L28 question

[mr_skater99]

Sup

About 3000km's ago i had the head done (and new radiator, hoses, carby rebuild, points, distributer, condenser, coil).

It ran great for a bit, and still runs fairly well but it is starting to use a lot of oil. It was smoking terribly, so i put the mechanics grade wynns engine fluch through it and am now running Penrite HPR-50. It hardly smokes at all, but still seems to be burning through the oil as i find myself topping it up every 1 - 2 weeks, dep on how much i drive.

I will do a compression test on the weekend to let you guys know, but it would make sense that if the head was all new then the possibly warn rings might not be able to handle the pressure???

My question, and please forgive me if it's dumb, but since the head has been done and is all nice and sealed and warn in now, can the rings be replaced through the bottom (sump)? Or does the head have to come off again. Can the rings just be replaced? i saw the engine when the head was off and the pistons and block looked in pretty good nick?

What advice can you offer, its still quite drivable with just topping up the oil, but i've come this far with it now so i might as well keep going...

Thanks guys

Scotty

[V8Patrol]

Pretty typical ..........

The "fresh" headwork you've had done obviously has placed added pressure on the bottom end of a tired old motor..... the end result being the oil cunsumption you've described.

Heavier weight oil has a slightly less chance of being burnt but it will still be burnt off just slightly slower than the light weight oil.

As for not pulling the head off to do the bottom end ........ forget it. Your best bet is to sacrifice the new head gasket and do it properly. Pull the motor out of the car and do the bottom end up properly.... the way youve posted up sounds as if you only interested in replacing the rings..... no mention of bearings...... in which case ya wasting your time.


Kingy

[mr_skater99]

Thanks for the advice. I rang a few places this morning and they all quoted my about $2k over the phone for a full rebuild, even tho i've had the head done in the last 3 months. They all said the engine needs to come out which is a pretty big cost.

Does this sound right? can anyone reccommend anywhere to get it done, prefersbly on the northside, but not essential. it will be a litte while till i have that sort of cash but just want to check out my options.

Thanks

Scotty

[fnqcairns]

Scotty ring repco and find out what a exchange block is worth, then ring a few of the wreckers around the place and see what they would charge to pull your engine mount your good head on the rebuilt block and then into the car.
It's been a long time since I needed any mechanical work done as I do it all myself but I would assume it would be cheaper than 2 grand.
I could be way out also.

cheers fnq

[mr_skater99]

ok so i checked the oil this morning and drove around a bit today then came home and did a compression test. numbering the cylinders 1 - front(radiator) to 6 - back(firewall) i got:

1 - 1190kPa
2 - 1190kPa
3 - 1190kPa
4 - 1190kPa
5 - 1050-1100kPa
6 - 1050-1100kPa

as i said i had the head done about 2 - 3mths ago. there is no leak in teh cooling system, it is still perfectly full and perfectly green. thermostat is about 6mths old.

The car does not really smoke at all, but all the plugs were blackish/brownish on the end like they had been burning oil.

These figures to me say that it's not the rings - but that doeant make sense. Can someone please enlighten a dumb ass like myself.

thanks

[fnqcairns]

My L28 50k ago (now 300k) had very close to 165psi on all, I have not checked since but it uses no oil to speak of, although if not caned every now and again it would smoke heavily on start up.

IMHO replace your overweight medium quality oil with a real heavy duty oil like dello 400 15w-40 CI+ or another HD oil, run it for 600km then take it to some sand hills or a beach and give it a thrashing for a day. Also use no additives with a true good oil they are a waste of time.

Your plug colour sounds fine.

cheers fnq

[mr_skater99]

I thought penrite was good oil? where do i get this dello from - don't think i have seen it at supercheap. Repco maybe? Anything worths a shot. Its still using about 300-400mls of oil a week???

thanks for your help tho mate. appreciate it.

[fnqcairns]

Hi again,
Oils are not oils when you look at them close enough.
Penrite is a good oil, it's just that there are a few other oils that are a few 'layers' above again with Dello being around the same price, is one of those cheaper but better oils out there.

You could try delvac 1 also but keep a hold of your wallet

Also Havolene is another good one.

There are others also.

Try you nearest Caltex distributer around $80 for 20L, nice cheap highest spec oil CI-4.

cheers fnq

[fnqcairns]

Thought I better clarify myself, this oil alone may not clear your problem up. The trick is to try and bring the piston/cylinder area back to a clean state so it has the best chance of fixing it's self or so you can better diagnose it. Some off the shelf oils are pretty dirty oils they leave carbon residues and don't really have the added detergency to then rid themselves of their 'dirt' as the oil ages.

Heavy duty diesel oils do have this ability so they can actually get between ring lands etc and clean the already deposited and compacted carbon away, not in total but best yet anyway.

It can be a good idea to run this oil for a 50% shorter period as the filter will have a bigger job on it's hands and also consider running a can of engine oil flush toward the drain also.

One more thing is to use a fuel additive like injector cleaner through it also, in the short term doing all this can increase oil consumption but if there is no true mechanical problems this will be short term as everything seats again naturally.

This has been my experience anyway and has actually saved a few engines (not mine) from rebuilds the professionals said were needed.

Have you checked for any external leaks lately?

cheers fnq

[mr_skater99]

i can't see any external leaks, but i will go over it in more detail. with the amount its using tho, i'd assume it would be quite easy to spot.

can you get delo from a caltex servo?

i will drop in a bottle of engine oil cleaner and then try a change sometime this week, new filter and a bottle of injector cleaner and see how i go.

really appreciate all of your help.

ta
scotty

[fnqcairns]

Hope it does actually help and I am not just spending your money!

Anyway you cannot go wrong with the Dello 400, and the 15w-40 is perfect for nearly all of Australia's climates and the molly in it is great at neutralising internal acids (among other things). In fact after a few fills of Dello and with an engine determined to be in fair condition you could consider extending the drain interval to near double as this oil is up to it but without an oil analysis to guide you best to leave that alone. Although I wouldn't be concerned about a couple of extra thousand between typical drains.

I have not seen it at servos but I think they could get it in as could some car parts place but you will then pay about as much as Penrite for it probably.
This oil I understand is Ok-ed by the manufacturers of big trucks to go 100k between full drains and the manufacturers of those engines don't muck around when it comes to the health of their engines like car makers do, trucks live and die by their reputations like no other vehicles.

Hope it all levels out for you in the meantime.

cheers fnq