• Please only use these forums for blogs, they are not a discussion forum

PollyMobiles Rebuild

Stani1029

Club Member
Paul says the cylinder walls are wet though so surely its that oil thats being burnt so its a bore or oil scraper ring issue
 
OP
OP
pollyp

pollyp

Club Member
ok I popped over to a friends for dinner to take me mind off the subject n get myself together.

to keep the blog in order this is what happened..

Sat 25th May

16:05
car assembled back together, forged engine ecu map uploaded, O2 sensor plugged in to correct idle mixture, primed oil n fuel n started her up


the oily cylinder made startup abit lumpy for few secs as usual as she clear her throat, 2k rpm idle cleared her up.
coolant is clear of bubbles. no major leaks yet and mixtures good. ok lets get her out n start break in asap.

@ 10:00 a gentle low rev light throttle pulse & glide drive through town to warm up towards the country road.
@ 22:00 on the country road i begin 1/4 - 1/2 throttle 2-3k pulse n glide, smokes badly. according to motomans guide I have 20miles to bed the rings in before oil change.
@ 28:00 raise upto 4k 1/2 throttle, at 30:00 I stop to check things and there's an awful oil leak round the pulley area, like dripping. hit traffic at 39:00
@ 48:00 raise to 6k 3/4 throttle

20mile, pistons still oily, plugs very sooty from the rich WOT, check compression and reads 10.9 11.2 11.4 11.0bar
change oil.

hows bads the leak?, this bad v v

DSC08322.JPG
DSC08323.JPG


18:18
changed oil
round two with WOT going up the rev in 3rd from 4k, 5k, then 6k
look at the smoke


so 40m into the break-in the pistons slightly less oily and compression is 11.0 11.2 11.4 11.1bar

20:10
fuelled up. resume WOT pulse & glide 4-6k for another 10m


21:00
reset the camera incase the battery ran out. slightly less smoke? or perhaps there's no sun to highlight it


21:30
the big oil leak is lowering the oil level and can't easily determine the level on a hot engine so to prevent starvation I tipped in the little bit I had remaining and make my way home

 
Last edited:
OP
OP
pollyp

pollyp

Club Member
Sun 26th May

12:17
cold oil level at 3/4, pistons looking just damp n rough now. cold startup once again rough to clear the oily cylinders. but something doesn't sound right. It sounds like a friggin diesel transit under load?

geez checkout the oil pouring out of the sump gasket at 12:00 during high-rev deceleration :eek:


12:55
check oil level tis fine. exhaust camera didn't record. RH lower engine bay totally soaked. still smokes under load

and then at 16:30 during high rev deceleration all the electrics died!
dash off but clock backlight still on, wideband off, no lights or indicators and prob no brake light but engine still works. WTF

pulled over

checking fuses including banging the dashboard, found the engine bay 65a battery fuse had blown, good thing I carry 1 spare

13:10
resume hard break-in only for the last fuse to blow again 4mins later oh FFS. car behind, drive afew miles with no workings lights till the nearest slip road


now what, got no more 65a fuses but got a 30a green fuse block. so took awhile to pry apart the 30a fuse n stick it onto the blown 65a fuse terminals.

13:30
switch on and yes we got ignition, lets get the heck home

few secs later boof the little fuse and electrics go out again! oh FFS lets just get home, even without lights. was interesting driving with no manners


right I'm home and fed up n don't trust the girl.

compression after 130miles says 10.8 11.2 11.4 10.9bar same as the first time. piston still damp.

Stani: they're new rings, new bearings, honed block, rings gapped to spec.
totally clued cos everything was built to spec this time and yet it still gets oily smoky pistons like the other 2 times I ran this blimey forged piston before. except this time I don't have the thick sooty fairy dust particles.

I honesty just need to know from an experienced expert, is this oily/damp forged piston with slight smoke a normal sign with this much miles and will improve? or will I be wasting fuel/oil/time/money/energy and should just resort back to fixing the stock engine or get another stock engine as backup?

or worst case is abandon the turbo project

Will: I just checked the intakes incase oils getting via the PCV but nope tis all dry

DSC08324.JPG
DSC08325.JPG
DSC08326.JPG
DSC08327.JPG
DSC08328.JPG


Enuo: both stock and forged engine now have new stem seals

personal situation is:
  • have until june 16 till moms insurance re-new, £200 for another year on top of my current £550 sky insurance
  • cancelling sky insurance early will only give me back a tiny amount of less than £300 last time I checked
  • busy at work and need a car for networking n meetings n events
  • buying another stock used car requires extra time, effort, money, insurance quotes, fuel, etc etc
  • throwing all the towels in and starting from scratch would be the easiest choice as an outsider but at a massive loss financially and emotionally. will never ever recover the investment back as a known fact.

