Engine Help

[Sooty Si 1]

Hi all, looking for a little help...156 JTS Veloce (2004)

 

A few weeks back I had been on a short journey, noticed the temperature suddenly rising past the 90 mark, so I pulled over immediately and switched off just as the warning light came on and the Infocenter displayed the "Engine Temp too high" warning. Popped the bonnet and noticed all the coolant had pissed out from the base of the radiator...fair enough. Called the breakdown service and got taken home.

 

Replaced the radiator and coolant, and the cooling system is absolutely fine now...but, she sounds a little different, almost like she's running a little rough. Idle is a not quite right and there seems to be a light vibration now across the rev range, particularly noticeable at about 3000 rpm, which then reduces and comes back at just over 4000, and so on. Also sounds different, like an ever so slightly deeper note to the engine.

 

Being a JTS, I'm used to seeing the P0120 and P0130 MCSF fault codes every now and then. Now I'm suddenly getting the following:

 

P0130 - O2 sensor circuit (bank 1, sensor 1)

P0139 - O2 sensor circuit slow response (bank 1, sensor 2)

P0159 - O2 sensor circuit slow response (bank 2, sensor 2)

P1131 - Powertrain

P0100 and P0110 - Powertrain (mass or volume air flow circuit / intake air temp circuit) ---- after I disconnected the MAF to see if it made a difference, which it did).

P1172 - Powertrain

P1173 - Powertrain

 

These have appeared on 5 different occasions, sometimes together, in various combinations.

 

The car still pulls well, a code for the Coilpack appeared once (P0351) indicating Ignition Coil "A" primary / secondary circuit, so I replaced the coilpack with a known good spare and it hasn't reappeared and doesn't run any better or worse, so may have been a fluke.

 

So, before I start ripping things apart, does anyone with REAL knowledge have any suggestions as to where best to start looking? Please don't reply if you're just going to say "Yeah mate, its a JTS, you need new cams, injectors, blah blah blah" because you heard it on a forum like AO. I'm not trying to be a dick, just haven't got time and money to throw at a 13 year-old car based on hearsay and forum-knowledge.

 

Thanks in advance guys.

[Smaky 73]

Sounds to me like the head gasket is on the way out, I'm guessing this engine is around the 120K mark? Pretty much as long as these metal plate gaskets survive, just keep an eye on your coolant level and check if the hoses are going rigid, this is a sure sign if this is the problem, the other codes though (powertrain) don't tally, you should only see those on a selespeed, so what's going on there???

 The MAF though may be failing, but if you're getting that and the lambdas together then as I said , it may be the start of the head gasket going, they lamdas just don't like coolant in the exhaust and they blame the MAF for everything, sadly I think with your mindset this is the end for this bella, though it is repairable, just make sure the head is not cracked.