OutNSpace

Backstory

It started with a ticking sound coming from the engine on the passenger side, which was driving me crazy. Every time I pulled into my garage it was there. Much more noticeable after the car was warmed up. When I bought the car I had done an inspection, but shame on me for not doing a PPI, which may have caught this. The sound did not happen when I inspected it, maybe it needed to warm up more first. Everything else on the car was perfect, no RMS issues, new AOS, clutch, IMS solution installed, engine mounts, tires, all good. At any rate, I started noticing the tapping sound not long after I took possession of the car and started driving it any distance.

I brought it to a local Porsche 'expert' shop that told me it was nothing to worry about, and that I should use a different oil weight. A few weeks later I noticed it was spattering oil on my garage floor upon start. This was coming out the driver side exhaust, which meant the 456 passenger side of the engine. Some googling led me to to this site, where I learned that this was a somewhat common issue with the M96 engine,. Also that it was often mis-diagnosed as 'noisy lifters'.

I had to know for sure and got a borescope and take a look. (Inexpensive I used for the video below of my #6 cylinder)

Wow - bad cylinder scoring. Huge bummer.

Googling and reading more about this I found that this has occurred with other 996 engines, some with much less mileage then my own. I spent a lot of time here on Rennlist reading about this and I now know much, much more about 996 engines than I ever thought I would! So, after a depressing few days I decided that I was going to fix this before bigger issues occurred.

Options for Fixing

1. Sell the car, pass on to some other poor buyer. PO did this to me but was not an option for me ethically/morally.
2. Sell it as a known issue, take a loss, and move on. Another non-option for me, I really like the car and want to keep it.
3. Buy a used engine off eBay. Risky, prices are not much less than doing a rebuild, and don't address the underlying problem.
4. Buy a rebuilt engine. There are a few suppliers:
RND Engines - too pricey
Vertex Auto - also too pricey
MB Motorsports - this is not a comment at all on their quality, etc. but I didn't like the idea of steel cylinders in an aluminum block
5. Send it out for rebuild. I've learned there are very few shops out there there that should be trusted to do this, Flat6Innovations would be my first choice. But at around 20-28K this was far too expensive for me.
6. Porsche crate motor (expensive!) or a much less expensive short block and use my own cylinder heads. Again, neither of these would address the original problem.
7. Rebuild/fix the engine myself. Still expensive! but not as much as other options, and comes with bonus of bigger engine and a challenging project.

So rebuild it is!

I am not a mechanic, but have worked on engines, and am very mechanical/handy. So I wanted to get as much information as I could before I started this to fully understand what I was getting into.

I started by getting the and reading lots of threads others had posted on rebuilds.

Here are some links I found very useful

Ahsai (Fantastic guide, and he has also graciously helped me with some questions I've had)
https://rennlist.com/forums/996-foru...engine-39.html

Logray
https://rennlist.com/forums/996-foru...he-finale.html

Redneck Rebuild
https://www.6speedonline.com/forums/...ld-thread.html

Flat 6 Assembly
http://www.flat6innovations.com/inde...ngine-assembly

IxOmega Build
https://www.lxomega.com/projects/cars/911/indexA.html

Boxster 996
https://dorkiphus.net/porsche/showthread.php?t=33667

And these videos:

Rebuild Goals

I paid a pretty fair price for the car but it didn't make sense to me to pour nearly what I paid for it into the rebuild. So I wanted primary to keep costs as low as possible, without sacrificing build quality.
I also wanted to do this myself for the experience, but also to keep the costs down. I was really interested in the rebuild class offered by The Knowledge Gruppe (Jake Raby) but the price didn't fall into my goals and I just could not justify it. I did sign up for their online course, but it unfortunately got cancelled.

Rebuild Costs

As I looked into this I found different approaches taken by others. I hope this doesn't turn into a flame war, but I'm going to list the options I came across:

1. Cylinder re-sleeving:

• Aluminum sleeves - Hartech (UK), LN Engineering Nickes
• Iron sleeves - MB Motorsports, others (google them)

2. Cylinder Re-boring and re-plating: Millenium Technologies

Yes, you can re-bore and re-plate the cylinders, and I called up Millenium to get a quote for this. They gave me a very reasonable price to re-bore to 97mm, replate and match with Wossner pistons, rings, etc. This was extremely interesting but in the end I decided to go with the LNE Nickies because:

1. Goal for me was to keep the car long-term. I was concerned with the decreased cylinder wall thickness, and out-of-round issues, as well as the fact that D-Chunking was not addressed.
2. Iron sleeving - this is not a comment on quality or durability, but I just did not like the idea of using iron sleeves. Maybe irrational, but just my preference. Again, I hope this does not start a debate.

I spent a good amount of time putting this all together, so I wanted to give others an idea of what the looks like. Breakdown attached as html file.