the most logical and least stressful option I think is:
  1. to fix the massive leaking sump gasket (stop the bleeding)
  2. continue the hard break-in (continue the long recovery stage after major surgery)
  3. see if the burning oil subsides over the coming miles (monitor if the patient recovers health)
[thats a nice medical analogy eh]
 
Last edited:
OP
OP
pollyp

pollyp

Club Member
a brief youtubing seem to suggest that the cold diesel-like sound is abit of piston slap from the cold loose forged pistons, which would normally expand out tighter under intense trackday heat, hence forged maybe unsuitable as a daily car?
 
Seems to make sense. As aluminium expands faster than most metal so it should close the gap as the engines warmed.
If your block is aluminium it will expand at the same rate to a certain extent leaving you with excessive gap still :(
Wouldn't say you need track day heat :confused: An engine should only get so warm because of your cooling system? So potentially overcooling? Keeping the engine too cool for the pistons to expand. At the simplest anyway
Or a rebuild again at the worst. Steel sleeves to stop the cylinder walls expanding away from the piston?

I hope what I've wrote makes sense :)
 

frank

Club Member
mine has that diesel like sound sometimes if i jab the throttle @ idle paul (the corsa piston engine and this untouched stock CGA3) its just the sparkmap i think mate (running plenty of advance at low load)
and my corsa piston engine smoked on 1st build if you remember, and i thought "running in" the freshly re-bored and honed bore would bed the rings in, but no chance :( and it was only when i stretched the expander rings so that the ends touched (you can see a 2mm gap in the pic below), and i could feel the oil control rings actually bite into the bores, that it stopped smoking instantly ,
you can see on arnold,s mallory vid that mine was,nt smoking eh (till i cooked the engine :D)
and stani,s was blowing that fuse when his nistune board was shorting on the ecu casing iirc

P5151030.JPG
 

frank

Club Member
I love the ending to your post frank..
Ah well cooked an engine.. built another :D
aye, the previous CGA3 engine had already been re-headgasketed (just incase :D) we,re down to 1 car now, so i have to always have a spare engine ready to drop in :)
 
OP
OP
pollyp

pollyp

Club Member
Seems to make sense. As aluminium expands faster than most metal so it should close the gap as the engines warmed.
If your block is aluminium it will expand at the same rate to a certain extent leaving you with excessive gap still :(
Wouldn't say you need track day heat :confused: An engine should only get so warm because of your cooling system? So potentially overcooling? Keeping the engine too cool for the pistons to expand. At the simplest anyway
Or a rebuild again at the worst. Steel sleeves to stop the cylinder walls expanding away from the piston?

I hope what I've wrote makes sense :)

these forged pistons are prob a different type of Alu and could expand at a higher rate than the block and steel liners, hence why JE recommends more piston-bore clearance as the power/heat increases.

the intense combustion heat (higher up the power/torque curve = more heat generated) is transferred to the block, head and pistons. on trackdays u spend more time at the high end.

the block and head is directly cooled by the 80-90C coolant and brief cool intake air and maintained by thermostat and oversized radiator. its maintained at 80-90C to balance the most combustion efficiency before the oil starts to degrade or the metal deforms so shouldn't usually be over-cooled unless u intentionally remove the thermostat.

the pistons on the other hand are only cooled via conduction through the thin rings to the bores and the hot oil spray underneath and briefly by the cool intake air so will become hotter than the block.
 
OP
OP
pollyp

pollyp

Club Member
mine has that diesel like sound sometimes if i jab the throttle @ idle paul (the corsa piston engine and this untouched stock CGA3) its just the sparkmap i think mate (running plenty of advance at low load)
and my corsa piston engine smoked on 1st build if you remember, and i thought "running in" the freshly re-bored and honed bore would bed the rings in, but no chance :( and it was only when i stretched the expander rings so that the ends touched (you can see a 2mm gap in the pic below), and i could feel the oil control rings actually bite into the bores, that it stopped smoking instantly ,
you can see on arnold,s mallory vid that mine was,nt smoking eh (till i cooked the engine :D)
and stani,s was blowing that fuse when his nistune board was shorting on the ecu casing iirc

thx v much frank.
so do you think I'm ok to carry on the break-in and the Top & 2nd rings will bed in fine (compression seems nice n even) before I get to take out the pistons and stretch the expanders? or will the excess film of oil passing the oil rings hinder the upper rings progress?

