Turbo questions
Discussion
As you may have seen in another thread I am the proud new owner of a 3.3 Turbo (930).
Now that I have lived with it for a weekend I have discovered some of its foibles and potential problems.
I filled it up with LRP on Thursday night (60 quids worth) and having covered 130 miles it is down to 1/4 tank - I make this 10.5 mpg & I assume this is not normal.
The loud noise I noticed (as the boost comes in) when I first drove the car now sounds like a mis-fire (in fact sounds like a Le Mans Porsche GT3), it's also got a burbling, banging, crackling exhaust on overrun. I'm guessing this means it is running rich which ties in with the fuel economy question above.
Finally the generator light comes on (and eventually goes out) when the car starts up, the lights flicker at night and there doesn't seem to be enough juice to drive the stereo. Is it likely that my alternator is kaput or are the alternators on these cars feeble anyway? Is the alternator buried inside the engine like with VW campers? & what sort of price would I have to pay for a new alternator or brushes - assuming I don't want to get my hands dirty.
Any help on the above gratefully received, I guess I will need to find a rolling road to have the mixture set up.
Cheers
Dan
Now that I have lived with it for a weekend I have discovered some of its foibles and potential problems.
I filled it up with LRP on Thursday night (60 quids worth) and having covered 130 miles it is down to 1/4 tank - I make this 10.5 mpg & I assume this is not normal.
The loud noise I noticed (as the boost comes in) when I first drove the car now sounds like a mis-fire (in fact sounds like a Le Mans Porsche GT3), it's also got a burbling, banging, crackling exhaust on overrun. I'm guessing this means it is running rich which ties in with the fuel economy question above.
Finally the generator light comes on (and eventually goes out) when the car starts up, the lights flicker at night and there doesn't seem to be enough juice to drive the stereo. Is it likely that my alternator is kaput or are the alternators on these cars feeble anyway? Is the alternator buried inside the engine like with VW campers? & what sort of price would I have to pay for a new alternator or brushes - assuming I don't want to get my hands dirty.
Any help on the above gratefully received, I guess I will need to find a rolling road to have the mixture set up.
Cheers
Dan
Thanks for all that.
AFAIK the exhaust is an OE one, the two tailpipes appear to be welded together (or is that a casting?). Doesn't look boy-racerish.
The 'misfire' I speak of is crackling under power, it's not pinking or detonation - seems to be coming from the exhaust or inlet.
Turning the 'getting ones hands dirty' issue on its head - is there a Haynes manual or equivalent available for this car? I am a chartered engineer so am fairly adept at spanner twirling but prefer to leave the hassle to someone else. Only trouble is, I don't know anyone I can trust yet.
AFAIK the exhaust is an OE one, the two tailpipes appear to be welded together (or is that a casting?). Doesn't look boy-racerish.
The 'misfire' I speak of is crackling under power, it's not pinking or detonation - seems to be coming from the exhaust or inlet.
Turning the 'getting ones hands dirty' issue on its head - is there a Haynes manual or equivalent available for this car? I am a chartered engineer so am fairly adept at spanner twirling but prefer to leave the hassle to someone else. Only trouble is, I don't know anyone I can trust yet.
Thanks for all your tips, this is all very interesting to me, I guessit's not so interesting to everybody else but at least reading this thread is not mandatory 
My alternator problems seems to have gone away (at least temporarily) - could have been sticking brushes I guess.
The comments about fuelling and/or economy have been very useful - in the main I have been hammering it about so the economy is bound to be low and I won't work out exactly how low until I fill up again.
Today I noticed that the heater doesn't work - I drive about 23 miles to work so there should be opportunity for it to warm up. I had the thermostat set to DEF and the sliders on defrost as well but no heat was coming out. Is it likely to be the thermostat or will I have to inspect the hoses?
Finally and potentially more worrying, I do leave the car running for a minute or so after I have been out for a drive (to keep the turbo lubricated). A minute or so after shut down a cloud of oil mist emerges from the OSR wheel arch - presumably this is venting from the dry sump tank and I guess it's not normal! What should I be looking for? Is it a vent hose that's fallen off?
My alternator problems seems to have gone away (at least temporarily) - could have been sticking brushes I guess.
The comments about fuelling and/or economy have been very useful - in the main I have been hammering it about so the economy is bound to be low and I won't work out exactly how low until I fill up again.
Today I noticed that the heater doesn't work - I drive about 23 miles to work so there should be opportunity for it to warm up. I had the thermostat set to DEF and the sliders on defrost as well but no heat was coming out. Is it likely to be the thermostat or will I have to inspect the hoses?
