sehorntx

I have been through two intermixes now. If I see it again. I'm going for a track day and driving like a madman until the engine implodes then walking away :)

I am a novice for sure. Only prior experience was taking out the engine before and removing/reinstalling cylinder heads after crack repair. I did have the spare block examined by my local machine shop to ensure no gross defects. The tools I literally made myself. For example to install the circlips on the 4-6 side through the little hole I measure the ID of the side of the piston then found an aluminum broom at Home Depot cut it to appropriate length. Then crammed those circlips in the tube by hand and installed those bad boys. I felt I had nothing to lose, car was just sitting in my garage and I didnt feel like popping for a new engine or used engine which may implode at any instance. Keep in mind my project could blow at any point but it seems to drive with good power at this point. This project is doable for anyone on this forum for sure. Cheers

Loren worked like a champ thanks!

Sorry about the confusion. I inspected my bearing found it to be in good nick and resused it. Lubricated it like hell and left it alone in the intermediate shaft tube. I did get a new cover plate though. I had no idea if the car would actually run again, so I decided to roll the dice on the IMS.

Thanks for the interest. My initial failure 4 years or so ago was bilateral cracked cylinder heads. Performed similar repair as Dharn55, removed engine had cylinder heads repaired and put motor back in all in the garage. I had recurrent intermix about 1 1/2 years ago from unclear source. Engine out again and cylinder heads sent off for check. Cylinder head repairs were intact. I had to assume a cracked block. during the last event I had purchased a 996 engine off ebay with a spun bearing just to get the extra cylinder heads (for $1000.00). Dissasembled my engine down to the crankshaft. Havent taken it to the shop. The only defect I could detect was that the coolant passage gaskets between the two halves of the block were distorted and deformed. So I suspect this allowed coolant under pressure to enter the oil passages after the car was shut off. Rebuilt the engine with my spare block and all my original parts from the first engine. New bearings, rings, valve job... The specialty tools I constructed myself. I had already made some for the cylinder heads during last rebuild. The other ones were mainly for placing the circlips to fix the rod wrist pins in place. Nothing terribly complex but a slow tedious process. I once again decided against the new IMS bearing. Did remove the outer plastic covering to allow better oil circulation. Bearing moved nicely no play. One of the more frustrating points was broken bolts and some striped bolt holes. Had to drill out several and re-tap, that was a pain in the arse. Fighting through the p0410/p0411 codes now. Cheers

Just finished rebuild on my 996. Failure secondary to intermix from cracked block. Rebuild with spare block. Running strong. Keep the faith. Working thru P0410 and P0411. Stalling sometimes at low idle coming to stop but fires up immediately. Learned alot, didnt buy any of the tools, made them myself. Tim

Hey Loren, 996 Rebuild complete. Car running strong. Another lost radio code 996 C2 Becker CDR 220 Type 4462 48/98 Serial #: X5018933 Thanks, Tim

Thanks guys. I had a recurrent intermix in my engine about two years after having cracks repaired in both cylinder heads. Engine cam out again and I have sent heads back to machine shop in California, but alas the cylinder head repairs checked out OK. After some procrastination I have now dissassembled down to the crankshaft. Previously I had purchased another 996 engine with a spun bearing in case I needed the heads. Now my assumption is that I have a cracked block and I am rebuilding with the block from my other engine. I had this block cleaned at checked out with a local machine shop, no defects. Wish me luck. This crap is turning me into a decent mechanic though! Here's a question: Do I have to have my crankshaft polished or checked before reassembly. Car was running fine but just intermixing. I am planning on making my own tools for the circlip placement, this looks doable without the cost of the porsche tools.

Thanks for the replies. I am down to the crankshaft. Just disassembled the bearing carrier. Many thanks.

Anyone know cost effective site to purchase above, or is Porsche only supplier?Thanks, rebuilding 99 996

Ditto on draining the oil. That will easily tell the tale. Also had ugly stuff on dipstick. Believe me I hope its nothing. I have 996 on blocks in garage with engine out. Still not sure what to do since my cylinder heads are not recracked. Cheers!

I hate to be a pessimist but having had 2 intermix issues that looks suspicious

I have been on break, sorry. I originally had cracks in both heads repaired about 2 years ago. the pressure testing was done at Costa Mesa R & D in California with John Edwards. Waiting on word on the oil cooler but I think its a long shot. I've looked closely at the cylinders and they look fine (no cracks). The coolant surrounding the cylinders was clean. I was only getting coolant into oil, no evidence of contaminated coolant. Thanks Dharn55 hope yours is running well.

My 99 C2 996 which sufferred intermix from cylinder head crack (bilateral). Had new intermix recently. Removed engine, unfortunately pressure testing of heads is ok. Testing oil cooler next. Anyone seen intermix from a block crack? Anyone looking to buy a 996 sans motor?

Both heads were resurfaced during last repair Head gasket for 1-3 head looks good (just removed) Pistons/combustion chambers 1-3 look good Can AOS cause intermix? Had oil cooler replaced prior to last head repair but am sending it in to machine shop for pressure testing Cracks were visible to the eye extending from spark plug recess #1 toward the valve spring adjacent to it