[Heath]

I bought a 2010 Grand Caravan with 60k miles on it from a dealer and at about 70k I noticed it was using a lot of oil between changes, 2-3 quarts. Not too much later I started getting a ticking noise once the engine warmed up. I ran a bottle of flush through and drained some nasty oil and pulled the valve covers. The upper was now pretty clean and all the rockers and rods were solid, no movement. I filled it back up and ran some MMO through as well and it started running better but still ticking like a bad lifter. I pulled the heads and replaced the lifters and cleaned a bunch of carbon build up off of the tops of the pistons. I started it back up and after about a minute the ticking started up again. It's now at 80k and no more oil usage but the ticking/tapping continues. When it's cold it takes about a minute to start tapping and once it's hot it starts tapping immediately. I'm wondering if a bad oil pump can do this or if it's vacuum related. It fades out at idle sometimes and definitely follows RPM. Sounds like a lifter but definitely not a lifter? Any ideas?

 

[ImperialCrown]

Welcome to Allpar. Valvetrains usually don't have issues on these engines. What are you seeing for oil pressure when warm?
Have you tried locating the noise with a stethoscope? Is it under the timing chain cover? Possible exhaust manifold runner leak?

 

[chuckt]

ImperialCrown, could the ticking be due to an injector?

 

[ImperialCrown]

Injectors may have a light ticking. You would hear it more with the hood up.
With the hood closed and sitting in the driver's seat, it really shouldn't be that audible.
Locating the noise source is the first step in diagnosis.