Mi16 Bottom End - Fubar'd Or Salvageable

[M@tt 77]

Well i won't know till tomorrow when the car is recovered back to my house but would anyone like to place a bet on how bad my mi16 bottom end is going to be after something let go at 110mph on my own private motorway this evening and proceeded to make quite a bad knocking sound.

 

I started hearing a knocking noise above the sound of the radio and the standard engine howl after a couple of minutes giving it some. The coolant temp and oil pressure gauges were both reading OK so i initially though the exhaust manifold might have cracked and it was a loud ticking because of that, so i listened for a few seconds but then it became quite apparent it wasn't that.

 

Luckily I was right on the turnoff for Newport Pagnell services so i swiftly pulled in but as i braked and slowed right down for the corner the oil pressure plummeted and Stop and Warning lights came on. Not good

 

I switched her off as i didn't really want to do anymore damage and she wouldn't start again anyway as the starters fooked. So i phoned the recovery people who luckily were based at the very services i pulled in at, only bugger is that they didn't have any drivers available to recover me back to Sheffield there and then so i got a courtesy car FOC and they'll bring her back up tomorrow.

 

so do we reckon its a regrind and some new shells or that it's proper fooked? answers on a postcard

Edited September 7, 2007 by M@tt

[Henry Yorke 269 3 Cars]

Gut feel is a spun shell as so often is the fate of the 1.9 Mi16 Fingers crossed though it is something stupidly silly like a lose hose or alternator belt etc

[Miles 331 1 Cars]

If the STOP light and oil pressure guage went, I bet there could be a hole in the block or looking on the brighter side the crank will be dead along with the rod or rods that have spun the shells

[allanallen 528 2 Cars]

£10 on no.4 shell spun.

 

bad luck though old chum, you could drop that turbiner in though!?!?

[M@tt 77]

Sorry should have said that the oil pressure dropped to nothing when revs was about 2k but would come back up if i revved her a bit more. Also i checked and there was no leaking oil as far as i could tell so dont think it's blown a hole in the block foryunately.

 

So probably just f***ed internals in that case then, oh joy.

 

I'm sure this is a sign to V6 the bad boy

[Toddy 7]

Hope its repairable mate!, I have a std 1.9 crank if its any use once you have diagnosed the problem.

[Henry Yorke 269 3 Cars]

The Yorks group will get the lamp post lover on the road again!!

[Miles 331 1 Cars]

V6's are the way forward, Mine has been me proof!!

[James_m 0]

Why do they do this so often? IIRC this was a rebuilt engine M@tt? Surely a motorway should be the most stable enviornment for the bottom end, with no real corners (i assume) to upset the oil pressure, why would there be enough metal to metal contact to spin a shell?

[M@tt 77]

It's got me stumped as yes i've done about 6k on it since i rebuilt it completely, granted it was by me but i folowed all the instructions and torque settings to the letter.

 

It was at about 5.5/6k for a couple of minutes before i noticed it, however it had been to curborough the week or so before and the oil was a little low which i only noticed after my first couple of laps. I then topped her up to the full mark for the rest of the day so i wonder if that had anything to do with it. :S

[M@tt 77]

Right well shes back and i spent this afternoon whipping the sump off to inspect the damage.

 

Once the oil was drained and the sump was off it was pretty apparent it was going to be a shell due to the debris found in the bottom of the sump

 

I thought i'd check the Mains first of all so i removed each of those in turn. There was some wear to th ebearing surface but nothing too major i dont think and the crank journal faces were spotless which was a good sign.

http://img.photobucket.com/albums/v230/meb...ll/DSC00082.jpg

http://img.photobucket.com/albums/v230/meb...ll/DSC00081.jpg

 

so then it was onto the big ends i gave them each a shake inturn and none of them really moved with the exception of number 3 which wobbled all over the shop, bingo!!. So i cracked the cap off and found the bearing was about 90 degrees from where it should be.

http://img.photobucket.com/albums/v230/meb...ll/DSC00094.jpg

http://img.photobucket.com/albums/v230/meb...ll/DSC00093.jpg

http://img.photobucket.com/albums/v230/meb...ll/DSC00091.jpg

 

The crank journal surface looked spotless again, which raised my hopes slightly but i'm not sure what other unseen damage there is.

 

So i now need some opinions on what's the best thing to do. Do i need to take the crank out to have it checked? or is there anyway i can do it with it in place. Also what about the conrod does this need removing or could i check it in situ somehow.

 

Also i really want to know what caused this, i saw from an old post that someone else who had a spun bearing was asked was it the same cylinder as mine 2nd from right from flywheel end so is there a particular problem with thjis cylinder to make it more prone to problems?

 

Cheers

 

Matt

Edited September 9, 2007 by M@tt

[Miles 331 1 Cars]

Those main bearing's look quite bad and you may have had some dirt floating around in the block, Or the wire from the oil tower as they never really give any problems for at least 100k and even then they should look clean.

It is odd why number 3 is normally the one to give problems,

Did you plasti Guage when you assembled the engine?

