Subaru of America BR-Z TechTalk Bulletin May 2012
 

My master technician dropped off the section of May's TechTalk bulletin from SOA for me while I was at work today. There's a couple odds and ends that might prove to be interesting and a few other things that might quell some fears or maybe even raise some concerns. I'm not near my scanner right now, so for now you'll have to deal with me just re-typing everything.

BRZ REPLACEMENT ENGINE INFORMATION

In the event a replacement engine is required for a BRZ, be aware it will not include driver's side crush cover for the fuel injectors as shown in the photo. The left side cover will need to be changed over from the original engine or replaced with a new one if it cannot be reused. The right side cover is included with the replacement engine assembly.


BRZ FUEL INJECTION OPERATIONAL CHARACTERISTICS

You may notice, or customers may question, various sounds that change in volume and character from the engine and direct injection fuel pump at idle. These may be described as "clicking" or "clacking" sounds or a similar description. The sounds described are most commonly noticed at idle during initial engine warm up.

Be aware that BRZ utilizes both port and direct fuel injection systems. These systems are operated in one of three modes: Port Injection Only, Direct Injection Only, and a combination of both together. The transition between these modes of operation will occur automatically based upon inputs to the ECM. As the injection mode changes, there will be associated changes in the volume and character of the sounds coming from the injection system. Upon initial cold start, both direct and port injection systems are functioning. Within a short time (roughly 60 seconds, dependent on many factors), the port injection turns off and only direct injection is active. As a result, there will be a normal increase in injector sound volume. Shortly after that, injection will change from direct only to port only. After additional time, the mode will change back to a combination of both direct and port injection. These mode changes will continue to occur as decided by the various ECM inputs and will vary under changing conditions. Similar actions will also occur during hot start depending upon catalyst temperatures and other factors. These sounds are most likely quite different from what you may have experienced with prior Subaru models and are not a source for concern.


BRZ MANUAL TRANSMISSION SOUNDS

You may notice, or customers may question, a "thump" or "thunk" sound intermittently when placing the new six-speed manual transmission into first or reverse while stopped. This is a characteristic of the transmission operation which occurs when any remaining input shaft rotation is brought to a quick stop by gear selection. If enough time is given for the shaft to stop turning on its own, then no thump will occur. No wear or damage is occurring as a result of this action. This sound may be more noticeable as the gear oil warms and gear selection is able to be accomplished with greater speed.








So this means that most of the noises I have heard so far are considered "normal" - intriguing.

I figured that all of the above was normal -- What I am more concerned about is the damn squeaking/chirping presumably coming from the drive belt tensioner pulley/device.

I hear that noise occasionally, too, at low RPM, mostly when shifting into 2nd. I dunno if it's actually the tensioner, but it sounds like tensioner chirping.

This is what I love about this forum. Collectively, we have all noticed, discussed and came up with conclusions with at least the last 2 issues. Its still nice to get some kinds of "official" statement on them though. Thanks!

Thankfully we haven't needed to figure out the first one!

It sounds more like the injectors if you ask me.

I'm really curious as to why they're even mentioning replacing engines...it's almost as if they anticipate it, along with the other two complaints of the injectors and transmission.

I don't think there is anything unusual about this. The engines are mechanical devices and when you produce this many even a 99.9% success rate means you are going to have dozens of failures that need to be replaced for some reason.

You'd think in the age of ubiquitous video that car companies would simply release a short video/sound clip demonstrating normal operation sounds and any deviant sounds to be expected. Seems so much simpler than vague descriptions like "thunk" and "click", which could refer to a variety of different sounds.

Let's not even talk about hard drives; 10% DOA rate is industry STANDARD. MTTF and MTBF...yeah, I doubt the engines in these cars are near 99%, but they won't be in anything except a boutique supercar.

I would guess it is because the replacement engine will not look like as orders and rather than wait for someone to need a engine and deal with it then they sent out the information right away.

No mention of the rear driver side side clunk. Can you relay that some owners are experiencing this?

MT -> Sport Car -> Youthful audience -> aggressive driving -> mis shift -> BOOM

Holy crap, where do you guys buy hard drives? My DOA rates are less than .1%... Now mean time to failure might not be met by as much as 2 or 3 percent, but... 10? Man, I'd drop that company like a hot potato.