Rom

I found the issue - I took off the manifold, and where it connects to the flange (the end that bolts to the cat), the pipe has completely sheered off! Since there have been no modifications, and I didn't hit anything under the car, that seems like a design flaw (i.e. it looked like circular stresses as the manifold, which is rigidly bolted to the engine, moves in a slight circular motion with acceleration against the cat, which is bolted to the chassis - of course, it could also indicate worn engine mounts though...). I saw one other person report this issue on the forums - although I don't know how common it is overall... Anyway, I could try welding it back, but I think I'll just try to find another manifold... Thanks! S. PS - boggtown - thanks for the feedback, but I was aware how to find the leak - I just wanted to know if there were any Boxster-specific issues before I went in!

Hi all, My '99 Boxster sounds like a Harley Davidson Edition right now, and I just wanted some opinions of common Boxster-specific exhaust faults before I get under and start removing parts. The car went from sounding normal to sounding like there is no exhaust at all within about 5-10 miles. It's coming from the rear left side of the car, and does not appear to be from the main exhaust assembly. I'm guessing an exhaust gasket either between the head and the header, or between the header and the first cat has reached its end of life... Are there any caveats with removing the Boxster exhaust system I should know about? I can reach the 3-to-1 header pretty easily, and should be able to remove it with no trouble, but if the problem turns out to be some where else, is there a description of the process somewhere? I don't want to go re-inventing the wheel! Thanks in advance for any comments! Shash

The impedance of speakers doesn't change (except with frequency, but that's just normal reactance). The nominal impedance will not change, so the speakers won't suddenly present a 2 ohm load because the amplifier is bridged. I believe you're mixing two concepts up: 1) Halving the impedence: If you give any given amplifier a load of 4 ohms and it gives 100W RMS of power, presenting the same amplifer a 2 ohm load, it will (theoretically) give you 200W RMS of output. The reason is that you halved the resistance, and therefore doubled the current draw. This can be proven with the formulas (I=V/R) and (P=VI), where I = current, R = resistance, V = voltage and P = power. If voltage remains constant (as it typically does), halving 'R' doubles 'I', and therefore doubles 'P'. 2) Bridging the amplifer: If you give any given amplifer a load of 4 ohms and it gives 100W RMS of power, presenting the same load two amplifiers which are inverse to each other will (theorectically) give you 400W RMS of output. The reason is that you are taking the sine wave input and pushing it through one amplifier as-is, and inversing the signal through the other amplifier, and using the outputs as the "negative" and "positive" going to the speaker (in reality they are both signals, but the inversed signal in one amplifier creates the potential difference). That means for any given point in the waveform, you end up with twice the voltage. Using the same equations as before, doubling the voltage, also doubles the current for the same resistance, and therefore you quadruple the power output. So, as you can see, in case 1 you have to physically change the load (speakers) to halve the impedence, and get double the power. In case 2 you leave the same speakers (and therefore the same resistance), but you use two amplifiers and end up with quadruple the power. Anyway, subwiz - if you can take a picture of the back of that unit, that would be great - just for my future reference! Thanks! Shash

Hi all, I received the new MAF from Autohaus, and it fit perfectly - it was identical to the old part and cost me $196.71 with free ground shipping and no sales tax. I fitted the unit last night and reset the ECU. The car seems to pull stronger and sound better. Now I'll just wait and see if I get another CEL.... Thanks! Shash

