Tech Tips: 1999-2004 Porsche 911 Carrera

Photograph Courtesy Porsche

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First, before buying a 996 it’s absolutely essential that you be willing to pay to have a professional inspect the car. Make sure you pick someone who has lots of experience with the 996. Having a service history that your professional can check is also a plus.

Once you’ve verified that the whole car is up to snuff and have it in your garage, we recommend first turning your attention to the suspension. Original components like shocks and bushings are typically completely worn at their current age. Other than the basics, you can install lowering springs and stiffer shocks to match for an even sportier feel. Also keep in mind that a good alignment makes all the difference in the world on these cars. It’ll make the car much more fun and safer to drive.

The second most common upgrade is typically replacing the stock exhaust with an aftermarket setup. Many owners enjoy the better sound and roughly 5-to-6-horsepower gain that can result depending on what system you buy.

Combine that new exhaust with an ECU flash and you could see gains of more than 10 horsepower. That doesn’t sound like too much, but the biggest difference the flash makes is in the torque curve. It also reduces the “throttle-by-wire” lag between the pedal and the stepper motor, which makes for a much more responsive feel and more power gains lower in the rev range. Although the ECU flash is probably the best overall bang-for- the-buck upgrade, it’ll set you back about $1000. There are quite a few companies who provide them, including FVD and Softronic.

If you’re planning on driving your 996 hard, you’ll want to expand the car’s oil capacity by adding the deep sump. Some companies offer a metal spacer that lowers the stock unit; if you use the original sump, make sure to remove it and inspect the inside. The rubber oil-control flaps are mounted to a cast-metal extension with rivets, which have a tendency to disintegrate and clog the sump.

Some owners modify their cars’ intakes. We specifically do not recommend changing anything in this area of the car. Modified intakes have a tendency to have trouble getting cool air, killing performance. They also often cause problems with how the air is directed through the air mass meter. A modified intake might sound better, but the factory system works best and doesn’t cause as many problems.

These cars represented a quantum leap in complexity over the previous model, meaning more sophisticated ABS, traction control and other systems. However, these more capable systems also come with an Achilles’ heel: They require additional maintenance and can lead to higher repair bills than previous generations such as the 993.

As for maintenance, rear main seal leaks are common. There’s a revised seal available that has a Teflon lip instead of the traditional rubber-and-spring setup. These seals are the same type found on Cayenne and are much more effective.

As you may know, the 996 was the first generation of Porsche 911 to sport a water-cooled engine. If the water pump hasn’t been changed yet, it should be.

Belt rollers tend to fail. You’ll usually hear a squeaking noise coming from the engine before any catastrophic failure. Locate the roller that’s squeaking and replace it.

Replace the coil every 50,000 to 60,000 miles. While you may not feel a misfire or observe a check engine light, a diagnostic scan may reveal a misfire code. It’s better to replace the coil at this point before the car starts running noticeably worse.

The most important maintenance item is changing oil more frequently than the factory recommends. Oil change intervals of 12 months or 6000 miles are necessary to avoid the somewhat common intermediate shaft failure. You should also check the oil filter elements every 12 months–and before the car goes on track–for metal particles that may hint at this condition. Cars driven harder and more often typically fare better than garage queens.

If your car is running with an original air-oil separator, that’s another item that should absolutely be changed before the car sees a track. It’s a $125 part.

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Comments
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AnthonyGS
AnthonyGS Dork
2/13/20 9:15 a.m.

Great cars, super bargain, well built, and fun to drive.  Heck, I own one.  I can't believe this article doesn't at least mention the IMS bearing.  If you are going to service the rear main seal, replace the IMS bearing at the same time or install the IMS solution and eliminate the issue.  

I plan on driving mine tomorrow when the weather is better.

docwyte
docwyte UberDork
2/13/20 2:27 p.m.

Great cars with some major Achilles heels, in the IMS, RMS and cylinder D chunking issues.  the last two cause catastrophic engine failure, which I've seen 1/2 dozen times here on track.    Numbers wise I'm sure that's an anomaly but it's what I've personally witnessed...

Tom_Spangler
Tom_Spangler PowerDork
2/13/20 3:11 p.m.

I still want one. Partially because it's the only 911 that will ever be remotely attainable for me. And I feel like I have to own a 911 some day.

