Ok, the s4 has been away for the winter and a couple mods are being worked on. Didn't start it for a couple weeks because it's in a garage and I was out of town, so I wasn't worried about it. Now it sounds like it has valve tap for the first couple minutes it runs. I thought it might be a one time thing but it has done it for the last three days straight. Any ideas?

 

Sounds like the lifters have leaked out their oil. You should be able to just drive it, lightly till they pump back up, but , I would just change the oil, & then run it. You might get the noise for a while, till the lifter pump back up, don't worry about it, & DO NOT drive it hard until it goes away.

 

That's about what I thought is the lifters bled down from sitting, but it has done it for a couple days now. I always let it warm up for a few minutes before driving (after 2 new sets of turbos in a year) and the noise goes away after 3-5 mins. Wonder why they keepbleeding down?

 

dont use lucas stabilizer, its the same as throwing tranny fluid in your engine.....too thick. if your running mobil 1 switch to a synthetic oil like red line, amsoil,liqui moly, ormotul. the problem your having is the exact reason we stopped running mobil one around here. i reccomend the red line. and bump up the weight. true synthetics flow with alot less resistence so its safe to run heavier weights. in my cars i am running red line 5w-40.

 

according to bently, "hydraulic lifters checking"
-irregular noise during cranking is normal
-hydraulic lifters cannot be repaired or adjusted. faulty lifters must be replaced.
-start the engine and warm until radiator fan has come on atleast once
-Increase the rpm to 2500 for 2 minutes
-If the irregular valve noise stops and then reoccurs each time the vechile is used in stop and go traffic
-replace the oil check valves
-if the irregular noise does not stop find and locate faulty hydraulic lifter(s)

 

hmmm..... could be wrong weight oil. I'm running 5-30 royal purple full synthetic. Where are the oil check valves located?

 

the oil check valves are located behind the cam gear in the cylinder head

 

i've never heard of anyone on here replacing oil check valves though, have you?