Bryce

Two things: something everybody should check and also asking for advice.

First something useful for the community about my bouncing oil pressure gauge. I am almost certain that it was a little rubber pipe that carried the oil from the case to the sender. The shop showed me the old part and it was kinked and twisted very badly. We suspect that the oil was getting clamped off and shooting through on occasion, so as to cause bouncing readings! The replacement part (updated part number) was so much better. It had all sorts of reinforcements on it so that it could never get twisted again. Although the needle is sensitive, once the engine is hot and going it's nice and smooth again!

Now for the disappointment and advice. Got my car back today. The shop test drove the car 3 times. I drove tonight about 60 miles, really stepping on the accelerator. At no time during acceleration did I get a CEL, which would happen every time before my fix. So, I am sure that lifters were stuck as the shop said. The car pulls strong. However, just driving in 4th or 5th on the freeway, around mile 50 the CEL flashed briefly and then went out. Then around mile 60 the CEL just turned on and I got the "Drive to Workshop" again.

I guess I read the codes and then take it back in. Maybe it was stale gas (7 months old), although I have a fresh tank now. Maybe they didn't gap the new plugs or something. Sigh. My heart felt like it sank when I saw that light.

I so wanted to be done, although I hope and feel like this is a minor bug.

deckman

It's the steady light and the flashing one, right? Do you have a code reader? It's probably something simple.

Bryce

The first time it came on it flashed for about 10 seconds and then went out. Then I got a fresh tank of gas. The second time it just came on (like a misfire) and is staying on. Car feels good.

Yes, I have a Durametric, and am eager to see what it says.

Bryce

Well, at least the codes are different this time! And the misfires that occured were on the other side (4, 5, 6). So, I'm hoping that this is just related to them not putting it back together completely tight, or some other small adjustments that have to be made. What do you know?

Valve lift: P1371, P1359, P1361, P1363 (valve lift control checksum error and cylinders 1, 2, 3, Porsche fault codes 637, 631, 627, 629)

Misfires: P0300, P0304, P0305, P0306 (Misfires on 4, 5, 6)

Oxygen Sensor: P0040 (Porsche fault code 294)

Engine-compartment temp sensor: P1157 (Porsche fault code 30) (The temp gauge appeared to be working fine to me, although this may be related to why the blow fan wasn't coming on right after I'd switch off the car)

Engine Purge Fan: P1675 (Porsche fault code 658) (Maybe this is the blower on top of the engine compartment?)

Sheesh, what a **** list!

Kevin

This is a repair shops nightmare. Did the shop go into the heads and check the valve springs? The valve lift is the intake tappets. Didn't you replace them? Did they replace the solinoids?

You should post ALL of the new parts that were replaced on the topend.

Carlo_Carrera

I have to ask even though I am probably way off the mark. Did you have your ECU and software checked?

The only reason I bring it up is because the battery died on my Turbo once and it wasn't replaced for quite a while and when it was replaced and the car started the ECU kicked out all sorts of crazy errors, the fuel pump was whining loudly, engine sputtering. The errors were cleared with an OBD and then the tech let the ECU reboot by leaving the key in the on position with the engine off for a few minutes. Everything cleared up.

The electronics in these cars is quite complex. Maybe it is part of the problem?

Bryce

The big ones were 996 105 225 25 (x12). Some orings and gaskets.

It literally goes on for 2 pages because we replaced a lot of rusted bolts and nuts. But I don't see any description that matches tappets or solenoids.

I will ask if they checked the valve springs in the head (this wouldn't require the complete cracking of the case, right? because we didn't do that). I do recall asking them to check the tappets because I was aware that they could become cracked, but they said they appeared okay.

Bryce

They have a PIWIS and said they did the appropriate scans and diagnostics. The problem didn't appear on their test drives, and only did on mine around the 50 mile mark.

Carlo_Carrera

I realize that your problems are very different than mine were. It just seems like you dealing with more than just a pure mechanical issue.

Bryce

Okay, so they are running a PIWIS test soon that will do some sort of oxygen sensor data collection that is correlated to the cam lifting and lobe selection from 0 to 6200 rpm. If that goes south, then I guess that means timing or a bad new lifter inside the head. They (and I) doubt it.

After that, they'll swap the solenoid actuators from one side to the other and we'll drive it around to see if the codes switch sides (which may be me, because it only happened once in about 40 miles). I didn't realize these run off the engine oil for the lobe selection. I sort of doubt they are bad because wouldn't the problem materialize around the time/rpm of the phase change state (small lobe to big lobe)? When I got the CELs I was driving a constant 75mph in 6th or 5th, so around rpms of 2500-3000ish.

Incidentally, I asked about the springs inside the head and he said he inspected them and there weren't any broken ones. I guess they could get tired (spring constant *k* gets smaller), but again this seems unlikely to me, and wouldn't they all get equally tired (so why one bank and not another)?

We'll see where it goes from here!

Land Jet

Would you kindly post a picture of the crimped hose location so that we might be able to locate it and check our own. Thanks.

Bryce

Hi Larry, it's right under the oil pressure sender, which is behind the oil filter housing.

Land Jet

Got it, thanks.

daytrip00

Any updates Bryce? I really want to know what happened. I really feel for you, man. I hope the car is ok!

Bryce

An update today.

They did the oxygen sensor readouts while doing the cam variation test from 0 to 6200 rpm and did not see any variation in the readings. So, it passes this test.

They did, however, notice that when driving and the fuel light came on, that the car produced the same misfires on 456. So, they are thinking perhaps there is a fuel pressure issue. They have rigged up a gauge in the fuel line to measure it as the fuel tank empties. I may take the car over the weekend to take readings as it consumes fuel.

I can only hope it will be finished soon.