I've not visually checked the expander in the bore last time tbh but when I tested the oil ring drag force (7kg?) against urs it did seem rather a lowish figure.

so I think plan of action for the next 2 weeks before moms insurance renews is:
  • reseal the damn sump,
  • continue hard break-in till 1000-1500m and see if the smoking & oily piston top improves,
  • if not, remove pistons and stretch the expanders and check smoke again,
  • if still smoking/wet, bin the engine.

I'll recheck the nistune board and battery lines cos it blew the fuse only during higher revs/vibrations.
 

frank

Club Member
7kg should be plenty paul, mine were 2kg before and 4 to 5kg after (but that was with the piston half inserted upside down, without the skirt friction and purely oilring friction tho)
my compression was always fine regardless, and with the old cast iron 1 piece oil control ring there were no problems years ago (they were just as springy as the 2 compression rings)
but these 3 piece ones rely on the tiny feet at the bottom of the expander ring to physically "push" the 2 oil control rings into the bore eh
 

frank

Club Member
here are the bores on the 72.5mm corsa piston block (for reference) paul :) loads of honing marks still visible, after 1 week of commuting, and mallory

P5271090.JPG
 
OP
OP
pollyp

pollyp

Club Member
7kg should be plenty paul, mine were 2kg before and 4 to 5kg after (but that was with the piston half inserted upside down, without the skirt friction and purely oilring friction tho)
my compression was always fine regardless, and with the old cast iron 1 piece oil control ring there were no problems years ago (they were just as springy as the 2 compression rings)
but these 3 piece ones rely on the tiny feet at the bottom of the expander ring to physically "push" the 2 oil control rings into the bore eh

ah looking back it was actually only 2.5 - 3.5kg so maybe I'll have to tweak them in the future

http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-78#post-583611

when my m8s finished using me endoscope I'll check if the bores are still honed
 
these forged pistons are prob a different type of Alu and could expand at a higher rate than the block and steel liners, hence why JE recommends more piston-bore clearance as the power/heat increases.

the intense combustion heat (higher up the power/torque curve = more heat generated) is transferred to the block, head and pistons. on trackdays u spend more time at the high end.

the block and head is directly cooled by the 80-90C coolant and brief cool intake air and maintained by thermostat and oversized radiator. its maintained at 80-90C to balance the most combustion efficiency before the oil starts to degrade or the metal deforms so shouldn't usually be over-cooled unless u intentionally remove the thermostat.

the pistons on the other hand are only cooled via conduction through the thin rings to the bores and the hot oil spray underneath and briefly by the cool intake air so will become hotter than the block.

Very true some swap out their thermostat for cooler opening ones too.
Just throwing ideas at you. Do you know what type of alu piston you have? 4032? 2618? The type affects their heat/expansion coefficient. Depending on their silicon percentage.
If JE are recommending a larger gap then I'd say they're 2618 their low silicon percentage allows for more heat expansion iirc. 4032 are the other way round. Could be worth looking into ?
 
OP
OP
pollyp

pollyp

Club Member
Very true some swap out their thermostat for cooler opening ones too.
Just throwing ideas at you. Do you know what type of alu piston you have? 4032? 2618? The type affects their heat/expansion coefficient. Depending on their silicon percentage.
If JE are recommending a larger gap then I'd say they're 2618 their low silicon percentage allows for more heat expansion iirc. 4032 are the other way round. Could be worth looking into ?

welcome ur ideas. i believe they're 2618 type so need bigger gap
 
OP
OP
pollyp

pollyp

Club Member
well change of plans

was just about to go out to warm the oil before draining the sump and fix the leak but the battery fuse decided to blow again.
replaced it with the last one and that blew too WTFH is causing it?

disconnected the battery and the engine dies so the alternators not providing charge (could be cos of the blown battery fuse).

while running, the battery reads 12.5v so definately not charging.

measured the alternators terminals directly and 0V? surely even with a blown battery fuse the running alternator should be outputting? so could it be a faulty alternator thats blowing the fuse? can someone measure their stationary alternator terminal resistance so I can check if mine has somehow shorted out?

also that bloomin black rich soot dust that I experienced in the last 2 attempts of running the forged engine has returned.


fckin cursed JE forged pistons.

now transport & insurance wise, no point in rushing to try fix the car within 2 weeks before moms insurance renews, tisn't gonna happen.
and no point spending extra time n effort n £300+ buying a used standard micra n tell sky to change car.

