Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Post Reply
 
LinkBack Thread Tools Display Modes
Old 08-15-2017, 03:21 PM   #1
Registered User
 
Coaster's Avatar
 
Join Date: Mar 2014
Location: Austin
Posts: 311
Garage
misfire on 4-5-6 bank after replacing head

I had a cracked head on the 4-5-6 side and had my shop replace it with a used one. No intermix, just coolant to cylinder.

A few days after getting it back I had a CEL for P0300 and P0304/5/6. Initial diagnosis was a bad cat due to the coolant running thru it. Replaced it with one from Woody.

A few days after that, same CEL - replaced the downstream O2 sensor. Timing was reset and is "dead on"

A few days after that, same CEL - diagnosis is bad coils and spark plugs, Both were changed about a year ago but they said the spark plugs look really rough.

I think the issue is related to the head rebuild and something tied to all three cylinders. The solenoid for the valves was swapped but the CEL didn't follow.

Some possible areas include the fuel system pressure, an electrical gremlin or short in the wiring related to all three cylinders, valve lift fault (flat based tappets), and MAF.

Any other suggestions on how to track this thing down?

__________________
2003 S, 6 Speed, PCM, PSM, Bose, Litronics with washers, on its' second LN IMSB, comfort top, UDP, 987 engine mount, 997 RMS, Koni Sport Shocks, H&R springs, Techno brace, comfort blinkers, nin8six windscreen, particlewave light up cubby
Coaster is offline   Reply With Quote
Old 08-15-2017, 04:14 PM   #2
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
Check the cam position sensor and the cam chain tensioner.
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 08-15-2017, 04:49 PM   #3
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,709
Garage
Insure the cam timing is set correctly, 180 degrees opposite the other bank
__________________
OE engine rebuilt,3.6 litre LN Engineering billet sleeves,triple row IMSB,LN rods. Deep sump oil pan with DT40 oil.
BYprodriver is offline   Reply With Quote
Old 08-15-2017, 06:27 PM   #4
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
Coaster,
Sorry to read your issues.It seems obscure.Can you get a Durametric or PWIS scan done ?
There are lots of other readings to observe and they may give a better clue.
Gelbster is offline   Reply With Quote
Old 08-15-2017, 09:38 PM   #5
Registered User
 
Pdwight's Avatar
 
Join Date: May 2013
Location: North Alabama
Posts: 2,079
Everything plugged it ?

I know it sounds simple.....but .....as an Electronics Tech for well over 40 years this is the case more times than not. Make sure the coil packs are plugged in....check everything that was touched. Then look at plugs where possible someone pulled on the wire harness instead of the plug for removal and pulled a wire or two out of the connectors internal pins.
Pdwight is offline   Reply With Quote
Old 08-16-2017, 12:48 PM   #6
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
Great point. When you push the connector of the wiring harness on the coil - listen very carefully for a 'click' sound of the latch engaging. No click = not connected fully.
Gelbster is offline   Reply With Quote
Old 08-16-2017, 05:38 PM   #7
Registered User
 
Join Date: Sep 2008
Location: Florida
Posts: 2,492
Quote:
Originally Posted by Gelbster View Post
Great point. When you push the connector of the wiring harness on the coil - listen very carefully for a 'click' sound of the latch engaging. No click = not connected fully.
I know that wire harness minimize the chance of hooking stuff up wrong but since the motor was worked on, given that all three misfires are on the same side, it is possible that all three coils are mis-wired, which would certainly explain the codes and the completely crappy way the car is running.
dghii is offline   Reply With Quote
Old 08-28-2017, 12:47 PM   #8
Registered User
 
Coaster's Avatar
 
Join Date: Mar 2014
Location: Austin
Posts: 311
Garage
Well I'm stumped.

It's not the plugs or the coils. The shop says they touched all the connections to ensure they were clean and tight. They reviewed hours of PWIS files and the code still pops up randomly. Fuel trim on bank 2 seems a little higher than bank 1 but I'm no expert.

One theroy includes a small volumetric difference between the old head on 1-2-3 and new/used head 4-5-6 which is causing the system to see a difference on the 4-5-6 side.

Another theory says it's an electrical gremlin potentially tied to the under drive pulley. It's a perception that the fault occurs at or near idle and the under drive pulley doesn't create enough voltage (perhaps from a tired alternator) and then the CEL goes off.

