Variocam Issue?

[freserf]

I actually watched that video about a month ago ... very good for showing actual activation and deactivation. Forgot about it though ... so now my understanding is that variocams are activated with power on ... then it requires temps between 0-133C, rpm greater than 1300, and throttle greater than 5%. Or, temp greater than 133C, rpm greater than 1480, and throttle greater than 4%. Variocams deactivate above about 5000 rpm. It was a good design for its time.

I did not see a code for the solenoid after unplugging it ... I'll let it run through operating temp to see if it sets. I am getting ready to swap coils to see if the misfires change sides. Will update later this evening.

[Homeoboxter]

Originally Posted by freserf

I did not see a code for the solenoid after unplugging it ...

I can`t remember now in what circumstances my car threw the code last time I tried this: only one solenoid was disconnected or both. If the CEL and the code is triggered because the camshaft position sensor detects a difference between the banks, then you will only see the error code popping up if you disconnect only one bank (if both work). I`m just guessing though..

[freserf]

Just swapped coils 1, 2, 3 to 4, 5, 6 with same result. If the bank1 variocam solenoid is connected it will give P0341 when rpms go past 1300 to 1500 depending on temperature. The activation of the solenoid is pushing the camshaft position sensor numbers out of wack thereby giving the code.

Also the misfire stayed on cylinders 1, 2, 3 with the emissions warnings. When I disconnect bank1 variocam, no P0341 but still have misfires. No misfires if I clear the faults and keep rpm's above 1000.

There are no timing codes, just chain rattle when the variocam kicks in if I quickly demand throttle. Without the variocam connected I can throttle to about 3000 rpm before I here significant chain rattle.

So I need to find out what is causing the misfires first ...

New sparks plugs, coils seam to be working normally. Battery is new, but haven't checked the charging system voltage yet. I assume charging is ok since there is no battery light on the dash.

[blue62]

Just for general information:
An important fact to remember when dealing with OBDII and it's related codes.

OBDII is not about engine performance!!!

It's primary function is Catalytic Converter performance.
It doesn't care about engine performance until that engine performance degrades to the point that it becomes harmful to the Catalytic Converter.

With that in mind:
Events such as misfires will set a code and the CEL on the first event.
Why??? Because misfires are immediately harmful to the Catalytic Converter.

An event that would cause a code for say a bad MAF sensor or a slow signal from an O2sensor needs two back events under specific conditions to set The CEL.

On the first event the corresponding code will be logged in the Pending codes memory.
If the event occurs on the next drive cycle, startup, as a back to back event.
The code is moved from pending to permanent and the CEL is lit.
If the event does not occur twice back to back then the codes is removed from the pending codes memory.


So Freserf:
If your reading this, if you unplug the Variocam solenoid and you do not get a code perhaps the DME/ECU does not see it as immediately harmful to the Cat.
So look in the pending codes on your scanner.

Hope this info helps in some way.

[blue62]

Originally Posted by freserf

Just swapped coils 1, 2, 3 to 4, 5, 6 with same result. If the bank1 variocam solenoid is connected it will give P0341 when rpms go past 1300 to 1500 depending on temperature. The activation of the solenoid is pushing the camshaft position sensor numbers out of wack thereby giving the code.

Also the misfire stayed on cylinders 1, 2, 3 with the emissions warnings. When I disconnect bank1 variocam, no P0341 but still have misfires. No misfires if I clear the faults and keep rpm's above 1000.

There are no timing codes, just chain rattle when the variocam kicks in if I quickly demand throttle. Without the variocam connected I can throttle to about 3000 rpm before I here significant chain rattle.

So I need to find out what is causing the misfires first ...

New sparks plugs, coils seam to be working normally. Battery is new, but haven't checked the charging system voltage yet. I assume charging is ok since there is no battery light on the dash.

Just a WAG on my part:
I would say the cams on bank one are getting far enough out of time to cause the misfires.
Chain rattle says loose chains.
P0341 indirectly points to Cam timing issue.
And you have looked at and changed plugs and coil packs.
But I am just guessing.

[Homeoboxter]

Originally Posted by blue62

Just for general information:

If your reading this, if you unplug the Variocam solenoid and you do not get a code perhaps the DME/ECU does not see it as immediately harmful to the Cat.
So look in the pending codes on your scanner.

Hope this info helps in some way.

It all makes sense, just one more thing to consider: changing valve timing not only affects performance but influences emission directly as well. So if it`s not working, that on its own should trigger CEL. When I did this test, CEL lit up when I hit the throttle.

[blue62]

Originally Posted by Homeoboxter

It all makes sense, just one more thing to consider: changing valve timing not only affects performance but influences emission directly as well. So if it`s not working, that on its own should trigger CEL. When I did this test, CEL lit up when I hit the throttle.

Yes if the valve timing change cannot be compensated for with fuel trims and ignition timing. It would most likely set the CEL on the first event.
Interesting piece of kit that OBDII

[freserf]

Originally Posted by blue62

Just for general information:
An important fact to remember when dealing with OBDII and it's related codes.

OBDII is not about engine performance!!!