I'm gonna simply renew moms insurance another year with myself (I pay £200) and continue using her car for work. meanwhile my cars taking low priority
 
Oh ok :) if I think of anything else (before frank of course) I'll let you know
Cant help with the alternator though bud.. unless you want any alternator reading? Not just a cg one
 

frank

Club Member
my alternator terminal is 13v ign on or off paul, i would have to disconnect it to measure the resistance ?
and you hav,nt trapped the alt wire when fitting the inlet mani have you ? (been there done that :D)
 
OP
OP
pollyp

pollyp

Club Member
preferably the same type of alternator but suppose any might do as a reference.

mine measures 92.3k ohm
edit: oh hang on, forgot to unplug it. just a sec...
 
OP
OP
pollyp

pollyp

Club Member
frank:
naa the inlet mani was already assembled n fitted the engine then feed the loom through beneath the mani.
electrically its been running spot on until the last few miles during high rev runs.

I unplugged the alternator as u said n remeasured it at 85.4k ohm, ok so least its not completely shorted

DSC08329.JPG


looked down n noticed the bottom of the alternator is fouling the turbo elbow, this could be the short? last time this happened, it was sparking n smoking, I had to reposition it away slightly

DSC08330.JPG


ok so checked if its loose, looked up and oh my well there's ur problem. no wonder the alternator belt appeared loose

DSC08331.JPG


So i suppose what happened was the prolonged intense high freq vibration from revving so high during break-in (and previous trackdays) had eventually caused the weak little alternator bracket thingy to fracture, allowing the alternator to drop, the electrical terminal pin thing penetrates the heat wrap and touches the turbo elbow, sparking and shorting out the charging loom which blows the battery fuse repeatedly.

well thats a relief that its not caused by the relocated battery cables or the ecu grounding.
 
Last edited:
OP
OP
pollyp

pollyp

Club Member
ok so just have to make a better alternator bracket bit and reseal the sump.

btw I'm out of 65a battery fuses. other than scavenge the scrappy where else can I buy a whole bunch of them big black fuse blocks for cheap?
 
OP
OP
pollyp

pollyp

Club Member
Nice spot paul. Hopefully thats perked you up a bit :D

yeah good thing I decided to remove the turbo inlet pipe to access the alternator better otherwise I wouldn't of spotted the obvious fractured bracket. its a relief and one less thing to worry bout and made me less depressed
 
OP
OP
pollyp

pollyp

Club Member
fuses have arrived

DSC08332.JPG


the downpipe side of the new gasket seals fine but the turbo elbow side appears to leak abit

DSC08338.JPG
DSC08339.JPG


well sump off again. removing it is a pita. hammer a screwdriver at the corner to pry it off, the sump lip will need abit of reshaping

DSC08333.JPG


small bits of sealant blocked by the pickup mesh

DSC08334.JPG


hmm most likely not enough sealant. sealing the sump is such a pain. gotta make sure its proper flat and smear alot of sealant on this time

DSC08335.JPG
DSC08336.JPG


only been 200miles and the oils quite dark, prob collecting alot of carbon/blowby

DSC08337.JPG
 
Last edited:
OP
OP
pollyp

pollyp

Club Member
scraped all the sealant off and sanded the lip down to bare metal

DSC08340.JPG


the edge where I've been prying the sump off is quite bent

DSC08341.JPG


well no surprise why its leaking, the front lip isn't flat

DSC08342.JPG
DSC08343.JPG


after few mins of hammering the edge flat n level, to check if its flat enough I smear some grease on the lip to represent the sealant

DSC08344.JPG


place a flat piece of glass over it and can now see if most of the lip is flat n level. needs more tweaking

DSC08345.JPG
DSC08346.JPG


the edge of the lips aren't flat so corrected it with a spanner

DSC08347.JPG
DSC08348.JPG
DSC08349.JPG


meh good enough

DSC08350.JPG


smear a thick layer of sealant all over

DSC08351.JPG


bolted the sump up all tight. it has to seal good this time

DSC08352.JPG
DSC08353.JPG


meanwhile the LH CV boot has loosened and spewed grease around so needs re-tieing
and the oil leak has sprayed oil ALL around the RH wheelarch and appears the brakes could be contaminated. I'll clean it up n soon see if can be saved or if it all needs replacing.
 
Last edited:

Enuo

Glorified Electrician
If you want to get that perfectly flat you shoukd try with engineers blue and a scraper eh
 
OP
OP
pollyp

pollyp

Club Member
just flat enough to let the sealant fill the rest. it was well offset so needed alot of bashing but is done now
 
OP
OP
pollyp

pollyp

Club Member
tday I was having a short evening nap cos had a slight headache and had a nightmare which started off with me parked by some street and few of u guys roaring past, particularly urs Chris in a partially painted white/grey (prob from when u were hand testing the grey paint), and someone in the passenger seat.