In the mean time I'd like to get a blue tooth OBDII reader that can be "permanently" installed and store scrolling data, once the CEL pops I can capture the data in the previous 5-10 mins via my ipad. Any suggestions until Fred's infotainment center is online?
__________________
2003 S, 6 Speed, PCM, PSM, Bose, Litronics with washers, on its' second LN IMSB, comfort top, UDP, 987 engine mount, 997 RMS, Koni Sport Shocks, H&R springs, Techno brace, comfort blinkers, nin8six windscreen, particlewave light up cubby
Coaster is offline   Reply With Quote
Old 08-28-2017, 05:16 PM   #9
Registered User
 
Join Date: May 2016
Location: Northville, MI
Posts: 249
What does the freeze frame pull up? It might give you a hint as to what was happening when the code was triggered.
bwdz is offline   Reply With Quote
Old 08-29-2017, 08:02 AM   #10
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
Quote:
Originally Posted by bwdz View Post
What does the freeze frame pull up? It might give you a hint as to what was happening when the code was triggered.
Now we are getting closer to diagnosis !
An old mechanic truism when faced with aberant problems is to return to stock (pulley) but that seems unlikely - but it is easy to try.
Whatever you do , be aware the DME may be slow to learn the new situation. We had an interesting Thread on such speculation recently. Doing a hard reset seemed to work.

Research carefully.
Gelbster is offline   Reply With Quote
Old 08-29-2017, 01:49 PM   #11
Registered User
 
Coaster's Avatar
 
Join Date: Mar 2014
Location: Austin
Posts: 311
Garage
Quote:
Originally Posted by bwdz View Post
What does the freeze frame pull up? It might give you a hint as to what was happening when the code was triggered.
Be gentle, I'm learning. What freeze frame? Can you explain this in simple terms. I don't have the data, the shop does. I'm looking for a blue tooth reader to record active data so maybe I can capture itat the moment it flashes.
__________________
2003 S, 6 Speed, PCM, PSM, Bose, Litronics with washers, on its' second LN IMSB, comfort top, UDP, 987 engine mount, 997 RMS, Koni Sport Shocks, H&R springs, Techno brace, comfort blinkers, nin8six windscreen, particlewave light up cubby
Coaster is offline   Reply With Quote
Old 08-29-2017, 05:20 PM   #12
Registered User
 
Join Date: May 2016
Location: Northville, MI
Posts: 249
The freeze frame is an OBD function. It records data when the code is set. It can be accessed with even cheap code readers. It will show you the snapshot of the sensor data at the moment the code set. It will typically show the baro, o2 readings, ect, vehicle sensor speed, load etc.. etc... If there are multiple codes the freeze frame function will only remember one but sometimes up to 3 freeze frames on newer cars. It will keep the frame from what is considered the most important dtc. Essentially what you want to do is drive around and gather data to see what sets the code but your computer already has a snapshot of all the sensor data at the moment it threw the code. It is as if you took a picture of the sensor data feed the moment it decides to throw the code. There are possible clues in there.
If you are suspecting increased compression from the head replacement there is also a way to use a starting system oscilloscope that most garages have to look for clues. Disable the fuel and spark and hook it up. Crank the engine over. The wave form of starter current draw spikes on each compression stroke of each piston. If there are different heights in the spikes on 3 of the cylinders you will see that and by following the firing order you can make a guess that it relates to the 4 5 and 6. Essentially you are using the power that the starter must use as a compression tester. I use this to look for potential misfires when I suspect internal engine problems as it can hooked up in under a minute and requires no removal of anything on the car but a relay or fuse and it can find me a dead cylinder in seconds rather than pulling parts off a car.
I recently found a problem on a supercharged Cobalt in my shop using the freeze frame. The car had been to multiple shops and dealers and had the problem for over a year. It would run great but once a week or so would pop into limp mode for map correlation. The car was highly modified with different injectors and small sc pulley. Everytime someone diagnose it everything was fine, it would test drive fine once code was reset and all sensors were in spec. The freeze frame showed 0 volts on the SCIP sensor. The SCIP and Map were replaced several times by different shops and the car would run great for a few days and then the code would come back. By seeing the freeze frame with 0 volts I was able to determine that there must be an intermittent connection and sure enough if you wiggled the plug hard enough there was, so it worked 99.9% of the time but the freeze frame showed that it must have a bad connection.

Last edited by bwdz; 08-29-2017 at 05:29 PM.
bwdz is offline   Reply With Quote
Old 08-30-2017, 09:32 AM   #13
Registered User
 
Coaster's Avatar
 
Join Date: Mar 2014
Location: Austin
Posts: 311
Garage
CEL last evening - about 30 min drive to local place to read intake cam deviation (bank 1 1.22 crk bank 2 6.61 crk). CEL came on after starting car to read deviation values.

