I'm guessing you mean the front engine cover as opposed to the cam shaft cover which is on top. either cover must come off in order to access the tensioners

 

Moved to the 2nd gen forum.

 

There is a way but special tools are needed as described in the service manual to hold tension on the chains to maintain timing (EN-46108). With your year though (pre-2010 and probable high mileage) a full timing chain kit is recommended.

Paul

 

Absolutely imperative while you are in there. I am of the belief that this is a full on mechanical project, meaning you have to remove the covers.

 

Hello!
I too am wondering if this is possible and I will explain why. So I recently did a full timing chain replacement with all tensioners and guides on my 09 CTS 3.6 (vin 7) with 135k. It was throwing the typical codes and it was clear that it needed done. So after getting the job all done which went very well. I have noticed the I have an engine rattle for a few seconds at startup until oil pressure is up. After the timing chain job I ran seafoam in the engine to clean it out and chained the oil twice. I then changed the tiny pressure valve that is the top of the oil filter adapter cap and I still have this startup rattle. This is extremely frustrating after all the hard work and money spent. The engine runs great! Lots of power and no dash lights are on. I have had a couple of people tell me and read a couple of places online that the cam phasers may need replaced. I am not the type to throw parts at it but I do know what else it could really be.
Does this front engine cover need to come back off to replace the phasers?
Does it sound like this is actually the problem? Any input would be very helpful at this point!

 

Hello!
I too am wondering if this is possible and I will explain why. So I recently did a full timing chain replacement with all tensioners and guides on my 09 CTS 3.6 (vin 7) with 135k. It was throwing the typical codes and it was clear that it needed done. So after getting the job all done which went very well. I have noticed the I have an engine rattle for a few seconds at startup until oil pressure is up. After the timing chain job I ran seafoam in the engine to clean it out and chained the oil twice. I then changed the tiny pressure valve that is the top of the oil filter adapter cap and I still have this startup rattle. This is extremely frustrating after all the hard work and money spent. The engine runs great! Lots of power and no dash lights are on. I have had a couple of people tell me and read a couple of places online that the cam phasers may need replaced. I am not the type to throw parts at it but I do know what else it could really be.
Does this front engine cover need to come back off to replace the phasers?
Does it sound like this is actually the problem? Any input would be very helpful at this point!

Yes it is possible with the appropriate timing chain holder EN-48313. It's not cheap for something you will probably only use once in a lifetime unless you're a mechanic. You will likely have to remove them with the camshafts attached for limited space reasons.

I highly doubt it's your actuators. You more than likely have the 3.6L chatter, that is the reason some Aussies refer to the Alloytec 3.6L V6 as the "Rattle tec". I can't say whether or not seafoaming the motor helped move you to this point, but it is highly unlikely that your actuators are bad if you didn't hear the noise until immediately after the timing chain replacement.

When I first heard it on my motor, it was about 3000 miles into an oil change. It was intermittent and I made associations that lead me to suspect it had something to do with air pockets forming in the oil passages from oil leaking out over time as the car sat. I switched to 0W40 Mobil 1 and immediately the noise was worse and far more frequent. I switched to 10W40 and have not heard the noise with that grade of Mobil 1 since, going on nearly two years now confirming my suspicion at least for my motor. I replaced my timing chains and actuators shortly after hearing the noise and the new parts had absolutely no effect. 10W40 did the trick for me and I suspect 10W30 would have the same effect given it has the same higher cold start viscosity. The thicker oil does not drain from the passages as fast.

There are complaints of the same noise in all versions of the motor, even the newest LGX, a google search and switch to videos should return a good number of examples.

CaddyFred if I'm correct about the noise I believe he is hearing, the insulation you mentioned would have no effect at muffling it.

This example has two noise phases, a slapping noise which is what I'd expect a bad actuator to make, indicating it was not locked, or could not be locked while the motor was off, followed by a rapid fire rattle immediately following engine run, which in my case would not occur until about 2 seconds after the motor started up. The second phase is what I've heard some of all of the 3.6L versions make;

Sign of a bad actuator;

Found this while searching for rattle examples. It's not a rattle but it is relevant to everyone who has the Direct injected motor. Scroll down midway to the one good video and listen to the sound of the motor at startup, apparently the result of a bad case of coaked valves. I use to hear that noise also although not nearly as bad. Premium fuel helps a lot, but cleaning the valves which I did really does a good job of making it go away.

Listen closely and you can hear it rattle a little at startup also.

$4700 in repairs at the dealership and now I have a...

Brought my 2010 SRX in to my local Cadillac Dealership because it was idling rough, trying to stall, and and throwing codes that both banks were running rich. They diagnosed it as both catalytic converters being clogged due to faulty fuel injectors. All 6 fuel injectors were replaced, both cats...

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I also have a cold start engine rattle for a moment until oil pressure builds. Just a thought but I didn't really notice the rattle until I removed the black fiber noise insulating panel from the top rear of the engine after finding a mouse nest under it last winter.

 

Here's a perfect example of what my car would do;

He has since updated and states that he changed the oil pressure sensor and the noise went away. That's interesting because I know from scanning that my oil pressure sensor reads 3 psi higher than it should, registering that value with the engine off.

 

Be careful if you attempt this method. In some cases the deposits may be obstructing full closure of the valves and you want to avoid getting any of the slurry that results into the cylinder. I did have some of the solvent seep through on the driver side bank in at least two cylinders considering I was able to detect that the level of solvent over the valves had dropped a little. The motor started and ran rough for about a minute before all of the contaminants were cleared. It does appear that valve sealing may be partly responsible for some are most of the reversion (intake popping noises) that is heard in some of these motors during cold starts.

It might be a good idea to pour a little bit of gasoline over each set of closed valves first to confirm a good seal before applying a solvent to them. The carb cleaner I used really does dissolve the carbon when given time to work. I also tried similar solvents in the can and they didn't come close to doing what the solution in the 1 gallon can did. They did however work very well at finishing the valves following the evacuation of the debris that was scrubbed free.

Read the first line of the first post in the thread and make note of it.

08 CTS DI Cleaning intake valves

Finally got around to completing this task. I am not recommending this method for anyone, just sharing what I accomplished using it. I used the Gunk carburetor cleaner sold in the gallon can at Advance Auto, along with about five 12oz cans of carb cleaner, a bore brush kit assortment from Harbor...

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