High Oil Consumption & Pinking
Advice required please;
In short, I have an oil consumption problem, and an engine pinking problem, which I’m not sure if they’re related or 2 completely separate issues, furhter to this I don't know what to do about them.
The car is an Alfa Romeo 156 JTS 2.0l Veloce - 52 plate, with 92K miles on the clock. It drives superbly, looks great & I love it.
I purchased the car back in May this year on 90K miles and it has what appears to be a full service history.
At 83K miles, in June 2009 the previous owner had the head rebuilt due to the cam belt snapping (I have the invoice).
About 4 weeks ago the engine management light came on with “Motor Control Failure” being displayed and the car went into limp home mode.
I took the car to my local main dealer and they tightened some pins in a connector block, successfully removing the problem. Whilst there they checked the oil & noticed it was low.
Since then I have recently checked the oil & it is low again, it took 1.3l to top up again and was after driving only 600 miles, I used genuine Selenia 5W/40 oil.
Also in the last week or so, the MCF light came back on for a few hours (without any drop in performance this time) it then went out again and has since stayed out.
My local dealer has advised that it is burning the oil one way or another as there are no leaks evident and therefore requires a wet/dry compression test to determine if its blow by (piston rings) or valve stems – but either way it’ll be expensive to repair…
Pinking Observations: -
Since owning the car I have noticed that the engine seems to pink, mainly while revving through 2-3krpm in 2nd gear (though can only be heard with windows down, without too much wind i.e. travelling 25-35mph)
It is worse in hot weather, after a long journey or with cheap fuel, but is always present to some degree, but barely noticeable (if at all present) when cold.
At worst it will pink when stationary, and pulling away can be particularly difficult then because the revs drop quickly as you engage the clutch, it’s as though there is a severe flat spot like the timing is way too far advanced maybe).
Performance wise, it feels good, though I have nothing to compare it too. In fact it seems to prefer it when I give it plenty of revs and drive it hard.
Oil Consumption Observations: -
I have noticed the occasional faint puff of smoke when revving it stationary whilst really looking for it, though it looks black and not blue as I’d have expected if burning oil.
The exhaust tail pipe is a bit sooty, almost as though it’s been running rich.
The temperature gauge mostly sits bang in the middle at 90, but sometimes on the motorway or in traffic it creeps up, though it never goes as far as the ¾ mark, but the hotter it gets the worse the pinking problem becomes.
The radiator is slightly corroded, and the air-conditioning condenser is fairly dirty probably causing reduced air flow, but by how much I’m not sure… I’m not sure of the best way to clean it?
1. Is it normal for the temperature to mostly sit at 90, but sometimes going very close to the ¾ mark?
2. Could using the Selenia race oil 10W/60 help reduce oil consumption, & is it advisable?
3. Are there any additives that can improve oil consumption in these engines?
4. Could it be a simple issue such as a blocked breather or something else like that?
5. Is this level of pinking/oil consumption a serious problem, i.e. is it common with the JTS, can I keep driving it, will it progressively get worse am I causing further damage etc?
6. Is it possible that one of the cams or both could have been set one tooth out when the head was repaired (please see history below) & would this make it pink?
7. Could the oil cause a carbon build up and make it do the pinking I’ve experienced, or would you think this is unrelated?
8. Do I just need to face facts and have new rings/head cleaned/valve stem seals etc?
Any advice will be greatly appreciated, sorry for the info overload.