Re: Wrote "bum" injector, not "burn." Letterspacing is a bit tight.

In the past year the has been a more than occasional noise upon cold startup that sure sounds like a loose tappet. It begins about 30 seconds or so after startup when the idle drops, along with oil pressure ( to about 19-21 psi. ) Having had the 20k oil change a few days ago, a check of the level showed it it to be one increment down. About 1/4 qt brought it to full. There's been no hard tapping for the past few cold starts. Being that the motor's capacity is now 2 qts less, and in spite of there being an "electricronically controlled" pump, the flow is possibly marginally adequate in this circumstance. However, there's never any valve noise at any pressure when the motor is warm.

Quote
Laz
In the past year the has been a more than occasional noise upon cold startup that sure sounds like a loose tappet. It begins about 30 seconds or so after startup when the idle drops, along with oil pressure ( to about 19-21 psi. ) Having had the 20k oil change a few days ago, a check of the level showed it it to be one increment down. About 1/4 qt brought it to full. There's been no hard tapping for the past few cold starts. Being that the motor's capacity is now 2 qts less, and in spite of there being an "electricronically controlled" pump, the flow is possibly marginally adequate in this circumstance. However, there's never any valve noise at any pressure when the motor is warm.

the oiling system is so marginal at idle that 1/4th quart difference makes any difference. At higher rpms and oil pressure and oil flow rates there is even less oil in the reservoir than there is at idle. If the engine manifested noises at idle from say even slightly foamy oil the kinds of noises it would manifest a high rpms would be horrific, though short-lived.

I think you had better look elsewhere for an explanation for that noise. It does not have to come from the valves. It can arise from the fuel injectors. The engine is now using direct fuel injection and DFI injectors operate at much higher fuel pressures. Thus given the times when the noise is present and absent I would look to the fuel injectors as a source of the noise not the valve hardware and certainly not the oiling system.

It seems to me it's not what's in the sump, but the actual pressure at the lifter(s.) It does sound like just one, on the driver's side. The dealer didn't specify any particular mechanism; just saying the 9A1 is a noisy engine. And yes, side by side with my old car, the 986 2.7, that one is milder sounding; more clickety than clackety.
Unless the noise comes back within a few cold starts, having the sump exactly topped up, without overfill, seems to be effective. Btw, the top up oil is the factory fill M1 0-40 Euro.



Edited 2 time(s). Last edit at 07/13/2013 07:18PM by Laz. (view changes)

I've got my 2009 S with 9A1 engine now for 4 years and 77000 km, and I remember going back to the dealer short after delivery to complain about, what I thought was, valve noise. They convinced me however that the noise originated in the fuel injectors, as Mark posted yesterday.
BTW the engine has been running trouble free all that time and I never had to top it up with oil, always perfect on the max level.

And it's been happening pretty much since the car was new. Hard to imagine it left the factory with a bum injector.
It's been quiet since I added the 1/4 quart to exactly top it up.



Edited 2 time(s). Last edit at 07/15/2013 04:10AM by Laz. (view changes)

I didn't mean "burn", but just one with a little bit more play.
OTOH one wouldn't expect the sound of a fuel injector change by adding some oil.

Didn't wear my glasses

Now, what that exactly constitutes in terms of DFI, who knows?

Even so, earlier today the indicator was one increment below full, and another couple (literally) ounces brought it to perfect again. Vagaries of the first touch up: no oil leaks or smoke. Considering the noise used to occur with almost every cold start, it's hard to explain otherwise, the only near as I can tell variable being oil level.



Edited 2 time(s). Last edit at 07/17/2013 01:09PM by Laz. (view changes)

How much has yours used during the first 20K miles?

My 987 2.7 dropped one bar the first season. Since then, it has taken 7.75 liters = 8.2 quarts at a change and has never used enough to drop even one bar between changes

some of this has been due to dealer underfill by maybe 1/4 quart for each of three chages thus far.

With 3 oil changes, are you changing about every 7K miles?

Sounds like you're engine is essentially not using any oil between changes. Good to hear.

I find the sensor seems pretty accurate. On mine, it must be located on the left side of the engine. If the car is sitting even on a very slight slope with the right side lower than the left, it will show 1 segment down. If the left side is slightly lower, it will show overfilled.

2100 miles; 12,000; 20,000.
Would go for every 5k, but another trip somewhere west could be happening in the next couple months, so it it might be another 8k or so to the next one.



Edited 1 time(s). Last edit at 07/17/2013 03:38PM by Laz. (view changes)