The culprit for the smoke that required the visit to Mine's this time around, was this particular hose at the back-side of the engine:
|You can see some rust in the crack - from not having a sufficient amount of coolant in the system, apparently
|Photo courtesy of Richard (fellow R33 GTR owner from the UK),
whose car suffered the same problem, at about the same time!
I scoured the web but just could not find a photo that showed clearly where these hoses attach (it really is a huge mess), so instead:
To replace these hoses, they chose to remove the transmission to access the back of the engine. They then flushed the coolant system, and checked for leaks. So now there shouldn't be any more problems going forward... at least not with these hoses.
Thus, the engine did not have to be removed, which means I was not tempted to open the wallet and install those optional goodies I was hinting at. Perhaps next time!
Although, from my research on this, I am now not sure why this piece is still there. That is, on a road only car, this oil cooler mechanism is obviously enough to keep the oil temperatures in check; but you need an external one if you run your car on a track, however once you install that optional external oil cooler, not sure why this needs to remain. In fact wouldn't it work backwards and heat up the coolant? Someone said that this could be to warm up the oil as the coolant warms up faster, but that doesn't really make sense as oil should be designed to lubricate at even colder temps. So I wonder if this should be removed in the future (one less thing to go wrong), or kept as a back up just in case? And, I wonder if these 4 hoses (shown in the diagram) are available in silicon?
In any case, Nakayama-san inspected the engine and confirmed that the engine suffered no problems from the incident. So that is a relief.
As for the catalytic converter, they weren't kidding when they told me it was "dead." Check this out!
|Looks like the honeycomb has degraded quite badly
|Other side... when I held this up to the light, could barely see ANY light coming through!
In any case, I've now got the HKS catalyzer installed, and the first thing I noticed wasn't just that everything smelled nicer (or more precisely, no smell at all...) but that the engine seemed more eager and responsive.
If I recall correctly, this is how the engine was back when I had it installed - very revvy, like a motorcycle engine, and extremely responsive (the engine was put in about one year after the Apexi catalyzer was installed so presumably it was still working well then). Boost comes on much quicker and the turbos make that funny whooshing sound much more clearly and frequently now.
And this is still with the bung installed on the Tomei exhaust...I'm now tempted to run the car without the bung and with a de-cat, just to unleash its full potential!
In any case, this incident has been a wake up call, so I think I will be having more work done on the car very soon. Stay tuned!