The 3sge oil burner has been pulled down and inspected.

[urantia]

Swapped my spare 3sge engine into friends celica over the weekend, becuase his 3sge burns about litre of oil every week.

And yesterday i got the oil burner onto the engine stand and took the head and sump off.
First thing i was amazed to see was the two valve collets i lost ages ago stuck to the oil pickup mesh! plus a host of other metal shavings, wow those things really serve there purpose! (protecting the engine from sucking up metal and pumping it around again).
I replaced the whole lot of valve stem seals awhile ago on this engine and it did not stop the oil burning, but when i took the head off i can see 1 of the valve stem seals was not clicked down p but it reduced it abit. All the cylinders are showing oil entering and burning.

Anyhow i popped out two pistons to inspect the rings and dam they look pretty good still, when the rings are closed in the bore they would have at most a 2mm gap. I'm not sure what the limit is here? is that too much?

One thing i noticed was the oil control rings did not protrude out of the piston like the compression rings did, the oil control rings arn't stuck as they can be rotated around. But i can see how oil would go straight past them and eventually end up in the combustion chamber. It seems to be the same for ALL 4 pistons (the oil control rings don't protrude out to even touch the bore from what i can tell. Is this the cuase of burning oil? or is this the way they are supposed to be?

The bore looks to be in pretty good nick for 240,000k's but will rehone as and there is slight wear marks on the sides of the bore inline with the direction of rotation of the crankshaft, i suppose this is from using shitty mixed oil over the years (friend did this) The bearings are looking a litte scorched and wearing down to a copper color. but are a tight fit and sound healthy when the motor was running, would it be worth chucking some new bearings in? or leave them as they are? (someone said chuck the old bearings back in if they didn't have a problem) I assume i can get a standard bearing size that will go straight back onto the rods/crank and will require no measuring and tolerances to be measured up? The crank journal's look as good as new.

Will post pics up.

[gianttomato]

Get a micrometer and measure it all up. Better to know for sure rather than throw a whole lot of cash at a motor that is essentially worn to the point it needs a full rebuild.

As a general rule of thumb, if there are wear marks you can feel when you run your fingernail across them, then it'll need to be machined.

Engine has done 240000 kms hard work on shitty oil so expect (and plan) for the worst. If it was smoking despite having done valve stem seals, then rings and/or bore are worn.

[urantia]

Thanx for the reply GT, thats a good trick using your fingernail. (gave you some positive rep). I'll pick up a digital micrometer tonight and start measuring.

Anyone have a 3sge (gen1) manual or somewhere to get the max tolerances to measure for the bore, pistons and rings??

Also i take it the oil control rings should spring out past the piston like the compression rings do? (when the piston is out of course)

[o_man_ra23]

The control rings arent meant to protrude far past the piston, and will settle into the piston with use. Check your piston to bore clearance, measuring at the most worn areas. The rings should only have a small gap in the bore to allow for heat expansion. Just checked the specs for 18RG... compression ring gap when in bore should be 0.1 to 0.28mm. 3SGE and pretty much every other motor on the planet should be in this vicinity(2mm is way too much). From the sounds of things, you need to do an overbore with new pistons. The bearings should be replaced whenever the motor is torn down, but dont forget to get the crank linished. Dont buy the bearings till after you get the crank back, as you may need a crank grind, in which case you will need undersized bearings. Suggestion is to get the head surfaced, and the valves ground while the engine is apart. Also, its a good idea to have the head bead blasted and the block acid dipped... this should clean up the carbon/oil deposits left in the ports, and clear all the caked on old crappy mixed oil that your friend used in the block. If your going to do an overbore, get new gudgeon bushes put in the small end of the con rods too, no point going to all this trouble and having something somewhere causing an unwanted vibration. And dont neglect the humble timing belt, and idler bearing, and check the clearances on the oil pump.

In short, this motor sounds like its at the end of its tether, and will need a full rebuild to spring it back to life.

