Bimmers like thicker oils.

 

[double vanos]

That new BMW turbo is a tempting piece of kit but I want to sit on the sidelines and see how well a silicon enriched aluminum bore (as in no steel liners) holds up to turbocharging. BMW's are so dam expensive I HAVE to get at least 200k+ miles out of them to justify the cost. Besides that, I never buy brand new models when they first come out; I prefer to let the rich guy 'fools rush in' and then after the market demand has been satiated, if the cars hold up well, I'll go in and talk discounts with the dealer. Salutations all!