[M@tt 77]

Nope i didn't plastiguage them when i built it i had the crank checked by an engineering place and they said it was all within tolerances. and it was installed with new shells.

 

What would you suggest i do? Do you think it's definately a crank out job? Judging the state of the bearings would it be worth while replacing the main bearings as well?

 

Cheers

 

Matt

Edited September 10, 2007 by M@tt

[Miles 331 1 Cars]

As Darren's said on the PSOOC, THe main's could be out of line which isn;t uncommon as the blocks warp and need line boring to get them true again, you'll be surprized how much differance this makes when you experance it.

Each engine and build are different as is the tolerances,

[Stonesie 0]

You might be able to salvage that rod by haveing it honed, the company i used to work for could do that but they didnt have line-boreing equipment (B&H Autokraft)

 

As has been said it looks like theres been a fare bit of debris in those mains, especially as theyre only 6K old, if you get away with a bottom end re-build make sure everything is clean and blast all the cleaned oil ways with compressed air just before fitting.... theres no such thing as too much assembly lubricant, oil just won't do. Your chosen engineering shop will be able to provide some

[pugman211 0]

forgive my stupidity, but what is plastiguage?

[Stonesie 0]

no stupidity involved fella, ask me about computers and you get ,

 

It's a thin bit of soft plastic, you put it between the bearing and crank in this case and torque the bearing cap down as normal, then take it apart and the plastic will be squashed flat.... compare how wide it is now to the chart you get with it and that tells you what the 'running clearance' is (the space that the oil has to fill)

 

 

This has some good pics of what i mean...... http://www.iroczone.com/projeng02.html

Edited September 10, 2007 by Stonesie

[M@tt 77]

Well after 2 solid weekends, just short of £300 and a pair of hands that look like those belonging to a blind blacksmith later my Mi16 is back on the road

 

All went fairly smoothly except for a small coolant leak which caused a bit of headscratching. She started on the first turn of the key and sounds nice and healthy once again although i think the timing belt might be a bit tight as i have a bit of a whine on it which i'll look at once .

 

A big thanks to Graham(Pugtorque) for the new piston rod, J_Turnell for sorting me out a new crank and Henry Yorke for taking it to the machine shop for me.

 

I took quite a few pictures as i went along which i'll hopefully write up into some sort of how to at some point.

 

Replacing a crank in situ is NOT a fun job at all so let it again be a warning to anyone with a Mi16 to seriously check and change your oil regularly, i've learnt my lesson!!

 

my pics are here for anyone who's interested

http://smg.photobucket.com/albums/v230/meb...I/Spun%20Shell/

Edited September 25, 2007 by M@tt

[pugman211 0]

Holy Crap!!!!

 

That big end in the video clip was proper goosed!!!!!!!!! Well done though for doing it all with the engine in situ. Any idea what actually caused the fault though????

[j_turnell 134 3 Cars]

Glad you got it sorted out feller.

[Henry Yorke 269 3 Cars]

Bish Bash Bosh - Crank Done

 

Just ready for the move now!! Oh and do you have 1000 miles of running in to do or is it just for piston rings you have to do that?

[pug_ham 242 3 Cars]

Glad you sorted it out Matt, only to happy to help.

 

Ready for running in with a car full of house stuff for the move.

 

Only need to run rings in for 1k afaik but take it easy for a few hundered to bed the bearings in.

 

Last set of bearings I fitted (to my 8v) got about 70 miles running in before a trackday at Croft a couple of years ago. Engine is still going strong now after a good few more trackdays.

 

Graham.

[James_R 3]

bearings don't really need running in as such, just a quick spin then change the oil to get the cr*p out done

 

Amazing turn around on this Matt good job hope you have many miles of joy with it

 

Did it spike it's oil temp suddenly on the motorway??

[M@tt 77]

The failure i'm pretty sure was due to Curborugh track day the weekend before with low oil. I foolishly hadn't checked the levels before i started and it was below min. I think hammering it round the sharp bends was probably just enough to set it on its way. The engine certainly "felt" a bit different that following week although i couldn't quitre put my finger on it and there were no disernable knocking noise.

 

There was no temp spike that i noticed either and in fact the oil pressure seemed to be holding up well when it did let go it was just when i slowed right down after hearing the knocking that the warning lights came on.

 

The timing belt definately needs sorting as i took it for a quick spin last nigth and it sounds like its supercharged

 

Now i've just got to sort the pissing knocking noise i've got from my suspension i think the rubber donuts moved from ragging the strut about when pulling the driveshafts out as the top metal inner cup is now at a funny angle and looking like its hitting the top mount plate.

 

And my drivers side central locking motor has given up the ghost as well i'm pretty sure

Edited September 26, 2007 by M@tt

[GLPoomobile 958]

The failure i'm pretty sure was due to Curborugh track day the weekend before with low oil. I foolishly hadn't checked the levels before i started and it was below min.

 

I got so much stick for driving back from Edinburgh to London with a dodgy oil pressure signal and no warning light!! Glad it's not just me who's a bit irresponsible