Boxster 986 2.5 engine issue

[rybol20]

At the start ,I would like to say hello to everyone. I am new on Porsche Club. My name is Marek, I live in Watton, Norfolk. Back in January, I bought my first ever Porsche, which is Boxster 986 2,5 1999, and I love it but......
About 2 weeks since I bought it, engine malfunction light appears on the dash, and engine starts running rough on idle.
I plug the car in to my diagnostic tool(its Launch X431 which, over 10 years diagnose a lot of cars with it). Faults :

• 174 Camshaft adjustement bank 1
• 322 toothed belt out of position bank 1
• 62 misfire emissions-relevant
• 50 cyl 1 misfire emissions relevant
• 51 cyl 2 misfire emissions relevant
• 52 cyl 3 misfire emissions relevant
• 75 misfire damaging to cat coverter
• 63 cyl 1 misfire damaging to cat conv
• 64 cyl 2 misfire damaging to cat conv
• 65 cyl 3 misfire damaging to cat conv

After reading various posts looking on forums and YT I ve decided to remove bank 1 camshaft cover and check Variocam chain guides, and found out they were badly worn so I went to Porsche Norwich and bought 2 sets for each bank. I ve replaced them. After repair engine was running smooth, no fault codes.
Around 30 miles after work engine light come back on. This time with diffirent faults:

• 174 Camshaft adjustement bank 1
• 75 misfire damaging to cat converter
• 68 cyl 6 misfire damaging to cat converter
• 66 cyl 4 misfire damaging to cat converter
• 67 cyl 5 misfire damaging to cat converter
• 62 misfire emissions relevant

Ive also done live data stream:

• Ignition timing 6.75 °crk
• injection time 1.92 ms
• range 1 cylinder 1-3 (TRA)4.02
• range 1 cylinder 4-6 (TRA2) 0.10
• camshaft postion 1 deviation 9°crk !

I decided then to delete all faults, keep driving until light will come back on, and check if same codes appear. After around 3 days and 60 miles light come back but with diffrient faults(same as first time, before variocam cam guides repair) !!Engine was shaking on idle:

• 174 camshaft adjustement bank 1
• 322 toothed belt out of position bank 1
• 75 misfire damaging to cat converter
• 63 cyl 1 misfire damaging to cat conv
• 64 cyl 2 misfire damaging to cat conv
• 65 cyl 3 misfire damaging to cat conv
• 62 misfire emmisions relevant
• 50 cyl 1 misfire emissions relevant
• 51 cyl 2 missfire emissions relevant
• 52 cyl 3 misfire emissions relevant

Live data stream

• ignition timing 4.5° crk
• injection time 2.59 ms
• range 2 cyl 1-3 FRA 0.96
• range 1 cyl 1-3 TRA 3.94
• range 2 cyl 4-6 FRA2 0.91
• range1 cyl 4-6 TRA2 0.25
• camshaft postion deviation 25°crk !!!!!!!

I ve deleted all codes and done live data stresm and deviation was still 25° crk!! I read somwhere that 10° is equivalent to 1 tooth out. not sure wether thats true or not.
Today I ve checked timing on bank 1 and it is as it should. Crankshaft on TDC and exhaust camshaft on bank 1 as it should , tool installed.
When I was replacing vario cam guides and realigning timing Ive notice that exhaust camshaft sprocket on bank 2 was roughly in the middle of its adjustement but on bank 1 ex camshaft sprocket was near the end of its adjustement. After variocam guide repair and realigning timing,ex camshaft sprocket was in the same place. not sure if its normal or not, in my opinion both ex camshafts sprockets on bank 1 and 2 should be roughly in the middle of its adjustement.

At the moment I can see few things that can be wrong:

• cam / crank sensor faulty
• Someone before me realign timing on bank 1 with badly worn out main chain guide or perhaphs faulty ims bearing (but no funny noises from engine) that why ex camshaft sporcket on bank 1 is at the end of its adjustement
• something else...

Just wondering if someone had similar problem and could advise? I would be very, very, very greatful .

Best Regards
Marek Rybak

 

[Cater_Racer]

I'm interested to see what responses you get Marek, I've got similar problems on our 2001 3.2S.

Whereabouts in the country are you, maybe we can help each other? We've got the car in Cambridgeshire ATM stored at Tom's place, but it will be coming to Chester later this month.

Gerry

Tom & Gerry Motorsport

 

[Motorhead]

Marek,

It sounds to me that you would benefit from the advice of an experienced Porsche engine builder who’s very familiar with the water-cooled F-6 engines. Steve Winter of Jaz Porsche is the Boxster Technical Advisor steve@jazweb.co.uk or you may be able to find a local Porsche Independent in Norfolk who would be able to help (there are a couple listed in the back pages of Porsche Post).

