c70Pete

Yes. Forgot about that one!

Hot oil and coolant are the primary culprits here

Mitigate by:

1. Adding 3rd radiator

2. Doing the "fan mod"

3. Keeping an eye on temps via monitoring oil pressure at 3000 rpm. If less than 3.2 Bar @3000 rpm then take few cool down laps

4. 50 weight oil with zddp

5. Reduce run session time on very hot days

And by all Means make sure you have full oil level!!

It had about 110.000km when I took it to the independent Porsche specialist that eventually repaired the engine. Although I did track the car twice, I assume the damage had already been done when I bought it at about 85.000km, since I had to add oil since I bought it. Of course, I don't know how the car was used/driven by its first owner. But it did get worse during my ownership, the ticking noise wasn't there (or at least I didn't notice it) at the beginning.

The oil: before the engine repair: Mobil1 0W40, since the repair (the indy always uses it) Mobil1 5W50.

I ALWAYS waited for the oil level test to finish before driving the car, and I topped it up whenever it went to 1 block above the minimum level. I didn't drive it fast when cold, I really took good care of it.

What I also did: change the thermostat to the LN Engineering version that opens sooner.

Bottom line: I'm afraid it will break down again after another 100.000km. When I browse second hand Porsches online, I often encounter cars with "new engine, only xxxxxx km" on high mileage ones. And I will not track it anymore!

You can track just cool off when your temps come up and change that oil every 4 track events. Mobil 50 is better than 40 but castrol 5-50 is also good stuff. Better than Mobil IMHO

I had my nr 6 scored on my 2005 997 earlier this year. The engine made an atypical ticking noise, and consumed about a liter of oil every 1500km. Within spec, but after the repair (new short block and pistons) I never had to add oil. I also noticed more smoke from the left exhaust (right bank).

This is how the piston looked:

_DSC9852.jpg by Rik Tytgat, on Flickr

thx for sharing..... what was the mileage on your car and how often to you take it to the track? this looks like cylinder looks like a tracked vehicle with no cooling and long oil drain intervals..... curious as to what oil you were using.... full disclosure... I had the same thing happen to my 99 996.... ticking with scored cyliinder and huge oil usage..... ended up buying a new motor.

I hear running pure distilled water AND the water wetter product is the way to go!

but be sure to put coolant back in the system in before winter time...

"rotating assembly" is the crankshaft, rods, front pulley, and flywheel.

I always have these balanced (weight matched, and lightened) when rebuilding an engine. It will add years and RPM to the engine.

so unless you take apart your engine to balance all the above parts *with* the new LWFW your saying don't do it?

I would not. But everyone must weigh the risks and make their own decision.

ok... thx for clarifying... that's why lots of the engines that have this mod added eventually give out early.. but not all though... its a crapshoot

"rotating assembly" is the crankshaft, rods, front pulley, and flywheel.

I always have these balanced (weight matched, and lightened) when rebuilding an engine. It will add years and RPM to the engine.

so unless you take apart your engine to balance all the above parts *with* the new LWFW your saying don't do it?

I have, and I would definitely recommend against using a light weight single mass flywheel unless the rotating assembly, and the flywheel, are fully balanced as a unit before the engine is assembled.

A lot of people seem to think that they can simply slap on an X51 sump cover and all is well, when the reality is that the sump cover is probably the least important component in the upgrade.

dumb question here... what exactly is the rotating assembly... is that not on the flywheel... is it a separate component?

as for the X51 baffled pan.. its does provide *some* benefit that's for sure... but I definitely agree that it is only the 1st (and IMO necessary step) in upgrading the oiling system... I'm curious if there are folks who have done both X51 AND deep sump pan (which holds about 1/2 quart extra only) that have seen more stable pressures in corners where oil pressure was previously unstable. I know of an outfitter here in Canada that makes a sump kit that holds a *complete quart* of oil with spacing hardware and that would certainly help to ward off starvation a bit better than just 1/2 a quart; if the oil your engine needs is suspended in one corner of the engine during a high g corner it will never make it back to the sump and hence never pumped to where it is needed... (this is where complete X51 oiling kit comes into play - pumping it back into sump) and the theory of having a full extra quart means that it was never pumped and is ready as "reserve"... many are doing this but I haven't heard any feedback that shows a change in oil pressure; I have an X51 pan only and *think* I see a SMALL difference but I will do more testing this summer that's for sure as I have made less than scientific observations.

