Help needed: Boxter fails to restart after rebuild / windows no longer work - Page 6 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Reebuck1 · 02-17-2014, 05:45 PM

Back to bank 1. This afternoon I checked the bank 1 solenoid to ensure it was functioning. I disconnected the solenoid from the harness and used a small 9V. battery to see if I could hear it click. I clicked it several times and it worked every time. I am not sure it would tell me if it were stuck but I could hear slight movement. I did not check wiring on the other side of the plug back to the main wiring harness. This shows picture shows the solenoid. It appeared to be slightly leaking before I cleaned it.

Moving to Bank 2. This is the exhaust cam slot showing vertical position with the crank still locked in the same position as when I checked bank 1. It was difficult to take pictures on this side but the exhaust slot matched the case split.

This picture shows the intake cam slot on Bank 2 pointing out board (away from the engine). Again difficult to see but appears ok to my untrained eye.

Thank you all for your help so far. Jake I'll buy your book as soon as its out and we all appreciate your comments. I think you should leave the chapter on wrecks in your book it may make us think twice.

OK guys what are your thoughts?

Jamesp · 02-17-2014, 05:54 PM

From what I've seen your timing looks off between the camshafts. Best advice I have is remove the engine from the car again, and carefully allocate the timimng again step by step. I had to do that. Then roll the engine several times when it is all back together checking the valve timing each revolution before putting it back in. I did that too. What bothers me is you have camshafts connected by a chain and I don't undersand how the camshafts could be off with respect to each other unless your variocam is playing up with you, or if you had the cams out and did not allocate them correctly. I'm a rookie, others on the forum have more experiance than I, and may have better insight.

Jake Raby · 02-17-2014, 06:26 PM

That's a 5 chain engine. I'll bet your deviations have an underlying condition impacting them... You just aggravated it enough with the IMSR to wake them up.

This is why we check deviations before a process as part of the pre-qual and if the values are out of my spec, the engine doesn't get touched. If it is we end up where you are if they reach the CEL triggering point.

These wear horribly, even at lower mileage. I will bet you this is impacting the values and you probably didn't do anything wrong. You just "finger Fu***ed" it by touching it. The CEL would have set anyway.

Moral of the story? Assume nothing and quantify everything, including cam deviations before the process is done.

Reebuck1 · 02-18-2014, 04:51 AM

Not the message I wanted to hear....But out comes the engine and trans and I'll try again. Jake I hear your message on the "some of the parts" and their relationship so I will pull the cam covers and look at guides and chains when I restart the process. When is your next class...I am interested. I really appreciate all the feed back. Can't say thanks enough.

Walter White · 02-18-2014, 06:43 AM

I have a little experience with drive chains monitored by electronics, in printing presses. The computer in the printing press would time the chain movement and throw an error if it didn't like the chain movement.

There would be a number of possible things that could be wrong with the chain drive. The chains do stretch, mostly by wear in the roller links. Sometimes a link will get stiff and not bend enough. The teeth on the sprocket wear too, sometimes enough to cause an error. The sprocket teeth actually develop a hook shape when worn too much. And sometimes we couldn't find anything wrong with the chain, the computer just wanted a new one installed.

Another thing I wanted to add. Make sure you have cleaned and reconnected all grounding straps. It is easy to forget one or two of them, and your computer may not read sensors correctly with a missing or poorly connected ground strap.

Reebuck1 · 02-18-2014, 01:08 PM

I cleaned and brushed all the grounding straps before engine install, so I'm guessing that is not it. I think Jake hit it when he suggested it is the SUM of wear on all the parts...5 chains...all cam teeth....CHAIN RAMPS....tensioners...etc. I believe I am going to have to tear down and remove cam covers and time the hard way. I do not think there is another way. If it is the sum of the parts the big question is which parts need to be replaced?? I am thinking about starting with chain ramps and maybe chains.

Jamesp · 02-18-2014, 01:38 PM

Quote:

Originally Posted by Reebuck1

I cleaned and brushed all the grounding straps before engine install, so I'm guessing that is not it. I think Jake hit it when he suggested it is the SUM of wear on all the parts...5 chains...all cam teeth....CHAIN RAMPS....tensioners...etc. I believe I am going to have to tear down and remove cam covers and time the hard way. I do not think there is another way. If it is the sum of the parts the big question is which parts need to be replaced?? I am thinking about starting with chain ramps and maybe chains.

Replacing the 3 main drive chains requires splitting the case. if you go that far you might as well do the bearings as well.

Jake Raby · 02-18-2014, 04:25 PM

Pull the cam covers, remove the valve train and the lifter carriers. Look for cracks in the area under the lifter carrier while you are there and some coolant in the region is the best tell tale sign. Why? Because its guilty until proven innocent and you may as well look for whatever you can while you can.

Replace the 4/5 chains, have the lifters ultrasonically cleaned and inspect the cams for wear and lobe taper as well as the crowns of the lifters for wear. If all is well slap a new set of wear pads on the variorum servo and put it all back together. Problem solved.