Freeze Frame
P0300
Fuel sys sta B1 OL, not ready CL
Fuel sys sta B2 OL, not ready CL
Calc load 1.96%
Coolant 203 F
ST fuel trim B1 0%
LT fuel trim B1 -1.57%
ST fuel trim B2 0%
LT fuel trim B2 -7.04%
engine speed 640 rpm
vehicle speed 0

CEL this morning - 30 min commute to work, came on about 1.5 miles from work just leaving a stop light in first gear making a left.

Freeze Frame
P0300
Fuel sys sta B1 CL, using Ho2S
Fuel sys sta B2 CL, using Ho2S
Calc load 33.72%
Coolant 213.79 F
ST fuel trim B1 3.89%
LT fuel trim B1 -0.79%
ST fuel trim B2 -9.91%
LT fuel trim B2 -0.79%
engine speed 4240 rpm
vehicle speed 21.7 mph

Another theory is the exhaust cam timing isn't dead on. Gelbster I think you posted this else where. Can the following be done with the engine in the car? Does it need to be dropped a little or come all the way out (Bank 2 // 4-5-6 side)? I think I read the cam timing could be checked/adjusted in the car with Jake's tools but not the standard Porsche tools. About how many hours would a shop charge to do it?

"use the adjustment tool 9612 (NOT the lock tool 9634) to assess the alignment. Yes, use the silver and red tool! Also note that Jake recommends - slacken the 4 adjuster bolts, adjust the Exh cam with the silver+red tool, micro -adjust the crank to align the pin hole (TDC pin 9595). Yes, this is the opposite way round to what is often recommended. The reason is that the cams are difficult to rotate (22mm wrench?) - so fix that first. The crank is easy - so do that last."
__________________
2003 S, 6 Speed, PCM, PSM, Bose, Litronics with washers, on its' second LN IMSB, comfort top, UDP, 987 engine mount, 997 RMS, Koni Sport Shocks, H&R springs, Techno brace, comfort blinkers, nin8six windscreen, particlewave light up cubby
Coaster is offline   Reply With Quote
Old 08-31-2017, 07:01 AM   #14
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
Camshaft Timing.
Pelican has a diy, there are some epic Threads Search for Poster "Insite".Sadly his superb photos got dumped.
Until the static timing is perfect, it is pointless discussing much else.
Bank 2 on a Boxster is difficult with the engine in the car - and I have done it many times. But I have all the special tools , a few other aids, a 2 post lift in a quiet ,cool garage and plenty of time .And it is still difficult.That Schnell Gelb guy had similar advantages and problems.
If your circumstances are less than ideal and this is your first time, I suggest an honest,competent M96 Indie. Ask here for recommendations.
Any fool can pop the green plugs and may be able to fit the special tool. Then the problems begin. The first is seeing the Timing Marks.
Gelbster is offline   Reply With Quote
Old 09-01-2017, 05:39 AM   #15
Registered User
 
seningen's Avatar
 
Join Date: Jul 2008
Location: austin
Posts: 823
Quote:
Originally Posted by Coaster View Post
CEL last evening - about 30 min drive to local place to read intake cam deviation (bank 1 1.22 crk bank 2 6.61 crk). CEL came on after starting car to read deviation values.

Freeze Frame
P0300
Fuel sys sta B1 OL, not ready CL
Fuel sys sta B2 OL, not ready CL
Calc load 1.96%
Coolant 203 F
ST fuel trim B1 0%
LT fuel trim B1 -1.57%
ST fuel trim B2 0%
LT fuel trim B2 -7.04%
engine speed 640 rpm
vehicle speed 0

CEL this morning - 30 min commute to work, came on about 1.5 miles from work just leaving a stop light in first gear making a left.

Freeze Frame
P0300
Fuel sys sta B1 CL, using Ho2S
Fuel sys sta B2 CL, using Ho2S
Calc load 33.72%
Coolant 213.79 F
ST fuel trim B1 3.89%
LT fuel trim B1 -0.79%
ST fuel trim B2 -9.91%
LT fuel trim B2 -0.79%
engine speed 4240 rpm
vehicle speed 21.7 mph

Another theory is the exhaust cam timing isn't dead on. Gelbster I think you posted this else where. Can the following be done with the engine in the car? Does it need to be dropped a little or come all the way out (Bank 2 // 4-5-6 side)? I think I read the cam timing could be checked/adjusted in the car with Jake's tools but not the standard Porsche tools. About how many hours would a shop charge to do it?

"use the adjustment tool 9612 (NOT the lock tool 9634) to assess the alignment. Yes, use the silver and red tool! Also note that Jake recommends - slacken the 4 adjuster bolts, adjust the Exh cam with the silver+red tool, micro -adjust the crank to align the pin hole (TDC pin 9595). Yes, this is the opposite way round to what is often recommended. The reason is that the cams are difficult to rotate (22mm wrench?) - so fix that first. The crank is easy - so do that last."
There is also the possibility that the chain from the intake to the exhaust is misaligned by a tooth or two or that your chain tensioner or the actuator has failed. Danny at Silent Automotive in Austin could address either for you easy enough.

