logray

Usually water pumps failing make more of a bearing noise rather than a knocking. Also the water pump is driven by the crankshaft pulley belt, which does vary with RPM, and so the noise should increase or decrease accordingly. If you open the engine bay, does the noise seem to come from the top of the engine or underneath? If you put your ear near the drivers or passenger side rear wheels is the noise more pronounced with either side?

Yes, it could mean the allocation is off by a tooth, the variocam pads are very badly worn, the camshaft flange that the sensor picks up is bent, or perhaps just the timing is off by 8 degrees (crank) and 4 degrees retarded at the camshaft for cylinders 1-3.. Can you also post your actual angles (camshaft) at idle and 3000rpm? Also year of car. Thanks.

Well you should certainly see your doctor for that condition. :rolleyes: As for the mufller I presume (side of engine)? Or perhaps catalytic converter (rear or car/front of engine)... yes they are known to eventually "go bad" or just "go bad" on their own. In order to diagnose the rattle you can remove one of them and shake it around in your hands... if you hear the same ratlle. But I think more commonly it is probably just a lose bolt. If you do poke around near them and do any sort of bolt tightening be sure to have let the exhaust cool down sufficiently first.

Loren, is this the same amount of fuel for the calibration procedure on a 996? IIRC it was like 12 liters for that model. Thanks.

If you bought the Beru, Bosch, or "Porsche" 4 prong plugs, they come pre-gapped to the right specs. I'm also not sure how one would gap a 4 prong plug anyways... at least I've never heard of anyone doing that before. I had a set of single prong NGK's, didn't really notice a difference with the 4 prongers.

If you pull the battery, some possible things you would have to deal with: Radio code re-entry Sunroof re-teach Gas tank re-calibration (very unlikely) Instead of pulling the battery, I think most people just connect a battery tender to the cig lighter, or string one under the boot lid to the battery. Other stuff not related to the battery, but important to consider Flat spots in tires (consider rolling the vehicle forward or back or taking it for a short drive to operating temp every few months) Rodents (be sure to cover it well - wash and wax first) For 6 months of storage, be sure to use a fuel stabilizer and fill the tank before letting it sit. 6 months is just about the limit for Petrol without stabilizer

Yes starters do get old and weak, but on an 2008 car that sounds pretty implausible, but not impossible. My guess is there is something else going on, perhaps a charging issue with the alternator, wiring, or possibly even bad new battery. BTW, nice car!!!!

Hey Phillip. Reply is over in the valve job thread...

The valve job was a gamble I took to fix the smoke and soot (and only forked out a couple grand for that work)... But now I simply can't ignore the massive soot still coming from cyl 1-3 after the top end rebuild. I'm working on validating these numbers sometime next week when some tools arrive, but with number like these, along with the massive soot - it's tough to keep driving the car with a smile on my face. compression all around 150psi (very very poor) leakdown past the rings all around 22-25% (only going to get worse, and likely the cause of the soot and low compression) Depending on how the validation test of the above numbers comes out will be a big part of my decision on what to do with the car next. Do I spend another $6k to do it right??? or $2k to just replace main/rod bearings and piston rings (if that would even work without touching the cylinders). I'm in the face of a major decision !!!! Sell the car, sell the valuable accessories and get into another 911 (and possibly replace piston rings/bearings as a "patch") Keep the car, sell the valuable accessories, return the car to stock, and rebuild the engine the right way (LNE nickies 3.6 bore). The car would be mine "forever" at that point. And some other options on the bottom of my list: Keep driving the car until it blows up or starts spewing oil out the exhaust (not that far away from happening). Sell the existing engine and accessories and do a Chevy LS V8 conversion Sell the existing engine and accessories and buy a used or remanned engine Replace only piston rings, rod and main bearings - don't touch the cylinders, and gamble some more (about $2000 more).

Beware ebay porsche center cap knockoffs. I got ripped on a cheap set years ago and ended up buying from a more trusted source...

What are the symptoms Carlos?

