How you boys drive the turbo scavenging pump with the gt3 ims? There is also a straight cut gear set that does not put a thrust load on the ims shaft to bearing.

 

I will never have answer to my question post#2..... . I tough it was a good question especially I would like to know if you have to replace other gears or the GT3 intermediate shaft fit perfectly...

 

The pump just fits right in on the 997 series as it's the same pump. The regular gt3s haven't had a problem with this with their higher revs and it's been used that Way forever with SC's etc... We probably don't want the noise Of the straight cut gear but good idea as it would be stronger etc...

 

Hmm they're usually size 0 but I'll ask James...

 

I am not sure we are on the same page here



This end does not fit the tt's turbo scavenging pump.

 

Sorry thought you were talking about the gt3 scavenge pump. In this case there's an adapter snout. Darn geeks why are we on here on a saturday night?

 

Or as I was saying other folks just pin the factory one as that's easier

Also the newer gt3 has that similar drive

 

Thanks!

 

Of the 996 Turbo failures you've seen, what is the breakout in terms of the total number you've seen, and number of failures by model year?

 

Not that I can add much here but I have had two here in the past for IMS separation failures, both of which were 02's, and a couple others that didn't look so good once torn down that I refused to put back in. Can't recall the years on those engines.

 

Thanks for the data points.

So just four? Do you recall if they had LWFWs?

 

Thanks for sharing such valuable info and video with us!
Btw can this problem will also result in changing greater degree of high rev camshaft or running your engine rpm above 7200 or greater? Tks!

 

Sorry, I'll do a "my bad" and stand happily corrected if need be but, I'm usually skeptical of these types of pronouncements. I like facts, and this sounds suspiciously like mechanic's urban myth. So....from the 2003 Porsche 996TT Owners Manual, Page 14 Under Break-In procedures covering the first 2000 miles...we read:

*Do not exceed maximum engine speed of 4200RPM.
*Do not let the engine labor, especially when driving uphill. Shift to the next lower gear in time.(Use the most favorable rpm range)
*Never lug the engine in high gear at low speeds. This rule applies at all times, not just during the break in period.

Now, they don't say why you shouldn't lug the engine aside from the obvious poor fuel economy. The also don't specify what constitutes favorable or unfavorable rpm's. In the later sections on driving tips and shifting, there is absolutely no mention of an rpm range, recommended or otherwise, aside from the obvious not downshifting into a gear that would cause an over rev condition(Not possible with a Tip). No mention of keeping rpm's above 3000 that I can find. To add to this, my Tip most definitely does not keep rpm's above 3000 unless I'm manually asking it to. At freeway speeds of 60-75mph, the Tip is in 5th gear and running 2200 to 2600 rpms. On flat and level, it will shift to 5th at speeds as low as 50mph/1900 rpms. Porsche engineers would not deliberately design the engine and Tip to operate routinely at rpm's that would be harmful long term. So I'd like to ask where exactly is it stated by Porsche that the 996 Turbo engine is happiest long term if run above 3000 rpm? Not saying I couldn't have missed it reading the manual, I certainly could have, and not saying that they may indeed make that recommendation on other models/engines. But I can't find a peep from Weissach on the subject. And again I'll stand happily corrected if they indeed make such a recommendation in writing.

Cheers
Mikey

 

umm - so is there a recommended part # ? Is it ridiculously expensive over replacing the OEM - since it is a GT3 part # ? Is there anything we can do to the OEM with or without replacing the OEM ? (Possibly weld it on or ?)

Thank you in advance .. as I maybe nearing to pulling my motor too to fortify the engine to Max out some 3076s

 

They were all stock clutch and flywheels. Somewhere I have pictures of one of the partial failures, showing a few thousandths axial gap between the gear and shaft(bolt failure). Cause can be debated until the world ends with no true answer to ever come to light. One has to consider its a similar fashion in how a gearbox ring gear is attached to a differential, abiet less fasteners but also considerably less load. Could it be poor harmonics, or load, or heat, or just poor design....sure. Who knows for sure though.

Ari, you can machine and install dowel pins and tig weld tem in place (chain sprockets need to be temp removed). Shaft and main gear need to be checked for runout both before and after the process. Still would recommend the gt3 components till my face turns blue but sometimes one needs an alternative solution. And then there's the customers who "know everything" and appear to have bricks for ears

Good thread