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      06-22-2013, 08:46 AM   #1
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Oil consumption ? remedy ?

Oil consumption was excessive - It smoked - I was told I needed valve stem seals

My car (didn't pass smog & couldn't renew registration);
2006 BMW 550I – 92,000 miles – V8 (N62TU)
Smokes (white/gray ) – failed visual – Smog Report (15 mph – HC ppm Measured 91 – Max. 49)

Symptoms & history;
It used oil (approx. 1 qt. per 2-3 tanks) and I read the history of V8 valve stem problems (internet & local shop research), I was about to have the valve guide/stem seals replaced or drive the car off a cliff. But it didn’t have the classic symptoms of defective valve stem seals/guides. It also ran like a rapped ape (old school for ran great). I’m a heavy truck mechanic with old school car experience (35 years). The plugs were clean and the exhaust smelled funny, also the exhaust dripped clean water no matter how hot or long it ran. I pulled the intake throttle housing and noticed excessive oil. Replaced the (ccv) diaphragms in the valve covers (torn) & read up on the cyclone oil separator (like a Dyson vacuum). Because I wasn’t happy with the oil consumption & residue in the intake, I fabricated a sponge with screen for each valve cover vent outlet. This cleaned out the oil residue and I assume it will reduce oil consumption while allowing crankcase recirculation, but it did not solve the smoke problem. I pulled the spark plugs and stuck a camera down a couple plug holes. Yes, the top of the pistons were loaded with carbon. So I sprayed Sea Foam in each plug hole, followed by a shot of low pressure shop air to help spread it around the piston. I let it sit for an hour or so, then reinstalled the plugs. I topped off the fuel tank with high octane and added 12 oz. of CRC Fuel System Cleaner (part #05063) to the tank. 100 miles later and what a difference – no smoke or water dipping out the exhaust after warm up. I’m in love with the car again

**The valve stem diameter was increase at a production point (you would assume) to remedy the guide problem. I could't believe BMW would continue to use inferior stem seals after this change. My vehicle has now passed smog test & no longer smokes. I did have to run the proceedure twice before it lowerd the HC levels within specs. And I will probably do it 1 more time for good measure. It cost me $200 to fix compared to the $4000 > $5000 I was told it would take for a guide/seal replacement **

**** Day 14 - 760 miles later NO smoke or excessive water from tailpipe - It also **** Does not need any oil ****
For those of you seasoned mechanics replacing guides & seals - This worked for me - my vehicle - my situation - but I believe you should diagnose each vehicle on an individual basis - Regardless of BMW guide/valve stem history.

**Note: I need to give full credit to my 25 yr. old friend/mechanic/smog tech/neighbor for his insistence I try Sea Foam. He works on BMWs, Mercedes and other makes. I never heard of Sea Foam (we used Justice Brothers in my hay day) and I didn't believe it would solve my issue. Although it was my idea to soak the piston tops first before spraying it thru the intake. I'll also take credit for the sponge/foam/screen in the PCV hose idea. **

**Corvette has just come out with a new valve cover/CCV/PCV system to combat their oil consumption issue.
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      06-22-2013, 05:47 PM   #2
JNoSol
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Great find. I can't imagine how long it took you guys to pull everything out to figure this out.
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