Firebird Posted October 23, 2012 Report Share Posted October 23, 2012 I have a 1998 Firebird V6 that had a complete engine rebuild about 20,000 miles ago and this past week the engine threw a rod threw the block. Has anyone ever heard of this happening? The engine was rebuilt by a professional shop that has done numerous engine rebuilds for me and I have never had any problems with their work. What makes this senario odd is the day prior to this happening I was checking the oil and I noticed that the oil pressure was great (an aftermarket oil pressure gauge was instaled in the engine bay). Prior to this the car gave me no engine trouble, heck I was using it for long trips (500 plus miles) and it was getting 32 mpg! Quote Link to comment Share on other sites More sharing options...
Schurkey Posted October 23, 2012 Report Share Posted October 23, 2012 Anything can happen. I had #3 rod of my '80 Honda Civic go through the oil filter mount on the front of the block. 58,000 miles; cruising down the highway at 70 mph in 5th gear. #3 rod journal was burnt black, all the mains, and the other three rod bearings appeared wonderful. It was--and still is--the only connecting rod I've ever seen in multiple pieces where the rod bolts did NOT fail. The bolts were bent, but the nuts were still threaded on them, and the bolts were still intact even though the rod was in four pieces. Go figure. Weird sh!t happens. Quote Link to comment Share on other sites More sharing options...
rich17 Posted October 24, 2012 Report Share Posted October 24, 2012 3800's are weird and dont take to rebuilds. I've seen many rebuilt ones go for a short period and fail again. Best bet is to find a low mileage unit. 3800's were made to 2007. They're out there Quote Link to comment Share on other sites More sharing options...
AL Posted October 24, 2012 Report Share Posted October 24, 2012 Ive also heard about them not doing well after a rebuild, not sure why but none ever have Quote Link to comment Share on other sites More sharing options...
Addicted to eaton Posted October 24, 2012 Report Share Posted October 24, 2012 the rebuild i did, i had Great success with. 40-50k miles be for i sold the 3800 powered gt. step one, have it hot tanked.. and SOAKED... then take a rifle brush and clean every oil passage... you would be amazed by that the hot tank doesnt get in there. its all about prep, sounds to me like they left an oil passage blocked. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted October 24, 2012 Report Share Posted October 24, 2012 Rob Eye could probably attest to dealing with quite a few dead 3800s. Quote Link to comment Share on other sites More sharing options...
Schurkey Posted October 24, 2012 Report Share Posted October 24, 2012 It's an engine, not a magic box. Rebuild it RIGHT, you'll have excellent results. Rebuild it WRONG, and it'll fail early. It's MUCH easier to do the job wrong or incomplete than to get ALL the details RIGHT. Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted October 24, 2012 Report Share Posted October 24, 2012 Is a magic box like a magic stick? But seriously, with how common 3800's are right now, it's much more cost effective to pick up a good used unit with lower miles on it then it is to do a proper rebuild. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted October 24, 2012 Report Share Posted October 24, 2012 It's an engine, not a magic box. Rebuild it RIGHT, you'll have excellent results. Rebuild it WRONG, and it'll fail early. It's MUCH easier to do the job wrong or incomplete than to get ALL the details RIGHT. This. Its all parts and tolerances, get any of those off and it will toss its cookies, don't cheap out on a rebuild. I'd wager the reason that rebuilds get a bad rap is sub-par work, bent cranks repaired, reused or never checked. etc. Quote Link to comment Share on other sites More sharing options...
Schurkey Posted October 24, 2012 Report Share Posted October 24, 2012 This. Its all parts and tolerances, get any of those off and it will toss its cookies, don't cheap out on a rebuild. I'd wager the reason that rebuilds get a bad rap is sub-par work, bent cranks repaired, reused or never checked. etc. Parts, tolerances, and DIRT. Particle contamination--dirt, machining chips, gasket-and-sealer remnants, lint from rags--little bits of abrasive "stuff" left in the engine due to improper cleaning and assembly methods--are responsible for most engine failures. You would not believe the crap I've cleaned out of crankshaft oil passages that the machinist claimed were "ready to install". Every part that I put into an engine, except lifters, get dunked in hot water and detergent. If it won't fit into a 5-gallon pail (the block, for example) gets hit with my pressure washer. EVERY drilled or cast passage gets a soapy brush run through it. Compressed air through EVERY passage to dry it; and compressed air over the outside to dry in order to prevent rusting. I prime and test lifters "on the bench" to assure that they pass oil and have acceptable leakdown. Poor inspection/re-machining/assembly practices OTHER than contamination are responsible for most of the remaining failures--installing the timing chain wrong so the valves hit the pistons, failure to torque fasteners properly or in the wrong order, failure to install seals or gaskets properly, etc. Failure to properly inspect re-used parts for wear--cylinder bores, piston ring lands, grooves cut into shafts by the neoprene seal lips. Cracked "hard parts"--connecting rods, blocks, crankshafts. The list goes on and on. INCORRECT parts selected for installation is a variation of this problem. Friend of mine was popping head gaskets on his S-10 pickup every time he took it on a longer (>100 mile) drive. Turns out that cylinder heads for a GM 2.5L "Iron Duke" four-popper can have the SAME CASTING NUMBER, but be machined differently by GM. There's a coolant passage drilling that can be machined in one of two different places, and if you only look at casting numbers, it's very possible to get the wrong version. The hole gets covered by the gasket, there's poor coolant flow, the head overheats at the back, and the gasket says "Good Bye". Failures due to defects of the "new" replacement components is--usually--a fairly small percentage. I'm not saying it doesn't happen, just that they're not near as common as reconditioning and assembly problems. Faulty Chinese lifters were an epidemic not that long ago. Defective machining on Chinese crankshafts is another semi-common problem. Quote Link to comment Share on other sites More sharing options...
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