Somebody's knockin........

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redfishsc

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99 K 1500 Suburban.

She started knocking really obvious today, occasionally squeaking instead of a knock. Knocks both cold and hot. You can hear the knock really obviously if you steth the exhaust manifold near Cyl 6&8.

Pretty sure I have a bearing that's spinning like CNN.

So either I'm looking at an engine swap or parting out. Shifts well, 4wd works. Trans fluid stays clean. Rear end a little noisy (slight gear moan, not bad bearing scrape).

Never did an engine swap. I have rebuilt a 10 bolt rear end before, a couple head gaskets. Just not sure if I want to dump all this time into this truck.

Open to suggestions. 5.3's are easier to come by, are these trouble to a less experienced wrench turner like myself? Especially on a 4wd.

Backstory for those interested:

1999 Suburban 5.7 with 240k. One of the previous owners apparently ran it with small/moderate amounts of coolant in the oil for a long while. My friend bought it from an impound lot, put 2k miles on it and parked it because he realized what was happening, as it got worse.

He gave it to me, the knocking wasn't apparent. I drove it gently home, diagnosed the low compression on one of the cylinders. Installed reman heads, new injectors in Dec 2017.

Was my first cylinder head job, and since I got two years out of something I paid about $1k in parts for, not a bad deal. A year later I had to do my wife's truck (same thing, 99 Suburban).
 
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Schurkey

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Never did an engine swap. I have rebuilt a 10 bolt rear end before, a couple head gaskets. Just not sure if I want to dump all this time into this truck.

Open to suggestions. 5.3's are easier to come by, are these trouble to a less experienced wrench turner like myself? Especially on a 4wd.
The last thing you need is to make your life more complex with an engine swap to LS.

I would be trying to confirm the diagnosis of engine failure. Pull some plug wires one at a time, see if the noise quiets-up. Compression test. Pop a valve cover, watch the rockers move. MAYBE you've got a cam lobe going flat, and the lifter is angry.

Even if this is a bottom-end failure, you could likely rebuild that engine easy enough; or find a "good used", rebuilt, or "new" replacement without too much trouble.
 

redfishsc

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OK, and that possibility (rebuild/replace) is becoming more and more attractive as I look at the prices of trucks right now. A Jegs motor is $1600 right now and a steaming heap of **** truck is $4K in my area.


Being a 4WD, will I need to drop the front differential to do an engine swap?
 

Redneckgeriatric

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what shurky said! no, you dont need to drop the front diff. there are so many nascar wanabe rednecks around you, you could probably get it pulled for free! just buy some budweiser, and say "i bet yall cant get that engine out in 1 hr". then buy more beer and throw some venison on the grill.
 

letitsnow

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If the heads are still good, maybe buy a rebuilt short block?

I put a new gm long block in my '99 k2500. The hardest part was getting the exhaust off. You've had yours off once already, so that shouldn't be terrible.
 

mariodave

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Dealing with the same thing myself. The previous owner replaced the engine about 3 years ago. At some point it was probably subjected to coolant in the oil. The pan was leaking oil so I pulled it and found metallic oil, and a small amount of coolant in the pan. I pulled some rods and main caps and the crank is rough, bearings shot. The crosshatch looks like new in the block. I am pulling it now and plan on replacing the crank and all bearings and oil pump. GM HT838 cam swap while its out. Hopefully I won't find any other damage and can save this engine.
 

b454rat

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SWapping an engine in these isn't really that hard. I did it to my 96 Yukon last summer. All the wiring connectors go on one way, so can't put the wrong connector on a plug. If your worried bout it, tape all the ends where they go, that will make it easier. Getting to the bell housing bolts can be fun, same with the convertor bolts. The thing I hate the most is draining/pulling the radiator. It doesn't matter what angle, how low you let it drain, the minute you pull the motor and it tilts, 25 more gallons come out. I hate antifreeze messes.....
 

Schurkey

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There's a lot less cooling system mess when you pull the block drains. If the coolant doesn't come out, poke a screwdriver through the sediment crust inside the drain plug hole, that builds up at the bottom of the water jacket.

Sbc = pull the knock sensor in front of the starter motor, pull iron plug out of right side behind motor mount.

Vortec 7.4 = two iron plugs, one in front of starter, lower on block than knock sensor. The other iron plug is lower than, and behind the knock sensor on the other side.

I don't know about TBI 7.4.

I put brass draincocks in, instead of iron plugs.
 
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