DaveK

Tomorrow I will have had my turbo 3 months exactly. It's a one owner car and had 21k miles on it when I bought it - immaculate condition. In 3 months, I've done 3.5k miles (they add up quite quickly!). However, they have not been entirely trouble free.

As soon as I got it, I found my headlights sometimes didn't switch on. Switch was replaced by the dealer - problem solved.

I also noticed my coolant dropped regularly. Front RHS radiator was replaced by the dealer a couple of weeks ago - although they couldn't see a visible leak, they said there was a faint smell of coolant on that side. Too early yet to know if that's solved the problem.

At the start of last week, PSM and ABS lights came on just as I started to move off my drive. Durametric showed offside front right wheel speed sensor. I cleared the code and it's not come back yet - it was very wet that day.

Thursday night last week, I was braking gently (was turning the car around) - and the brake pad wear light came on. I know I have almost new brake pads (checked them when the tyres were replaced 2 weeks ago) so I know that was a false alarm. Didn't come on the next time I started the car and hasn't come back since.

On Friday of last week (it was a cold morning) heated rear window didn't come on (switch didn't illuminate). It did come on half way to work - so I assume the relay is sticking when it's cold.

Today, a few times my brakes have felt odd. It's hard to explain exactly - but under fairly light braking there will be about half a second where the brake pedal feels odd. It feels a little like the ABS triggers - but I don't think it is that - it's almost like something grinds (and no, it's not my worn out brake pads!). It only happens for 1/2 a second or so, and at the moment fairly rarely so I've not had a chance to figure out exactly what it's doing. If it is the ABS, then it's triggering when it shouldn't - but I guess that could be related to the wheel speed sensor fault I got.

I will probably call the dealer tomorrow and have a chat, although at the moment the failures are a little intermittent (and it would probably have been better not to clear the wheel speed sensor fault but I wanted to see if it came back).

I am beginning to feel like I've bought a car that was built on a Friday afternoon - after a lunch at the pub. If this continues, my 996 turbo ownership will be fairly brief. It's pretty disappointing.

Macster

I think that part of the car's problem and this no fault of your's, but the car has not been used much and some of these problems arise from lack of use.

Dealer should have pressure tested system. This would have generated a visible leak. But a smell of coolant at one corner and none at other almost as good, though smell could be coming from a leaking hose and not a holed or cracked radiator.

As for brake issues, when I first got my 03 I noticed holes in brake rotors clogged with "stuff". I took car to DIY car wash and with "no spot rinse" selected (cause water pressure less) "blasted" the holes clear/clean. I had to move car a bit to uncover holes hidden by pads, but in the end all holes clear of any and all stuff.

Once in a while when I wash car -- at DIY car wash -- I use wash wand's soap setting to thoroughly wash the brake hardware. I avoid jamming nozzle right into or against pistons to avoid possibly forcing water past piston seals into calipers, but I do strive to wash away any brake dust that collects and it does collect. The water runs nearly black for a moment or two from mainly brake dust.

Be sure to rinse hardware thoroughly and then drive car and use brakes enough to get them hot enough to dry the hardware so no water remains which will cause the brake rotors to rust very quickly.

Oh, when I leave car wash I note the brakes do not seem to grab with much bite first time used. A bit scary actually. But once I applied more pressure brakes gripped just fine and they do not exhibit this symptom at any other time. Funny but I though with the holes in the rotor the brakes would grip better even if wet. Oh well.

If wheel speed sensor fault reappears if you want to locate sensor and unplug it from harness then reconnect. My thinking is some surface corrosion has built up and this disconnect/connect will remove the corrosion and "fix" the problem. I've had a few other instances -- cam shaft postion sensor on another car -- where just a disconnect and reconnect of the sensor's connector fixed an intermittent check engine light and error code. Corrosion.

Sincerely,

Macster.

Joe Weinstein

Also, tell me what tires you have on the car, and how much tread depth is left, front and back. (following a hunch...)

DaveK

Tyres are definitely not the problem. When I bought the car, it had Pirelli's on - fronts were about 2/3rds worn and they were horrible.

I put (4) Michelin PS2s on about 2 weeks ago. They have transformed the grip, and braking has been vastly improved - until the odd feeling today.

Joe Weinstein

OK, brand new PS2s all around in OEM sizes? If so, nevermind my thoughts....

number9ine

All of these issues--speed sensor, wear sensor, PSM, ABS and grinding--are probably related.

