Variocam thoughts and questions

[sfkjeld]

Thought I’d update my 1341 CEL issue. After spending nearly $2k trying to solve the issue, I gave up. Either I can smog the car for another 2 years or I sell as a parts car. I’ve been driving the car nearly daily since I last chimed in. The car still runs beautifully despite one cam 6 degrees off. The CEL is thrown in exactly the same pattern. Only when the car is fully warmed up and only during City driving. I can still jump on the freeway and drive to LA without throwing the CEL.

As it turns out, I need another CA smog cert this April. The plan is to return to S Car Go in San Rafael. They got the car smogged last spring. Evidently, the smog test itself does not trigger a CEL. The shop obviously can clear the CEL and set the drive cycle readings. So am hoping it’ll still pass.

Finally, I am really amazed the car can run so well with the cam timing so far off. Wouldn’t being off by 6 degrees cause a symptom? Backfiring? Performance issues?

[sfkjeld]

The shop got my car to pass smog! And I am heading out in a few minutes to receive my 2nd Covid vaccination. It’s been a very good day.

[Homeoboxter]

Congrats! For both!

If the car works fine and passed smog then I guess you can just keep using it as is. Maybe it needs just a slight adjustment at the cam sprocket and no need to move the chains around... Did Modderman say anything specific about the required repair?

[sfkjeld]

Thanks!

The car runs great. I guess the cam adjusts too slowly and throws the CEL. I assume the nature of the smog test doesn’t test for the rate of timing adjustment. I think the car sits on rollers and the exhaust is measured at idle and at a high rpm.

So yeah, in theory, I can drive it as long as I want. But in the end, it is still essentially a parts car. I am coming around to it tho. Liberating, really. I don’t worry about it like I did with the 911s I’ve owned. It’s kinda nice.

Modderman thought it prob needed to be torn down. If it had been a 911, I’d have done it. But a 20yr old 2.7 Boxster, it didn’t make sense.

[sfkjeld]

As described below, I’ve had a 1341 CEL issue for over a year. Exhaust cam timing. The interesting part is that the car always runs great. And if the CEL is fully cleared with the Porsche Durametric scanner, it will pass CA smog (I’ve done it twice).

I put in a low temp thermostat a few months ago. The car def runs cooler unless in traffic on a hot day. Then it runs as it had with the stock 185 thermostat.

But it appears running cooler seems to effect the 1341 CEL. I have a cheap scanner and periodically clear the CEL when I annoys me. With the lower temps tho, the CEL isn’t thrown so quickly. I can go weeks now and it was days before. But now, if I leave the CEL on, the computer clears it once in a while. I assume it’s because the vario cam works better with a cooler motor? Anyway, weird.

[Homeoboxter]

Originally Posted by sfkjeld

As described below, I’ve had a 1341 CEL issue for over a year. Exhaust cam timing. The interesting part is that the car always runs great. And if the CEL is fully cleared with the Porsche Durametric scanner, it will pass CA smog (I’ve done it twice).

I put in a low temp thermostat a few months ago. The car def runs cooler unless in traffic on a hot day. Then it runs as it had with the stock 185 thermostat.

But it appears running cooler seems to effect the 1341 CEL. I have a cheap scanner and periodically clear the CEL when I annoys me. With the lower temps tho, the CEL isn’t thrown so quickly. I can go weeks now and it was days before. But now, if I leave the CEL on, the computer clears it once in a while. I assume it’s because the vario cam works better with a cooler motor? Anyway, weird.

Just hypothetically, if the O-rings inside the variocam are worn out/broken and they no longer can hold the pressure as they are supposed to, they can leak more when the oil is hotter and thus thinner, leading to more frequent triggering of the CEL. So it does not work better in a cooler motor, just it`s more likely to fail when it`s at normal operating temperature. Assuming this to be correct, thicker oil would give you even less frequent CEL.

[sfkjeld]

Originally Posted by Homeoboxter

Just hypothetically, if the O-rings inside the variocam are worn out/broken and they no longer can hold the pressure as they are supposed to, they can leak more when the oil is hotter and thus thinner, leading to more frequent triggering of the CEL. So it does not work better in a cooler motor, just it`s more likely to fail when it`s at normal operating temperature. Assuming this to be correct, thicker oil would give you even less frequent CEL.

Yes, that was my theory as well. I went to a 40wt oil but didn’t really notice much difference.

Any idea why the CEL would be clearing on its own? Is it documented anywhere what the 1341 CEL algorithm might be? What sets it off? How many degrees off, at normal engine temp, and maybe the number of times it has to happen? Over a period of time maybe?