AnthonyGS
AnthonyGS Dork
2/13/20 5:08 p.m.

Tom, lots of reasons to get one.  Get a 99 or early production 00 and enjoy the heck out of it.  This is the one car I have gotten that my wife says I can never sell.

Feedyurhed
Feedyurhed UltraDork
2/13/20 7:34 p.m.
Tom_Spangler said:

I still want one. Partially because it's the only 911 that will ever be remotely attainable for me. And I feel like I have to own a 911 some day.

Me too...............it's like you just can't go through life with out at least one 911. 

AnthonyGS
AnthonyGS Dork
2/14/20 8:56 a.m.
Feedyurhed said:
Tom_Spangler said:

I still want one. Partially because it's the only 911 that will ever be remotely attainable for me. And I feel like I have to own a 911 some day.

Me too...............it's like you just can't go through life with out at least one 911. 

These cars are the best kept secret of the 911 world.  I'm going to summarize lots of other articles and people here.

 

It's a 911 with functional AC, heat, and still light.  It's as fast as the old air cooled 911 turbos.  It's more analog and raw than the newer water pumper 911s.  The only thing wrong with a 996 are the headlights, but they grow on you.  

nderwater
nderwater UltimaDork
2/14/20 9:24 a.m.

I was curious whether anyone had started restomodding 996s yet and found this.  I feel so conflicted:

Tom_Spangler
Tom_Spangler PowerDork
2/14/20 9:36 a.m.
AnthonyGS said:
Feedyurhed said:
Tom_Spangler said:

I still want one. Partially because it's the only 911 that will ever be remotely attainable for me. And I feel like I have to own a 911 some day.

Me too...............it's like you just can't go through life with out at least one 911. 

These cars are the best kept secret of the 911 world.  I'm going to summarize lots of other articles and people here.

It's a 911 with functional AC, heat, and still light.  It's as fast as the old air cooled 911 turbos.  It's more analog and raw than the newer water pumper 911s.  The only thing wrong with a 996 are the headlights, but they grow on you.  

Yep, they are modern enough to be very livable, but still have some of that 911 essence.

However, part of me feels like a 986 Boxster is 3/4 the car for 1/4 the money. As much as I'd love to have a 911 some day, it's hard to ignore the value there.

nderwater
nderwater UltimaDork
2/14/20 10:23 a.m.

I'd say the 986 Boxster is 1/2 the car for 1/4 the money ;)
The lack of power and (more significantly) torque means the Boxster doesn't really feel like a Porsche should until you're revving the snot out of it.

AnthonyGS
AnthonyGS Dork
2/14/20 10:51 a.m.
nderwater said:

I'd say the 986 Boxster is 1/2 the car for 1/4 the money ;)
The lack of power and (more significantly) torque means the Boxster doesn't really feel like a Porsche should until you're revving the snot out of it.

I own both a 986S and 996.  It honestly is dang hard to believe the main differences in the engine are 0.2 L, intake and exhaust systems.  The 996 feels like it has way more power above 4,000 rpm all the way to 7,000.  Sure the 986S can rev to 7,000 but it honestly feels done after 6k or maybe a bit more. The difference in driving both back to back is stark.  

Many experts have assured me the cams and heads are the same....  they drive like they have different cams with different power bands.  

 

Olemiss540
Olemiss540 Reader
2/14/20 11:34 a.m.

The Cayman S' rock like fall in depreciation is what is driving 911 values into the GROUND IMO. Similar power numbers, similar (low) curb weight, mid engine layout, updated interior, etc.

The fact that transmissions are a consumable item and cost serious coin to rebuild as well as the fact the engines are almost certain to explode during hard driving makes the 996 911 an incredible performance value as long as its still running. The car is almost a consumable due to the cost repair v replace equation once the engine pops or tranny/diff explodes. 

I have seen atleast 6 996s bellowing smoke/doa at track events in the last 4 years and I dont do many PCA events.....

The real deal is to buy a rolling chassis for nothing and throw an LS3 in it for a killer 996 combo I would think.

docwyte
docwyte UberDork
2/14/20 11:45 a.m.

