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High milage engine question

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Old Aug 11, 2013 | 09:56 AM
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Default High milage engine question

So, gotta '98 Z28 LS1 6spd. Has 152,000 miles on it.

(1) What are some of the causes that might make the engine gradually lose power or torque? (p.s. thinking of doing a cam swap, but not sure about the high mileage thing)

(2) Have also noticed that when I punch it, 1st - 5th gear, frequently, the inside of the car gets this pungent smoke smell. Gear shifting is as smooth as silk all the way through 5th. Smell stays in the car for a while till it all airs out.
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Old Aug 11, 2013 | 10:38 AM
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With a 98, all you would have to worry about is the oil pump. Connecting rod bolts are not as good as later years, but not an issue as long as you're not spinning the engine to the moon.

As long as maintenance has been done, I wouldn't worry about much. Your smoking could just be slightly worn valve seals. I probably would just leave them alone, especially if you are planning to mod stuff later.
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Old Aug 11, 2013 | 01:08 PM
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That smoke smell is probably giving you the hebe jebees but it could be as simple as a broken PCV line check behind the intake. i just went bigger on the cam @ 136,000
look at it this way when it lets go is anyones guess but the **** blows out the bottom
most of the time and a reasonably priced short block will fix it in addition to going bigger.
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Old Aug 11, 2013 | 08:43 PM
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Those miles aren't that big of an issue if taken care of, a cam swap is good in a way as you get to replace things such as oil pump, timing chain, lifters, etc...
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Old Aug 11, 2013 | 09:30 PM
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That's around the miles that my cam went in 98 as well. Change valve seals. Oil pump timing chain, springs, push rods
However you may think about doing a compression test if your worried about it
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Old Aug 11, 2013 | 09:39 PM
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Compression test will really tell how worn the engine is at that mileage. Like said, valve seals, timing chain, gaskets, lifters, ect.....

It's fine for a cam swap. Personally, if this isn't your daily driver, it's not a bad time to pull the motor and just do an overhaul of parts that wear out. Gives you an opportunity to get the heads off and have the valve seals replaced along with lifters and trays.
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Old Aug 12, 2013 | 08:14 AM
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I don't think that's bad MI at all we,ve got a wrk truck at our shop with a 6.0 and 300,000 the only thing done was oil pump and timing chain. N trust me since it ain't mine I drive it like I stole it lol
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Old Aug 12, 2013 | 09:42 AM
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Originally Posted by Grimes
With a 98, all you would have to worry about is the oil pump. Connecting rod bolts are not as good as later years, but not an issue as long as you're not spinning the engine to the moon.

As long as maintenance has been done, I wouldn't worry about much. Your smoking could just be slightly worn valve seals. I probably would just leave them alone, especially if you are planning to mod stuff later.
Thanx. Yeah, stock rev limiter is in place. Even so, rarely do I go past 5K rpm. Thinking of doing a cam swap soon.
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Old Aug 12, 2013 | 09:47 AM
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Thanks guys. Yeah, wanna go with a cam swap soon, but it is my daily, so can't be down for a long time, and gotta be mindful of the whole smog thing...I'm in California.
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Old Aug 12, 2013 | 03:26 PM
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Yuck California. Got any relatives out of state you can register car in
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