2l of missing oil!

[Doc007]

I'm doing an oil change on my 2l Duratec with a Cosworth dry sump. I got about 3.8l from the dry sump via the drain plug, 200ml from the filter and 300ml syphoned from the DS tank.

I was expecting about 6.5l.

I don't want to start undoing the oil hoses willy-nilly, only later to find them leaking!

Where should I look first?

 

[ScottR400D]

I'm not sure how the Cosworth DS varies from the Raceline but in my early days I disconnected the hoses but got very little out of them. 

Since then I've just syphoned the tank, drained from the finger filter and removed the main filter and usually got what I expect, close to 6.6l if not more. 

The bulk of what I get out comes from the tank not the sump. 
 

[aerobod - near CYYC]

How many miles has the car done since the last confirmed fill, Doc, and has it done some track days since then?

My 2.0 Duratec has always been an oil drinker at continuous max revs, consuming that sort of amount during a couple of track days (my consumption is quite normal though when just driven in a spirited fashion on the road). The Caterham manual alludes to the fact that oil consumption can be high in certain circumstances, recommending oil level checks after every track session.

[Doc007]

Thanks aerobod. Hadn't considered that it might be low. 
Now I'm not sure how much to put in.

The amount I removed?

Assume it's empty and put 6l in? What happens to any excess? Being dry-sumped presumably the crank isn't going to be hitting it?

[KnifeySpoony]

Put in the amount that you took out, then check the level- simple as that. Top up as needed. Re: oil burning - my car (also a 2.0 duratec) is primarily track driven and burns/blows-by very little oil. I typically top up maybe 100ml every track day. Next time, check your oil level prior to changing it so you know where you're starting imo. 

[Ian Macquarie]

Did your Syphon tube reach the bottom of the tank?

On my car the tank baffles prevent that. (Different car though).

[SKC]

It's likely it'll still be in the sump.

Same sump design as the CSR, no actual drain on the lowest part of the sump to drain the oil.  So what most owners are doing is similar to you and then refilling with new oil.  So basically draining about 2/3 of the oil and then refilling with fresh oil and quickly contaminating it.  We've just had a 60,000 mile, 200 CSR in due to crankshaft bearing failure.  This is likely to have been caused by contaminated oil over a period of time.

As a result of this and other CSRs we've seen, we've written a process for carrying out an oil change on such an installation. 

Please see the link below.

https://premierpowerengines.com/csr-oil-change-process/

Please be aware, this is a two person process.

Regards

SKC

[KnifeySpoony]

Hmmm, I know that Exige/Evora with remote front mounted oil coolers leave a LOT of oil the system during an oil change, and those cars aren't blowing up willy nilly. Any oil change is just another serial dilution, but of course the more you get out, the better.