G40 ran low on oil

[paulpolo]

Hello,
So i've been rebuilding a G40 engine to swap into my GT, I finished and swapped it in recently and have been running it in. Unfortunately at the weekend the oil breather pipe from the block (which i'm just venting to air) got kinked and all the oil was shot all over the bay. First I noticed was I heard the lifters ticking (oil buzzer never went off!) and saw smoke (from oil on the manifold), I immediately switched it off. I'd only travelled 2 miles but looking at the road it was leaking the whole time since I left home. There was no oil on the dipstick, and it looks like the dipstick is still in the block ok, so it must have popped some other seal or gasket. Timing belt is covered in oil so that'll need re-doing.

I'm fearing the worst, but I did a compression test after i filled it with oil and it was still 12bar across all cylinders. I was planning on taking the sump off next and then undoing one of the crank bearing caps and looking at the bearing, but in light of recent stupidity I thought I better ask to see if thats a good idea? Or do I really have to strip the engine down again?

[JoeH]

Well 12bar on all cylinders is a good figure...

[grayg40]

first i would see how much oil comes out of the sump drain first, if you have none left it might be worth checking one big end cap and bearing. but if you still get ruffly a litre of oil out the sump drain plug i wouldnt bother. but thats just me personally.
the comp is good, just clean the engine and put more oil in and see where the leak is before stripping again or you might not find the cause.

[hayesey]

I doubt you'll have done any serious damage.  Perhaps put a few thousand miles of wear on to the bearings in those two miles but nothing that should mean a rebuild is necessary.  If you'd spun a bearing or the engine had seized, you'd certainly have noticed it.

There can still be a fair amount of oil in the engine and not register on the dip stick at all.  If the buzzer didn't go off then it must have had some pressure still (unless someone has bypassed the oil buzzer & light or something daft).

[hayesey]

as for where the oil came out, are you sure the dip stick was fully seated in and clipped in still?  That's usually the first place it comes out of if the crankcase breather is blocked.

[paulpolo]

Cheers for the replies guys, hopefully it's not too disasterous then.

I've degreased the bay, just got to work out where all the oil came from, it looks like the rocker cover gasket blew on the front side and leaked straight on the manifold. I'll check the dipstick but the tube looks like it hasn't moved and the actual dipstick was seated.
Both the oil sensors were plugged in (and I know the wires have continuity as I only checked them last week) so hopefully there was still a bit of oil left.

[hayesey]

then it sounds like it'll be a simple fix.  Also make sure to replace the breather hose so it doesn't happen again!

[paulpolo]

Just thought i'd update and say there wasn't as much oil left in the bottom end as i'd hoped, it was about 1 litre. Changed the timing and charger belts and sorted out the breather to a proper catch tank.
There is now a noticeable piston slap which does mainly go away as it warms up i'm hoping its going to be ok. So i'm driving it again now and i'm pretty sure it's overfuelling, the tail pipe is very sooty and it smells rich plus it wants to cut out sometimes when coming up to roundabouts, so i've checked the CO Pot and its dead on 550ohms and the blue temp is fine, the lambda is a brand new bosch item and there are no fault codes in the ECU (using VWTool to look). I've got 13.6v across the battery (old alternator but new regulator). so my next step is to hook up my aem wideband see what it says, just wondered if anyone had any other ideas? Also can i start tweaking the CO Pot until it looks good on the wideband?
Also it feels like its got no power up to 3000rpm, as in it feels slower than the GT engine, after 3000 its quite savage, to me anyway is this how all g40's are? having never driven one before i'm not sure

[GR40]

Was the engine you got standard or did it have any mods on it!? Like bigger injectors or anything of the short.

[paulpolo]

I rebuilt it completely so its standard apart from 76mm wossners, 65mm german toothed belt kit (on standard charger) and PPP chip to suit.

[paulpolo]

So I stripped the engine down and found the big ends are all worn on the outside edges, Haynes says this is radius wear due to tapered journals on the crank. I measured them (with a digital vernier, so not super accurate) and didn't find any taper, so i'm guessing this is the result of running out of oil. The mains are fine but i'm replacing them anyway. Is there a good way to check the little ends are ok? (i've wiggled them around a fair bit but can't detect any play)







Would anyone care to say whether this is a usual amount of carbon build up for about 1500 miles?


Any advice much appreciated.

[GR40]

These are my pistons after 200.000km. So I would say that that amount of carbon build is normal.

[GR40]

top view

[paulpolo]

Cheers, not too bad then.