DOES A “REBUILT” ENGINE HAVE ANY REAL SET CRITERIA? It seems as if every (in diminishing value) dealer, Machine shop, repair shop, mechanic, used car salesman, or seller on ebay has a different definition of what a “rebuilt engine” is. I’m looking at a mercedes diesel with 180,000 on it and the seller says that the engine was “completely rebuilt”. I asked if the pistons were replaced and got a “no, they didn’t need to be”. how about valve guides? “no,they didn’t need to be” was the answer. injector pump? “no” the answer again. how about the oil pump? “why would you do that” was the reply. well…I have only built about a dozen Mercedes engines and I have found that most "experts don’t know what they are doing. Anyone out there know if there is an actual definition …let’s say from Bureau of Auto repair or a standard set by ASA? Ray please don’t even let Tom read this…I don’t want to spell my name or say where I’m from. Thanks
REBUILT means that if any of the parts within the assembly meet the specifications as far as wear they’re reused. And only those parts that fall out of specifications for wear are replaced. REMANUFACTERED means no matter if the parts within the assembly are within specifications as far as wear, they’re replaced with new parts. Along with any updates to those parts that may provide longer life or better performance.
So rebuilt means only the parts that were found to be worn were replaced.
Tester
The “rebuilt” engine is a buyer beware areana. Your asking if their is some kind of standard like when a food producer can call its product “light”?Not to my knowledge
It does seem that firms like GM will tell you what minimum standards their crate motors have and you can certainly tell your rebuilder what parts you want replaced and what quality you want. Getting what you want is not a problem.
For people that install a rebuilt engine in their car be sure to keep all documentation as to exactly what was done,it will help you recover some of the rebuild money.
Then there are the “classics” where people perfer that the engines not be rebuilt as they want to maintain control over standards of any rebuild.
The term “Rebuilt”, like “Tune-up” has no set definition. It means whatever the user wants it to mean. In your case, the seller considers a set of rings, rod bearings and a gasket set means “Completely Rebuilt”.
HUMMMM…THAT’S TOO BAD CAUSE IF YOU DON’T KNOW HOW TO PROPERLY MIC. A CYLINDER BORE OR DON’T HAVE THE CORRECT EQUIPMENT THEN YOU CAN SAY THAT “IT WAS WITHIN SPEC.” I DOUBT THAT THE SHOP TESTED THE OIL PUMP FLOW AND PRESSURE AT OPERATING TEMPERATURE BEFORE DETERMINING THAT IT WAS “OK”. AND NOT REPLACING VALVE GUIDES AFTER 180,000 MILES WHEN YOU HAVE THE ENGINE APART…I THINK IS JUST STUPID. THESE KIND OF OMISSIONS MAKE ME WONDER IF THEY LOOKED AT A CHAIN RAIL TENSIONER AND SAID “LOOKS GOOD TO ME! LET’S USE IT”! MAYBE IT’S JUST THAT EACH PISTON AND RING SET IS OVER $350. X 6…AND AN A NEW OIL PUMP IS OVER $400. AND THAT SPECIAL TOOL FOR THE VALVE GUIDS COST’S $55 AND WE’LL NEVER USE IT AGAIN SO, “THOSE GUIDES LOOK PRETTY GOOD TO ME”. THANKS FOR THE REPLY
That’s why I install remanufactured components and not rebuilt. This way I know all the parts are new in the component with the latest updates.
Tester
YEAH, i THINK YOU’RE RIGHT, FORTUNATELY I KNOW MORE ABOUT THESE ENGINES THAN THE SHOP THAT “REBUILT” IT BUT IT STILL IRKS ME WHEN I SEE AN ADD IN EBAY SAYING “ONLY 300,000 MILES, NOT EVEN BROKEN IN FOR A MERCEDES DIESEL” THAT WAS ACTUALLY IN ONE ADD.
Kindly don’t use all caps in your reply. Thanks.
The word rebuild is often beaten to death. There is one proper way to rebuild an engine and an assortment of other no so proper methods.
When it comes to a vehicle that is advertised as having a rebuilt engine then someone better have a stack of receipts for parts and machine work.
Many car owners are also under the wrong impression sometimes.
A friend of mine, now deceased, was a lifelong mechanic and replaced a head gasket in an SVO Mustang (2.3 Turbo) and the guy who owned this car told everyone who would listen this car had a “rebuilt engine”.
I’ve actually been at my friend’s shop and this guy was there with 2 of his buddies and he was still talking about this “new motor”. My friend must have repeated “I did NOT rebuild this engine” about 6 times while I was there.
One can only imagine what the owner of the car was saying when he attempted to sell the car later on.
Testor is correct with his statements about “rebuilt”, and Remanufactured.
However, the quality of workmanship is determined by the reputation of the builder, and the quality of the components used. When someone is trying to sell you something and you have that gut feeling they are being vauge about what they are telling you, then it becomes “buyer beware”. The addage “You get what you pay for” holds true, and the fine print in the warranty tells all–again, being backed up by the seller’s reputation. “No Warranty—No Sale”. Just ask: “Who-What-When-Where”
I agree with snowshoe.When you see the words ‘rebuilt’, the quality of the job is a direct correlation to the skill and diligence of the rebuilder. It could be a quality job done right, and give good service, or be a hack job, and break on you in short order. I learned this lesson early with an old VW when I was still in school. I, myself, did a hack job, took a lot of shortcuts to get it done quickly, and the engine threw a rod within 6 months, destroying the block. I’ve never done that again. Every one afterwards included multiple and repeated measurements, trips to machine shops, lots of micrometer, feeler gauge, and plastigage work to make sure everything was within specs as I go. I only had one engine fail on me in an untimely manner, and that was due to a flaw in a replacement camshaft.
