Bad Rod Bearing

[Musashi450]

Ok this is going to be a long post but I really appreciate the input in advance. I recently finished up a rebuild of my 7 bolt and at the same time added a couple things (EvoIII 16G, profec B spec II, DIS, fidanza, act 2600, BS removal, blah blah blah) Needless to say I was pretty excited to get this thing up and running. What led to the rebuild was a rod bearing spinning on cylinder #2. The bearing had gone bad because I had magical lost all of my oil. Come to find out later that a couple of valves were bent and that I had probably been burning oil faster then I realized. Alright so since then I've learned a lot in the process and am all the better for it.

Yet here I stand again. Yesterday I was tuning the EMS that I had just put in and while trying to do a third gear run realized that my boost wasn't holding steady with my boost controller. Great...... So I start playing with the gain settings and start boost settings. I'll admit the engine was seeing repeated boost very quickly up to 15PSI and up to 20 psi for literally half a second which it should not have (It would spike 5PSI then slowly rise, but I'll tackle the boost creep when the car frickin runs) Anyway sure enough it develops a knock. I get it home rip off the oil pan and realize that the cylinder #1 rod bearing is toast. It looks like it may have spun but then popped back into place (this would make sense because the sound was decently loud at first then appeared to sound very faint) . The bearings that were put in were the trilayer clevites. So cylinder 1 made it to the copper while cylinder 2-4 scuffed up the first layer. Could this be due to the copper in the oil or did this happen prior to bearing 1 going bad? I'm literally shot on funds by this point and am really up a creek without a paddle. I can feel that the crank journal for rod 1 is going to need to be reground (...again)

After doing some reading their are two things that I've realized I've done wrong so far. I obviously didn't give the engine a very good break in procedure although I dont know how much if at all this applies to just regrinding a crank and changing the bearings. I also switched to synthetic oil way to early. The car has probably yet to see 50 miles. I'm going to take out the engine, take off the rear and front seals, remove the crank, get it machined, get matching bearings and throw it in after double checking oil clearance via plastigauge. At the same time I'm replacing the front seal and water pump since I did not do this the last time. I should also mention that while trying to fix the boost problem the car saw a max coolant temp of 205 (this was during my constant flooring it to test my boost settings and looking for the change in boost spike, this was also when the knock occured. Normally the car ran at about 194) Their appeared to be no knock according to the EMS. Actually the EMS basemaps are set up so that the car runs pig rich WOT (about 10~10.5:1) which was also confirmed by the spark plug in the first cylinder. The metal in the oil is VERY fine (I actually didn't even see it until I went and looked for it the second time) and so I'm hoping I didn't do any damage. I DO NOT have the funds to take off the head and get this thing hot tanked so I would also appreciate any advice people would have on flushing the oil system out. My main question of course though is what is the cause of this! Also the bearing from cylinder 1 is copper going from the inside out next to the hole which would lead me to think low oil pressure in that cylinder. But I'm confused then because that cylinder should see the highest oil pressure while none of the other bearings spun. Again any and all suggestions/help are appreciated. I'll try and get some pictures of the bearings up in a bit.

Edit: Most importantly forgot to mention that the stock cluster was showing good oil pressure.

-Chris Lawrance

 

[fallenauthority]

Well I do not know the cause of your spun bearing, I do know you should NOT regrind the crank again, These cranks have been deemed non serviceable, meaning once they are damaged they are done. But that has mixed results, some people do fine on reground cranks, some dont. I dont see where your break-in procedure had anything to do with the failure. Many engines are built fresh and thrown on a dyno and ripped on and work perfectly fine with no catastrophic failure. What you really need to do is to find the source for the spun bearing and fix it before it happens a third time. Has your front case/oil pump been replaced recently? If not now is the time to do it right, replace that sucker. Make sure you have a guarantee of proper oiling from here on out. Good luck. Feel free to contact me further if needed.