Even if the brakes are new, there could be a number of issues with their fitment. a misaligned brake pad could lead to uneven wear (and the premature death of the wear sensor). Because you say that you saw the PSM and ABS lights on, there may be something stuck in or around your caliper and the ABS sensor disc.

I'd pull the brake pads and check:
-dampers (if they were never replaced on a car this old they can definitely affect brake feel and pad seating)
-pad fitment
-uneven wear on pads
-wear sensor fitment
-debris, foreign objects in/around caliper and wheel hub

If you don't feel comfortable doing this yourself, ask the dealer to. It should be part of their standard troubleshooting for ABS/PSM fault. PSM depends on ABS, so if one goes, so typically shall the other.

Porsche's maintenance interval for brake fluid is every 2 years. If you're feeling something strange at the pedal this could be part of the problem.

On to your other issues. The radiator issue--it happens. There's a lot of air going through the front rads and at high speeds. A little road rash, and anything from a Chevy to a Camry will spout a leak. Let's hope that's the problem, but I wouldn't dwell on it. For the rear defroster, I'd check the switch itself. Pull out the horseshoe and have a look at it, there may be some gunk in there (like spilled soda from the ill-placed cupholders in non-nav 02s).

Think of it from this perspective: You purchased a used car that saw little use over seven years of driving. That means it probably saw relatively little maintenance (see the bald tires you bought it with), and with disuse there's more opportunity for "ghosts in the machine." Be prepared for a few more, but don't be disillusioned. Few cars are hassle-free, and your Turbo's exceptional performance and design should be weighed when considering the somewhat trivial issues you've seen thus far.

I hope it all gets sorted! Drive it like you stole it, maybe that will chase away the ghosts.

Mark

DaveK

Yes - OEM sizes.

jimq

My wear sensor on the 964 will come on after I wash my car and spray the brakes sometimes. Maybe when they put the wheels back on they buggered up a connector on one of the hubs.

DaveK

Thanks for all the answers.

I have changed the front discs / pads on the 964 before so checking the pads / sensors etc. on the turbo shouldn't be a big issue. I will have a look at the weekend - if it's not freezing cold or raining, since I can't get the turbo in the garage.

If it comes to it, I'll have to take it back to the dealer, but I'd prefer I had more consistent failures before doing that. Brakes felt fine today.

I took the car home at lunchtime, only to notice that I'd driven with a pen in my pocket at the weekend which had drawn all over my leather seats. Wonderful. Although I doubt it's done my leather any good, much scrubbing with white spirit did remove it (followed by lots of leather cream).

As a result, I wasn't in the best mood, and really did drive it like I stole it. And I must admit, suddenly the problems don't seem quite so serious. As I get used to the car, it continues to impress me. Today was the second time (first time was shortly after fitting the new tyres) when I've felt the limtiing factor in taking a roundabout was not the grip / tyres - but that I didn't want any further g-force!

Land Jet

Just a side note. Sometimes the ABS and PSM lights come on and are related to the MAF. Don't ask me why but that is how the system has been programmed. Did the dealer read out your diagnostic codes for any of your problems?

DaveK

I know that's the case - and I think it's because ABS / PSM need MAF readings to function correctly. Hence with a failed MAF, they disable themselves - and hence show the warning lights.

No, I read the codes myself using Durametric. Although I already knew about the failed MAF / PSM & ABS warning light issue, I was pretty confident it wasn't that even before I checked the code because it didn't happen when I started the car / was putting my seatbelt on etc. - only immediately as I started moving. So I guessed it was a wheel sensor, and it seems I guessed right (not that it helps me fix it!).

Mr. C4

ABS and PSM could also be a simple thing as a bad brake bulb incl. the center one.

DaveK

Surely not. Why would a blown brake light bulb cause ABS and PSM to disable themselves? That would be very poor design.

Just to add to my list, it looks very much like the replacement radiator did not fix my coolant loss. I am going to order a new cap for the expansion tank today - although I don't have any evidence that it's the problem, it's a simple fix and is worth trying before the car goes back to the dealer again (which will have to be after Christmas now anyway).

Mr. C4

Yes it will! Read my post on the 3rd brake light issue and you will understand why.

Last930

Lots of the plastic expansion tanks have seemed to go bad and develope small , sporadic leaks. A pressure check should spot this.