Steve Rothwell answering your ENGINE MANAGEMENT queries
ALFA ROMEO GT
Q I would like to hear your opinion on a problem with my 2007 Alfa Romeo GT 1.8. Twin Spark. It has done 137,000kms. The problem occurred three times in last six month. The car does not like not to be used, let’s say, for a week. Once in Italy, when it was very hot; once in Holland when cold; it refused after 5-6 days to run on all four cylinders. After 20-30 seconds the engine started running normally. Since then, I start the engine each day for a few minutes, to get the oil circulating. I forgot to do that last week. And, again, after four days, it refused to start normally. But this time it did run on all four cylinders, but (in one cylinder?) a valve-adjuster rattled like a machine gun for half a minute. When I switched off the engine and restarted all was normal. My guess: when standing for a longer period one (or all) automatic valve-play adjusters drain themselves of oil. But then: why not run on all four cylinders?
On the other hand as a local garage suggests there may be a carbon built up in the valveadjustment mechanism (of one cylinder). They say using a cleaning agent and running the engine for some time, may help. I would appreciate your opinion.
A This is actually a problem which is detailed by Autodata as being a common issue. The source of the trouble is due to the Camshaft Position (CMP) actuator draining after standing for a long period. The reason for this is that an oil non-return valve was not included in the actuator at manufacture.
The remedy will depend on the engine number of your Alfa, for engine numbers up to 3575550 the remedy is as follows:
► Remove cylinder-head. Fit non-return valve to oil gallery of camshaft position (CMP) actuator.
► Refit cylinder-head. Fit modified camshaft position (CMP) actuator. Fit new cylinder-head cover gasket. For engine numbers above 3575550 the remedy is slightly easier
► Just fit the modified camshaft position (CMP) actuator. Fit new cylinder-head cover gasket.
The part numbers of the modified items are: Camshaft position (CMP) actuator – 71738360. Non-return valve – 60677899. Cylinder-head cover gasket (JTS) – 60669492. Twin Spark cylinder-head cover gasket – 60655592.
Once the modification is completed the problem should be rectified.
BMW X1
QI have a 2013 BMW X1 2.0 sDrive 1.8d (engine code N47). I think that the DPF now needs replacing as I have replaced the MAF sensor that was preventing the vehicle from going into regen. If you could take a look at the screenshot that I have sent to you please, can you give me your opinion if it needs replacing or can you suggest some other things to check before I carry out replacement of the DPF.
Actions so far: rough running earlier this yea