He's straight-up, honest to a fault, and very knowledgeable. His rates are very reasonable, IMHO.
__________________
Drivers: '15 Panamera Hybrid (wife's), ' 01 996 GT2, 00 Boxster S, '96 993 Çab/Tip (wife's)
Race Cars: '75 911 RSR Replica & '99 Spec Boxster
mike@lonestarrpm.com
seningen is offline   Reply With Quote
Old 09-01-2017, 06:28 AM   #16
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
I did not get into details but
No, with the engine in the car there is no space for the silver/red adjustment tool.Only the Exh lock tool.The "E" shaped tool.
If the EXh cam is correct , and the intake cam notch correct, the timing may still be off. How? Well for one example the Actuator is sticking. This i beyond average diy to resolve. Cam covers off etc.
It seems simple enough when you read it ,but it isn't.
Danny the Indie in Austin seems like a great suggestion.
Good Luck.
Gelbster is offline   Reply With Quote
Old 09-25-2017, 05:34 AM   #17
Registered User
 
Coaster's Avatar
 
Join Date: Mar 2014
Location: Austin
Posts: 311
Garage
Thank you all again. The issue was related to timing bank 2 with the UDP installed. There is a mark on the UDP pulley they were using for timing and it is not quite aligned with the original pulley. Once the UDP was replaced with the original pulley (which I keep in the car tool kit), the cam time was off. They did pull the motor mount and drop the front of the engine a few inches to redo the cam timing on bank 2. It's been a week since I got it back and no CEL and the gas mileage has gone back up.
__________________
2003 S, 6 Speed, PCM, PSM, Bose, Litronics with washers, on its' second LN IMSB, comfort top, UDP, 987 engine mount, 997 RMS, Koni Sport Shocks, H&R springs, Techno brace, comfort blinkers, nin8six windscreen, particlewave light up cubby
Coaster is offline   Reply With Quote
Old 09-25-2017, 07:16 AM   #18
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
" The issue was related to timing bank 2 with the UDP installed. "
Just Bank 2 ? Not Bank 1 also ?
Both Banks are timed at TDC Intake/Exhaust for Cyl 1 so how is only Bank 2 affected?
When they timed Bank 2, they automatically re-timed Bank 1.
Note the new UDP was probably missing the timing HOLE - so it is impossible to lock at TDC. That may have caused the issue?
Gelbster is offline   Reply With Quote
Old 09-25-2017, 07:27 AM   #19
Registered User
 
Coaster's Avatar
 
Join Date: Mar 2014
Location: Austin
Posts: 311
Garage
Only bank 2 was rebuilt due to the cracked head. AFAIK, Bank 1 was never opened/timed/re-timed or modified. The misfires only showed on Bank 2 in the PWIS - flat 0's on bank 1 (I went to a tech session at the local dealer so got a fair amount of free diagnostic eval using Porsche tools and techs).

Yes, the UDP missing hole was absolutely an issue. The UDP has a mark indicating where the time hole would be and they were using that (by eye I guess). Once the original pulley was installed everything could be locked and set properly.
__________________
2003 S, 6 Speed, PCM, PSM, Bose, Litronics with washers, on its' second LN IMSB, comfort top, UDP, 987 engine mount, 997 RMS, Koni Sport Shocks, H&R springs, Techno brace, comfort blinkers, nin8six windscreen, particlewave light up cubby
Coaster is offline   Reply With Quote
Old 09-25-2017, 07:41 AM   #20
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,027
That makes sense.
What probably happened was when they re-timed Bank 2 ,the UDP was not at TDC intake cyl1.
When they fitted the stock c/s pulley the error on Bank 2 was obvious. Then they had to remove the scavenge pump, loosen the 4 bolts on the EX cam sprocket, adjust .
For more Boxster Camshaft Timing details ,this link has a helpful drawing:
https://www.renntech.org/forums/topic/51555-cranks-but-no-start-misfire/
The best Boxster Timing DIY is from Insite here:
http://986forum.com/forums/performance-technical-chat/26418-diy-setting-cam-timing-m96.html
Photobucket dumped all his excellent photos - great opportunity for someone to re-do and Post as a DIY?
Alternative photos from Nutrod are here:
http://www.nutrod.com/Nutrod/Pics/Pages/Install_Head_4-6.html
I hope this helps


Last edited by Gelbster; 09-25-2017 at 09:26 AM.
Gelbster is offline   Reply With Quote
Post Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 06:15 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page