nickjaxe
05-15-2009, 11:50 AM
Hi guys, my S3 88" 2.25 diesel is give very odd problems, it started about 6/8 weeks ago,
When starting in the morning for my trip to work for the 1st mile or so it had an irregular mis with some odd diesel cackle and blue smoke at idle, soon as it started to warm it ran fine,
An injector I thought so I got them serviced and re-fitted them exactly the same, I even took them back to the shop for them to be re-tested but the guy said they were fine, I hate having to relie on other people,
Anyway it was bugging me so I took the head off to make sure the hot spots were ok and not about to drop, they were fine,
Off with the sump out with the pistons, the only problem I could see with the pistons was an odd gap above the top ring around about a third of the way around this was on 2 pistons allowing the ring to move up/down,
Anyway I fitted 4 new pistons the bore had only about 3 thou of ware,
I also fitted a new skew gear that fits under the injector pump and all the crankshaft shells 70 psi oil pressure,
Since re-fitting the engine I have checked the compressions and they are all around the 430 psi mark with no back pressure,
But its starting to sound worse than ever now its only done 50 miles since re-fitting but on cold start-up there is a distinct sound of what sounds like something blowing but no signs of anything with the engine not sound right at all,
I set the pump timing to were it should be I get a lot of diesel knock when giving it gun with some black smoke, the if I go to idle speed after a run it starts putting out blue smoke, which in my experience is normally a sign of retarded pump timing but I have never had both blue and black smoke, I have altered the timing retarding it quite a way just about getting rid of the diesel knock but its quite rough all the time when driving,
Any ideas guys, I am now starting to think that maybe the injector pump may be the problem but I have no idea of symtoms that a bad pump can give????? anybody know much about the DPA pump fitted to the 2.25D and how problems show up I just dont want to throw good money at a pump that maybe fine.
Nick.
When starting in the morning for my trip to work for the 1st mile or so it had an irregular mis with some odd diesel cackle and blue smoke at idle, soon as it started to warm it ran fine,
An injector I thought so I got them serviced and re-fitted them exactly the same, I even took them back to the shop for them to be re-tested but the guy said they were fine, I hate having to relie on other people,
Anyway it was bugging me so I took the head off to make sure the hot spots were ok and not about to drop, they were fine,
Off with the sump out with the pistons, the only problem I could see with the pistons was an odd gap above the top ring around about a third of the way around this was on 2 pistons allowing the ring to move up/down,
Anyway I fitted 4 new pistons the bore had only about 3 thou of ware,
I also fitted a new skew gear that fits under the injector pump and all the crankshaft shells 70 psi oil pressure,
Since re-fitting the engine I have checked the compressions and they are all around the 430 psi mark with no back pressure,
But its starting to sound worse than ever now its only done 50 miles since re-fitting but on cold start-up there is a distinct sound of what sounds like something blowing but no signs of anything with the engine not sound right at all,
I set the pump timing to were it should be I get a lot of diesel knock when giving it gun with some black smoke, the if I go to idle speed after a run it starts putting out blue smoke, which in my experience is normally a sign of retarded pump timing but I have never had both blue and black smoke, I have altered the timing retarding it quite a way just about getting rid of the diesel knock but its quite rough all the time when driving,
Any ideas guys, I am now starting to think that maybe the injector pump may be the problem but I have no idea of symtoms that a bad pump can give????? anybody know much about the DPA pump fitted to the 2.25D and how problems show up I just dont want to throw good money at a pump that maybe fine.
Nick.