EDIT: LOL, I see this post was from March, I guess I'm not awake yet. Time for some more coffee. :beer: .... Engine S/N doesn't yield mileage. However, if you post the serial numbers of the two engines we can validate the years and serial number for you. Have you cold leak down tested each engine? That might be a good place to start... I agree to stay away from wrecks. Also the low miles on the 2000 doesn't sound good, from reading generally these engines seem to last longer and have fewer issues if they are driven regularly and hard. That being said, if the 2001 requires a bottom and top end rebuild, the 2000 with retrofitted LNE bearing/etc. might give you more mileage before major rebuilds than you would get on the 2001. It's a tough call for sure! Also I am currently standing in the face of a rebuild myself, for low compression and lost ring seal. I might be interested in whichever engine you decide not to use as an option versus rebuilding what I've got.

2 part epoxy would be my choice if you are in a bind and know where the leak is.

I agree with wvicary and would certainly try to source a proper connector and harness for that instead of trying to make your own. I bet you could take that to your local parts counter and they would have a connector and wire setup for you in no time and for very little money.

If you mean a hairline crack I don't see why it wouldn't work as a cheap "fix". However, if the plastic is quite old, chances are the fix might only be temporary. The crack could grow or more could appear in a short amount of time. Not to mention you would have to probably first remove the tank and then pressurize or create sufficient vacuum in the reservoir to locate the leak(s). All that time and effort... All to save a few hundred dollars on a new reservoir? Or am I missing something obvious here.

P/N 98610090500 Does anyone have a listing of the individual part numbers and quantities included in this gasket set? Thanks in advance!

99612301376 left 99612301475 right BORG WARNER might be the supplier, as they are listed as OEM for the genuine Porsche part on many websites. K16

As for checking which terminal of the sensor is positive, did it not come with color coded wires or a marking? Perhaps it doesn't matter which goes to which in that case, as long as one side is grounded. You could connect a multimeter to the terminals and measure ohms. Blow some air on the sensor and observe the change in resistance. If it doesn't change then you have the wrong terminals. Or flip the leads around and repeat the test - confirming whether it matters which pole is positive and which is negative. That comment I made was meant more along the lines of making sure the IAT you select provides the appropriate resistance based on the temperature and what the computer expects to see. Otherwise if it gives the wrong impedance values, the IAT might be feeding the computer the wrong temperature, which is counter productive to what you are trying to achieve. Example (I'm not sure what the 996 DME expects, this is just an example for GM): Temperature Ohms 48 degrees F 7000 87 degrees F 1930 146 degrees F 560

I would ground through same connection (DME) that the existing sensor uses. IMO, this should prevent any sort of ground loop or better path to ground situation.

Here is a DIY on replacing the AOS on a 986. After reading it, you should be the judge of whether or not you can perform the procedure - since you are the only one who knows your abilities. Also I encourage you to spend a few minutes with the search feature on this forum to locate some posts about how to properly diagnose the AOS. It could be that your problem is not the AOS, and in those posts that you can find with the search feature there are plenty of definitive methods to validate whether your AOS is bad or not.

I take back what I said earlier about using a separate ground for this case. Let's say you create a better or different path for ground, it might be possible to create a ground problem and damage something. Going back to your diagram I think you should be fine.

One thought perhaps is that the use of spline grease seals, lasts longe, and provides better thread wear protection than conventional motor oil (both are oil derivatives), which the latter is commonly used to aid the installation of the rubber seal. In practice though, for this connection, I would be surprised to see many leaks using the older conventional method. More likely problems (leaks) would be due to improper torque or threading than the grease IMHO. Just a theory though.

1. Oil is fine. 2. Put the filter into the car first. Then screw the housing onto the car.

No problem, yes I think I understand what you were asking. And my answer is pretty much the same. The car only has one ground system with many ground points. Everything, the engine, the DME (multiple pins), instrument cluster, lights, radio, etc. etc. etc. all share the same ground AFAIK. I don't think you will encounter any problems using that ground for your new sensor from an electrical perspective. I'm not sure how the computer will cope with a different sensor, but assuming it provides the same voltage and impedance ranges as the orig sensor I don't see why it wouldn't work. Perhaps 1999Porsche911 would chime in, although I haven't seen him here for a long time.

I would think the ground you are looking at is sufficient. You could test this easily with a multi-meter. Another way would be to take ground from a separate ground point since you are adding another air intake sensor. The car only has one "ground" system AFAIK, eventually everything is grounded to the chassis. Let us know how it goes.