 

[TSIfreek]

Yea the motor will need to be pulled out and cleaned again since it has some debis in it. Throw that crank away and get a new one or have a good core and make sure its machined coorectly if you do go this way.
The engine breakin and oil you used has no effect on your problem it would have happended anyway. Remember the crank runs on a thin layer of oil not the bearings themselves.
Make sure the rod caps are installed corectly and the oil clearance checked. If your not sure have a good reputable dsm shop do it.

 

[Musashi450]

Unfortunatly I dont know of any reputable shops in the area that work on DSM's. Honestly the budget is only allowing me to take care of this myself (I'm ok with that, I'm very comfortable around an engine; inside and out) On the issue of turning the crank, I've been doing some research on the subject and the nitride coating that Mitsu provides is suppose to me up to .020 thick. Furthermore I can't understand how a coating that would help the stength of the crank have any affect on the rod bearings. I was reading some posts from a slowboy rep and they are using reground cranks to make 700+. I understand that this is controversial territory but I really dont believe that a reground crank is the problem assuming that the crank is ground right and the clearances check. I would LOVE to be proved wrong at this though because it would be a simple answer. Again though, why then so bad on just cylinder 1? All rod journals were reground along with the mains. Once I get the engine out, I'll grab pictures of those as well. I am indeed replacing the front case and water pump this time around. When I initially inspected it, all the gears seemed to be turning freely so I felt their wasn't a problem...I know not exactly the best inspection in the world and I learned from it. Actually what does one look for when inspecting the front case? And assuming the front case was the problem then again why cylinder 1 where pressure should be at its best!? Slowboy chime in on the cranks, I almost called you guys today on this issue!

 

[alexg1323]

my guess is the engine was not cleaned properly before reassembling or there is an issue in the oil pump. the service manual gives pretty specific directions on how to inspect the front case.

 

[andymoraitis]

I would strongly recommend that you also check the piston oil squirters on number one and number four since these have a tendency to stick open when they become clogged and reduce oil pressure. On the issue of cut cranks, I have mine cut .025 under and it came as a refurb from SBR.

Hang in there,

Andy

 

[Musashi450]

I have considered the issue of the oil squirters but in all honesty don't know enough about them and their adverse (or so I hear) affects. Time to do some research. So far, I got about half of the surrounding parts out before I called it a night. Tomarrow I'll disconnect the fuel system, upic, and take the bolts out from the transmission. I'll also upload the pictures then.
Note to self: LABELED bags for the bolts.

 

[TSIfreek]

Things that could have happened: rod cap not put on correctly(backwards), bearings / rods not spotless when assembled, improper torqueing, rod journal not machined corectly, debis in the oil system, crank not ground perfecly round. It can be alot of things I am just thowing some things out there.
Thing is the rod bearings get there oil from the main bearings so the #1 main bearing should also be looked at as far as if there were any debris in the system or possibly some maching debris got left in the crank oil passage ways causing the problem???
Yea if you want post some pics of the bearings as they were in the engine. To early to tell yet so dont jump to conclusions.

 

[Musashi450]

So I figured I would enlighten everyone reading this with an epiphany I just had. I decided to run downstairs and go look for the oil squirters. Turns out I couldn't find ANY looking from the underside of the block. I'm thinking wow that's strange. This engine was one of those JDM engines after the one a had a lonnnnnng time ago decided to lose all its radiator fluid and warp the head.

I went back and looked at the papers from when I bought the engine probably about 5 years ago and to my surprise is says 6 bolt 4G63T on it!! I then remember when I had Mitsubishi put it in that they had said something about the crank not fitting and so they took my old crank (7 bolt) and transferred it to the new engine along with some other parts! The problem is I have NO idea which parts. Still now maybe I'm getting somewhere. I have a 6 bolt block, without oil squirters (Weren't these N/T's though?) with a transferred 7 bolt crank.

