I got a Z28 Camaro with the LT1 2 months ago. After about 1000 miles, the car lost oil pressure on the highway and upon inspection we found that the main bearings had spun on the #7 and #8 cylinders. We rebuilt it - the block was line bored, crank and rods 7 and 8 reconditioned, and new rings and bearings were installed. Now, 1000 miles later, the car has lost oil pressure again.
What could cause the bearings to fail twice in a row like this?
2006-12-02 04:59:14 · 6 answers · asked by jeff_is_sexy 4 in Cars & Transportation ➔ Maintenance & Repairs
I had barely finished breaking it in - it had hardly any hard use.
2006-12-02 05:05:54 · update #1
Besides that, it's an automatic.
2006-12-02 05:06:34 · update #2
The cam bearings were replaced at the machine shop, so I assume he checked everything to do with that. The block was also acid washed. I'm assuming the crank was as well, it was machined by a shop.
2006-12-02 05:18:31 · update #3
Your transmission's torque converter might be out of balance putting stress on the back part of the engine. If everything you said was done properly, the engine should of lasted far longer.
2006-12-02 05:19:08 · answer #1 · answered by Lab 7 · 0⤊ 0⤋
Check the alignment of the cam bearings. They are new too, I hope? Be sure the oil galleys are all clear and the bearing holes match up to the galleys. Also use a micrometer on the crank and crank journals for over or undersize and make sure the bearings are the right thinkness for the crank and journals.
Use plastigauge on assembly.
That really sucks!
The same thing recently happend to my best friend on his LS6
Chevelle. The result is obvious, but the machine shop is claiming they dont do that shabby work. I would take the motor to a different shop for an opinion on workmanship. If they say all the galleys and clearances are fine I would use it as a boat anchor and get another motor, but I think you will find what I have stated if you look hard enough. Also check the holes in the crank for blockage. Bearings need oil, so it it has to be stopping somewhere if the rest of the bearings are not scored.
Good luck!
2006-12-02 05:16:03 · answer #2 · answered by peedeesuave 4 · 1⤊ 0⤋
It's unusual for that to happen twice, especially on that engine. Oil for the #7&8 ROD bearings (there are only 5 mains) is supplied thru the crank. The oil is delivered from the rear of the engine forward, so those rods would be supplied before the front ones. No oil supply would cause almost instant failure. I would say you have a partial blockage in the oil galleys that feed the rear two mains. # 8 rod is fed by the #5 main, #7&6 are fed by the #4 main. I would say the block was not properly cleaned after the initial failure.
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2006-12-02 05:22:49 · answer #3 · answered by tech 3 · 0⤊ 0⤋
Bearings might want to very last 10 years. It won't be able to be the bearing, because even the most inexpensive might want to very last. yet you probably did not tell use the make, kind, or 12 months. It makes a huge distinct. no matter if it really is a rear wheel rigidity, then the fronts have tapered bearings that require careful preload adjustment. You surely modify the bearing nut to 0 end play, and effectively 0 preload, precisely. the gap between bearings should be thoroughly full of thick bearing grease. There should be no previous metallic chips or shavings left from the previous bearing failure. If the spindle has difficult parts, it a lot be polished comfortable with emergy paper so as that bearing slide actual adequate. If the spindle is worn to the point of bearing being to free, it a lot get replaced. no matter if it really is a the front wheel rigidity, then there commonly is a much better unmarried bearing unit with countless inner bearings, which will or would no longer come already greased and sealed. the substantial reason behind installation failure with a lot of those bearings is by pounding them in. The effect causes damage. they should be hydraulically pressed in or drawn in with threaded puller. No hammering. it truly is purely allowed for elimination. the purely different situation often is the perfect torque on the axle nut that tensions the bearing. it would want to't be too tight or too free, because it really is what keeps the bearing factors perfect aligned. in various of circumstances the axle nut is large and receives a severe torque, something like 100 and fifty ft lbs. commonly it really is staked to circumvent loosening.
2016-11-30 01:26:23 · answer #4 · answered by barby 3 · 0⤊ 0⤋
The problem may be with the oil pump itself.
2006-12-02 05:15:15 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Too much throttle without downshifting.
2006-12-02 05:01:41 · answer #6 · answered by Anonymous · 0⤊ 0⤋