Fans & Camshaft Deviation QUestions - 986 Forum - The Community for Porsche Boxster & Cayman Owners

AKnowles · 02-03-2013, 06:30 PM

After getting my drivers side tire patched today - I found a nail in it while filling it up with gas - I decided to check out the car with my handy dandy PST2 for other prevative maintenance. While I was there I noticed two potential oddities:

Fans: I was checking the fans and fan 1 runs at half speed during the test, but fan 2 runs at full speed. Does this mean the resister on fan 2 is bad? Assuming both fans should run at the same lower speed (based on prior searches).

Camshaft Deviation: At idle both hold a rock steady ready, but cam 1 is at 0 and cam 2 is -6. From what I have been able to determine (yep, more searching) it is within specifications. But the question I have is ... is the -6 a camshaft timing issue that I can adjust using the DIY camshaft timing (which is what I am thinking) or is it an issue between the two cams (intake/exhaust) and needs to be adjusted by removing the valve cover?

Of course, the other question would be ... should I even bother and if I do should I take it to a Porsche shop to do it?

Any feedback apprecaited. This one is out of my normal comfort zone for determing the cause/issue as I'm just not that familair with the tools and motor yet.

thom4782 · 02-03-2013, 08:58 PM

If the PST2 operates somewhat like a Durametric, trigger the fans in low speed operation. And then trigger them in high speed operation. If a fan runs at high speed but not at low speed, swap the high speed and low speed relays for that fan and see if you get the same result -- still works at high speed, but not at low, then fan's ballast resistor is likely brOKen. If you get the opposite result -- doesn't work at high speed but now works at low, then one of the relays is brOKen.

Cam shaft values loOK OK to me, but more experienced people should weigh in here. My car deviations are flat and the angles are -5.4 and -6.4.

Topless · 02-03-2013, 10:10 PM

As I understand it, +/-6 is within spec. A higher deviation is most often worn chain tensioner pads. Replacing chain tensioners and guides is roughly equivalent to an IMS retrofit in terms of labor costs at most shops.

FWIW I think far more drivers have suffered ulcers and heart attacks from staring at a Durametric diagnostic screen than actual IMS failure.

AKnowles · 02-04-2013, 03:11 PM

Thanks for the input. I'll have to see if I can figure out if the PST2 has multiple options for the fan speed. I may not have left it on long enough to see if it will auto set the speed or if selecting the fan twice will change the speed. I just selected each fan one at a time and listened to it. Fan 1 was mslow and fan 2 was fast. Could tell just by the noise.

As for the camshaft deviation, I wasn't worried (yet) about the IMS. I was just trying to figure out if the -6 degrees could be adjusted so both were at 0. And if so, where to adjust it.

I do know if I open up the motor I'm going to want to change the tensioner pads. If I have to open it up and pull the transmission, well there is no reason not to change the IMS. The big question was it is something the average home mechanic can do of it is is such delicate work that it is best to let a professional do it. I've rebuilt a few motorcycle engines and have reworked top ends and retimed cam chains on other motors, but never a boxster.

Topless · 02-04-2013, 03:50 PM

Most any Boxster repairs can be done at a home garage with a good set of tools, basic wrenching skills and patience. German cars have a very precise procedure for everything. Follow the procedure carefully and you will be fine. Skip a few steps or just decide to wing-it and you are likely fecked.