Are the measurements for these both these cranks the same with the exception of the flywheel bolt pattern? I think what I'll do now is buy a 6 bolt crank and a new flywheel and hook it up. Then buy all new std bearings, front case, and water pump and put it all in. Its 3 in the morning so sorry if this post is somewhat out of order.

Edit: Ok so now I'm officially confused. It is indeed a 7 bolt because the oil pan that fits up to it is a 7 bolt.

My guess is that Mitsu used my old shortblock and crank while taking the JDM head. I appreciate them throwing away my engine. Alright so anyway I'm still confused about the fact that their are no oil squirters. I must just not be seeing these things. Does someone have a detailed picture as where to find them because I haven't found them yet. Thanks!

Alright I didn't realize how different the 1G oil squirters were from the 2G's. Does any one have any good methods for cleaning them out in case they get clogged?

What about replacement oil squirters, I haven't seen any.

Regards,
-Chris Lawrance

 

[Musashi450]

Hello all!
I posted a problem I had a while back spinning a rod bearing on cylinder 1. I had recently rebuilt the bottom end and while tuning I started to hear a knock right after the car was seeing intermittent boost (ie. WOT, coasting, WOT, coasting, etc., was checking boost spike and creep)

After taking the engine out and to the machine shop it showed that all the other bearings had been worn including the mains, especially the thrust surface of main 3 (thrust bearing). He thinks that the problem was low oil pressure on startup however the pump was primed by cranking without spark or fuel. After reading, I've decided to change this process the next time around by spinning the pump with a drill. Still though, the fact that rod 1 had spun confused me with his theory, because that should theortically have the highest oil pressure.

I then thought maybe that an oil squirter got stuck open. I was again proved wrong when the machinist said no oil squirters were present (?! this was a JDM engine that I had installed a long time back before I really knew what I was getting myself into. The rods themselves have oil squirters in them. I believe its an EVO III bottom end but would need a Japanese CAPS program to verify this. Still I'll be double checking this when I go to deliver some parts.)

I then became aware after some reading that the filter is bypassed during high loads. Another important fact is that I dont remember the person that was helping me with the rebuild ever aligning the thrust bearing. This with a 2600 (we'll ignore the fact that its a 7bolt all together since I don't know the type of metal the EVO III bottom ends were made of) is gonna equal a walking crank. I'm thinking that the thrust bearing was wearing down and causing oil contamination which was being picked up by the filter however, once higher loads were seen during the tuning process, the filter was bypass, and spun rod 1 (being closest to filter).

This works for me but I need others that are more experienced with rebuilds to chime in and tell me whether this is actually likely. Also I need to know how quickly a misaligned thrust bearing can cause walk. Before the first rebuild their was no sign of crankwalk and the play was without service limits.

Thanks all

 

[95blackGsTurbo]

A misaligned thrust bearing will cause all sorts of problems. On any rebuild you always replace all of the rod and main bearings, check them for the proper clearance, check the crank for endplay and polish the crank. Without doing all of these you are asking to have something go wrong. If I am reading right, #1 bearing went out and you only replaced that one? I'm hoping that isn't the case. Also if the machine shop misaligned ANYTHING I would never take it there. We get paid a lot of money for a reason. Something like that should have been caught WAY before that motor ever saw a car. Also did you break it in properly? Regular oil, no synthetic and did you prime the system properly? Did you see oil pressure before you started or just start it and hope oil pressure builds?

 

[92awddsm]

Can you get a picture of the bearings?

We can all sit here and guess but the bearings will tell the truth. Was the #1 rod reconditioned last time the bearing was spun? Was the block hot tanked and oil galleys brushed clean in both the head and block? If you did not clean the oil galleys in the head, it could have still had debris from the last bearing problem which could have circulated through the block and killed the new bearings.

There are numerous other things that could have happened so the pics are really important.

 

[Musashi450]

Sorry if their was confusion in the last post.

No, all of the rods and main bearings are being replaced along with the crank, front case, water pump, and timing pulleys that I didn't get to the first time.

