oc_s2k

Sounds like head has no oil between 1500-3000 rpm, but does it very infrequent. Car has 88k miles and has had two head jobs. I tried adjusting valve lash and inspected what I could see with just valve cover removed. My best guess would be oil pump. Anybody have any ideas or seen this before?

AP1Drew

It could be the timing chain tensioner.that's a common ticking noise. why were the head jobs done?

oc_s2k

I had a miss shift from 6-2 I meant to go to 4. Piston kissed valve on cylinder 1. Paid good shop to fix,they did good job r&r head but machine shop they used didn't do good job on valve seat so it burnt and lost seal after about 15k. Second time I r&r head myself. Has lasted 40k with no prob except one mentioned.

05TurboS2k

.... with all the probs you had we're looking at a number of variables and this is hard to guess for us with the given info and not hearing it first hand.

Running dry is unlikely given the oiling system here IMO.

Anytime I hear about valve related noise on a S2K I immediately assume it's the TCT (timing chain tensioner), a poorly designed item on the motor. It's oil/spring driven and has a bad habit of not providing enough pressure thus allowing slapping of the chain and guide to occur. It's intermittent and related directly to oil temp. Worst situations are at low revs and hot oil, so when you're running it under load a while like you would on the freeway and then exit and come to a stoplight....the ticking starts up first there most often. A blip of the throttle above 3,000 rpm will make it stop usually but it'll start coming back more often and more easily with time. An oil change helps but not for long, also better oils will do better, mobil 1 is horrible synthetic and will bring TCT failure sooner. Amsoil is a better choice.

The solution is to either remove the TCT worm gear and sand blast it and reinstall or just replace the unit. Neither is a great fix, I went through 2 units in 37,000 miles. The second lasted only 5k. Sandblasting with a course sand will make it last a bit longer by providing traction for the oil to grab a hold of and better drive the worm gear and keep it from binding with the housing. Alex@ballade motorsports here on the forum claims to have a excellent solution, though I've not seen it myself I expect it's probably a good one. You might contact him about the matter if that's indeed the cause.

Now say it wasn't the TCT.....

If I was to assume that it was getting oil fine (check wear to establish this) then I would remove the valve cover and try pushing each valve down one by one manually. You'll need to turn the engine over slowly a couple times to do all the valves but try pushing them down and see if they stick or don't pop back up nicely. Check carefully for any valves that are harder to move than others or don't return as easily. I'm wondering if you've got a valve that isn't seating, as a result it's snapping into place on the valve seat, possibly intermittent because the valve itself is spinning a little and only sometimes sticking.

Similarly I wonder if a retainer isn't properly seated to the spring, maybe its popping partially out of place or something strange like that is occurring. You could have someone with the proper tool check that for you rather easily, whatever you do, don't drop valves into the head while screwing around of course.

oc_s2k

Thank you for good info. The sympton you describe as a bad tct is exactly when noise does occur. It is hard to reproduce but would seem most likely because I notice more when driving low speed after commute to and from work.