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Re: seized 8v71 by Roger S.
Post New Message As a long time detroit diesel mechanic 33 years i build detroit engines for a transit authority in iowa i have seen and worked on a large number of 8v71 engines seized up depending on the engines condition beforehand it probably overheated due to a loss of coolant or due to fan not engaging or radiator not doing its job such as lugging the engine in to high a gear on long hills or mountains it also could be due lack of air from a plugged air cleaner most busses have a shutdown to kill the engine when it is overheated or loses oil pressure but whether it has one or whether it was working at the time is anyones guess. You can rebuild the engine in the bus but it depends on what kind of bus that determines the amount of work involved. I can give you some friendly advice that will possibly save you some big bucks on your little adventure! Detroit Diesels are famous for getting antifreeze in the oil.The glysol in the antifreeze causes a loss of lubrication between the rod and main bearings the crank and bearings will get so hot the bearings will weld themselves to the crank and seize the engine i am not saying that is what happened to your engine but it has happened to many of them but before you alot of money on this or before you go out and buy another engine you should know a couple of things.First there is a good chance that the block is cracked the very first thing i would do if it was mine is drain the oil take the oil pan off and remove the oil pickup tube two bolts in the front and two bolts in the back it requires a nine-sixteen wrench and or a rachet and socket the main caps are numbered you need to take down #3and#5main bearing caps 99 times out of a 100 if the block is cracked it will be in one of thes two journals and where they crack is in the area where the cap mates with the block they are a high torquing engine and there is a lot of stress on the bottom end what you are looking for is a jagged line starting from the bolt hole on the block working its way to the outside of the block these cracks can be really hard to see if you are not used to looking for them a lot of times if you look at the main bearing caps you can see the impresson of the crack on the cap if someone did not tell you you would think that the cap had the crack in it not the block the important thing is some people will tell you the crack will not hurt anything but in reality it does that crack that starts from the edge the inside edge of the bolt hole you only see part of the crack it really runs up the bolt hole through the threads and over time the bolts work their way loose and when the back one comes loose it lets the back of the crankshaft drop down which puts weight on the rear engine seal and causes it to leak excessively and can cause a bad vibration which over time can break the crank and cause the front seal in the transmission to leak and also the misalignment can knock bearings and bushings out of the transmission.I have not touched on other problems that you can have as a result of your seizure it is a real good chance that the cylinder heads are cracked from the heat I think that you have enough information to get started if you decide to buy another engine you really want to get a guarntee that the block and cylinder heads are not cracked i am new to this computer thing i have collected quite a few engine parts over time if you do this yourself and need moral support or used parts or rebuilt parts i might be able to help you Roger
All Messages in ThreadAuthorDate
Post New MessageSeized 8v71 Phil 7-25-02  
  Reply to MessageSmokey engine room with 8v71 Claus 10-23-05  
  Reply to MessageRe: seized 8v71 Mark O. 7-28-02  
    Reply to MessageRe: seized 8v71 Billy Bob Thornton 9-3-02  
      Reply to MessageRe: seized 8v71 charles seaton 9-18-02  
        Reply to MessageRe: seized 8v71 Roger S. 12-13-02  
          Reply to Message8v71 john 2-9-03  
          Reply to MessageSeized 8v71 Alirio Gomez 6-14-06  
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