1222 code, oil in intake 91 325ix

[Stangkiller97]

I just recently picked up a 91 325ix, auto, 113k for the wife. When I test drove the car I did notice it had a CEL (1222) and a bit of stumbling idle. After purchase I first did the plugs (Bosch coppers) and fuel filter. For about a week the stumbling went away but it still threw the same engine light. Next step I did cap, rotor, new plugs again (NGK) timing belt, water pump, thermostat, coolant temp sensor, oil return tube seals, as well as any old rubber I found along the way minus coolant hoses. Now a big side note, when I replaced the timing belt I did notice the old one had a bit of excess slack in it. Not to the point it jumped teeth but it did leave a rather nasty groove in the back of the timing cover. Another note is that I am getting excessive blow by all the way up into the air filter. I finished all of the above work about a week ago, it still throws the same CEL but the idle smoothed out. Until this morning I noticed the idle starting to stumble again. So ideas on next step? Should I replace the O2, maybe a coil? I realize that I may be looking at some major problems with the oil in the intake.

[jlevie]

The O2 sensor is overdue for replacement by 13k. Replace it and have a smoke test run to see if you have eliminated all intake leaks.

Excessive oil in the intake can be due to excessive blowby from bad or worn rings, oil being sucked into the intake from worn intake valve seals/guides, or intake leaks into the crankcase. At this mileage I'd tend to discount the rings or head as causes and suspect the oil return tube seals, dipstick o-rings, oil filler cap, or valve cover gaskets & bungs. A properly run smoke test should reveal any leaks in those areas. A leak down test will tell if the rings are a problem.

[nando]

check the o-rings in the spring loaded drain tube under the manifold, a vac leak there can also cause excessive oil in the intake.

[Stangkiller97]

I forgot to mention that I did do a valve adjustment. The valve cover gasket is new and so is the breather hose (I could crush the original in my hand). I also already removed the manifold and replaced all of the associated gaskets there. While the manifold was off I did have to re tighten the dip stick tube, but did not replace any o rings. I did do the oil drain tube seals when the manifold was off. I will search around for a place to run a smoke test, and grab an O2 once I can get budget approval. I will also do a quick compression check the next couple of days as I just picked up a gauge last night. How worried should I be about the timing belt being loose? Is there any way that it could be the root of my problems here?

[jlevie]

Any time that you replace the valve cover gasket you also need to replace the four rubber bugs. Did you do that when you adjusted the valves?

If you replaced the timing belt and tensioner the belt shouldn't be loose now.

[Stangkiller97]

No I did not replace the rubber seals. I just pulled the spark plugs and their ashy and carbon fouled again.

[Stangkiller97]

Ran a compression test and I'm around 160 on each cylinder. While the car was running I removed the oil fill cap and the idle dropped then tried to die, I placed my hand over the hole and the idle came back up. I still haven't done a smoke test, but I did order an O2 that is coming in today. I know a smoke test will tell me if I have a vaccum leak for sure but just for note taking sake:

I have replaced/ checked:
Vaccum line on FPR Replaced
Breather hose replaced
Intake boot replaced
Intake manifold gaskets replaced
Throttle body gasket replaced
Oil Drain tube Seals replaced
Dip stick tube O rings good
Dip stick tube mounting clamps good and snug
Valve cover gasket replaced
Did not do the rubber bungs
ICV hose replaced
ICV cleaned


Couple thoughts, what about the triangular gasket on the intake manifold?

number 4

http://www.realoem.com/bmw/showparts.do?model=1203&mospid=47311&btnr=11_0859&hg=11&fg=40

In order to remove the valve cover one has to remove the bottom two bolts from this setup, perhaps I broke the seal and ruined the gasket?

Also, I did not replace the cam shaft seal when I did the t belt, could that be an issue here? Or would this not cause a vaccum leak?

Also my plugs are digusting, After one week of running them they were completely covered over in carbon and oil.

[lateracer]

Have you done a fuel pressure system check? A bad FPR can cause a rich running motor. I went through the same set of steps for a poor running situation minus the intake manifold gaskets, but my problem wound up being a combination of ICV goo and tiny cracks in vacuum hoses (credit = jlevie's consistently correct advice to get a smoke test).

Given what you've posted, this doesn't sound like your problem though.

It sounds like you should do a leak down test. It's not as easy as a compression test, but given the stuff you've done so far, it's well within your mechanical abilities. I would suggest buying the tool and doing it yourself (the tool cost about $50 from Harbor Freight, which is less than some shops charge for the test). Between the smoke and leak down tests, you'll be able to pinpoint or eliminate a long list of possible problems like valve seals, piston rings, lower cylinder wall scratches, etc.

My track car still has decent compression numbers, but burns oil like it's nobody's business. Leakdown pointed out some bad valve seals that I need to address soon.

[Stangkiller97]

Have you done a fuel pressure system check? A bad FPR can cause a rich running motor. I went through the same set of steps for a poor running situation minus the intake manifold gaskets, but my problem wound up being a combination of ICV goo and tiny cracks in vacuum hoses (credit = jlevie's consistently correct advice to get a smoke test).

Yeah, after doing numerous searches I can't count the number of times I have seen jlevie recommend a smoke test for the same symptoms I have. I'm going to call a couple of places today and get it in. Then I'll have to swing by harbor freight over the next couple of days. I always like an excuse to buy tools.
I'm really hoping I dont have to tear into this motor, especially with only 113k but if it needs to be done then it needs to be done.

[jlevie]

Lets see what the smoke test shows. With what you've replaced, there shouldn't be an intake leak, but the test will tell for sure. If there are no leaks, or fixing leaks doesn't solve the problem, a leakdown test would be my next choice.