a lot of the oil trying to drain back into the sump gets "stuck" in the cylinder bank towards the outside of a given corner, and the oil in the sump stands up on the same wall of the sump. Not a good thing.

yes but I thought with x51 with the walls built in *around* the tube it forces a much smaller perimeter and keeps the oil in place during high g cornering so the pick up tube has something to suck in... it also has the baffles that open and close to trap oil in that little box round the pickup tube... in a non-x51 pan I can see the oil being cornered on the far wall away from the pick up tube but I don't believe this is happening with x51 pan... unless of course that corner is so long and sweeping and you are generating serious g force for a long time so that it picks up all the oil the x51 pan has collected and now its stuck on top of one of the heads waiting for the g-forces to stop so it comes back down... <- that can definitely happen and from what I'm told will blow the motor; so the question is whether putting in an extra litre of oil with a deeper sump pan makes that condition less likely and I think it does..

btw ... I never knew the x51 pan with baffling allows an extra 1/2 litre of oil... interesting...

I have, and I would definitely recommend against using a light weight single mass flywheel unless the rotating assembly, and the flywheel, are fully balanced as a unit before the engine is assembled.

A lot of people seem to think that they can simply slap on an X51 sump cover and all is well, when the reality is that the sump cover is probably the least important component in the upgrade.

dumb question here... what exactly is the rotating assembly... is that not on the flywheel... is it a separate component?

as for the X51 baffled pan.. its does provide *some* benefit that's for sure... but I definitely agree that it is only the 1st (and IMO necessary step) in upgrading the oiling system... I'm curious if there are folks who have done both X51 AND deep sump pan (which holds about 1/2 quart extra only) that have seen more stable pressures in corners where oil pressure was previously unstable. I know of an outfitter here in Canada that makes a sump kit that holds a *complete quart* of oil with spacing hardware and that would certainly help to ward off starvation a bit better than just 1/2 a quart; if the oil your engine needs is suspended in one corner of the engine during a high g corner it will never make it back to the sump and hence never pumped to where it is needed... (this is where complete X51 oiling kit comes into play - pumping it back into sump) and the theory of having a full extra quart means that it was never pumped and is ready as "reserve"... many are doing this but I haven't heard any feedback that shows a change in oil pressure; I have an X51 pan only and *think* I see a SMALL difference but I will do more testing this summer that's for sure as I have made less than scientific observations.

the x51 oil pump and line is what is needed for sure...

don't mean to hijack the thread here but I understand that adding a LWFW can potentially damage out your crank! have you looked into this?

Hi,

I can highly recommend Courtney Walsh of EU Autowerks in the Toronto area... Courtney has rebuild many many 996 motors personally and has a large customer following and great reputation for quality work.

905-850-7600 and ask for Courtney or Domenic.... Domenic is the service manager and has been through this many times.... good luck.

I am just wondering if anyone has a specific recommendation about tire size for an 01 C4 running 17x9 wheels rear and 17x7 wheels front. Also, I am planning on purchasing mich pilot sports. They seem to get pretty high ratings from what I can find.

I have the same setup as you.... I'm running 225/45/17 and 255/40/17 ... I've run PS2, SO2-A and now on Kumho Exsta XS.... if you can find a wider front and rear combo without sacrificing diameter it would be stickier that's for sure... but I think with a 7" front your are limited to a max of 225...

I'm not sure about RoW cars - as far as I know all US cars had the J loop cooler.

Was your car originally a US car?

Here is a link to book article on the upgrade - I did not do the electric fan part - just the turbo cooler.

http://books.google....ved=0CAgQ6AEwAQ

Hi Loren,

did you notice a difference in oil pressure when tracking after installing the turbo cooler? is there even a way to tell oil temp in our 99 996 c2?

