Air bubbles in the coolant reservoir

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iamdub

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I'd fix it for a couple hundred bucks and a day in the driveway. Do it before the water damages the bearings. If the heads are bad, you can find known good 706s (or equivalent) or some 799s/243s and have them shaved a little to maintain the compression.
 

Tonyrodz

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I'd fix it for a couple hundred bucks and a day in the driveway. Do it before the water damages the bearings. If the heads are bad, you can find known good 706s (or equivalent) or some 799s/243s and have them shaved a little to maintain the compression.
Don't recommend some 862's? My buddy says he has some"good" replacement 862's. My luck I'd have the same problem. I've read somewhere on here that some of the 862's are porous.
 
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Doubeleive

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Not just gonna drop an engine in it?
eh I don't know for a little more money I can find another whole truck, I guess I can try the blue devil stuff first and maybe that will do the trick but I pretty much have my mind set on just finding another truck there are a couple around that aren't too pricey I see a 04 denali for $4k with 150k on it. I messaged about a couple others one is 100% likely a scammer and the other has been listed for 11 months lol so....well see
 
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Doubeleive

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I'd fix it for a couple hundred bucks and a day in the driveway. Do it before the water damages the bearings. If the heads are bad, you can find known good 706s (or equivalent) or some 799s/243s and have them shaved a little to maintain the compression.
it's a LM7 looks like a set of heads is about $300? then what else I see a set of bolts is about $60, then gaskets both head and valve covers and probably intake, what else? it's got the tickey tickey at start up so probably a set of valves/springs?
 

iamdub

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Don't recommend some 862's? My buddy says he has some"good" replacement 862's. My luck I'd have the same problem. I've read somewhere on here that some of the 862's are porous.

I couldn't think of the number for the similar heads as the 706 so I just said "or equivalent". 862 is it. The 706 uses a better casting process, but if you're trying to fix it on the cheap, a known good 862 will be fine. Just avoid anything Castech to better your chances. Or, since they'd be from a newer vehicle and likely more plentiful, the 799/243 is a great head, but you'll lose a little compression. It may not even be noticeable. I'd still have them shaved since it's cheap to do and will ensure a perfectly flat surface. The machinist should also clean them so that'd be a little bonus, too.
 

Larryjb

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I'd fix it for a couple hundred bucks and a day in the driveway. Do it before the water damages the bearings. If the heads are bad, you can find known good 706s (or equivalent) or some 799s/243s and have them shaved a little to maintain the compression.

Given the evidence of bearing damage from the report, I'm not sure I'd put that effort into the engine.
 

iamdub

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it's a LM7 looks like a set of heads is about $300? then what else I see a set of bolts is about $60, then gaskets both head and valve covers and probably intake, what else? it's got the tickey tickey at start up so probably a set of valves/springs?

Ticking at start up is a lifter(s) bleeding down and having to pump back up after the engine is started. They would be cheap, but since the strike a while back, the price for OEM ones has more than doubled.

I hope that $300 price is for refurbished heads! I got some low-mile 799s from a 2010 for my brother's LM7 for $300. We decided not to shave them and he hasn't noticed any loss in power. He wouldn't because it was so sludged up to begin with that it ran a little weaker, anyway. Maybe used parts in CA are more expensive, but you can find used Gen3 heads for dirt cheap around here at the salvage yards. Use your best judgement based on the vehicle and engine's appearances and yank the heads. Bring 'em to a shop to get cleaned and milled .020"-.025" and slap 'em on.

You'll need heads, head gaskets, exhaust manifold gaskets, exhaust manifold bolts and head bolts.

If the intake manifold and/or rocker cover gaskets are original, replace those as well. If they're not so old and aren't "flat" when you remove the covers or manifold, they can be reused.

Clean off the top of the valley cover when you remove the IM. Pull up the lip of the knock sensor seals and add RTV all around them. If you remove them, there's a good chance they'll break and you'll be replacing the knock sensor harness and maybe the knock sensors themselves as a preventative measure. It's one of those things that you either don't touch or completely replace. But peeling up the lip to add RTV is harmless and a good PM.

I've never had a problem with the $12 Dorman exhaust manifold bolt sets. Use high temp anti-seize on the threads (same with the spark plugs).

The cheap Summit Racing head bolt kit is a re-labeled OEM kit. Good deal here.



If it were me and I wanted to get by as cheaply as possible, I'd run used OEM lifters as long as they didn't have high mileage on them, maybe something around 150K. Maybe find two people that did an AFM delete on a NNBS and get their non-AFM lifters? Don't forget to replace the lifter guides- OEM ones are only about $25 for all four, IIRC. I'd get the cheapest but known good set of heads I could find and run 'em as-is. Worst case the valve seals are a little leaky, but burning a tiny amount of oil, maybe just at startup, is far better than having coolant leak into your engine or the engine overheat from being ran with low coolant.
 

iamdub

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Given the evidence of bearing damage from the report, I'm not sure I'd put that effort into the engine.

I couldn't read the report- way too small even after I clicked on it. Still, if it's not an excessive amount of bearing material, it may be fine. These things can take some abuse and come back from it. If the bearings aren't spun, fix the issue(s) and run heavier oil to "fill in the gap".
 

Tonyrodz

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I couldn't think of the number for the similar heads as the 706 so I just said "or equivalent". 862 is it. The 706 uses a better casting process, but if you're trying to fix it on the cheap, a known good 862 will be fine. Just avoid anything Castech to better your chances. Or, since they'd be from a newer vehicle and likely more plentiful, the 799/243 is a great head, but you'll lose a little compression. It may not even be noticeable. I'd still have them shaved since it's cheap to do and will ensure a perfectly flat surface. The machinist should also clean them so that'd be a little bonus, too.
What do you think about 317 heads?
 

iamdub

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What do you think about 317 heads?

Flows like the 243/799 but much lower compression than those heads from larger combustion chambers, so even a bigger loss of compression over the 706/862. You'd have to mill too much off of them to regain the lost compression.
 

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