What exactly goes bad due to high mileage?
10-08-2005, 04:28 PM
#3
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mine's doing okay with just over 100,000 miles, although the damn headlight motors just started making noise 
Nothing different here from when I got it, enjoy, mash the gas, and repeat often!
Derek
Nothing different here from when I got it, enjoy, mash the gas, and repeat often!Derek
10-08-2005, 05:52 PM
#4
Originally Posted by Villain281H
mine's doing okay with just over 100,000 miles, although the damn headlight motors just started making noise Nothing different here from when I got it, enjoy, mash the gas, and repeat often!
Derek
Nothing different here from when I got it, enjoy, mash the gas, and repeat often!Derek
10-11-2005, 02:31 PM
#6
my car has 143,000 on it. it seems like it is on its way down hill. its got some valve train noise it didnt used to have. with the mods in my sig, all i could do at clay city was a 12.73. it hasnt been retuned since i put in the comp cam, ls6 intake, or midwest converter, but i think it still should have done better than that.
10-11-2005, 04:40 PM
#7
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damn, your definition of "downhill" is a car with 150k on the clock and UNTUNED cam/intake/converter that's running "almost" mid 12?! 
talk about high standards!
As far as "longevity mods", catch can is probably one of the best mods for that.
talk about high standards!
Originally Posted by moeZ28
my car has 143,000 on it. it seems like it is on its way down hill. its got some valve train noise it didnt used to have. with the mods in my sig, all i could do at clay city was a 12.73. it hasnt been retuned since i put in the comp cam, ls6 intake, or midwest converter, but i think it still should have done better than that.
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10-11-2005, 08:07 PM
#8
Originally Posted by longdaddy
damn, your definition of "downhill" is a car with 150k on the clock and UNTUNED cam/intake/converter that's running "almost" mid 12?!
talk about high standards!
As far as "longevity mods", catch can is probably one of the best mods for that.
talk about high standards!
As far as "longevity mods", catch can is probably one of the best mods for that.
10-11-2005, 08:47 PM
#9
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drive the crap out of it, works well for me and my 142,000 mile Ex police car 
replace cats would be the only thing id suggest, MAYBE sparkplugs... coolant flush and trans service...
replace cats would be the only thing id suggest, MAYBE sparkplugs... coolant flush and trans service...
10-12-2005, 11:37 PM
#10
What exactly goes bad due to high mileage? This may be the wrong forum but i dont really know where to post so mods feel free to move it for better results. But what exactly fails on these motors due to high milage? I keep up with the regular maintenance oil, trans, coolent, gear oil etc. and taken some measures to prevent problems..ls6 pump, new radiator, waterpump, etc. im working on 135k and after we get some quirks figured out we will finish up on the tune..with 370 at the wheels, I dont rag on it much, but i do if im in the mood, what would be going out due to high milage?
10-13-2005, 12:22 PM
#14
This is kind of a tuff question. Personally I've never heard of a motor just failing. It's either due to poor oil pump's (spun bearings) or someone screwing up by missing a shift and floating a valve (broken piston, sometimes through block) I have never once heard anyone say my engine just gave out after XXX miles due to being old. I'd like to know though cause im at 105k
10-13-2005, 01:00 PM
#15
This question has appeared on the board a few times in the last couple weeks, and 777 had it right when he said it was tough to answer. It’s been on my mind as my car edges toward the dreaded six digits. I haven’t read an all encompassing answer yet. 777’s hit it as close as any.
I’m going to add to your question and broaden it, if I may. For any modern (arbitrarily 1960+) internal combustion engine, what tends to wear out first?
I’m going to go against my policy and show my rear a little, but I admit that I don’t know all the parts of a four-cycle gas engine, and I can’t give a detailed technical description of how one works (other than what you lean in a high school science class). Many, many people on here can if they will, and if they can articulate it well enough in written form.
These aren’t specific questions, I’m just throwing them on the table to help anyone who wishes to answer:
Do cam lobes wear out?
What about piston rings?
Seals and gaskets?
Cylinder walls?
Lifter springs?
Do push rods bend slightly and... keep from lifting the valves open correctly? (I think that’s what they do)
Do things just get dirty and gummed-up? What about in the intake?
If you were to rebuild an engine and put it back to stock, what would you first want to replace and what would you try to keep, other than the block?
Let’s say your engine wasn’t well maintained. Specifically talking about the engine, what would you look to replace first?
I’m going to add to your question and broaden it, if I may. For any modern (arbitrarily 1960+) internal combustion engine, what tends to wear out first?
