Any engine Gurus in?

[Bowler]

Guys

I need some help with understanding a problem with my car, so I can at least make some semi-informed decisions over next steps. It’s V6 2.5 Mondeo, with 180k on the clock. Bangernomics at work

Runs sweet as a nut, but is using/losing oil

12 months ago I noticed it was leaking a small amount of oil from the sump, so I changed the gasket. In the process of changing theis, I took the sump baffle out to check for sludge Etc and there was nothing – it was clean as a whistle. To keep it this way, I’ve changed the oil very ~6 months (~9k miles).

A couple weeks ago, I noticed oil on my drive. Sure enough if is leaking via the gasket again (plus misting some out of the crank seal). There may be some oil out of the exhaust, but there’s no oily smell, but there’s a small amount of misty type of smoke even when it is hot (a bit difficult to tell with the weather being so cold)

Having changed the sump gasket so recently, I’ve sort of determined that it must be a crankcase pressure issue or the oil is getting through the rings.

I’ve had the rocker breathers off and they are all clear, so the next thing is to possibly change/clean the crankcase breather and replace the PCV. To do this requires the removal on all the inlet manifold (x2), injectors, fuel rails Etc. Factoring in all the gaskets and other parts that are likely to worn out, means that I’m staring at £180 in parts just to get to the breather/PCV/hoses.

It’s using about a litre per month (1500 to 2k miles), but is definitely not dumping this amount through the sump gasket.

I’m inclined to get it emission tested before I do anything, as if it’s a definite MOT failure (due in 3 months), then I may just forget it and move on. If it's a common problem with a known fix, then I've no problem in spending the money, but you'll understand that I don't want to throw good money after bad, if it doesn't.

Any ideas what this could be?

Any Duratec 25 Gurus out there, that can point me in the right direction or at least give me some tips?

TIA

[Rich's Granny]

Engine oil only dissapeares for two reasons. Either it leaks out of somewhere which will be fairly obvious or its being burnt by the engine. Caused by worn bores/piston rings or worn valve stems/guides, possibly valve stem oil seals. Valve stem seals and or valves are a relitivly easy fix meaning a top end overhaul. pistons/bores/rings however pretty much mean a rebuild or replacement engine.
Difficult to diagnose without seeing the car but there are various checks that can be made.
Do you get a cloud of blue smoke at start up ? especially on a warm/hot engine or does it start to puff a bit of smoke while sitting in traffic ? This would point to top end issues.
Does it smoke at all under hard acceleration ? this would point to bottom end, piston/rings/bore wear issues.
unfortunately these are the signs of high mileage especially on a petrol engine. They are generally not as long lived as an equivelent diesel. Obviously proper maintainance plays a big part.
what you really need is a garage who uses good old fashioned diagnostic equipment who can perform a 'cylinder leakage test' which will confirm whether its a valve or piston problem. From what I've read about these engines you seem to have done well to get 180k out of it. I've heard of quite a few that have suffered crankshaft/big end/main bearing trouble at much lower mileage than yours.
I've got a diesel MK3 mondeo with the same mileage on it that I've had for 8 years and I'm pleased it doesn't use a drop (touch wood).....

Edited by Rich's Granny on Friday 22 February 21:12

Edited by Rich's Granny on Friday 22 February 21:14