driving below 2800 RPM = trouble?

[vath2001]

How much for this coffee pot? And for these garden tools? And what about the plastic pig holding flowers? I don't see a price on the Boxster?

[RandallNeighbour]

6:47 am

Tables set up, many many loads of crap taken to front yard.

burned out boxster is only $500. Price is negotiable

I have done my morning duty and will now wash dog, bmw, porsche, and do a 15 gallon water change on the marine aquarium at my office.

Then I'm off to a funeral of a distant friend (very close to my older brother, but not me) who was murdered on Monday morning and his body was set ablaze like the Boxster in this thread to cover up the beating he received. (No need to post "I'm sorry for your loss" comments. I just thought it was odd that I'd be commenting on a thread for a burned out Porsche and the same thing happened to this guy!)

Heck of a day, this!

[billybill]

Wow. Interesting story. I guess I should change my driving style. I was shifting pretty early and also skipping gears like going 1-3-5. That was to save my clutch mostly. Or can I still do this just rev higher?

[Brucelee]

Unless you are lugging the engine, I would like someone to explain to me how the RPMs contribute to IMS failure? Are you suggesting that a flawed engine design responds BETTER to more internal stress and friction?

How can that be, please enlighten me.

Again, I am not talking about lugging the motor, although I am not sure how the Tip will allow you to lug it if you are in auto mode.

I am open but skeptical!

[shaman1204]

Originally Posted by Brucelee

Again, I am not talking about lugging the motor, although I am not sure how the Tip will allow you to lug it if you are in auto mode.

I am open but skeptical!

Hey Brucelee, I just watched Enter the Dragon a few days ago on TV, it never gets old. You really can't lug the engine if it is in auto mode, but if you are in manual mode and you are in 4th gear and have to slow down due to traffic, etc. and don't downshift manually, you can definitely lug the engine in that scenario.

[jmatta]

If I've understood Jake Raby and Charles Navarro's comments correctly, the higher rpm translates to higher oil pressure which feeds the IMS bearings at a greater volume, reducing friction (I know, the bearing is supposed to be sealed, but likely leaks).

This is also why they recommend removing the outer seal to allow greater oil flow.

And for what it's worth, I only use Royal Purple in my Box S. Tried it in my '73 911, but leaked too much; so back to good 'ol 20W50 Castrol GTX Dino juice (though it's looks like Brad Penn going forward).

[Bladecutter]

Originally Posted by Brucelee

Unless you are lugging the engine, I would like someone to explain to me how the RPMs contribute to IMS failure? Are you suggesting that a flawed engine design responds BETTER to more internal stress and friction?

How can that be, please enlighten me.

Again, I am not talking about lugging the motor, although I am not sure how the Tip will allow you to lug it if you are in auto mode.

I am open but skeptical!

From everything that I have gathered from the information presented on several other Boxster forums, here's what I understand as being the issue:

At lower RPMs, the Vario-Cam system is actuating the valves at certain rpm ranges.
During the period that the VC system is being actuated, this places an additional load on the IMS, as the IMS is what connects the Camshafts to the Crankshaft.

During high rpms, the cams are already in their maximum position, so they don't place any greater load on the IMS and its bearing. At lower rpms, there is a much greater strain.

Lugging the engine, which technically qualifies as any event that start out at a low rpm in a high transmission gear, with large throttle opening, places a large strain on any engine, but on this engine, because of the design using an IMS, and the weak bearing, this wind up becoming a weak link in the engine.

If you think about most other engine designs, the camshafts are directly actuated by the crankshaft either by a timing chain, a timing belt, or by timing gears. This engine is different, and presents a weak link between the two.

So, here is the most simple way to explain the current thinking on why Boxster engines are having a high rate of IMS bearing failures:

Basically, lugging the engine places a greater load on the IMS and its bearing than is healthy. Excess load on the bearing leads to seal failure. Seal failure leads to oil intrusion, which washes away the lubricating grease in the bearing. Long oil change intervals combined with lugging and cold running lead to fuel contamination of the oil, which leads to fuel contamination of the IMS bearing, which then leads to its failure.

So several things can help lessen the chances of IMS failure:

More frequent oil changes with top quality oils. Somewhere in the 5k to 7500 range is being claimed as the best.

Run the engine up through the rpm range in every gear, and stay away from the 2300 to 3000 rpm range for long periods of time (don't drive cross country at exactly 55 mph).

Have the IMS bearing seals removed to allow constant oil access to lubricate it.

Buy a 2009 Boxster instead.

BC.

[Perfectlap]

I think there's a happy medium...don't stay below 3k and maybe don't keep it up too high either. I'm guessing if your Boxer engine stays between 3-5K RPM 90% of the time and you go no longer than six months or 7.5K miles on the same oil you should have a long lasting engine. and of course keeping the RPMs no higher than 3k before the oil temp is up too

p.s.
Advanced Auto Parts has a special sale on Castrol Syntec, 5 quarts and a K&N oil filter for $25. Pep Boys sells it for $7 each. I plan to buy four of these lots, go with Honda Civic filters and sell the four of them for $15 or whatever. They sell for $13 each without the sale. That ought cover the two Mahle Boxster filters I picked up for $20. I'm going to go with 5w40. Hasta la vista Mobil1 and short shifting.

[pbanders]

FWIW, I feel sorry for any owner who is so concerned about IMS failure that they feel they have to drive at over 3K all the time. If you really believe the motor is that poorly engineered, either spend a wad of cash to get Jake to fix it for you or get rid of it.

I drive the cars I own for my pleasure, if they can't take the way I want to drive them, then I'll get something else.

[cvhs18472]

Originally Posted by pbanders

FWIW, I feel sorry for any owner who is so concerned about IMS failure that they feel they have to drive at over 3K all the time. If you really believe the motor is that poorly engineered, either spend a wad of cash to get Jake to fix it for you or get rid of it.

I drive the cars I own for my pleasure, if they can't take the way I want to drive them, then I'll get something else.

Here, Here.
Ed

[LoveBunny]

Most IMS failures come in stop and go street driving, or in cars driven by Women.

This part makes me laugh because all of the men who have driven my car shift waaaay lower than I do, even my dad. I love the sound of the engine rev. I do a lot of stop-and-go city driving though so that sort of sucks.

[Brucelee]

Lets try this.

Yes, one should avoid lugging the engine. There is no exact RPM rule for this, as in first gear, you should not be able to LUG the engine, and in 6th gear, it is quite easy.

Second. The engine should be able to run safely between just above lugging and to just about red line. So, any exact RPM rule is clearly not appropriate for the issue of grenading the engine. The engine SHOULD NOT grenade.

Re: The IMS, Porsche should just fix the issue if it has not already.

Regarding wear: Higher RPMS cause greater wear than lower RPMs. Any auto engineer will tell you that, assuming you are NOT lugging the engine.

The whole drive it like you stole it advice is purely infantile, if you are talking about engine wear.

Having said that, if you want to trash your engine, be my guest. Just go to the track and beat it until it dies.