00 box s rpms drop @4-3 then climb? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

mn box s · 07-01-2006, 07:37 AM

I have recently had my car in for 60k service it has 55k currently the shop said it was a solid car. I purchased it about 3 weeks ago about a week after it was in for service the cars rpm's drop when under moderate to heavy acceleration. if you start @ 2k give it throttle it climbs near 4k and then hesitates rpms fall to near 3k then climb past 4k and may hesitate around 5.5k but not as drasticaly as 3-4k. I had the shop do trany flush and fill, also this is a 6 speed manual, it happens nomatter if a/c on or off and if traction control is on or off doesnt seem to matter eather. Please help. If the clutch was slipping shouldnt the rpms keep climbing and the car hesitate. Not rpms drop? any info would be good thanks.

deliriousga · 07-01-2006, 08:01 PM

If it were the clutch, you should have a spike in rpms when the slipping occured rather than a drop in rpms.

I would guess one of your sensors (O2, MAF, Cam, Crank, etc.) is going out causing a rich or lean condition in the mix. The only way to tell is to plug it into an OBDII and record a drive to see exactly what happens just before it drops in rpms. It can also tell you what codes you may have even if the CEL has not come on. Here is a good one that reads PST2 codes and can clear the airbag light too.

insite · 07-05-2006, 06:45 AM

sounds like my car when the MAF went bad. unplug the MAF and go for a drive. if the problem goes away, you have found the culprit.

btw - who did the tranny flush / fill? you trans has hypoid gears; if they used incompatible fluid, the shear from the hypoid cuts will degratde the viscosity of the oil.

mn box s · 07-05-2006, 07:51 PM

sounds like your dead on deleriousga? I forgot to mention Ive had o2 problems my row #1 bank #1 is going bad Ive had chk light on and off Its off now but still should be in the hard data in the ecu. my guess was it was going closed loop but figured with out a chk light on it couldnt be it? but probably is. hope so. Also someone else mentioned that that happened with their maf. These should be similarly related problems. Ill post if the o2 fixed the problem once completed thanks. If anyone else has insight please add.

mn box s · 07-05-2006, 07:54 PM

the shop that did the tranny flush and 60k was an approved porsche only shop. they are flat six, Bloomington MN. They seem very knowledgeable. I would recomend this shop to anyone in MN.

insite · 07-06-2006, 03:39 AM

Quote:

Originally Posted by mn box s

sounds like your dead on deleriousga? I forgot to mention Ive had o2 problems my row #1 bank #1 is going bad Ive had chk light on and off Its off now but still should be in the hard data in the ecu. my guess was it was going closed loop but figured with out a chk light on it couldnt be it? but probably is. hope so. Also someone else mentioned that that happened with their maf. These should be similarly related problems. Ill post if the o2 fixed the problem once completed thanks. If anyone else has insight please add.

seriously, try unplugging the MAF. the car will go into a default program mode. if the MAF is the issue, the car will drive perfectly with it unplugged. then you know what you need to buy. your issue truly sounds EXACTLY like mine at the time my MAF went south.

mn box s · 07-15-2006, 08:49 PM

ok about a week has passed since I posted a possible o2 problem with rpms. As I informed you (all). I have taken my car to the two worthy shops, one being the dealer. They have told me my clutch is slipping. I had problems buying into this theory from the begining. Not that Im afraid thats the problem just know one has been able to explain why, due to the symptoms. Once again the Rpms slip up about 1000 r's then down 1000 r's (roughly) and then the car pulls and pretty hard (Full throttle). I am now guessing they may be right I just want a good explination. The dealer said it was the dual mass fly. But why would it grab after it starts slipping? The other shop said thats just a porsche thing. well there are plenty of cars out there that have about the same clutch set up. what about physics? no cluch smell? Anyone have a good explination thats all Im looking for. Currently my car is going into the shop mon its sat, for a new clutch and poss. a fly. Should I go with the factory again? I hear they only last 50k thats pretty weak in my book even if it is a wear part.

Adam · 07-16-2006, 07:54 PM

I think I experienced the same thing coming up onto an on ramp to the hwy. The car dropped rpm and felt sluggish. I was thinking "clutch slip' but then I thought the rpms would rise not fall if there was some slip. Very strange. It has only happned that one time and aftewards it pulled fine. I dunno....keep us posted.

mn box s · 07-23-2006, 11:42 AM

Well I finaly have an ansewer. It was the clutch! I just replaced the clutch,fly and press. plate. My clucth was just down to the rivets and I think that may have been a contibuting factor to the strange slipping. Porsche said they only last 40-50k and mine went out @55k so they were right. The garage manager got in and drove it 10 ft and said it was the clutch because of a high engaugement point on the pedal throw. The new clutch is in and wow! I lift the pedal now about 1/4 - 1/2 in, and its engauged. Very noticeable if any of you are not to that point yet I guess pedal throw is a big give-a-way on these cars. nice to know and thanks for the info everyone.