Starting a thread to document my work and get some help.

Symptoms

• Burning a quart of oil every ~250 miles
• Running lean, with +6% LTFT on both banks. STFT are more erratic at idle and quick acceleration. Sustained acceleration the trims stabilize around +/- 3%
• Low power up steep inclines (cannot pull 4th, wants to stay in 3rd @3,000 rpm going 55 mph)
• Low MPG (uncalibrated ultragauge showing 9.5)

Specs

• Rebuilt w/ top hat sleeves
• Professional valve job on heads
• Kent H180 Torque camshaft

Diagnosis

• Perfect idle, ~680 rpm
• Perfect oil pressure and temps
• 180 PSI compression on all cylinders
• Carbon sooty plugs, some have white speck deposits. I think running lean and my short-trip heavy driving style account for this. Not sure about the white specks though
• No apparent blue smoke out of exhaust
• Performance seems great on everything other than steep inclines
• screeching can sometimes be heard at 4k+ rpm
• PCV separator super clean, replaced with Frame PCV valve

To summarize, there are 3 primary issues:
Running a tad lean, burning excessive oil, and low power up steep inclines.


What to check next? I think the plan is to replace the fuel injectors with ebay remans (may have a vacuum leak in the intake), and replace spark plugs to hopefully address the lean issue. I already replaced MAF. O2 sensors were new w/ the rebuild (bought from Atlantic british).

For the oil burning, on my first break-in I did mess up a bit and spike the engine to 4k rpm almost immediately. Maybe the rings are bad (but compression is good). Valve stem seals were replaced by the machine shop. I need to be able to figure out whether its rings or seals?

For low power, I have no clue. The compression is perfect. Even if I was burning oil and running lean, I would think with good compression I should be able to tackle these inclines no problem?

 

If white specs mean detonation then you know why you have low power.

What are your engine codes telling you about misfires and MAF air volume?






Won't bad rings always yield oil smoke out of the exhaust?

 

No engine codes other than an intermittent pending P0441.

White specs from my research suggest oil burning, residue can be leftover zinc or other elements in the oil. I don't know anything about detonation... wouldn't the knock sensors pick that up? I do get a ticking, and it sounds like its coming from the fuel rail (using a stethoscope, sound is strongest on the fuel rail).

 

 

Maybe snake a borescope (about $12 on eBay for your smartphone) through that spark plug hole and see if there is any pitting on the piston or on the head for that cylinder chamber?

 

Competition Cams 1590-12 10W30 break in oil. Running 15w-40 Rotella exclusively since. Like I said, during the break-in I spiked rpm to 4k for a minute or two, freaked out, turned it off, fixed issue, and did the break-in again, no issues.

Haven't done a leak down test, but since I have great compression, what can a leak down test tell me? My concern is that you can have good compression and still leak oil past the valve guides and oil control rings. While this may be happening, it doesn't account for low power on inclines

I did do that, bit hard to see due to focus. Saw some carbon buildup but didn't look excessive. I'll check again when I replace the plugs.

 

Your 10-30 break in oil was not synthetic, right?

 

Pretty sure its dino, nothing internet says anything about it being synthetic

Checked the dipstick today after a day trip. 90 miles of highway driving, plus 3 hours (~40 miles) of off-road driving (10-25mph, lots of hills, heavy engine breaking). Dipstick is down 1/4" -- how much is that... 0.25 quarts?

 

Yeah I believe from the bottom to the top of the line = 1 quart. Someone correct me if i'm wrong.