Jeff

 

[Cater_Racer]

Hi Marek,

Have you thought about the Lambda and MAF sensors? Could they be the cause?? I'm going down that route for my misfire/lack of power issues.

Gerry

 

[rybol20]

Thank you very much for reply.

Jeff,

Thank you for Jez Porsche contact. My plan is to go through everything, check things through easter holiday as I have 4 days off, if no progress I will contact Jez Porsche, so many many thanks!

Marek

Gerry,

I am in Watton , Norfolk (Norwich area). Certainly I would like to help each other. My engine is 5 chain and your one I think is as well ?2001?

Thing is with my car, its running a bit rough on idle but if you open it up it goes as it should..over 3000-4000rpm.

Today I manage to check crankshaft sensor (all readings perfect), I ve checked Voltage on VarioCam plug bank 1 (voltage measured between pin 1 and 2 , supply to variocam solenoid, 12V with ignition on, so ok). Bank 2 the same. I also checked resistance in Variocam solenoid and its around 13 ohms which is normal as far as I know.

Tomorrow I am planning to check cam sensor. I will update. However while I was doing checks today I ve notice that camshaft position sensor is mounted to inlet camshaft. That means to me that my 25° deviation can be present because of variocam unit/solenoid fault?, because crank is connected with exhaust camshaft by chain and 2 guides, then exhaust camshaft is connected with inlet camshaft by chain, two guides and vario cam. So if variocam is faulty it can adjust inlet camshaft when it shouldnt or not at all and ecu will through code about inncorect timing etc. That means after camshaft position sensor check and lambda sensor I will need to check variocam. At the moment I need to dig in how to test it. As far as I know it need to be check while engine is running.

As soon I will do some checks I will update.

Best regards

Marek

 

[irb26]

Hi

The errors 322 (timing chain out of position, bank1 and bank 2) and 174( canshaft adjustment bank 1 and bank 2) both point to canshaft timing faults as you are probably well aware.

There can be a few causes ranging from the simple to more complex (and expensive). The cam adjustment solenoids can sometimes be problematic on these engines, as can a few other things such as excessively worn timing chains, tensioners etc, or a badly timed engine and also the obvious IMS issues. I've seen rebuilt engines come back from specialists that have had the timing 180 degrees out, so if someone has been tinlering with your engine before you go the car then double check everything.

If your Launch has the facility see if you are able to activate the cam timing functions in 'drive links' or whatever equivalent menu launch use to activate engine functions - it might give an indication of whether of not the cam timing/phasing is working correctly.

One of the cheapest checks may be to drop the oil filter and check if it is full of metal particles - this can indicate ims issues, or other signs of impending mechanical problems - just bear in mind that you will probably see little particles of chain tensioner material in there but this is not metallic and usually down to wear and tear if there isn't too much of it.

if this is ok then look to your engine timing, tensioners, vario cam solenoids (and wiring to them - this can got brittle) etc.

If you havent got it already then get a copy of the 986 workshop manual which can usually be found online as a pdf download for nothing.

Its a wealth of info that will give you all your nominal values that you should be checking against, teardown procedures and the wiring diags.

Thanks

 

[Cater_Racer]

Hi Marek,

We've put an order in for a Launch X431 CRP123 to be delivered this week, but won't be able to do much before 23/24th April when we get to Thruxton. The problem with race cars is the constabulary take dim view of testing on the A1M. Tom has got a long 150 mtr drive so we will be able to run it up and down to make sure it's working.

I will get back to you with data and figures after Thruxton.

 

[rybol20]

Hi. Sorry for late reply, but last two days been manic!

Gerry

Thats good news. Yes, as soon you do some tests please let me know how you getting on. Also could you advise what do you think about new launch x431. (i am thinking to update my one.)

Many thanks

Marek

irb26

Many thanks for all info, really appreciate it.

First thing Ive done, I removed oil filter and checked it. There was one tiny particle (plastic),no metal, but around 200 miles before I bought Porsche, it had service!

I bought as well Porsche Boxster manual /workshop repair in pdf (copy of orginial), and as you said, lot of informations in there.

My LAunch is old now (2012) and cant see the option of checking variocam and timing chain settings etc.

When I was replacing Variocam chain guides Ive notice that someone been there before (in the engine)!. For example 4 bolts on each ex camshaft sprocket a bit rounded, too much sealer between cam cover and cylinder head.....