Hello all,

This is my first post in the forum. I recently purchased a 2000 996 with 111K on it. Since I am a dealer, I was able to pull all service records, etc, from Porsche and found (before purchasing) that no major problems occurred with the vehicle since new. Oil changes were done at the very least, every 5000 miles and all scheduled maintenance was completed. After purchasing the vehicle, I drove it TWO MILES before I heard a pop followed by large bellows of smoke from the exhaust. I took it to the local Porsche dealer where they diagnosed a failed oil cooler. After replacing the oil cooler and flushing the engine and cooling components, I drove the car home. After driving 143 miles, I noticed my coolant level dropping and my oil level increasing in addition to it being a milky white cooler. There was oil in the coolant reservoir as well. Both the compression AND leakdown tests were perfect. Any ideas as to what may be causing this? Thank you!

Wow, I thought I was reading about my 2000 C4 with 81k miles. I had the same problem, failed oil separater, reduced coolant, increased oil level, oozing coffee color fluid. I had the cracked cylinder wall problem. :cursing: $16,000 later I had a rebuilt engine installed. :angry: Odd thing, the original engine did not use much oil at all, the rebuilt engine uses more oil. I hope it lasts. I am disapointed with the 996 engine.

The safe way to go here is a 3.6 motor that you have reliable service history on and Jake Raby's IMS update... the 3.6 and 3.4 engines have their gremlins but I think the 3.6 engines are stronger with the exception of their IMS shaft... more IMS failures on 3.6 than 3.4 motors... even if I bought a used 3.6 996 I would drop tranny and replace the shaft via Jake's retrofit kit... a must with the 3.6 cars.... the 3.4 cars... its a pure gamble due to cylinder wall failures and cracked cylinder head potential...

Usually less than 2 hours.

Most respectable shops have a fixed fee (barring any broken or worn parts).

thx Loren.. I suspected as much... my shop wants 3 hours and another 1/2 hour to install a tie rod.... I'll have to speak to them about that... 3 hours seems like a lot...

how long does it take a shop to do an alignment? how many hours? I have row 030

Huh Pete???

My '99 has 76K on the clock and it burns less than 1/2 quart of Mobil1 in 3K miles.

This car is not my daily driver but I do run it like it was meant to be driven and thus far it has been bulletproof short of two O2 sensors going south over the years.

While I agree that like any high strung engine there may have been some issues early on, at least in my case (I speak only for myself) I'd say a proper break-in and these are very good motors.

One thing I am pretty sure of is that my original 3.4 is not going to be ready for the scrap heap anytime soon.

hey... 1/2 a quart every 5000 isn't bad for a 76,000 mile 3.4.... if your not tracking the car it should last a long time... high oil usage is a sign... but 1/2 a quart is nothing to be concerned about...

As a future buyer of a 996 I think that this thread is really helpful, but at the end of the day what I have understood is that if yo buy a car with 60-80k miles (98,99 model) with full service history and every documentation present, then the chances of real problems are remote.

Then again others might say it is a gamble, but what isn't ?

Andronikos

well... 60-80K is a high mileage 996 as I don't think they will go beyond 160K

full documentation and verifiable service history helps.... but what most potential buyers don't do is a leakdown and compression test... remember the cylinders of these cars tend to "oval" over time... especially by the 60-80K mark depending on how the car was driven... which practially guarantees you problems...

I don't know if you'd get the best time in a C4 using that method. It used to work great in my WRX though. I'd rev it to 5,000 RPM, drop the clutch, and floor it at the same time. That car was AWD also, but a more evenly distributed AWD than the C4 and you needed the high revs to get the turbo spooled up.

With my C4S I find I get launches better with more clutch slip than just dumping the clutch. If you've got PSM make sure you turn that off, otherwise it will stop the fun immediately. I rev my C4S and then slip the clutch out very quickly, but don't dump it. Once the car's hooked up and the clutch is out, floor the throttle. You may smell the clutch burn, you'll get more clutch wear, but you won't get the immediate and brutal shock to the system with dumping the clutch and you'll still get a good launch. That's been my personal experience.

I used to do the same thing in my AWD Talon way back in high school, and it worked great for the same reasons. In two years of racing that thing I actually only went through one clutch.

I don't launch my C4S very often, but I agree with your method for slipping the clutch versus dumping it.

what rpm is best to shift for 1/4 miles times? 6,500 or right till 7,200 rpm?

Took it to the shop, turns out that one of the hoses that goes into the air oil separator was cracked in two places.

wow! glad to hear they found it... you were right in assuming a crack somewhere else...

