Maroc - SAU.COM.AU - content - Aujourd'hui 07:33

More weird shit

Story time again. Not as weird as some previous weird shit failures of mine, just a story of how stupid these cars can be. So, my old Datto has been doing odd things over the last month or so. Maybe a couple of months? For a car that usually sits with the oil temperature gauge bang on 90°C, unless in thick traffic on seriously hot days, it had taken to running at like 98 or 100, and more particularly, if you gave it much in the way of revs, it would increase T noticeably. Like you could see it moving up from 98 to 100 as you accelarated. (And not even accelarating hard - just normal away from the lights stuff). On the rare occasions where I got to really load it up and run it hard towards the top of the rev range, on a couple of occasions (both occasions on the same corner where I like to have some fun) it made horrible noises that sounded like the little angry men with hammers going to town on the top of the pistons. This first happened on a really hot day, so I just supposed I had the usual R32 hot fuel issue that they seem to have. But the second time, it was not a hot day. On both occasions I heard the noise start up and backed out of it right away. I'm not silly. And I wasn't willing to try to provoke it again, for the purposes of diagnosis, except to deliberately hit it one more time on the same day as the 2nd event. The noise was the same (on a different surface, so it clearly was nothing to do with road noise, which given the quality of the bitumen on the usual spot, was a mild possibility of being related) and so I backed out of it, convinced that there was a real nasty noise of the sort you don't want to hear. It's been using a little bit more fuel. Like... 0.5-1 l/100km more. Over a couple of fills. That doesn't happen without cause, in my car, with the way I drive it. Oh, and it used more than 2.5L of oil in about 8000km of driving, which has never happened before. But.... that 8000km coincides almost exactly with running it at ~17 psi of boost, compared to the years and years before of only running 12 on the stock turbo, or a year or so of 10psi on the highflow, immediately prior to turning the boost up. And, the 8000km of running at higher boost is as a result of the (greatly delayed) installation of the R35 AFM and the new Bosch injectors. And the tune on those was good, and the car ran really nicely on that tune. So, it would be hard to blame those things. (There is a caveat about the tune here though, that when we first tuned it we didn't get the injector settings quite right and the tune had some bodges in it in the low load, and cold and warm start tables to patch over that error. But this did not affect high load stuff at all.) So, the mental gears start spinning. What could be causing it? Pinging...because it's hot? Because it's got some other problem? Because of breathing oil vapour (through the stock PCV system - no catch can). Is the noise NOT pinging? Is it an exhaust gasket flapping? Or the plenum gasket? Is it heating the oil because there's suddenly some horrible bearing problem that's flogging the oil? So, onto the dyno it goes. Need a safe space to push it to see what the noise is, what is causing the hotness, what the hell else is going on. I throw the car at my bro-in-law and fly off to Brissy for a couple of days. He eventually gets to my car about the time I come back from Brissy!! Straight up, it seems mostly** fine. It warms up from cold and the ECU reports the thermostat opens up and holds it at 93°C. That seems fine. Maybe a smidge hot, but, a degree here or a degree there, and given that it's on the dyno? Seems normal. But, if you give it a hit on the dyno to over 4000rpm, it suddenly shoots the coolant T up to 100°C, and it takes a while to cool down. **Mostly, except that it stinks like it has a fouled cat. That gets hot and burns off in the first minute son the dyno0, but still smells rich. OK, so the thermostat is maybe a bit suspect. The thing is running on wastegate at this point, so only ~14 psi, lazy as all hell to ramp up, and he goes over the whole fuelling map. It's rich everywhere, so fuel gets pulled out everywhere. This seems wrong, but it's what it wants. Once this is done, the boost controller gets switched on, on LO (maybe 15-16 psi, lol), to see if the noise can be provoked. (Because it hasn't made any weird noises so far). Tunes up ... OK. Maps are good. But it gets hot even quicker. Suspicion now is sufficiently high to give up, let it cool down, get a new thermostat for it. Inspection down the front shows coolant has leaked down near the alternator. Cannot see where it has come from. The pompa del agua is only 6 years old and looks as clean and fresh as the day it went in. Can't see leaks at the pump's weep hole. Can't see gasket leaks. Can't see cracks in castings. Can't see shit. Change the thermo and wash the shit stain away. It hasn't been seen since! With the new thermostat in it will take two full runs before the temperature climbs above 90 and it cools back down pretty fast. The old thermostat looks fine. Can't see why it would be being emo. But it seems like it's been cutting itself in its bedroom. And now the boost gets turned up a bit more. And..... the noise starts. And.... it is the bloody rubber hose at the throttle body. The clamp had shat itself. Cracked through the bit at the back (where it is hard to see). The noise is the air escaping through that connection, and quite possibly the clamp flapping against itself. Would explain the high pitched metallic sort of noise that was a reasonably convincing replica of detonation. And now the bloody fuel needs to be put back in. All of it. Everywhere. Because now we're not losing all that air. Mongrel. And we've now got the injector settings right, so now the bandaids have been pulled off (already done earlier in the game) and it now drives really nice and is making 250 rwkW on 18 psi, which seems like a nice place to be. Oh, and it used a full tank of VERY EXPENSIVE petrol going nowhere on the dyno over a couple of days. I should have done all this a month ago!!! Before Trump-O-Ween started in the gulf. No idea if the oil usage is a real or imagined problem yet. That remains to be resolved. So the moral of this story? Dunno if there is one. But the car had more than one problem, at the same time, that seemed to start at about the same time, that are completely unrelated physically and systematically, but both played a part in driving me crazy from a diagnostic perspective. And even my bro-in-law was led down the garden path by it for quite a while before he worked out what was going on. Bastard cars.