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Piston Ring?
contaminated - 8/2/10 at 02:05 PM

Help!

Having finished a fairly (ahem) spirited run with the boys yesterday I noticed that I had blown a load of oil into the catch tank. Now this has happened before after a recent oil change. Despite filling to the correct level it usually blows a bit of excess out on the first very quick run.

On this occassion though I clearly have a build-up of gases in the crankcase. Some oil has also leaked out of the oil filler cap.

It could be that the crankcase breather is partially blocked (not checked yet), but clearly it's not blocked enough to prevent oil blowing through it into the catch tank!

If the problem isn't a normal level of gas being prevented from escaping it must be increased gas in the crankcase. This leads me to think that a piston ring may have gone.

Additionally I didn't like the look of the oil when I checked levels. I can't be too specific, but it looked a bit brown and watery. Possibly un-burned fuel in oil? So piston ring again? No oil in coolant.

Comments welcome, but if it is a ring (and I'll confirm by doing a compression test when I find someone with a gauge):

1. How bad a job is it?

2. How expensive?

3. What else should I check at the same time?

4. Do I just stick another engine in and have done?

Thanks all

Dan


mookaloid - 8/2/10 at 02:08 PM

mine used to do this when the air filter on the top of the catch tank blocked up. Worth checking this if you have one?


iscmatt - 8/2/10 at 02:09 PM

what engine is it?


contaminated - 8/2/10 at 02:14 PM

I will check it, it's a possibility. My catch tank is a bit of a bodge job which can't help. Basically a drinks bottle with a hole drilled in the vent!


contaminated - 8/2/10 at 02:14 PM

quote:
Originally posted by iscmatt
what engine is it?


Sorry. 2.0 litre zetec on 45s.


RAYLEE29 - 8/2/10 at 03:42 PM

so what does your breather system consist off? does any of it go back through the induction system? do you have at least 3 5/8 dia vents from the crankcase either to atmos or back through the engine? if not it could just need a better breathing system.
Ray


contaminated - 8/2/10 at 04:32 PM

quote:
Originally posted by RAYLEE29
so what does your breather system consist off? does any of it go back through the induction system? do you have at least 3 5/8 dia vents from the crankcase either to atmos or back through the engine? if not it could just need a better breathing system.
Ray


Consits of the zetec OEM valve with the actual valve removed and connected to a catch tank. Another pipe from the cam cover breather.


cliftyhanger - 8/2/10 at 06:43 PM

compression test needed methinks. dry then wet. always with WOT, and best if all plugs out. If any of the figures seem low, that should indicate the problem. If unsure post them all up here.

A ring (or set), plus all the gaskets etc will probably be more than a secondhand engine. Plus the bores would need a hone (not expensive, or very easy DIY)
Alternatively, if you take the engine apart to do the rings, and then "refresh" the engine with new rings/bearings etc it will last a very long time.....as long as the bores are not damaged.
All this based on the fact it is rings, but that needs investigating before jumping to conclusions!


contaminated - 8/2/10 at 08:00 PM

Agreed. WOT?


cliftyhanger - 8/2/10 at 08:30 PM

quote:
Originally posted by contaminated
Agreed. WOT?

Wide open throttle!


contaminated - 8/2/10 at 08:32 PM

Ah, ok. ta


Angel Acevedo - 9/2/10 at 02:52 PM

quote:
Originally posted by cliftyhanger
compression test needed methinks. dry then wet. always with WOT, and best if all plugs out. If any of the figures seem low, that should indicate the problem. If unsure post them all up here.

A ring (or set), plus all the gaskets etc will probably be more than a secondhand engine. Plus the bores would need a hone (not expensive, or very easy DIY)
Alternatively, if you take the engine apart to do the rings, and then "refresh" the engine with new rings/bearings etc it will last a very long time.....as long as the bores are not damaged.
All this based on the fact it is rings, but that needs investigating before jumping to conclusions!


Second that,
Here in Mexico, second hand engines are not cheap, so a couple of times I´ve blown head gaskets, I dig in for rings, bearings and Gasket set.
That gives me peace of mind regarding life expectancy.
Mind you, these has been done on engines of doubious (sp?) origins.