Hi, Firstly, I personally would never buy a Monster cable for anything. It's WAY overpriced for what is simple technology - their marketing is what gets them sales! A good quality RCA cable (I don't mean the $2 cables) would be equally as good, especially over such a short distance. The only way to improve audio quality by any measurable amount is to used balanced line cables - in which case you'd need an amplifier capable of accepting balanced line inputs, and a balanced line transmitter to convert the standard RCA to a BLT output - or fibre-optics, which is an even bigger headache (unless you build your own custom modules). Anyway, as to your issue... It sounds like your installer is basically using the low-Z (impedance) output from the factory amplifier and is trying to feed it in to the high-Z RCA inputs. Either he placed a resistor (or variable resistor) in-line with the signal, or he turned the sensitivity down on the Alpine amplifier so that it's usable. The Porsche amplifier does some high-pass filtering (i.e. since it sends low frequencies only to the door speaker and >500Hz to the dash speakers - and he only tapped in to the dash speaker feed), which would explain your issues - you basically need to get a full band signal to the Alpine for it to work for you. I've not seen the back of a MOST-compatible CDR-23 (which is what I assume it is, since you mentioned fibre-optic). If those units do NOT have the C1 connector (which contains 6 pins: FL+, FR+, RR+, RL-, Common Ground, and Remote Turn-on), then you can either just put an aftermarket head-unit, or you can get an original OEM system that does have connector C1 (e.g. an older CDR-23 or a CDR-220, or something). Then you could retain the OEM look, and still get it to work. Of course, if you have a MOST-compatible CD changer, then that won't work any more - but then again, that would be the case even if you got an aftermarket system. I'd be interested to see a picture of the back of a MOST-compatible CDR-23, as well as a picture of the pin-out diagram normally stuck to the top of the head unit. As for your bridging question - if he is indeed using the low-Z output from the OEM amplifier, then I suspect the amplifier went in to protection mode since the sensitivity probably couldn't go low enough to prevent the high voltage output from the OEM amplifier from exceeding the Alpine's maximum input voltage threshold (which is probably only around 4 volts). The tweeters are passive devices, so would just blow up if over loaded. The Dynaudio's come with a passive crossover, so again couldn't really go in to any kind of protection mode. The amplifier does have output protection - although I have no idea why he said it was the "tweeters" - since the tweeters, mid-range and mid-bass speakers are all being fed through a single passive crossover. There is a way to fix this - add a series resistor of suitable value between the OEM amplifier and the Alpine. That would attenuate the signal enough so that everything is happy (it's called impedance matching). However, since you are losing all of your low frequency signals anyway, it's kind of irrelevant. Essentially, to fix your issue, you must eliminate the OEM amplifier. Someone of suitable electronic experience could easily open the OEM amplifier and tap off the high-Z signal *after* the fibre-optic conversion (essentially you can use the amplifier as a fibre-to-RCA converter at high-Z levels, and ignore the entire power output stage - this would give you a clean full-band signal). That would mean you could pretty much keep everything as-is. The alternative is a new head-unit (or OEM head-unit with line-level (high-Z) outputs, assuming your current CDR-23 doesn't have them). Either way you will be able to bridge the new Alpine and keep everything happy (and sounding good!). If I can see a picture of your CDR-23 connectors and the pin-out diagram on top I may be able to help you more... I mean no disrespect to your installer, but too many installers have only a basic knowledge of electronics (and certainly no electronic circuit theory) and only know how to connect together off-the-shelf parts, follow instructions and physically fit components in to a car. There's a lot of science in audio engineering, and sometimes it's taken for granted! Unfortunately this can lead to consumers not having all the options since installers don't realize there are more options! Thanks! Shash

That would drive me crazy... Speed doesn't kill, stupidity kills. Send her on some proper advanced driver training (not the lame "defensive driving" schools - but proper driving classes which talk through the physics, road conditions, visibility, and safe handling at high speeds)... It would help in both low speed and high speed situations, and help recognize dangerous conditions (especially when wet or icy). Then you won't have to worry about her speeding - she should know what a safe speed is at all times :) Anyway, about the speedo... Mine is way off too. When I measure against my accelerometer and against RADAR speed sensing it seems to be around 10% off. Thanks! Shash

I'm pretty confident this is a MAF-related issue... It may not be, but I think it is. Cleaning it definitely made a difference, and I got no CEL's for a while. Now I am starting to get the same kind of CEL's again, in both banks (which usually eliminates the O2 sensors). I'll see what the new MAF does - doesn't hurt since it needs one anyway... Thanks! Shash

I built my own harness for my Alpine HU... Just used an ISO connector -> bare wire converter, and spliced the wires in to the Alpine -> bare wire harness that comes with the unit. That worked for the power. For the audio signal, I retained the OEM amplifier and built an RCA lead up that I spliced in to the special Becker connector, and connected to the back of the Alpine. I believe you can actually get a proper harness from Becker, but I was impatient ;) Besides, my method allowed me to build an attenuation circuit in to the harness so that I could impedance match the input of the OEM amplifier and the new Alpine (I was experiencing an issue where I would get to number "3" on my Alpine volume control, and it would already be at max volume due to the OEM amplifier being too sensitive). I actually put the OEM stereo back in now, but I will be ripping it all out again for a completely custom ICE setup. Thanks! Shash

