996 Cam Timing screw-up.......Pls HELP!!!
 

996 3.6ltr Cam Timing HELP!!
Several months ago I replaced the Clutch and RMS on my car '02 996 C4S 3.6ltr engine. At the moment, I also replaced the IMS cover. After a couple of months I saw that the IMS was still leaking, so I decided to disassemble again and install the LN Eng bearing kit.

I just finished the installation and it seems tha I screw it up!!! The cam timing is off !!!!!!!!!!!!
I did lock the Intermediate shaft, but this time I decided to use the method proposed by Wayne, which involves locking the Intermediate shaft sprocket using three set screws through the holes of the IMS cover. Not sure what went wrong. Maybe I did not tightened them enough, but it seem that one of the cams jumped, because the timing is off.

I started the engine and I immediately got the Check Engine light. I read the codes and I got P300, P301, P302,P303, which means misfire in cyl 1,2 and 3.

Now, my question. Is it possible to adjust the timing on a '02 3.6 996 engine while on the car? If so, can anyone explain the procedure for this?

Thanks in advance


PS: I posted on the 996 forum first, but it seems that it is not as active as this one, so I am taking my chance here ;)

Did you remove the tensioners?

Did you see if the cams were aligned when you put it back together? Pelican Technical Article: Boxster Intermediate Shaft Bearing Replacement and Upgrade (IMS) - 986 Boxster (1997-04) - 987 Boxster (2005-06)
(Figures 133-138)

Yes, I did remove the tensioners, but I think the issue was that the Intermediate Shaft was not locked well enough. I tightened the set screws before removing the IMS cover but then when the cover was out the screws were loose, so it might has slipped while removing the cover.

Now the problem I have is that I can only find info on re-timing the earlier 996 engine, but I could not find anything for my engine '02 996 VarioCam Plus. I read some post stating that the procedure is different, but not explaining how to do it. maybe Porsche52 can jumped in!!! :D

Thanks for your input

Disclaimer: I am no expert, hopefully someone with more experience will chime in. However, if it was my car, I would not start it again. First I'd pull the rubber plugs and check the timing of the four cams as described in Wayne's article. Assuming it is off, then I would do a leakdown test after the cams are timed, to make sure none of the valves are bent.

I think the 2 tensioners are different. Is it possible they were reversed, perhaps causing a jump of chain?

Right, you want to check the timing first (as mentioned and discussed in the article) prior to starting the engine. Spin the motor around and check the timing to make sure that is indeed your problem, before you start tearing off the side cam covers.

I don't have the 3-chain timing procedure done just yet (I have the motor, but we haven't had a chance to get to it quite yet).

-Wayne

Thanks for the inputs. I will re-check timing visually this evening (and not start it again!!) and post the results.

Wayne, do you have any idea where can I find info about the procedure for this engine?

Thanks

Don't think I would want to time the cams with the engine still in the car...

We have a fixture for positioning the cams initially..

http://forums.pelicanparts.com/uploa...1174274206.jpg

Then degree wheels and dial gauges are needed..

and a fixture to hold the dial gauges (indicators)

I made a post awhile back showing some of this

http://forums.pelicanparts.com/911-engine-rebuilding-forum/336439-cam-timing.html


fixture and dial gauges

http://forums.pelicanparts.com/uploa...1174274291.jpg


degree wheel


http://forums.pelicanparts.com/uploa...1174274445.jpg


Even if you could time the cams with the engine in the car... It would be easier to drop the engine and do it..

Ok, just checked the timing and the Bank 1 (driver side) is off. The top camshaft is perfectly vertical at TDC, while the lower camshaft is a few degrees off (slightly turned to the left)

Bank 2 seems to be ok, both perfectly vertical at TDC.

The visual check seems to confirm the code I got...Misfire on Cyl 1,2,3

So now ....how do I fix it?????

TimT

I understand that the procedure you are posting is for a full assembly of an engine. In my case it seems the the only camshaft that jumped during the IMS install was the exhaust camshaft on Bank1 one. This might be simplicity driven by ignorance, but isn't it possible to re-dial the exhaust camshaft on Bank 1 without having to mess with the rest, which in principle ( and confirmed but visual inspection) are properly timed?

Thanks again for your inputs

Yes.............

TimT

What do you think about this procedure for retiming the exhaust camshaft. Might this work? Is there anything on the VarioCam vane system that might complicate this.?

"The relative position of the exhaust cam (lower cam) to the IMS, and there fore the crank is fixed and does not change. It is only the relative position of the intake cam (upper Cam) that changes. So if the bottom cam is not straight up and down (use a straight edge and the joint between the cover and the head to check this) than the timing of that cam is off. I can give you a fairly simple way of adjusting this. To turn the crank take off the serpentine belt and use a socket on the main pulley. The engine rotates clockwise looking from the rear of the car. Try to turn it in that direction if you are going more than a few degrees. First get the engine close to TDC for Bank1. Then rotate the crank until the exhaust cam is straight up and down. Now loosen the 4 bolts on the exhaust cam sprocket (this assumes you have removed the scavenger oil pump to have access to these bolts). Now you can rotate the crank to TDC, this should only be a few degrees, without rotating the cam. Once the crank is at TDC and the cam is still straight up and down re-tighten the bolts on the sprocket ( I tighten two of them, then put some Loctite blue on the other two and tighten them, then remove the first two and put Loctite on them and put them in. The torque for these bolts is in the manual."

Best

Ok, thanks to Doug (Dharn55) my car is up and running strong. The procedure mentioned on my previous post worked perfectly. I only had to remove the four cam plugs, take the oil pump out (just four bolts and some ingenious prying to make space for it to slide out)

Doug you are the MAN!!!!!

Hello,
I have the same problem on my Boxster 3.4
Any advice how to fix it easy , maybe i have to re-timing it ?

here are some photoshttp://forums.pelicanparts.com/uploa...1430582098.jpg

Same problem
 

Hi Mario
I would like to connect with you regarding the actual steps you took to correct the timing on the cam shaft. I have done the exact same scenario. Hope you can help

Thank you
Andrew