Like I said in previous post, Ive spoted that exhaust camshaft sprocket on bank 1 was set to its maximum adjustement and bank 2 was roughly in the middle, which I think thats how it should be. I thought its strange that is on its maximum adjustement. It indicates to me (not sure if I am correct), that top chain guide (between IMS and bank 1) is badly worn or IMS gone, but also there was a problem before and someone readjust timing on bank 1 with damaged guide or ims bearing that why exhaust camshaft sprocket is out. Then I thought there might be nothing wrong with guide or ims but whoever was doing the work on the engine before, install ex cam sprocket incorectly (tooth out etc). Dont know whats going on there.

Also I notice a slight wining noise, very quiet and I think its coming somwhere near the flywheel, so it could be release bearing or....ims!

Not sure wheter is good decision or not, but Ive decided to remove gearbox (car is allready a bit dismantled, all covers removed ,bits and pieces) , remove bank 1 cover, remove both main chain guides and check them, also I will check IMS bearing and I will remove variocam solenoid, and try check it.

As soon I know anything I will update (I will be doing work thursday/friday)

Many thanks for help

Marek

 

[irb26]

I think i'd be inclined to check everything on the timing chain side of things (all of them) if someone has been fiddling about with the timing then there is likely to be a reason. Its probably to try and sort out the same running issues that you described.

The engine isn't likely to run as smoothly as it should until you have the timing bang on anyway.

sounds like you have many hours of work ahead of you !!

 

[Cater_Racer]

Checking exhaust there's one side clean as a whistle the other is black and sooty, seeing as there's only one throttle body and the injectors are electronic what can cause that?

 

[Cater_Racer]

Hi Marek,

Just a quick update on where we are with our problems

we ended up buying the Launch CRP129, which I know is a compromise but @ £225 seemed a powerful option for reasonable money.

We haven't fully got the recording mode working yet but the analysis of codes seems to be working, but the car isn't giving any error codes.

We pulled the plugs on the RH bank and all three are sooty running rich. The LH bank look perfect. So we are thinking the air oil separator might be the culprit.

Gerry

 

[rybol20]

Hi Everyone.

A little bit of update but not much of a progress!!

Gerry.

What symptoms you have on a boxter? My bank 1 is a bit sooty as well. Bank 2 normal. I dont think it will be a problem with oil separator, as it dump oil through a hose to inlet manifold, so all 6 cylinders will be sooty, I would say. I did replace my one as well, while replacing variocam pads.

To all

I have spent few hours yesterday, and I am more confused now, than before I started

1) I removed gearbox, and checked IMS bearing. To be honest, it is in very good condition, no funny noises, movement etc.

2) I removed 2 chain guides IMS - bank1, and they are nearly as new.....scratches obviusly, but very fine...

3) I was learning online, and porsche manual, about variocam (how it works and diagnosis etc), and I ve notice that bank 1 solenoid should be black , and bank 2 solenoid should be grey (not painted metal, zinc).

My solenoid on bank 1 is not painted(zinc) and bank 2 as well, they look identical apart from plastic cap at the top. Bank 1 has got black plastic, and bank 2 grey/creamish plastic. Could anyone advise if thats ok? Any video Ive watched, Bank 1 solenoid was all black(top plastic and whole body). Maybe early boxsters had 2 solenoids same colour, but caps were diffrient (black, and creamish)?

I`ve attached photo of my solenoids

BANK1

BANK2

4) I did see on some posts, videos, that apparently piston which moves in variocam, should have green seal in the middle groove?? other says there is piston on its own, no seal, which I agree, as for me groove is not deep enough to take seal o-ring. Can anyone advise?many thanks

5) Inlet camshaft . After Ive removed cams unit with variocam, I ve notice that tooth on inlet cam (cam sensor pick up tooth) is bent !!! Now.....not sure wheter it was bent before or I bent it, while re-installing cams unit last time! Cam sensor possibly can read wrong crk° if thats bent. I will put it right.

6) While checking IMS bearing, I did remove chain tensioner (CRANK TO IMS)

Ive notice straight away that tensioner is damaged. I can press it with my finger without much force nearly half way in, where bank 1 and bank 2 tensioner, can only press it few mm. Ordered new one.

7) Finally chain guide/s between crankshaft and IMS. After all checkes Ive decided to put my endoscope to check those chain guides. Unfortunetly, tried few diffirent holes etc but can`t get access to it. Does anyone know, if there is access through a sump? How can I replace them? Do I need split whole engine? [8|]Why I am asking? After removing tensioner and not able to scan guides with endoscope, Ive looked through tensioner hole. I put long screwdriver and start fidling with guide. It does move to left and right badly. Can someone tell me if thats normal or am I looking for engine strip?!!![]

I recorded video and I am attaching link to it. Its on my youtube. If someone dont want to click the link, just go to youtube and type in:

Porsche Boxster 986 2.5, Crank-IMS chain guide...ok or not?

Link to video:

https://www.youtube.com/watch?v=bzXdHqcMFRo

Again....Any advise/help would be greatly appreciated!!

