| Author | Message | ||
     Richard Treacy Grand Master Username: richard_treacy Post Number: 2039 Registered: 4-2003 |
Apparently not. I had a repeat of an event from 9 ½ years ago on my Turbo R on Friday and Sunday. I was worried that the car had appeared to use almost a litre of oil in 300km driving to Canberra as I do every Friday night. Then, when I stopped smartly in the main route through the city, suddenly there was a plume of stinking dark smoke behind me. It cleared, so I figured that it was from another vehicle. Then last night departing for Sydney, I pulled into the service station at Manuka, and the same thing happened on a smaller scale. I figured that the turbocharger had collapsed, spewing oil into the induction system. However, I continued to Sydney, observing mabe a 20% loss in power and a roughish idle. Then I twigged again this morning, remembering what had happened in 2000 after the dealer had changed the oil for me – the last time I ever had any work done by a garage by the way. Sure enough, the oil filler cap was cocked slightly. Hence, the air flow into the breather system via the flame trap had skyrocketed, sucking gulps of oil with it as the oil sloshed around when braking and upsetting the engine management system. Closing the cap properly cured it all instantly. This is just a note for the records, as such a small omission can give such a dramatic and alarming effect. RHT. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2040 Registered: 4-2003 |
Other symptoms were: • Sluggish off the mark sometimes, depending on just how well the unlocked cap was sealing I assume • Loss of torque especially between 2000 and 3000rpm (sounds familiar ?) • Lack of Whoosh when backed off from full throttle as if the wastegate were always on bypass • 100-140 km/h in third was OK but perhaps a little down, but in second on kickdown only a little performance was lost • Left alone (ie not held manually in second until 4500RPM), full-throttle changes 1-2 around 125 km/h (it has that wonderful 2.28:1 final drive) were accompanied by turbo shutdown for ½ second – knock sensors working overtime to shut boost as if running on straight premium unleaded and not V-Power Thank goodness mine is a rare non-cat injected Turbo R, otherwise the cat would be destroyed. Watch that filler cap if you have a Turbo with a cat, or even maybe a non-turbo with a cat. I had noticed all this from time to time over the last fortnight since someone was having a look underbonnet, but once corrected it was all too obvious. Only when the exhaust billowed did I become really worried that something was really amiss. On SYs, with their inadequate crankshaft rear main arrangement, loss of crankcase depression also causes rear main oil leaks past the scroll. That is unless, as on our T-Series, a proper rear main PTFE oil seal has been retrofitted. That may be caused by a blocked flame trap (worst until the valve stem seals have been upgraded to late SZ spec) or due to a broken filler cap seal too. RHT. | ||
| James Feller Prolific User Username: james_feller Post Number: 115 Registered: 5-2008 |
Wow RHT, that would have given you quite a scare I bet, I would have been on tranquilisers if it happened to me..... but yes ok point taken check the oil cap is closed!!! My Turbo does occasionally puff the smallest amount of blue smoke on initial start up if hot. I believe this is normal, it is very faint in colour but it comes from a small drop or two of oil deposit in the exhaust system from the turbine. I have been told the turbine does require oil lubrication. I assume this is normal as it never blows smoke at all not even black sooty smoke when the foot is floored and we are racing towards the horizon!!!!!!!!!! Merry Xmas ALL and watch the buggers in trees with Radar guns!!!! J | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2044 Registered: 4-2003 |
James, Panic was the wrong emotion: more resignation that, one day, the turbocharger will drop its guts. Mine has covered around 300,000 hard kilometres already. It�s such a reliable part that I may just overhaul it soon anyhow so I may forget it forever. Besides, being a Garrett T04B, pretty much a standard truck turbocharger, they are common and not expensive. It�s just the thought of undoing high-temperature joints with bolts that have probably seized five minutes after the motor first ran which is daunting. Incidentally, many people talk of rebuilding these with the ceramic ball bearing option and different sealing arrangements. Nice idea, really good for competition but short on longevity. Remember Italian and Japanese high-revving motors with roller bearing crankshafts ? Same story: great until they let go with no warning and an almighty bang. Unmodified, I can hardly complain about the turbocharger�s performance, and certainly not its service life. The turbocharger has a positive oil feed of course. Well known is that, when a garage exhaust extractor is used, the oil is sucked into the exhaust side past the turbine bearings and seals. When started after removing the extractor, blue smoke can persist for a minute or so. The exhaust is normally under pressure, so when the turbine is put under depression by an exhaust extractor, the oil sealing works in the reverse direction from normal. Leakage into the exhaust under that circumstance is quite normal. Many times these cars wrongly fail their pollution test when the testers use an exhaust extractor and the exhausts system becomes contaminated with oil. That is especially acute with a catalytic converter, as it may take quite some time for it to clean itself, if ever. Even our e-workshop manuals are specific that an exhaust extractor will give rise to this phenomenon. Sure, a little seepage may occur after being parked, but I have never seen it I admit. The sealing on the turbine side relies on the pressure as there is usually no conventional lip seal due to the heat environment. RHT. |