Tools Cost

You will need the right tools. Some are obvious, but just so there are no surprises, here is what I got:

• Engine Stand. Harbor Freight has a lot of choices
• I didn't want to spend the money and have not needed it so far: 996 Engine Yoke
• High jack stands. I used these: Harbor Freight 6 ton jack stands and they were high enough to get the engine out
• Floor Jack and Transmission Jack. I had a floor jack, and got the transmission jack at Harbor Freight again
• Cam Timing Tools (thanks Ahsai!). These from eBay are specific to my M96/03 3.6L VarioCam Plus. A 3.4L engine will need different tools
• Cam Alignment Tools. Again, eBay and specific to my engine
• Rear Main Seal Tool - you may be able to install without this tool, but for $60 I felt this was worth it
• For filing the rings, yo will need a
  ring squaring tool
  ring squaring tool
  and also a http://www.ebay.com/itm/332104328874
• Ring Compressor - you could use a cheap spring type one, but why take the risk for this price?
• When it is time to refill the coolant back into your engine, you will need an
  Airlift type cooling system filler
  Airlift type cooling system filler
• Optional, but recommended to get the Durametric Tool

I hope you are adding this up because, yes, the tools alone are expensive.

Other Items/ Costs

If were were looking at my parts list carefully you may have noticed things like new knock sensors, MAF sensor, and injector work. Basically, if you are going to tear down the engine then you need to replace all of that, along with new chains, seals, gaskets, chain guides, etc. Also, all of the engine bolts are stretch bolts, which means they cannot be re-used. You could opt to go with lower cost OEM replacement bolts, but I went with the ARP bolts, which are re-usable.

Also, if you've had scored cylinders and are seeing oil come out the tail pipe, it means the cats are probably coated with that same soot and need to be replaced. I opted to replace mine with an x-pipe and did not list that cost in my sheet, but you should be aware of it.

Final note is that you might be able to rebuild with re-bore/re-plating and get away with re-using some of these items, but I went this route because I wanted to go for long term reliability.

Engine removal / teardown

There are enough posts and videos out there about removing the engine so I'm not going to post on that. It took me about 4 hours total, and the most difficult part was removing the A/C compressor back bolt. One 'trick' I recommend is to remove the intake throttle body and intake tube. Took me about an hour fiddling with that bolt before I did that, but afterwards it took about 3 minutes.

I've disassembled everything and have sent out my block to LNE for re-sleeving, and am patiently waiting for them to be completed.
I also sent out my heads to Len Hoffman at Hoffman Automotive, who did an unbelievable job cleaning, pressure testing, porting, and R&R on the valves.

I've also spent lots of time cleaning parts. Lots. Of. Time.
To help with this, I got an Ultrasonic Cleaner off eBay. Yup, another tool expense. I got the 15L one and it worked great, but some parts I had to do 1/2 at a time. If I had gotten the 20L all of those parts would have fit right in.

Next post I'll upload some disassembly photos, more to come....

808Bill

Thanks for sharing!
Any specialty tools needed?
Did you take pictures of the rebuild?

Doug996InKC

From your itemized parts and service spreadsheet I noticed you had the rotating assembly balanced. May I ask the shop name that performed the work? And what were the exact parts that were balanced?

I will be starting a similar thread soon. My block and heads are currently with LN and Hoffman.

wildbilly32

Ahsai (Fantastic guide, and he has also graciously helped me with some questions I've had)

^^^^
This guy! Keep him close. He knows...

tomcat

OutNSpace

I have not had this done yet, but have had this work quoted out from a shop local to me.

The parts involved include everything that rotates:

• crankshaft / rods / pistons / pins / rings / rod bearings
• dual mass flywheel / clutch / clutch / plate

Ahsai did an amazing job of balancing his pistons / rods / wrist pins / rings. I was really keen on doing this myself but since the entire thing needs to be balanced on the crank with the DMF, etc. I decided not to spend money/time with a piston balancer and scale, etc. and to just send the whole thing out for that. For that, I called quite a few places around me to understand what it involved. What I found is interesting. Most places only balance to within 1 gm. In fact they only wanted me to send them a single piston / rod / wrist pin / ring set. Nope.

I finally found the shop I linked above, who happens to live close to me.

This guy is the real deal - he has an ultra precision shop with some unbelievable tooling (Rottler F67A / H85A / VR10 - more fun stuffI learned about), and will balance the entire assembly to within .1 gm. This is likely better than it came from the factory and I hope I will have a ridiculously smooth running engine in the end.

charlieaf92

OutNSpace

Head job was completely redone, valve seats, guides, pressure tested, ported, everything. From speaking with a few folks its debatable whether the lifters need replacement or not. These had interestingly been replaced by the PO not too long ago. Visual inspection shows no wear whatsoever, and there doesn't seem to be a lot of info on tolerances for these. Lastly, if they give me an issue I figure I can always replace them later.

Hradec

I rebuilt my engine about 2 yrs ago. I did not add all my receipts, but I think I spent between 15-20k very happy with it. Now is the time to install the "insurance policy " parts and make it a better reliable engine. I chose not to do anything to increase horsepower, just reliability. I went this route because of a very respected person in the collector car community.

there is no end to performance mods and money to be spent. Went for reliability

Coopduc

Coopduc

OutNSpace

Yes, I did discover that! Almost useless for a bottom end rebuild. I ended up googling and buying the PDF version of the the 'technical shop manual' for that, and also went through the forum links I posted several times.

Coopduc

808Bill

I too would be interested!

JTT

FYI, Hartech uses Nikasil coated alloy sleeves, not iron. (not a flame, just clarification)...besides, now I'm subscribed Looking forward to seeing your results. I would REALLY like to try this one day myself. Thanks for posting!