It's primary function is Catalytic Converter performance.
It doesn't care about engine performance until that engine performance degrades to the point that it becomes harmful to the Catalytic Converter.

With that in mind:
Events such as misfires will set a code and the CEL on the first event.
Why??? Because misfires are immediately harmful to the Catalytic Converter.

An event that would cause a code for say a bad MAF sensor or a slow signal from an O2sensor needs two back events under specific conditions to set The CEL.

On the first event the corresponding code will be logged in the Pending codes memory.
If the event occurs on the next drive cycle, startup, as a back to back event.
The code is moved from pending to permanent and the CEL is lit.
If the event does not occur twice back to back then the codes is removed from the pending codes memory.


So Freserf:
If your reading this, if you unplug the Variocam solenoid and you do not get a code perhaps the DME/ECU does not see it as immediately harmful to the Cat.
So look in the pending codes on your scanner.

Hope this info helps in some way.

Never thought of it that way ... protect cats ... one of the last cars I rebuilt required a new cat because it was melted and rattling around ... never gave a code though ...

[freserf]

Originally Posted by Homeoboxter

It all makes sense, just one more thing to consider: changing valve timing not only affects performance but influences emission directly as well. So if it`s not working, that on its own should trigger CEL. When I did this test, CEL lit up when I hit the throttle.

Which code set?

[freserf]

Originally Posted by blue62

Yes if the valve timing change cannot be compensated for with fuel trims and ignition timing. It would most likely set the CEL on the first event.
Interesting piece of kit that OBDII

Yes, very helpful or leads one in the wrong direction ... it is easier to diagnose if I had full engineering specs to go by ...

I left the variocam unconnected and drove around the block and it ran fine up to 25mph ... so I am left to pull the bank1 head cover and take a look at the variocam ... checking for anything odd such as really worn pads. Might be able to get to it this week ... just need to make a hold down tool for the cams. I'll update my progess ... thanks again for all of the input.

[blue62]

Originally Posted by freserf

Yes, very helpful or leads one in the wrong direction ... it is easier to diagnose if I had full engineering specs to go by ...

I left the variocam unconnected and drove around the block and it ran fine up to 25mph ... so I am left to pull the bank1 head cover and take a look at the variocam ... checking for anything odd such as really worn pads. Might be able to get to it this week ... just need to make a hold down tool for the cams. I'll update my progess ... thanks again for all of the input.

Hey good luck with it. Keep us posted

[Vza]

I had to replace my solenoid for a list of codes. Codes will cause a cascade effect making it difficult to find the root of the problem. If you hear your solenoid thats good at least you know they're working. The durametric allows you to turn various systems of the car on and off. You can activate either solenoid and hear the engine note change. You can also see your cam deviation to see if your timing is set within spec. I think it was + - 6. Misfire codes will get thrown if your timing is off....i would take a look at your cam deviation. Sometimes durametric sells returned items for a discount. You can call and ask. V

[freserf]

Thanks ...Depending on what I find with the bank1 variocam ... I'm pretty sure that something is amiss inside causing the P0341 when the solenoid is activated ... my best guess is one or a combination of problems. Variocam actuator, timing out of time, or lastly, or, etc.

I'll visually check the timing first and then proceed from there ...

[Homeoboxter]

A simple check is if you just pull the green plug at the cam position sensor and take a peek onto the variocam with a mirror and a flashlight, or borescope if you have one. If the pad is disintegrated or badly worn you should be able to see that. In my car it was completely broken off and caused the timing jump.

[freserf]

That does sound correct ... I was getting my old smartphone out so I could attach my endoscope camera ... I'll post the results ...

[freserf]

Dropped the oil cover today and found signs of wear ... one piece of aluminum. I also noticed tiny, tiny particles of metal in the oil ... most likely from the cover sump area itself collection over time. I also noticed the fingerprints of whomever was the last person to install the cover.

[blue62]

Originally Posted by freserf

Dropped the oil cover today and found signs of wear ... one piece of aluminum. I also noticed tiny, tiny particles of metal in the oil ... most likely from the cover sump area itself collection over time. I also noticed the fingerprints of whomever was the last person to install the cover.

The plastic looks to be the color of the Variocam actuator pads.
The metal particles and possibly the piece of aluminum could be from an actuator as well.
Looks like cam cover removal is next

[Homeoboxter]

Originally Posted by blue62

The plastic looks to be the color of the Variocam actuator pads.
The metal particles and possibly the piece of aluminum could be from an actuator as well.
Looks like cam cover removal is next

Yep, don`t bother with the camera...

[freserf]

Is it necessary to hold the cams in place to remove if I have to pull them anyways?

[Homeoboxter]

Originally Posted by freserf

Is it necessary to hold the cams in place to remove if I have to pull them anyways?

It`s recommended. Only one side of the cams is held down if you pull the cover which will expose the cams to a single sided stress because of the pressure from the valve springs. The camshafts are basically rigid steel tubes and they may break. The chance is not high that they will break, but they can. And you will need to hold them down once you put the cover back on, so you need a tool. You can get a set for cheap on ebay or amazon, or you can make your own. My build thread has pictures about the set I used, that may give you an idea if you wanna build your own.

Good luck!