Cheers, Owen

[urantia]

o_man_ra23, informative very informative!

Thanx for clearing that up.

One thing to note was the compession readings i got on this engine, 190PSI across all cylinders, probably the excess oil cuasing the high readings, but adding some oil down the spark plug hole and doing the compression test again netted 210PSI across all cylinders. I'm not sure what to think of that.

But in any case i will measure up the piston/bore and recheck the ring gaps with a proper digital caliper. Then i will know whats actually worn. (still trying to get ahold of the gen1 3sge tolerances/wear limits)

[thechuckster]

for something that's done a hard 200K i say a rebuild (crank/bearings/rings/pistons/bores/valve seats) opportunity shouldn't be missed. You've got it apart already, so you may as well fix it good-and-proper.

[o_man_ra23]

The ring gap should be measured with feeler guages. Check to see if you can get a haynes manual which includes this motor, they are an invaluable tool. The oil you added down the hole will take up some air space, and in a motor which has a very small combustion chamber (once the dome of the piston is taken away from the chamber volume), this can make a remarkably large difference, so it is not uncommon to see a 20psi increase.

Cheers, Owen

[urantia]

yep makes perfect sense.

Also i should mention its my friends engine and i owed him about $400 for something rather. And i said i would find out why it's burning oil and if it's just rings or something i'd replace them. A full rebuild might not be worth it for me, unless he pays me.

If it were my engine most definetly do it all while the engine is out.

Cheers all. (will still put up some pics later tonight) And perhaps someone can tell me what they think of a few things that i'm concerned about.

[urantia]

Well Daylight sure makes a difference, looked pretty good at night, but daytime really shows where the wear is happening.












It'll clean up alright:






And what was sitting on the oil pump filter when i took the sump off:

[Chrisso]

Hi Urantia,

Here's a link for the celica BGB's.

http://www.celicatech.com/imagearchi...online/bgb.php

I've been using these myself as I'll soon be rebuilding a gen 1 3sgte after I pulled the sump off and found only a quarter of a bearing remaining on the no.2 con rod. Basically planning on everything that o_man_ra23 suggested plus the guy who's helping me wants to do a little extra machining on the head, ports and valve seats.

Chris.

[-==L=a=N=c=E==-]

for a downloadable source of bgb, follow the link in my sig.

[tricky]

But in any case i will measure up the piston/bore and recheck the ring gaps with a proper digital caliper. Then i will know whats actually worn. (still trying to get ahold of the gen1 3sge tolerances/wear limits)

You'll need more than digital verniers to measure the bore. With vernier calipers, you are only measuring the top of the bore, which gets comparatively bugger all wear. Ideally, take 3-4 measurements down the bore (and another set at right angles to check ovality). For this you'll need a comparative bore gauge. If you don't have one (or can't access one), get the bore measurements done when you get machining done.

I'd be getting a mic onto those crank journals to check if you need to go U/S. Those bearings are a bit mank too. You should be replacing bearings when you do rings anyway, otherwise there's not much point in freshening it up.

Those bores aren't too badly worn, but some of that pitting is a worry, and the vertical wear marks might not hone out either, so you might need to go O/S there.

When you look at it that way, a $900 3S-GE from an importer could be a cheaper idea, depending on what your friend wants to do.

[urantia]

Chrisso dam i been looking for something like that forawhile now!! good find!

Lance Thanx again mate your resources have come in handy on numerous occasions!

tricky, bore gauge added to the list! cheers for that! on close inspection of the bore, where those vertical wear marks are i don't think they are too bad, as the crosshatch pattern is still seen thru the vertical marks. But the measurements will tell all. Thanx everyone for there wisdom which is invaluable.

[Sam_Q]

I know this may be an old thread but ...Holy crap!! thats a valve collet amounst that crap in your sump, thats increadale

[urantia]

LOL well spotted. Yeah i dropped those bastards down there when doing the valve stem seals. So thats where they ended up : P