Fair enough. I guess what I really meant was that under higher loads - like a big pothole - the car is as firm or firmer than stock. So not less comfortable, just not more comfortable. But all bumps now feel 'round' instead of 'square'. So, more firm but less harsh, if that makes sense.

I found that my old shocks tended to resist compression initially, and then give in all of a sudden. The result was a feeling of 'slamming' when you hit bumps. If you've ever tried to set up shocks on a dirt bike or a mountain bike, you'll know what I mean. Whereas the Bilsteins respond to everything, to the point where the car actually squats slightly on acceleration now, but also brakes more smoothly because the center of gravity shifts forward more naturally.

It's all pretty subtle stuff, I guess. But I've always believed the fastest suspension is the one that's matched to the conditions. For me, this was it.

ok... I know exactly what u mean here... the slamming or more so the suspension *crashing* onto a pothole is eliminated with a muffled and controlled thud which feels more round than square... so basically it takes the edge off of potholes by reacting quicker to the input... that's a great quality to have in a shock absorber...

I too have been looking at the Bilstein shocks. I have put them on my BMW and they are a little stiffer than my stock shocks were. Control is great. Let us know how they work out. I will be in the market for shocks in the next year or so.

would you say your BMW rides more comfortably with the Bilstein HD than with the stock shocks?

I know you weren't asking me, but... : )

I don't think there's a simple answer to that question. (I also have put Bilsteins on one of my previous E36s). What characterizes a gas shock is its rising spring rate under load. The more you compress a gas shock, the stiffer it becomes. A really well engineered gas shock will manage that process better, so the spring rate changes in a more linear way. This is even more pronounced when you're not lowering your suspension, since the shock has more travel through which to vary its spring rate.

The net effect is that a great gas shock will feel more comfortable than your stock shocks when it's being asked to respond to small bumps. But compressed further, such as by a big bump or by lateral loading as you corner, that same shock will actually feel stiffer than your stock setup. That's why I like them for a 100% road-driven car: in a lot of situations, they'll actually out-handle a lowered, stiffer setup with aggressive sway bars will (sways transfer impact from one wheel to the opposite wheel in a corner, making it harder to keep all the rubber on the ground).

(Then there's rebound damping, which would make this post twice as boring...)

So, based on my experience, I'd say that the answer to your question is likely to be "Mostly, yes. Sometimes, no."

okay... I can see what you mean.... I like the idea of more control when I need more speed but I like the idea of the shock absorber absorbing small bumps, potholes in regular speed situations... sounds what I'm looking for...

so you say sometimes no... can you describe these situations when its *not* more comfortable... curious about this one...

I too have been looking at the Bilstein shocks. I have put them on my BMW and they are a little stiffer than my stock shocks were. Control is great. Let us know how they work out. I will be in the market for shocks in the next year or so.

would you say your BMW rides more comfortably with the Bilstein HD than with the stock shocks?

My 2000 C2 used to run on the left side of 0 in the 180 maybe go up a little bit in stop and go. I don't have JE's humidity (I am from Houston, no potshots) but do have the high heat (yesterday in Fort Worth Texas it was 102). Even with decent traffic flow temp was at the middle or high side of 0 in 180. Using the HVAC hack (hold recirc and top button down for 5 seconds) my coolant temps were up to 107C (I know Loren, this is not accurate but on the fly seems to match coolant temp gauge). I can see some junk in my radiators (cleaned them last year). Probably need to do it again. Also, noticed that my oil pressure was about 0.5 bar at idle versus about 1 bar in "reasonable" temps (~80F).

I did the fan high speed fan mod and I notice my temps dropped a good 10-12C in traffic!! very happy with this.... when your temps drop your oil pressure will rise to normal.... the needle strait up is 93/94C

this mod also helps at the track... I have it on all the time during tracking and it definitely bleeds off heat nicely...

Mobil says it is okay to mix on their website. Whether Porsche says it's okay I don't know :P

well if you would do a mix... then say 5 quarts 15W50 with their new "extended protection" 5W30 (say 4 quarts)... would be best? because of the extra supersyn? I really don't know about this as the 30 type oil would boil much sooner than the 50 weight... how does that affect engine at high operating temps?