Please, ALL CAPS are difficult for most people to read and they are considered SHOUTING.
Just something to go along with Bustedknuckles comment.
Many years ago, and against my better judgement, I installed a rebuilt (not by me) engine into a VW Bus. This long block was procured by the bus owner from a rebuild facility in Oklahoma City.
About 2 weeks after installation the bus owner came by and said the engine had scattered. It had been running great up to that point.
After getting the engine out and partially diassembled I discovered the reason for the scattering. Those who are familiar with the air cools know they do not use a head gasket and the heads are simply a precise fit against the cylinder jugs.
Apparently the head did not fit precisely on one side and the rebuild place made no effort to flycut the heads or lap them in. This led to the engine sucking air around the head/cylinder junction and the excessively lean condition (much worse on an air cooled engine) simply burnt the pistons up until they came apart.
Since I had an upcoming trip to OK. City on the following weekend I dropped by the reman place and had a talk with the owner, who denied all responsibility of course.
After about 15 minutes of back and forth he made the comment that he had sent 70 reman engines to Tulsa and 63 of them failed within 2 months.
He also stated that it was “not my fault” and the “guy who was rebuilding them no longer works here”. That led to a comment by me about replacing the lousy builder who left with another lousy builder since it’s obvious that engine problems are continuing.
That’s probably about as good an example of lousy workmanship as one could find.
How much blame do we put on VW? They did improve with the type IV and provide a sealing ring.
The bus is unforgiving on these engines. The “rebuilder” probably put on used heads maybe even used piston sets. I avoided both these practices and had satisfied customers and plenty of people that would buy the heads I did not re-use. No short-cuts allowed on the VW air cooled.
I even liked to use new cases,plenty of people bought the old cases also.
A example of what you get from a bulk rebuilder and a guy who has to live in the town that his customers do,sure I cost more but you did get what you paid for.
Don’t blame VW. The original design was simple, elegant, and durable. Because a sloppy engine builder skipped steps doesn’t condemn the design. The head seal surface was a machine-to-fit design that worked very well when fitted properly. I didn’t ever have a failure here.
I never had problems with cylinder/head fitment on the air cools since I have a flycutter and always lapped the cylinders into the heads with fine valve lapping compound; followed by checking the fit with Prussian Blue.
Another cause of those cylinder/head failures was a number of people who were overtightening the case studs. This led to thread pulling which in turn caused a poor fit and problems at the cylinder/head junction.
Many could not believe that 20+ ft. lbs. was plenty of torque for the cylinder head nuts.
On those latest cases I think the figure was 18ft-lbs. Unbelievable.
When I was in college I worked as a mechanic for about 3 years part-time. Our shop did everything that didn’t require specialized equipment like alignments. My first year there was the year Unleaded gas was introduced and many oils couldn’t handle the higher temps of the unleaded engines. We saw a 300% increase in engine rebuilds that year. This was a small shop (3 mechanics and one was the owner and I only worked part time). We started turning down rebuilds because there were just too many for our small shop. The owner felt that we could do it, but quality would suffer. We got into a little system…During the week we would take in 1-2 vehicles for engine rebuilds. The full-time mechanic (Bill) would remove the engines and have everything ready by Friday evening. The owner Jim and I would come in Friday evening and start taking the motors apart (hey what else is there for a 23yo to do on a Friday night). Depending on the engine we would have both engines torn down by midnight. Saturday we would send everything over to the machine shop his brother owned. And usually have it back in the afternoon. We would also buy all the parts we needed for a good reuild (bearings, oil-pump, possibly cams or new cranks)…what ever it took.
Then on Sunday we would spend anywhere from 10-20 hours putting the motors back together. Many times this would flow over into Monday. Then Bill would come in on Monday and spend 1-2 days putting the motors back in and hopefully get them running again by Wed or Thurs. We could only do this 10 times a year or we would loose ALL our other customers. The owner Jim gave us plenty of time to do the work RIGHT. Nothing was ever rushed. We would check each others work to make sure everything was right…(mainly Jim would check my work, which was OK since he was an EXCELLENT mechanic).
To do a rebuild right you need PATIENCE. You can be the GREATEST mechanic in the world, but if you don’t take your time and check and recheck your work it’s NOT too difficult to screw things up. Jim probably could have doubled the engine rebuilds he did for a lot more money, but he wanted to do take his time and do things right.
Personally I would avoid vehicle with a rebuilt engine. It typically means something either went really wrong or the owner neglected it to failure. Few vehicles die of engine failure it is typically another reason.
You have no idea if problem that lead to the rebuild (or partial) has damaged the rest of the motor.
I consider rebuild a bad thing not a positive. That is unless of course you know the motor was sourced from a reputable engine builder with a receipt to show so.
I read the part about the unleaded gas and I thought OK it led to valve seat/guide problems. But you say the problem was oil breakdown due to higher operating temps,I am just not buying that one. I also was pounding out rebuilds in the mid-seventies,VW’s because they were junk when new. I don’t think all those dropped number 3 exaust valves were related to unleaded gas. They were dropping them on leaded gas also. Probably poor number 3 cylinder cooling due to poor placement of the oil cooler (they fixed that after awile)