The thing to remember here is terminology. RON (Research Octane Number) is used in most of the world (Europe, Australia, etc), and ((RON+MON)/2) is used in the US. Since MON ratings (Motor Octane Number) have a lower numerical number, it reduces the overall numerical value. So "93" in the US is about the same as "96" (actually probably closer to 97) in Australia. The main difference between RON and MON is the way it's tested. The RON number is tested at 600RPM and the MON number is tested at 900RPM (with a few other differences, including inlet/mixture temperatures). It is generally thought that the R+M/2 method is better, since it gives an average of two tests - and since the MON number tests fuel under harsher conditions, it does appear to be a better test. So even though your fuel may be well within the RON spec, you could still theoretically destroy your engine if the MON number is too low. Considering how improving fuels is a costly exercise, I do worry that when using the R+M/2 method, that fuel manufacturers could skimp a little on the MON rating, increasing the RON rating to make the combined average look high. Most cars on the US roads wouldn't really care (low performance automatics), but a high-performance engine could easily be destroyed. Then again, maybe I'm just being paranoid... Living in California though, I generally only have access to 91 R+M/2 (theoretically equivalent to around 95-RON), and haven't too many issues - I also have to use this sub-standard fuel in my turbo-charged Evolution, which means I'm definitely not getting the performance I should... Unfortunately, California simply has too high of a demand on premium fuels, so they have to reduce the quality to have enough to go around. Bottom line is that your car will be fine on 91 R+M/2 - that's what almost everyone in California use. Thanks! Shash

Actually, looks like Autohausaz has them for $196 - so I just bought it! They have free ground delivery too (although I chose a quicker method of shipping!). Thanks Chris! Shash

Hey guys, Thanks for the responses... Looking at the other thread it looked like there were places cheaper than Sunset - but if they are the cheapest now I guess I have no choice... I guess companies have caught on that Boxsters have lots of MAF's that fail and have decided the increase the prices (no doubt because they think if you can afford a Porsche, you can afford overpriced parts)... Chris - Thanks for the offer, but I've already diagnosed it, and it's definitely a MAF issue. I cleaned the MAF a while back and it helped for a while, but now it's back to MAF-related issues, including MAF-related OBD-II codes. Thanks! Shash

Hey guys, I wanna buy a new MAF (1999, 2.5i), but is it just me, or have prices doubled over the last couple of years? I was reading a thread on here that said that the MAF was about $160 from thepartsbin.com (in 2004), but looking there now it's $270.95! Any idea where I can get one reasonably priced? Thanks! Shash

Hey all, Does anyone know if there are any products out there to upgrade the stock driveshafts, hubs and bearings on the rearend of a 986? With the extra power I want, I'd like to upgrade those components... One possibility is to retrofit parts from the 996, but I'm not sure if everything will just bolt straight on, or need some conversion. Any comments would be appreciated! Thanks! Shash

Do you smell fuel from the tail pipe after you turn over for 5-10 secs? If so, you are probably getting fuel okay. In that case I'd concentrate on spark. If you are handy with a multimeter you can verify the pulses from the ECU, verify power to the ECU, and verify power to the fuel pump. I'm not sure of your skill level and don't want to suggest something that inadvertantly causes more damage. You may have to take the car to the dealer. Whereabouts are you? It would be ideal if you were near me, but I'm guessing you're not since I am not 60 miles from a Porsche dealer (I'm in Los Angeles right now, but live in the Bay Area)! Thanks! Shash

I cleaned my MAF and noticed a significant improvement too. I don't get any CEL's so I don't need to replace it - I just cleaned it for the performance benefits, and it worked (and besides, I want to sell the entire engine/gearbox right now to start my project!). Thanks! Shash

I usually just go to the dealer and they give me the code for free ;) (if Loren's codes don't work!) Thanks! S.

Hi, I would check all the fuses first - your ECU or pump fuse may have blown or might not be contacting properly. Does the engine "try" to catch (i.e. it turns over slowly, then fast, then slow again, etc)? I was troubleshooting a Nissan SR20DE engine a few years back and it did the same thing because the car had been sitting unused for a little while. Turned out the fuses weren't contacting properly (they were fine, but had corroded a little - my friend neglected to disconnect the battery when leaving it sitting). After a couple of hours of troubleshooting I had the idea to replace the fuses anyway - and suddenly it all came to life! If the fuses are fine, then as seafeye said it could only be air, fuel or spark... If you have an OBD-II tool, you could also check for codes. One thing to check is your relays - a friend of mine recently had some troubles with his 993 - it turned over but wouldn't start like yours. Turned out to be his fuel pump relay. Finally, you do have fuel right? Your fuel gauge may be broken, and showing an incorrect level. Thanks! S.

