I need input
10-20-13, 08:51 PM
#1
I need input
Fiend of mine with an sc with around 275-300k on the motor is complaining to me that his cars losing power "100 Hp" he told me and he wants to tune it up, through aem/hks tuner, headers, throttle body, cams, I take and exhaust for his 1uz.
I told him before that the motor will need a rebuild just from hearing what he told me and the mileage of the motor. In my opinion if his motor is happening to lose compression and needs a rebuild I suggested that he just go with a 1jz swap.
He tells me that it'll be cheaper to just add the mods I stated above but told him that it'll be pointless without his motor getting rebuilt. what do you guys think he should do?
I think it would be cheaper and smarter to go 1jz since he actually wants power gains and it'll last him on the long run vs modding te 1uz that needs a rebuild anyways.
He doesn't agree with me and I told him to post up on here but he doesn't want to make himself look dumb so I'm asking on his behalf,
I told him before that the motor will need a rebuild just from hearing what he told me and the mileage of the motor. In my opinion if his motor is happening to lose compression and needs a rebuild I suggested that he just go with a 1jz swap.
He tells me that it'll be cheaper to just add the mods I stated above but told him that it'll be pointless without his motor getting rebuilt. what do you guys think he should do?
I think it would be cheaper and smarter to go 1jz since he actually wants power gains and it'll last him on the long run vs modding te 1uz that needs a rebuild anyways.
He doesn't agree with me and I told him to post up on here but he doesn't want to make himself look dumb so I'm asking on his behalf,
10-21-13, 06:06 AM
#2
At that mileage....performing expensive mods sounds very risky and almost silly. Find the true cause of the problem before wasting money on mods that might have to just be resold for a loss when the engine blows and he gives up on it.
If my engine was that bad, I would definitely go for a nice clean swap. The only 1UZFE engine I would get rebuilt would be the VVT-i version. Those are worth rebuilding for sure, but if he's on an older 1UZ with significant problems...just swap.
The 1JZ is a worthwhile investment. And if he looks to sell the car down the road that would be a very good selling point. Any pics of his ride? Has he checked the ECU for bad leaking or burnt caps?
If my engine was that bad, I would definitely go for a nice clean swap. The only 1UZFE engine I would get rebuilt would be the VVT-i version. Those are worth rebuilding for sure, but if he's on an older 1UZ with significant problems...just swap.
The 1JZ is a worthwhile investment. And if he looks to sell the car down the road that would be a very good selling point. Any pics of his ride? Has he checked the ECU for bad leaking or burnt caps?
10-21-13, 07:31 AM
#3
If I had an SC400 with around 300k miles, I would use that for my DD until the engine blows, but I wouldn't dump money into it thinking the engine will redline over and over and over, without a rebuild at least. Either rebuild the existing motor, swap it out for a new 1JZ as Biddles suggested, or use it/part it out and get another SC!
GL on HIS decision!
GL on HIS decision!
10-21-13, 01:09 PM
#4
depends on if its really 100hp down or not. I would get rid of it for a boosted 6 anyways, but a compression test is the true answer, and you may be surprised that a 1uz that has been taken care of will still have good compression at that age, but if its had a hard life of missed oil changes and no maintenance then it could be down on some power. how much would be a pure guess without doing the test. If its healthy and not overheating, allowing it to breathe easier via some mods and a tune up is not a bad thing at all. these motors can rev out higher than the standard rev limit even at that age. The only time you really pay for trying to add more power is when you turbo or supercharge a motor with worn rings, as all the blowby will not let the turbo drain, but you can slap all the n/a mods you want on it and live with the extra crank case pressure for a while if you choose to.
A quick but not fool proof test is to remove the oil cap and see if it is sucking in air or shooting out air and oil at you. If it is shooting out a good amount of air and oil at you at a steady pace you may actually have a worn rings on your hands, if the air comes out in rhythmic pulses then even more of an indication of combustion passing some of the rings. Its not fool proof cause you kind of have to know the engine, as in a few drops of oil spraying here or there can be normal, but its the conditions and amounts can be a give away when having issues and down on power, or the vehicles idle speed is too low.
also check the oil for coolant and the coolant overflow for oil (becomes a brown milkshake together). If you see that then you know you have at least one bad headgasket.
it really just depends on how healthy it is currently running. I have seen some 150k motors I would never touch, and I have seen some 250+k motors that run reliably day in and day out.
A quick but not fool proof test is to remove the oil cap and see if it is sucking in air or shooting out air and oil at you. If it is shooting out a good amount of air and oil at you at a steady pace you may actually have a worn rings on your hands, if the air comes out in rhythmic pulses then even more of an indication of combustion passing some of the rings. Its not fool proof cause you kind of have to know the engine, as in a few drops of oil spraying here or there can be normal, but its the conditions and amounts can be a give away when having issues and down on power, or the vehicles idle speed is too low.
also check the oil for coolant and the coolant overflow for oil (becomes a brown milkshake together). If you see that then you know you have at least one bad headgasket.
it really just depends on how healthy it is currently running. I have seen some 150k motors I would never touch, and I have seen some 250+k motors that run reliably day in and day out.
Last edited by Ali SC3; 10-21-13 at 01:19 PM.
10-21-13, 01:46 PM
#5
im ohnestly going by what he has told me, he said it doesnt run well and he feels a power loss, but yeah thats what i told him to do, just run a compression test first, he is in the process of doing a tune up atm, i told him to replace his plugs, wires, cap, and rotor, and i think he just did an oil change recently too.
10-21-13, 02:55 PM
#6
the most famous time that happens is when one of the coils go out, you loose half the power, and alot don't notice that is the problem. 1uz's generally run strong, so If the power loss was recently I would look into the problem, and its usually not the bottom end on a 1uz, especially on a 92-94 model which had the strongest internals. I would be shocked if the 1uz in question had 300k miles on the original coils, they are almost guaranteed to fail at some point.
Last edited by Ali SC3; 10-21-13 at 02:59 PM.
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10-21-13, 09:05 PM
#8
Lexus Test Driver
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I stopped reading the OP after, I saw someone wanted to mod a motor with 300k...no. Fix it first then mod it, use it as daily and buy something boosted, or just go ahead and swap in a boosted i6
10-22-13, 07:02 AM
#10
my uz has 252k and it runs ok, power loss is a given with age, but if its only a few 100 bucks to get it back running then its worth it, if it costs 1500+ obviously id go for a swap, who wouldnt? i dont have the $ to go 1j but im thinkin about swapping another uz when mine dies. vvti of course.
10-22-13, 08:35 AM
#12
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Low mileage 1UZ's are pretty cheap since they are not that popular. Plus the 1jz and 2jz swaps are so common people ask a good chunk of change for them. So about $600 for a 1UZ with decent miles and just drop it in. Then add mods.