Previously the oil pump was packed with grease and the engine was turned over without spark or fuel but I don't believe we had hooked up the sender yet. I now realize that this wasn't very smart and plan priming via the hand drill method and at least wiring up the stock sender harness to check for pressure.

Another possible problem (although not as major) is the fact that it was started up with regular oil but switched to synthetic in probably 20 miles. This process has been a very expensive lesson in what not to do which is why I'm spending the time this time around to research and not rely on a friend. I'm also having the machine shop put together the bottom end this time around instead of doing it myself.

I'm not completely 100% sold on a "break in procedure" just because I've read so many contradictory posts which say to take it easy while others say to intermittently give it hell to seat the rings.

I can't get pictures until next week when the machinst comes off of vacation but I definitly plan on getting them then.

The bearings that I did see: 1 was down to copper in the center (appeared to be a lack of oil) while all the other rod bearings showed advanced wear down to the second layer (shiny aluminum). Unfortunatly I have not seen the mains yet.

I had only brought in the bottom end for them to hot tank and washed the head myself and and cleared out the gallies but never put a brush so I may have them hot tank the head as well. Before the previous machine shop had hot tanked and cleaned both.

 

[92awddsm]

I can't get pictures until next week when the machinst comes off of vacation but I definettly plan on getting them then. The bearings that I did see: 1 was down to copper in the center (appeared to be a lack of oil) while all the other rod bearings showed advanced wear down to the second layer (shiny aluminum). Unfortunatly I have not seen the mains yet. I had only brought in the bottom end for them to hot tank and washed the head myself and and cleared out the gallies but never put a brush so I may have them hot tank the head as well. Before the previous machine shop had hottanked and cleaned both.

Is the wear even all the way around the bearing or just in the center of the top and bottom halves? Are they grooved or mainly smooth even wear? Again, was the original spun rod either replaced or reconditioned?

As for the head, make sure it gets a good cleaning and clean the lifters following the proceedure in this link. http://www.vfaq.com/mods/lifters.html

Bearing shavings can be forced back into the oiling system without ever making it to the pan. If #1 rod bearing fails, it can pass shavings into all of the other rods and mains and into the head and lifters also. It is very important for everything to be absolutely clean before reassembly. Pay close attention to all of the oil galleys and bearing feed holes while cleaning.

 

[Musashi450]

Is the wear even all the way around the bearing or just in the center of the top and bottom halves? Are they grooved or mainly smooth even wear? Again, was the original spun rod either replaced or reconditioned?

On rod 1 it was just in the center. Further wear could be seen down to the aluminum around but with copper in the center (the width of the oil feed in the bearing). As far as the other rod bearings are concerned they had even wear down to the aluminum on all 3. Again I haven't seen the mains but I was told that they are all word down (I believe to the copper) with advanced wear on the thrust surface. The machinist also stated that they were worn down on the bottom bearing. Sounded odd but I may have misunderstood him and figured I would see for myself when I come in to drop parts off.

 

[92awddsm]

On rod 1 it was just in the center. Further wear could be seen down to the aluminum around but with copper in the center (the width of the oil feed in the bearing). As far as the other rod bearings are concerned they had even wear down to the aluminum on all 3. Again I haven't seen the mains but I was told that they are all word down (I believe to the copper) with advanced wear on the thrust surface. The machinist also stated that they were worn down on the bottom bearing. Sounded odd but I may have misunderstood him and figured I would see for myself when I come in to drop parts off.

You still havent told me weather the #1 rod was reconditioned(resized) or replaced when it originally spun. With the wear in the center on the top and bottom halves, that leads me to believe that the big end isnt round. If that is the case, it is probably what caused all of the other damage.

 

[Musashi450]

completely read over the question, sorry about that. Yes the rods and crank were recondition however the machine shop which I took it to this time confirmed that all the clearances were in spec and ruled that out.