I then primed the fuel n wideband, started her, struggling abit prob cos of oil in cyl so raised revs to clear it out, then began blipping up down to warm up.
then next minute big black smoke n some sparks in the mirrors!

shut off, look under and blimey saw some big pieces of bigends etc scattered about on fire, me trying to blow it out lol.
look in engine bay and wondered where the hecks the engine? oh its upside down underneath (wtf)
then the fire engine came along cos of fire.
then me muttering how on earth I'm gonna get it home cos got no recovery service then woke up :/

dunno what the hecks my brain worrying bout, prob envisioning the worse that could've happened recently and saying don't mess it up n get breakdown cover?
 
Dont eat strong cheese mate :p and chill more, youre doing great work and its really inspiring to see you going so far with it :) (breakdown cover is useful though :p )
 
I didn't use breakdown cover since feb 2012.:eek: I am so glad that my car is still survive since feb 2012. i think i should get breakdown cover for my second year soon.:oops:
 
OP
OP
pollyp

pollyp

Club Member
joe I don't eat much cheese (except only on special occasions I have a parmo up here in the north) and yeah the stress of long hours at work is prob getting to me.

jk I've never had breakdown cover since I first drove cos I usually carry my own tools n parts to fix minor things during roadtrips but the rare occasion such as my first crash, when this forged engine big end came loose etc, the cover would be nice, especially for such a tinkered car and is more likely to breakdown, should consider it.

who where you with and how much? cos I asked sky bout it and their breakdown don't cover my k11 cos its beyond 10yrs old.
 
OP
OP
pollyp

pollyp

Club Member
ok resumed progress since 9am. centre beam on, downpipe on, lower brace on, LH CV boot zipped, the RH brakes was too oily so gave em a good clean/sanding

DSC08354.JPG
DSC08355.JPG
DSC08356.JPG


made a new alternator bracket, the red colour was a bonus

DSC08357.JPG
DSC08358.JPG


much sturdier. oil primed.

lets fire her up, do afew runs and report back tonight. hope the leak finally goes.
 
Last edited:

r-reg-sr

-------
Site Supporter
nice going mate,,,,,,,,,,,,,,,,,pads and disc spoil with oil ? ,,,,,one tip boy malcolmt flung me :) put pads discs on some bricks pour a little petrol then let the zippo flick,sucks out the oil and uses it like fuel,,sort of like the brimstone/sulpher:)
 
OP
OP
pollyp

pollyp

Club Member
quick update @ 180m break-in while the videos uploading.

good news: compression seems to improve a touch and smokes less.

bad news: still gushing out oil somewhere and pistons still oily
 

SirChris

Educated Bodger
Paul... I will take your dream as a compliment. My car registers in your car radar. :D I know how you feel I have nightmares about mine and it going tits up. You will get there.
 
OP
OP
pollyp

pollyp

Club Member
so drove her out to the country road and camera shows she still smokes abit only under load but when I stopped to check, it still leaks alot of oil. where on earths it coming from? can't be the sump that I just fixed, maybe crank pulley seal?


so went back home. removed pulley and some oil spots there

DSC08359.JPG


pulley looks fine

DSC08360.JPG


the seal itself also looks like new, no signs of damage

DSC08361.JPG
DSC08362.JPG


new seal on and wiped the area clean

DSC08363.JPG


drove normally down the road for 10mins and it seemed fine, no leaks yet but then once I began to open the tap n rev higher from 12:00s she begins to leak badly once again


so during low rev low load its ok but once we increase rev n oil pressure she gushes out.

the only cause I can think of is that new oil pump timing cover o-ring seal which could be loose? leaking past the o-ring under high oil pressure and trickling down the timing cover to the lowest point.

I applied sealant all along the inner lip of the timing cover but not on the oil pump o-ring seal as mentioned in haynes but I never had this sorta leak issue before.

the original oil pump o-ring was black whereas the new ones are orange (nissan4u shows the timing cover uses 2 identical o-rings inside), so could it be wrong thickness?

I think next task is to somehow fit a camera near that oil pump o-ring area to verify that's the leak and check the timing cover bolts tight.

if it is the timing cover then its an engine out job :/

compression so far has been:
10.9 11.2 11.4 11.0 after 20m
11.0 11.2 11.4 11.1 after 40m
10.8 11.2 11.4 10.9 after 130m
11.2 11.5 11.8 11.2 after 180m

slowly improving so its still early days in the breakin-in process
 
Last edited:
Top