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Discussion Starter · #1 ·
Hi All,

I'm desperate as I cannot figure out whats wrong with my 2002, 156 2.4 JTD 10V.

Brief history:

Last thursday went to work as usual and after a days work was eager to get home, got in the car turned key all lights on dash ok but no cranking noise ! shoot wasn't in the mood for a hide and seek trouble game ! Pop the bonnet, checked battery, found negative terminal loose ! Got me a spanner 10 and tied up the battery lead. got back in tried again no cranking !

Got a friend to jump start with cable leads - nothing, still no crank, but all lights and electrics working. friend suggested starter is gone. So we decided to give her a push and start her on 2nd gear. Surprisingly car started. Got home put her in the garage and decided to check her out next day.

Next morning went down to the garage and decided to see if she cranks. guess what she fired up as if nothing happened ! Obviously if she done it once, there will be a second time ! Studied all the threads posted on the site in relation to such incidences and after ruling starter motor is not the culprit, went for the crankshaft sensor ! Went to buy a new one, and got the lucas brand. As i waited for my friend to come over with a jack that can lift the car well above ground I decided to clean egr valve, throttle body and MAF taking care of doing everything right as stated by the alfa gurus in this forum. That all sorted, it was time to replace the CPS. Took me a good hour but with some help from my friend, we got through and fitted the new one.

I noticed that the old CPS was covered in engine oil, not sure if this is BAD or normal ??

Happy with all the work done it was time to start her up. All good fired up at once then the shock ! tried revving and it stalled giving engine oil pressure fault on the red display. You can imagine how I felt ! Anyway back to the threads ! all seemed to indicate various engine parts to tackle and check e.g egr, MAF, fuel pressure pump etc etc. All checked and since I cleaned these before I guess all are ok. I did switch the MAF with one i keep spare and all good just to be 100% certain, car starts idles perfectly but when revved slightly over 1500, stalls and signals the oil pressure fault.

I'm honestly out of possible faults except that maybe the NEW CPS Fitted is not working or fault but cannot be sure.

ANYONE might know what could be at fault ? I was seriously thinking of putting back the Old CPS but the thaught of going through that :censored: hassle again scares me !!!

Any suggestion really appreciated,

Tony
 

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A failed crankshaft sensor will not prevent the engine turning over. It will turn over, but not start.
 

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Discussion Starter · #3 ·
A failed crankshaft sensor will not prevent the engine turning over. It will turn over, but not start.
Hi Dave,

So what could have probably failed now ?

At least some good news, new CPS stays !

Can you shed some thaught on what could have now went wrong. One remark, on fitting the new CPS i had to remove the dip stick metal tube leading to the bottom of the engine block and also move the diesel filter aside to gain space to click on the CPS chuck. Could it be the diesel filter is acting stupid ? I noticed it has a sensor to it maybe this went bizerk and is causing the cut off ? Just pondering but having no previous experience with an alfa diesel engine i'm open to all suggestions. I'm not sure if this can be cleaned or when it was replaced. Can it be i startled some sediment embedded in it and this might be causing a fuel pressure cut out, hence stall ?

Tony
 

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My point was that your original fault didn't point to the crank sensor at all.

But your new fault could!
 

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When mine had a bad MAF, it would idle fine but cut out when I tried to drive off. Try your old MAF again, I bet it will be ok then.
The oil pressure warning will be caused by the stalling so don't worry about it.
 

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Discussion Starter · #7 ·
Progress, Decided to get an original second hand Bosch MAF with the correct part No. also ordered new temp. sensor once at it.

I cleaned all the hoses and checked for leaks in the vacuum and turbo hoses. Next, Will check the injectors and see if they are acting up !
 

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Decided to get an original second hand Bosch MAF with the correct part No.
Are the other two MAF sensors you mentioned earlier not genuine Bosch...?
 

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Try a new fuel filter too.

Was the replacement crankshaft sensor a proper Bosch unit? Did it come with an O-ring? Was there an O-ring on the old crank sensor you removed?
 

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Discussion Starter · #10 ·
Hi guys to answer your questions;

1. i changed diesel filter.
2. Yes old cps had a grey o-ring which came out with it, was still in its original place.
3. New cps is Lucas brand.
4. Maf sensors are all bosch original.

I noticed yesterday that on starting her there was some white smoke from exhaust and the car and garage floor were covered with black soot after a 2-3 minutes.

Also i noticed the red coolant in the reservoir was gone. I turned off engine and topped coolant with distilled water. Turned on engine and noticed the coolant was bubbling big time ! She still cuts off just over 1500 revs ! I am going to change the thermostat next and temp sensor as these are still the original from factory.

To be honest i cannot see any mayo on the oil cap and dip stick oil level is good. No sign on the floor or around the engine bay of coolant leak ! Im just hoping its not a cylinder head gasket !

This coolant leak got me worried big time.

At this point im pretty sure its not the new cps the problem !

Can be one of three.

1. Maf sensor.
2. Thermostat and temp. Sensor
3. Cylinder head gasket.

Any suggestions from your part ?
 

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Coolant gone and white smoke from exhaust is pointing to head gasket, but on the Diesel there is also the EGR heat exchanger.
 

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Time to carry out a compression test or leak down test.
 

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Discussion Starter · #13 ·
Yes i'm afraid so, I have got me a good second hand egr heat exchanger for 20 euros noticed the difference when looking inside the old and the replacement part. Original one inside shows no sign of black soot in the channels, the replacement part has black soot inside. Although i'm not taking chances i'd probably be on my way to taking out the head ! Compression testing is a must at this point !

Anyway I noticed the engine has still all the original components to it. It seems the original owner never had to replace any parts in these last 14 years, except for oil service and cambelt. My luck, I guess I shall be doing all the ancillary engine component replacements !

The positive aspect is that she will be good for another 10 years of trouble free issues after this overhaul !

thanks
 
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