Quote:
Originally Posted by pfbz
Exactly the kind of info I was looking for. Thanks!
Tell me if I have this correct...
Years & IMS/RMS Issues:
- 1999-2001. 3.4L engine. Potential issues with RMS (rear main seal), IMS (intermediate main shaft) bearing, AND thin cylinder walls. IMSB can be upgraded to LN (ln engineering) version if you get to it before it fails.
- 2002-2004. 3.6L engine. Same issues with RMS and IMSB as earlier models. Cylinder wall issue resolved. Also upgradable IMSB
- 2005-2008. Both 3.6L and 3.8L engines. Improved RMS, improved IMSB, BUT IMSB no longer replaceable without an engine teardown.
Factory replacements & upgrades:
- Engines replaced after 2005 will have improved RMS and improved (but non-replaceable) IMSB.
- Engines replaced after 2002 will have original 3.4L thinwall engine, or improved 3.6L engine?
What about single row vs. double row IMS bearings? Are both replaceable without teardown? Is there a cutoff date when they switched? Is one notably better than the other? |
You are correct. Porsche only accepts a like engine for core charge. So 3.4 for a 3.4 & 3.6 for a 3.6 the 2 engines use Different DME computers so you have to stay with the same engine design unless you change the DME also.
All IMSBs 1998-2004 are replaceable without engine disassembly until the changeover to the final version in early 2005 requiring a visual inspection of the IMSB to verify which was used. The original double row is the best, changed to single row during 2001.