In reply to Olemiss540 :

Having done a LS swap into my 951, I'd never recommend doing one again.  It's far more time and money than what anyone will lead you to believe and if you want to track it, you have more issues to overcome, like proper cooling, oil control, etc, etc.

AnthonyGS
AnthonyGS Dork
2/14/20 12:27 p.m.

Bellowing oil at a track day could be an overfilled sump or failed AOS ($120 part).  The failure rates aren't any worse than any other performance car.  Yes the cost to rebuild is high.  It's really no surprise how overblown the issues are, largely thanks to the internet.  Almost all issues can be addresses via maintenance and minor repairs.  There is an 04 anniversary 911 running around with over 400k miles if we want to compare anectdotes.  The 04 X51 has more power and the worst IMS bearing and is a 3.6 so its more likely to have bore scoring and D chunk failure too.  

If you get one, plan to maintain it, or know the consequences.  

Everyone always touts the LS as the answer after Miata but no one ever discusses the early oil pump failures, LS6 valve spring issues or 7.0L Z06 engines dying prematurely.  No performance application is free of concern.

spandak
spandak HalfDork
2/14/20 12:27 p.m.

In reply to docwyte :

Your Porsche knowledge has been coming up a lot lately and your build thread on the turbo... mad respect. 
 

As a recent purchased of a 986 I have my eye out for a cheap 996. 

docwyte
docwyte UberDork
2/14/20 2:49 p.m.

In reply to spandak :

Thanks!  I agree with Anthony that the IMS/D chunk failures are less than what it seems on the internet.  It's just that both cause catastrophic damage that's not worth fixing, so you end up throwing away the car. 

I know my sample size is too small to be statistically relevant but I've seen 6+ cars with that motor have total engine failure on track.  (911's, Boxsters/Caymans).  It's enough that I wouldn't track one unless I was willing to totally write it off, or had a spare motor ready to go in...

Olemiss540
Olemiss540 Reader
2/14/20 3:02 p.m.

It helps that you can buy a brand new LS1 shortblock for $2 grand assembled. 

If you think IMS failures on track are purely anecdotal scare tactics, then you are obviously swimming in the deep end of some sort of koolaid. I am sure as a street car it's not nearly as big an issue though.

Agreed the price of a LS swap is going to be double what you expect since mine cost a BUNCH as well, but you would still have a hell of a track car for $25k all in with all of the LS shortfalls addressed. Would much rather do that than swap in a junkyard replacement 6 cylinder but I honestly may be overestimating the costs of a replacement Pcar motor which would be slanting my judgement. I think a 996 with a LS swap would be an amazing car, similar in power to a 996tt at a much lower cost and I would assume higher reliability on track. Mine runs 175-180 degree water temps which is 15 degrees cooler than my old s50.

AnthonyGS
AnthonyGS Dork
2/14/20 3:22 p.m.

I don't think it's a scare tactic.  I've held a failing IMS bearing in my hand I personally pulled from an M96.  I think the scare comes in that the failure rate is way overstated.  You can service the IMS bearing in an M96.  Do the maintenance.  Or you can go with the IMS solution and worry less.  

Rebuilding an M96 is expensive, that's a fact.  

There are also spec 996s running slicks at the track on factory IMS bearings without problems too.  A spec 996 is a very fast track car in capable hands.  There are scads of spec Boxsters running hard too.  These cars have some issues addressed for track use.  All of this is solvable.  Scaring people away from a great car without addressing the issues from both points of view isn't being objective.  

If you want to track a relatively stock 996, there are dos and don'ts that go along with it.  The idea your engine will explode if you do is way overstated.

The main problem with 996s is under-informed owners getting in over their heads and having unrealistic expectations.  The sky is falling internet vibe around the cars is great for keeping the cost of entry low.  

 

 

Olemiss540
Olemiss540 Reader
2/14/20 3:43 p.m.