Happy Easter[]

Many thanks

Marek

 

[Cater_Racer]

Thanks Marek, I'm sure our problems are the same.

I'm a bit ignorant about this cam solenoid issue.

How does the solenoid work?

Is it purely RPM related or are there circumstances when the ECU decides on operation other than straight RPM?

Is it active at low revs and releases at higher rev bands? or the other way round?

Surely it would be activated on both banks simultaneously?

Gerry

 

[Motorhead]

Marek,

Regarding the solenoid valves, the PET gives the following information:

Cyl 1-3: Black 996 605 901 00

Cyl 4-6: Grey 996 605 902 00

Maybe you can identify them from the part numbers?

Here’s a link to the PET which you may find useful … just input your car’s details:

https://www.porsche.com/uk/accessoriesandservice/classic/genuineparts/originalpartscatalogue/

Jeff

 

[rybol20]

Hi Gerry

To be honest with you I couldnt find much informations about variocam. There is some ....

Best I found is this:

"VarioCam

VarioCam, the adjustment of the intake camshafts at engine speeds of approx. 1,300 rpm* and 5,920 rpm, produces a major part of the engine output, the engine torque as well as the good exhaust values at idling speed. Engine speeds below 1,300 rpm produce a slight overlap in the valve stroke curves for the intake valves in relation to the exhaust valves.

This particularly affects low proportions of hydrocarbons (HC proportions) in the exhaust gas before the catalytic converters. If the engine exceeds the 1,300 rpm mark *, the intake camshafts are adjusted by 12.5° (by 25° if measured a the crankshaft).

Adjustment of the camshafts to produce a greater overlapping of the valve stroke curves for the intake and exhaust valves results in improved cylinder charging and thus an increase in engine torque. In the case of engine speeds above 5,920 rpm, the intake camshafts are returned to the basic control times (as for engine idling speed). If the intake valve closes later, additional amounts of intake air can be drawn in. This produces a recharging effect since the flow of air is not interrupted. This also results in improved charging of the cylinders and an increase in performance.

* The value 1,300 rpm increases to 1,480 rpm with engine oil temperatures of approx. 133°C."

"VarioCam

To increase the torque and to improve cylinder charging, the engine has two VarioCam actuators which are installed in the chain tensioners of the camshafts. The two actuators are operated by electromagnetic valves activated by the DME control unit.

Functioning

When the ignition is switched on, the electromagnetic valves of the camshaft adjusters are supplied with positive potential. If the engine is started, the control unit applies ground to terminal 25 (camshaft adjuster for cylinder line 4 - 6) and to terminal 52 (camshaft adjuster for cylinder line 1 - 3) if the following conditions are fulfilled (VarioCam activated);

Also I found that oil is injected to variocam underneath the unit. Oil pressure pushes piston in variocam up against solenoid, then solenoid, depends on engine load, rpm, controls that piston (up or down)I am planning to connect oscilloscope when I will fire up engine again and compare bank 1 with bank 2 solenoid and compare them, see how they work, learn a bit more.

Thanks

Marek

 

[rybol20]

Jeff

Thank you for reply.

I knew about this website, but thank you very much.

Problem is Jeff, I couldnt find any numbers on my solenoid. After 5 min with scotch brite and wd40 numbers appeared. However not numbers I need!!. There is two lines of numbers:

Bottom line is date of manufacture : 29/10/98

Top Line : 21.502.139

Thats all Ive got. I tried google those numbers and cross them somehow with part number...but nothing!

I am thinking of buying new one, because Ive notice that oil is coming out from it!! It was sitting on my table since yesterday (all clean and dried), and today pin was covered in oil!!

Not sure if thats ok, but from my experience, oil in electrical unit (solenoid etc) its a not a good sign!

Today I took sump off but not access to chain guides at all. I manage to look on both chain guides through tensioner hole and bank 1,only half of each guide, and they seems good condition as others bank1 and bank 2. Just waiting now for new tensioner.

If I will not find any more info by tomorrow eve, I will order that black solenoid, and see whats happen. They are new between £400-£500, but manage to find new one, but old stock in orginal box for £230.

Will update tomorrow.

Thank you

 

[Cater_Racer]

Hi Marek & Jeff

I've found my problem! When we had the LSD and comp clutch fitted, the exhaust was scrapped. I went for a new Stainless de-cat system.

Just been speaking to my comp car builder and he's admitted that he used the lambda sensor out of the old exhaust on one side he couldn't extract the other side so fitted a new one. They are mismatched!

Gerry

 

[rybol20]

Hi Gerry.

Thats good news. I hope car is running now as it should!

When I asembly all back together, I will test my o2 sensor as well. Take care

Marek