New re-build issues

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jambo_gtir

Member
Hi all, just rebuilt my engine (second time) and have noticed it smokes quite a bit especially going down hill. I'm guessing that this is just all the assy loob being burnt off though and the fact the rings are new and need to bed in first?
Is this normal? i dont remember it doing this the first time i re-built it :?
 
S

skiddusmarkus

Active Member
How many miles are on it and how did you run it in?

My guess is as you go down hills and are off the throttle, oil is getting past the rings and burning off.
 
J

jambo_gtir

Member
i have only done 100 miles since rebuild. I used new valve stem seals mate yes.
It's worrying my a bit...I'm hoping its nothing bad
 
J

jambo_gtir

Member
well, I have now clocked up 700km and it's still burning oil on the overrun. Took it to Brighton this weekend from Portsmouth and it seems to clear up on the motorway, but it is still doing it.
People keep telling me its ok and just the rings taking a while to bed in, did any of you guys get this?
Re-bored with CP pistons and rings (gapped to 23thou), new stem seals and gaskets.
 
bensmith907

bensmith907

New Member
I had that problem for about 1mile after rebuild then it went. Time to check the obvious-

Compression check,
Turbo inlet for oil
Maybe the breather
 
P

pulsarboby

Guest
tbh it shouldnt really be smoking at all especially after 700 been clocked up.
may possibly be a turbo seal hopefully, either that or theres a major prob with piston/cylinder

pain in the ass but try pulling the manifold away from block to see if any of the ports on the head are wettish with oil, if so then thats your problem cylinder
 
J

jambo_gtir

Member
cheers for suggestions guys, I think I'll do a compression test first then go from there. I thought if the turbo seals are on their way out it would smoke under boost?
If it is something more serious I'm driving the thing off a cliff, not taking that engine out again, had enough now.
 
J

jambo_gtir

Member
Fusion Ed said:
24 thou sounds large, was this recommended?
Click to expand...
Well thats the thing mate, on the sheet that came with the pistons, i had to work out what the gap was which came out at around 18 thou. But then going on the website and some forums and they all said 23-24 thou. The oil rings were 15 thou and it said not to touch them so i didn't.
I gapped my last rings on the first re-build to 18 thou like Nissan say, but running 1.1 bar and the Mines destroyed these, 18 thou was not enough (as was evident when i got the pistons out).
 
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J

jambo_gtir

Member
Apparently the sheet that comes with the CP pistons is not quite right and the tech support line said that the multiplier of 0.055 on the sheet is an abolute minimum and they suggested a multiplier of 0.07, which for an 86.5mm bore, comes in at 0.238....hence why i gapped them all to 24 thou.
I'm really hoping it is the turbo or something silly like a breather.... really don't want to get that shtting engine out again....
 
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pulsarboby

Guest
oil control rings you do not gap so your correct there

i normally gap the rings to 30thou to allow for expansion 'as you really dont want them closing up on you' so to be fair i dont think your too far out of spec.
weve built enough of them now at those gaps and nearlly always use cp pistons and no probs with expansion yet even on track!

are you 100% sure youve got the rings fitted the right way up (any markings, writing on top)?
also spaced gaps properly?

as said earlier.....try compression test and see if any wet oily deposits on cylinder ex ports to confirm any possible cylinder/piston probs
 
J

jambo_gtir

Member
pulsarboby said:
oil control rings you do not gap so your correct there

i normally gap the rings to 30thou to allow for expansion 'as you really dont want them closing up on you' so to be fair i dont think your too far out of spec.
weve built enough of them now at those gaps and nearlly always use cp pistons and no probs with expansion yet even on track!

are you 100% sure youve got the rings fitted the right way up (any markings, writing on top)?
also spaced gaps properly?

as said earlier.....try compression test and see if any wet oily deposits on cylinder ex ports to confirm any possible cylinder/piston probs
Click to expand...

Ok thanks for that mate, I'll give it a good check over at the weekend. I took my time re-building it and double checked everything so im pretty sure I fit them all correctly. If you gap yours to 30 thou, that's good news, thought I had done them too much.
I gapped them to 18 thou as said earlier and the engine lasted 5 months before piston 4 shit it self. When I got the other pistons out I could see the rings had closed up fully and were scoring the bores. The heat from this friction was obviously too much for the pistons to take.

Anyways, thanks for help everyone, I'll let you all know if i get to the bottom of it.
 
J

jambo_gtir

Member
Well just to let you all know, I did a compression test last night and got 11 bar on all four (160 psi) so was quite happy with that. It seems cylinder 2 was the oily one and like some of you have said it appears to be stem seals.
I will need to modify and old spark plug and use the airline trick to be able to change these stem seals in situe, not looking forward to it to be honest.

Oh and I dropped a soldering iron tip into the engine by accident and spent 5 hours trying to get it out!!! got it in the end.....lesson learnt, keep the plug holes covered when you remove spark plugs
 
J

j0ff

Member
You can get the valve collet removal/insertion tool from snap on in the uk, I think it's about £35
 
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pulsarboby

Guest
you dont need a spark plug and airline to do this, you can do it by threading nylon rope down the plug hole when shes coming up on compression stroke, get it from the £1 shop a big roll of it.
once the engine is at tdc the rope will hold the 4 valves firmly shut to enable you to compress the springs. once youve done that cylinder just turn the engine back off tdc and simply pull the rope out
 
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