I'm thinking I'm probably going to keep the Boxster and modify it. I could sell and upgrade to an S, but the amount I'd lose in the transaction, I think I'd rather upgrade. I know self-modified doesn't really keep it's value as much - and thinking about it, I doubt I'd sell something that I significantly modified. The reason I mentioned the 350Z and Elise was because they both have good handling out of the box, and the 350 in particular has an easy upgrade path. As for uniqueness though - a modified Boxster is probably the most unique - and I do love the roadster format (I would never get a 350Z Roadster). Thanks! S.

Good points... I don't know if I'd go with the M030 suspension over some aftermarket coilovers (H&R, Bilstein, etc). I have a 1999 2.5i, so I'd go to a 3.4L (I might as well sell it and buy an S if I go to 3.2). Thanks! S.

Hey all, I've been thinking for a while that I wanted to get something else... I'd like a more power, and more performance-focused (the setup on the Boxster is a little soft). I've been thinking 350Z Track Edition or Lotus Elise (which I have had before in the UK, although it was a Series 1 with the 120BHP K-Series - immense amounts of fun though!). Alternatively, I could just upgrade the Porsche to a 3.4L (I would do all the work myself, so I'd be looking at spending about $15K for everything I want, including brakes, suspension, etc)... I like the Porsche brand and image... But would the car still be "sale able" in the future (if I ever sold it - don't think I've seen an upgraded Boxster for sale yet)? So, what would you do (assuming you weren't biased to the Porsche brand, that is!)... Thanks! S.

The vibration seems to have mostly gone away now, and OBD-II registered no warnings or faults. I think maybe it's time to do a service... ;) Thanks! S.

Hi all, I was just on my way to work this morning in my 1999 2.5i manual transmission US-spec Boxster and was cruising at about 3000RPM on the highway. As I approached my exit I dropped a gear and engine RPM's went to about 4500RPM (blipping the throttle, synchronizing the revs, etc). At that point I noticed a very abnormal vibration from the engine. I lowered the revs immediately and just cruised in to work at lower RPMs. When I got to work I accelerated up at rest (out of gear) and the vibration seems to start around 4000RPM. If I rev up to 4500RPM and then let go of the accelerator, the revs drop to idle, but at around 1200RPM there is a slight hesitation on its way down. That could be normal from the sudden vacuum, and different cars behave differently, but I'm pretty sure mine didn't do that before. The oil levels are normal, and the engine only has about 74,000 miles on it. No warning indicators light up. I haven't got my OBD-II diag tool with me, so I'll run a code check later and see if anything comes up. Before I jump in and start running diagnosis, does anyone know if this is a known issue with the 1999 2.5's, or have any idea what it could be? I don't think it's driveline related - the vibration occurs out of gear, at rest and with the clutch depressed (so the clutch plate is not touching the flywheel). I'm guessing it could be a faulty spark plug (missing at higher RPM's), but then I'd have expected a check engine light and probably a slightly different feel. It could also be a broken engine mount, but again it doesn't sound/feel like that kind of vibration. It almost feels like an unbalanced crank or a big-end bearing problem. Any comments appreciated! Thanks! S.

Resurrecting an older topic, but does anyone know the difference between the A5 (OEM) canvas and Haartz Sonnendeck (Twillfast) material? I need to get a new top now, and the Sonnendeck is a little cheaper - although I think it would probably be better to get the original A5 canvas. Any opinions or comments? Also, has anyone done business with topsonline.com (eBay user) - they sell both the A5 and Haartz materials ($695 and $625 respectively plus $30 shipping), both with glass window (made by Robbins Auto Top)? I can fit it myself, so don't need an installer - just the best price on the parts! Thanks! Shash

I got mine in a kit I bought from Frys Electronics (US west coast only, I believe). Places like Home Depot don't carry it. My kit is a full kit of virtually every type of common security bit available - I think it cost me around $30, which is pretty cheap considering it has so many specialist bits. Thanks! Shash

Oops! You're right - It was T20H - I've modified my post accordingly. Thanks! Shash