: 06 3.6 startup rattle idle drops then surges



repnatl
04-04-13, 09:19 PM
This is new i start it up when its cold and it rattles for a few seconds then is good then it stumbles and idle drops to 200 then jumps back to normal. No dtcs or driveability issues this is weird it has done it for the past few days.

glake89
04-05-13, 09:42 AM
Old school-
Rattle= oil all drained out of system, faulty check valve.
Idle= fuel/air mixture fluctuation.

ktr-sb
04-05-13, 01:49 PM
Yeah, he's replaced the valve in the cap. Now I'm wondering if the pin in the anti-drainback wears. My LY7 is still rattle-free since I did my chains and replaced the cap 20K ago. I recently switched to Mobil 1 High Mileage (10w40, IIRC) and it seems a lot happier (like new, even). Or maybe OP has some sludge left over - how's the filter look at OC time?

repnatl
04-05-13, 02:39 PM
Oil filter has extremely fine particles in it nothing major no sludge in the oil pan or pickup tube either. Think ill replace the entire oil filter housing so all of it is new and see what happens.

conedoctor
04-05-13, 04:22 PM
Do the oil filter mod and call it good, you will have none of these issues anymore.

Replace the oil filter with the one form the V8, lets see who gets it and who doesn't ;)

repnatl
04-05-13, 06:45 PM
Swapping the v8 in would cure most of my issues lol. What mod are you talking about?

repnatl
11-20-13, 01:41 PM
So I replaced the second oil filter cap from the dealer and still has the exact same startup rattle. I'm thinking the oil filter housing adapter is next if that valve at the bottom failed.

Cadillac Cust Svc
11-21-13, 11:21 AM
So I replaced the second oil filter cap from the dealer and still has the exact same startup rattle. I'm thinking the oil filter housing adapter is next if that valve at the bottom failed.

Hello repnatl,

I am sorry to hear that replacing the second oil filter cap didn’t address the concern you were experiencing at the startup. Please keep us updated and feel free to reach out to Laura or myself if you would like any assistance working with the dealership. I will be on the lookout for your future updates.

Gregory W.
Cadillac Customer Care

08SRX
11-21-13, 06:40 PM
I'm not sure if you are in fact replacing the correct part. The check valve sits in the bottom of the oil filter canister and if it is faulty you cannot just replace the "cap". When draining the engine oil, open up the oil filter and remove any oil left in the bottom of the filter housing. You will then see a valve, press on it with your finger to ensure that it can move freely. It should come back up as it is spring loaded. If it does not close properly due to cold, it may starve upper areas of oil.

repnatl
11-21-13, 07:12 PM
That's the theory I'm having also. The valve in the filter cap is what I thought was the issue and now the valve in the housing could be the main issue the whole time.