I’m going to go against my policy and show my rear a little, but I admit that I don’t know all the parts of a four-cycle gas engine, and I can’t give a detailed technical description of how one works (other than what you lean in a high school science class). Many, many people on here can if they will, and if they can articulate it well enough in written form.
These aren’t specific questions, I’m just throwing them on the table to help anyone who wishes to answer:
Do cam lobes wear out?
What about piston rings?
Seals and gaskets?
Cylinder walls?
Lifter springs?
Do push rods bend slightly and... keep from lifting the valves open correctly? (I think that’s what they do)
Do things just get dirty and gummed-up? What about in the intake?
If you were to rebuild an engine and put it back to stock, what would you first want to replace and what would you try to keep, other than the block?
Let’s say your engine wasn’t well maintained. Specifically talking about the engine, what would you look to replace first?
10-13-2005, 01:27 PM
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Do cam lobes wear out? Yes, but not as much as they used to with roller cams. Flat tappet cams were more prone to this type of failure.
What about piston rings? The cylinders tend to wear more than the rings.
Seals and gaskets? Newer gaskets and seals are more resistant to drying-out than older types of paper and cork gaskets. Neoprene is your friend.
Cylinder walls? Yes. Typically the reaon an engine needs to be rebuilt (if nothing specifically broke) because compression pressures begin to drop as the cylinder walls begin to wear in a tapered shape starting wide at the top and tapering in towards the bottom. Smoke from the tailpipes is the biggest indicator that a worn engine is beginning to show signs of fatigue.
Lifter springs? Lifters fail, springs also fail. More common in performance engines/cars than family drivers.
Do push rods bend slightly and... keep from lifting the valves open correctly? (I think that’s what they do) Not from wear, but bending a rod is easy if you over-rev the engine.
Do things just get dirty and gummed-up? What about in the intake? Absolutley. Carbon and gunk build up quite easy. Oil can coke on journals and other surfaces as tolerances begin to open up and hot spots begin to cook the oil.
LSx engines will last longer than older small blocks used to due to many improvements in fuel management, materials used, overall engineering.
What about piston rings? The cylinders tend to wear more than the rings.
Seals and gaskets? Newer gaskets and seals are more resistant to drying-out than older types of paper and cork gaskets. Neoprene is your friend.
Cylinder walls? Yes. Typically the reaon an engine needs to be rebuilt (if nothing specifically broke) because compression pressures begin to drop as the cylinder walls begin to wear in a tapered shape starting wide at the top and tapering in towards the bottom. Smoke from the tailpipes is the biggest indicator that a worn engine is beginning to show signs of fatigue.
Lifter springs? Lifters fail, springs also fail. More common in performance engines/cars than family drivers.
Do push rods bend slightly and... keep from lifting the valves open correctly? (I think that’s what they do) Not from wear, but bending a rod is easy if you over-rev the engine.
Do things just get dirty and gummed-up? What about in the intake? Absolutley. Carbon and gunk build up quite easy. Oil can coke on journals and other surfaces as tolerances begin to open up and hot spots begin to cook the oil.
LSx engines will last longer than older small blocks used to due to many improvements in fuel management, materials used, overall engineering.
10-13-2005, 01:57 PM
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My car has 175k miles on it. I am the second owner of this car and the first owner put 160k miles with no problems. It did begin to burn some oil and due to negligence, it threw a rod... But who knows how long it could have gone with proper care.
BTW, it had 150 dry shot of nitrous on a completely stock motor for 145,000 miles of it's life.
BTW, it had 150 dry shot of nitrous on a completely stock motor for 145,000 miles of it's life.
10-13-2005, 01:58 PM
#18
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Yeah I've been wondering about this too. Since I'm having a hard time finding a M6 T/A with decent miles, would it make sense to buy a high mileage one (like for 9 or 10g) and then just redo the entire motor? Maybe even up it to 383 or something? Because I guess it would make sense to up the cubes while I'm working/changing the motor.
10-13-2005, 03:40 PM
#19
By all means, I would recomend a high miles LS1. I'm just asking general questions. There are people on here with over 200K on their stock bottom end and no real problems. My car pulls hard as hell and runs perfectly, though it has over 90,000 miles.
Buying a new LS2 402 is chaeper and puts out more power than most strokers, it seems.
Buying a new LS2 402 is chaeper and puts out more power than most strokers, it seems.
10-14-2005, 04:59 PM
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what about fuel injection cleaning or what if you have a car that you just put a ls6 manifold on and want to clean out the heads and the pistons and valve from all the burnt oil deposits..whats best for that...