Finally and potentially more worrying, I do leave the car running for a minute or so after I have been out for a drive (to keep the turbo lubricated). A minute or so after shut down a cloud of oil mist emerges from the OSR wheel arch - presumably this is venting from the dry sump tank and I guess it's not normal! What should I be looking for? Is it a vent hose that's fallen off?
I'll keep my clown face on for the moment.
I just found out (whilst sneaking down to the BMW dealers for a bit for my M5) that the heating works when you operate the 'emergency' heater control. So now I have manual control over the heating but not thermostatic - reading through the owners manual suggests that this manual lever needs presetting somewhere for the thermostat to work. Conclusion - not a heat exchanger (thankfully). However GR4 your mountain of spares has been duly noted and I will get back to you once have found any definite problems.
Domster - the oil is not coming from the exhaust or inlet, it is coming from the dry sump tank, I guess the vent for the tank should be plumbed into the inlet somewhere but it seems to be venting to atmosphere instead. Will have this inspected. (PS - the car is still good vfm in my book at this moment in time).
I'm compiling a list of the problems with the car for when I refer it to the tech for checking. I'm thrifting them off the list when I find the cause of each problem.
List now reads:
1. Oil mist from OSR wheel arch
2. Heater Thermostat NF
3. Check AFR (just filled up - average 12.75 mpg over 180 miles mixed driving)
4. Alternator suspect
5. A/C - check for leaks and recharge if OK.
My pre-purchase inspection confirmed that the car had three wheels was painted grubby yellow and had 'Trotters Independent Traders' written on the side - think it had the spoiler delete option!
Item 6. Search for and locate fourth road wheel........
I just found out (whilst sneaking down to the BMW dealers for a bit for my M5) that the heating works when you operate the 'emergency' heater control. So now I have manual control over the heating but not thermostatic - reading through the owners manual suggests that this manual lever needs presetting somewhere for the thermostat to work. Conclusion - not a heat exchanger (thankfully). However GR4 your mountain of spares has been duly noted and I will get back to you once have found any definite problems.
Domster - the oil is not coming from the exhaust or inlet, it is coming from the dry sump tank, I guess the vent for the tank should be plumbed into the inlet somewhere but it seems to be venting to atmosphere instead. Will have this inspected. (PS - the car is still good vfm in my book at this moment in time).
I'm compiling a list of the problems with the car for when I refer it to the tech for checking. I'm thrifting them off the list when I find the cause of each problem.
List now reads:
1. Oil mist from OSR wheel arch
2. Heater Thermostat NF
3. Check AFR (just filled up - average 12.75 mpg over 180 miles mixed driving)
4. Alternator suspect
5. A/C - check for leaks and recharge if OK.
My pre-purchase inspection confirmed that the car had three wheels was painted grubby yellow and had 'Trotters Independent Traders' written on the side - think it had the spoiler delete option!
Item 6. Search for and locate fourth road wheel........
chris_n said:
they're pretty noisy on full boost anyway so you could just be describing the normal state of affairs.
I'm coming to the conclusion that this is the case, but I'm aware this could be wishful thinking so am taking the car to a specialist anyway. My main concern was due to the car's Jekyll and Hyde nature which I wasn't aware of before (My M5 was so well behaved in comparison).
chris_n said:
Your fuel consumption situation is certainly consistent with my experience - trickle round off boost and the petrol gauge needle is quite well behaved, but start using it as it's intended and it quickly takes a dive!
Been trickling around a bit but I've only been trickling around looking for places where I can floor it.
chris_n said:
As for popping and banging on a trailing throttle - mine certainly does it, not sure if it ought to but I've always presumed it's because the Bosch K-Jet is pretty notorious for over-fueling. Got to admit I quite like it, all adds to the sense of occassion around driving the car.
It does all point to overfuelling, my Ascona rally car (16v Astra with Twin Weber 45s) does exactly the same.
chris_n said:
One question - you mentioned you are using LRP, I didn't think you needed to on this engine because it's got hardened valve seats? I've always used Super Unleaded Hope I haven't been doing something daft!!!
LRP is much more common round my way than Optimax or other Super unleaded. I didn't want to use normal 95RON because of detonation. You're right about the valve seats; alloy heads and valve seat inserts are fine for unleaded.
Thanks all for the help, given the MPG situation this car is not going to be a daily driver so I am planning to take it to Cadwell on 18/10 and Donington 15/11 - maybe I'll see you there......
>> Edited by DemolitionDan on Monday 29th September 09:52
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