Originally Posted By: tech230
Originally Posted By: clinebarger
Originally Posted By: tech230
Wouldn't the oil be milky if the head gasket was bad? The oil I drained, which was the same oil I sent to Blackstone, was not milky at all. Was black like it always is after 5,000 miles. I've already put 400 miles on the new oil & pulled the dipstick, & it's not milky at all. Just condensation on the oil cap & filler neck. I'm gonna do what Blackstone says though, & change the oil every 2,000 miles or less till I figure it out. Still runs great & doesn't misfire, overheat, or anything. Just the high lead, sodium, & potassium levels worry me.
Not necessarily If the leak is small enough! The intake is "dry" on LS engines so it's not the intake gaskets. No oil cooler on a 4.8L.
That leaves a head gasket leak or a Busted/Cracked cylinder head.
Worth it to replace head gaskets, or should I just replace the whole engine? Engine runs great but has 223,000 miles on it. Has brand new fuel pump, new a/c compressor, rear end work done, & suspension work. So this is a truck I intended to drive for another 4-5 years as I got a lot of time & money invested in it. Didn't expect the head gaskets to start going, as this truck has never been overheated or abused in the 6 years I've owned it. I've owned older Chevy & GMC trucks they never had engine problems. Only had to replace normal stuff like fuel pumps, u joints, alternators, starters & a/c compressors due to high mileage.
I would drop a good used LQ4 or LQ9 6.0L in it, I bought a wreaked 2006 3500 Express Van with 86,000 miles last month for $800 with a sweet running LQ4.
A LQ4/LQ9 will bolt right in place of a LR4 4.8L (You will have to use the LR4 flexplate on a LQ4)
The PCM will need to be tuned for the increase in cylinder air-mass....Which is only super critical at WOT/Open Loop operation. I can do the tuning for $200 if needed.
A LM7 5.3L is also a good in-between option that does not require PCM tuning (I have verified it with a wide-band), In reality.....The LR4 is tuned a little rich from the factory.