From wikipedia:

In 2013 PCNA settled a class-action lawsuit brought by Bruce Eisen et al., without accepting liability. The lawsuit sought compensation for owners of MY2001 to MY 2005 Boxster and 996 cars that had experienced an IMS failure. The original action was to include the 1998 and 1999 M96 units, but the IMS failure rate on these 3.4L cars was so low that it was decided to exclude them from the action.[6]

Porsche agreed to compensate owners of cars made between 4 May 2001 and 21 February 2005 who had experienced an IMS bearing failure within the first ten years of the car's life, or 130,000 miles, whichever came first. Owners who had changed the IMS bearing as a preventive measure were also eligible for compensation. However the schedule of payments was weighted heavily in the favour of cars purchased through the Approved Certified Pre-Owned Program ("ACPO").

docwyte
docwyte UberDork
2/14/20 5:27 p.m.

Tyler Hoover aka Hoovies Garage swapped a LS into his 996 when the factory motor failed on track.  Than the LS failed on track. 

Having been down that road, there's simply no way a swapped car is going to be more reliable than a factory built car like the 996 turbo or the GT3.  Knock on wood my Turbo has been bullet proof and that's me running it at high altitude in high temps.  

It may be cheaper at the outset but it won't be in the long run.  That's a lesson hard learned, I could've bought that 996 GT3 in 2010 (the same time I bought the 951, then swapped it) for the amount of cash I ended up spending on the LS 951.  Then had a track ready, factory built, bullet proof platform that would've been worth 50%+ more than I paid for it...

Olemiss540
Olemiss540 Reader
2/14/20 7:29 p.m.
docwyte said:

Tyler Hoover aka Hoovies Garage swapped a LS into his 996 when the factory motor failed on track.  Than the LS failed on track. 

Having been down that road, there's simply no way a swapped car is going to be more reliable than a factory built car like the 996 turbo or the GT3.  Knock on wood my Turbo has been bullet proof and that's me running it at high altitude in high temps.  

It may be cheaper at the outset but it won't be in the long run.  That's a lesson hard learned, I could've bought that 996 GT3 in 2010 (the same time I bought the 951, then swapped it) for the amount of cash I ended up spending on the LS 951.  Then had a track ready, factory built, bullet proof platform that would've been worth 50%+ more than I paid for it...

Wait. You put $40k+ in a 951 LS swap? Ouch.

That's a suck.

Also, atleast when Tyler dropped the LS he probably could fix it for a total under a grand. That's the benefit versus an IMS based Pcar motor....

A mezger is a 25k engine block, so it's tough to use in a discussion based around an m96 versus an LS.

I will quit replying so others get a chance to weigh in (or this thread dies into the abyss). Its fun to chat about since I dont have any "car guys" at my locale.....

docwyte
docwyte UberDork
2/14/20 11:09 p.m.

In reply to Olemiss540 :

Over 6 years of development, plus the $10k purchase price of the car, probably.  But I never added up the receipts and I did a lot of horse trading, selling off old parts, etc, etc.  No way Tyler could've fixed the car for under $1000.  Parts alone?  Maybe, but then there's labor and also the time and parts to get to the root cause of it blowing up in the first place, which I suspect was oil control.  I'm just not seeing LS's at the prices you talk about. 

When I replaced my original junkyard LS with another one, that was a minimum of $2k+ for the short block and that's not with it filled with high dollar rods/pistons etc.  I had specific issues to deal with, namely my environment.  High altitude and high heat made it extremely difficult to keep temps under control.  I spent a lot of time/effort/money to come up with a combination that worked, meanwhile other LS 944 guys on the swap board who ran at sea level couldn't understand why I had to do what I did, they simply didn't have the problems I do up here.

That's why I'm so blown away by the performance of my 996 Turbo up here.  Even with two turbos generating a ton of heat, it simply doesn't get hot on track here, water temps stay at 185-190F...

03stampededak
03stampededak
2/19/20 6:56 a.m.

In reply to Olemiss540 :

Where are you seeing heavy depreciation on Cayman S cars? I feel like I keep an eye on 09+ Cayman's pretty closely and while I've seen some good looking base models, I can't find a well optioned "S" under $40k.  Much want.

 

Olemiss540
Olemiss540 Reader
2/19/20 9:34 a.m.

In reply to 03stampededak :

Next time try searching for a 2006. 

AnthonyGS
AnthonyGS Dork
2/19/20 2:14 p.m.
Olemiss540 said:

In reply to 03stampededak :

Next time try searching for a 2006. 

An 06-08 Cayman S may be one of the best buys right now. 09-12s are rare mostly due to low sales caused by the economy.

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