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1975 BMW 2002 headache

I became the proud owner of a BMW 2002 a few years back when a friend of mine said to me “if you can get it out of my shed you can have it!” I put some fresh gas in it and a fresh battery (it had been sitting in said shed for a good decade) and it started right up.) I drove it back home and started to work changing out almost every unseen part on the car. The car was producing copious amounts of white smoke on the freeway when I got off the gas. I pulled the head off and had it welded up and rebuilt and reinstalled it. The problem now is copious amounts of blue smoke when getting off the gas at higher revs. It’s acting as if the valve guides are leaking, but I just had all those replaced along with valves, seats, seals and so on.

could this be caused by the piston rings? I measured the cylinders and they were within tolerance. could it be a bad rebuild on my head? any thoughts on the matter would be appreciated before I go pulling the head off again.

Thanks,
Ray

Have you done a compression test? How do the plugs look?

You had the head “welded up”?
Clouds of blue smoke when “getting off the gas” are caused by the vacuum in the cylinders spiking and pulling oil in from the head.

I Did have the heads welded up. There was a lot of corrosion around the water journals. at least one was corroded all the way to the cylinder. The auto machine shop welded them up, machined the heads, and replaced all the valves and guides.

I need to do a compression test. Currently the car is stored 200 miles away at my son’s house. I’m heading up there this weekend. I’ll pull the plugs and do a compression test then.

I haven’t been driving much lately due to the off power smoke.

Now you know why it was in the shed…I suspect you can buy a mechanically sound 2002 model cheaper than making yours mechanically sound…

Before you spend any serious money on it, just make sure the body’s in good shape, they’re known to rust.

It was stored indoors and doesn’t have any rust. It’s been a California car all it’s life. I’ve already had the radiator recored, replaced the heater core, the struts, shocks, CV boots, rebuilt the drive shaft, replaced the 4 speed transmission with a 5 speed, had the exhaust rebuilt front to back with the addition a good header, replaced the drag link and tie rod ends, replaced everything made of rubber (though I still have the door seals and windshield gaskets on my short list of things left to do. I had thought I’d fixed the off power smoke by getting the head rebuilt, so it’s a setback.

It’s time for a COMPLETE engine rebuild…You are obviously past the point of no return with this car…

I don’t have any first hand knowledge but I have been told that if you do the valves and not the rings you will end up with oil consumption problems. Doing a valve job increases the compression and overcomes the worn rings. Kinda seems like that’s what happened.

You could have had the blue smoke all along, but it was masked by the white smoke. Sounds like old and tired rings. One sign of bad rings is to run a motor up in the rpms and have a car behind observe for a puff of smoke when you decelerate and then get back on the gas. In your case you don’t need the observer to see the smoke so you must be getting a good puff of the blue smoke. If you are using oil, adding 1 qt. per 500-1000 miles that will add more evidence of oil blowing by the rings.

I’d join one or more of the BMW forums and get some recommendations on who supplies good rebuilt short blocks, if it turns out to be rings. Unless you have a great rebuilder handy, you’re more likely to succeed with a short block from a known, proven source.

Of course, there’s always the option of dropping $5,000 on a higher-capacity (2.2L) replacement engine from Metric Mechanic…

I was hoping I wouldn’t have to get into the bottom end, but if it needs it it needs it. I’ll do some tests this weekend and see what comes up.

I think Uncle turbo makes a good point. there is a good chance the blue smoke was hiding in the white smoke. I fixed one problem that made the other problem apparent.

I think I have some good leads to go on here.
thanks everyone for your help.

White Smoke (coolant/water)

  1. Clogged CVV /oil seperator
  2. Blown head gasket

Blue Smoke (oil)

  1. Clogged CCV / oil seperator
  2. Valve cover gaskets?
  3. Valve GUIDE Seals
  4. Valve stem seals (?)
  5. High oil level
  6. Worn piston rings

Bing is correct about reworking a cylinder head and ring problems being exacerbated immediately afterwards.

Wow, a '75 BMW 2002. Is it a tii? I’ve had a few 2002s, starting with a '69 in '74. If it has no rust in the rear strut towers, you definitely have something worth spending money on. Once the rust monster gets hold of a 2002, you may as well give up. Yes, I’ve had almost as long an affair with BMWs as I’ve had with MGs.

What I suspect is that you got billed for new valve guides and seals, and didn’t really get them. Unfortunately it’s impossible to prove.

I have a NOS 2002 head gasket kit hanging on my garage wall. I bought it several years ago, and sold the car before I installed it. I suspected bad valve guide seals on that engine as it exhibited symptoms similar to yours. I also have a NOS rebuilt Kugelfischer injection pump. I bought a 2002tii a few years ago that the seller swore needed the pump which he’d never installed. All it needed was one of the nipples from the pump, so it’s new, less one used clogged nipple.

I ran some tests and check it out, it looks like it needs a bottom end. I need to narrow my projects down to one, it may be time to pass this one along to someone else to finish.

I wish you weren’t in northern California Ray.

I took the time and did a compression test. it was bad news. 75 PSI plus or minus a few pounds on all four cylinders. definitely needs a bottom end.

I hope these suggestions help you …

FWIW, we owned a '71 2002 for nearly twenty years and over 200K, with one factory-rebuilt engine installed when I was assigned to Germany and drove like the Germans did. It was an excellent car and we had lots of fun with it, and it sounds like you have a good one despite the engine.

1.) We belonged to the BMW Club for most of the time we owned ours, and trailing blue smoke on prolonged deceleration (especially downhill or at high speed) seemed a common observation by Club members. The Club tech reps were almost unanimous in saying you could fix it by replacing the valve guides with “harder” versions, whatever that meant. When they re-did your valves they may have used the standard valve guides, and the mechanic probably did not know about this since these engines are now rare. Our car smoked too, but we never needed to add oil so it must have leaked but a small amount.

2.) I would recommend joining the BMW Club (if they still exist) and checking it out with them. You will probably enjoy the car more. They will probably be able to show you how to get the proper valve guides if you decide to fix them.

3.) Rebuilt engines or short-blocks may be available through BMW enthusiast shops (the BMW club would have information on these) and they may be more reliable than engines rebuilt by a local mechanic, who may not have much experience with BMW four-cylinder motors.

Good luck and enjoy your “Flasher” (that was a common nickname in Germany because they often were often seen flashing their headlights into the rearview mirrors of cars they wanted to pass)!

Worn rings can certainly cause blue smok upon deceleration, years ago it was much more common than valve guides (probably because it’s really hard for a flathead to suck oil up through the guides). The other possibility is that the rings are stuck from sitting 10 years. I would change the oil again and add a product that claims to free rings and flog the car for a month.
Shouldn’t be hard to flog a 2002, everyone who bought one of these 30+ years ago did. At this point what do you have to lose?