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[Marks DTM Calib]

25ml of oil in the pot is much to much, the combustion chambers are not much more than this, 1ml tops would be the suggestion 

The usual culprits I find on the later DBW V6 for coolant leaks relating to the engine itself (excluding ancillaries such as split rad or failed bypass valve which are far more obvious) is the water pump and the oil cooler to block joint (the latter being the most common for some reason!).

Before digging to deep the compression test needs re-visiting 

[Ulap31]

As the weather been wonderful and I was home early, I had time to redo compression test.
Results are with hot engine and about 2 mg oil in cylinder 1 and throttle bodies removed
Cylinder 1 140 psi
Cylinder 3 120 psi
Cylinder 5 170
Didn't bother with bank 2 as I assume I'll get similar readings.

Previously was doing small journeys when problems started regarding the Mayo, before that was driving daily to south London until the problems started.

I'm aware of mayo and condensation with these V6s as this is my 3rd omega now

[JamesV6CDX]

Please for completeness can you test the 2-4-6 bank at WOT and report back the results?

When you say not running right - what symptoms?

I don't usually offer a "mobile mechanic" service anymore due to work commitments keeping me too busy, but I do occasionally like a challenge and WGC is not that far from me in Buckinghamshire, I would gladly take a look, are you around next week? (weekdays?)

[Ulap31]

The car sounds fine on idle, as soon as you go into drive it sounds like it's missing even when cold.
Once warmed up you can hear it's tappety. I have steam from the rear exhaust quite a lot of mayo in filler cap no water on dipstick and terrible petrol consumption.
James I would be really grateful if you could help out with the car as it's frustrating the hell out of me. When are we talking about in the week as I work local in the day

[05omegav6]

Define appalling economy... My 3.2 auto estate struggled to beat 22 mpg on a 23 mile commute in traffic... Manual one was nearer 27...

[Ulap31]

Consumption is roughly 16 miles to a gallon and worse if it's stop start traffic

[JamesV6CDX]

Let me come and do a proper assessment and series of checks incl live data and checking Cambelt setup so on

[JamesV6CDX]

Any coolant loss?

[05omegav6]

Consumption is roughly 16 miles to a gallon and worse if it's stop start traffic

To be expected if you're doing five mile journeys from cold...

[JamesV6CDX]

Also just seen you had a recent timing belt.... Who and where fitted this please? And sorry for personal question but what were you charged?

Pm sent re logistics btw

[Ulap31]

I did the cam belt change with new contitech kit and used a Sykes pickerant locking kit, new water pump and thermostat were also replaced at the same time.
Have since checked the timing a few times and still looks spot on (might be wrong though)
This was changed after the rough running started as I wasn't sure of the previous history.
I checked oil cooler then and could see no seepage from the cover plate.

[Ulap31]

Compression results
This is hot and throttle bodies removed and about 2 mg of oil with no change to compression
Cylinder 1 140 psi
Cylinder 3 120 psi
Cylinder 5 170 psi
Cylinder 2 115 psi
Cylinder 4 100 psi
Cylinder 6 190 psi
Used a Gunson comp tester so not to cheap a tester

[Nick W]

Assuming correct test procedures, that's still a very wide range across both banks, which would strongly suggest bad cam-timing. Considering how well mine ran with all four cams a tooth out, I wonder if each pair is incorrectly timed to each other.


If you only do short trips, then the exhaust steam is probably a distraction from your real problem.

[Lazydocker]

Assuming correct test procedures, that's still a very wide range across both banks, which would strongly suggest bad cam-timing. Considering how well mine ran with all four cams a tooth out, I wonder if each pair is incorrectly timed to each other.


If you only do short trips, then the exhaust steam is probably a distraction from your real problem.

2nded. I think I saw something in historical posts referring to backing plate marks on a cam belt question... I think it's a red herring because there is mention of kit too but, IMO, stripping the heads off is still a way down the line after some further diagnosis.

[omega2018]

25ml of oil in the pot is much to much, the combustion chambers are not much more than this, 1ml tops would be the suggestion 

Ok I was just trying to give a figure but equally 1ml is way too low.  i'm not sure how you could easily measure 1ml.  the general recommendation, not specific to the v6, is a tablespoon full which is 15ml.  reduce that for having 6 cylinders instead of the usual 4 but increase it as its 3.2l rather than 1.6 or 2l.

each combustion chamber on the V6, piston at tdc, will be 59ml in size. quite easy to calculate given 10:1 compression and 3175ml piston displacement, over 6 cylinders:

where x is the total combustion volume
x = (piston displacement + x) / compression ratio
x = (3175ml+x)/10
10x = 3175+x
9x=3175
x=3175/9
so x is 353ml. 6 cylinders, so each is 353ml/6, i.e. 59ml