So the lash adjusters were bad (mainly the reason it sounded like some tribal band with pots and pans under my valve cover). They replaced ALL 16 under warranty.

Never removed the cams, so the timing is fine.

The car was quiet for a little less than a week (without the 3" exhaust on) Then the noise came back, louder than EVER. I put the exhaust on, its not blowing oil like it was....(bad turbo) but the noise is stil there (didn't worsen).

Put my ear on the valvecover tonight, its the exhaust cam thats making all the damned noise.

Now when chasing a head noise, shouldnt you replace cams AND lifters?? AND do a compression test just for ****s and giggles?

None of that was done. I have cams off an SRT with like 12k miles on it. Im wondering if the lobes on the cams (we dont have rocker arms) could be bad...or if the bearing was bad. This noise is pissing me off, so is the fact that the car is running like a dog.

Does anyone have ANY ideas?? []

Paul...I want you to hear this...so I dont feel so crazy. Ive had four people agree and say yeah thats lifters, but theres no oil starvation going on, so wtf is the problem? Valves? Cams? Cam bearings? Cam Lobes???

 

Remember Hee Haw? Probably not, but they used to sing this song about having bad luck. That's what keeps playing in my head.
You have asked a lot of questions. I will try to give answers or best guesses.
First, my question. Do you have an oil presssure guage? If so, what kind of oil pressure do you have?
Q; should you replace cams and lifters?
A; In this case, it'd be cams and followers and yes you would replace the cam and it's respective followers if either of the two were wiped. The cam "seats" each lobe to it's mated follower during break in and should always remain mated as a set. However, if the cam lobes or followers were determined to be in good shape, and it was the lash adjuster that was bad, the adjuster could be replaced and the cam and follower remain in place paired.
Q;should a compression check have been done?
A; Okay, here's the deal. I, myself as a car owner and mechanic would like to know what my compression was, sure. As a mechanic who works at a dealership myself (luckily not flat rate but have done so), I will tell ya they were going to cut as many corners as they could being flat rated, but, if corporate tech support was involved, (as often they are concerning warranty claims), they dont care about the mechanics flat rate and will make him jump through all kinds of silly hoops before they "ok" the replacement of a part. Now, in defense of the mechanics, most are good, well intentioned people who would love to be able to spend all day on your car, (I know I would) but that doesn't make the dealership/garage any money, so in this case you have to ask, is a compression check really necessary to correctly diagnose this problem? I would say no. Especially if I found a defective adjuster or had insider info on a batch of bad adjusters or some thing like that. Cylinder compression is good to know, but in this case, probably not really necessary.
Q: what could cause this?
A; lack of oil pressure, improper hardness treatment to the cam and/or follower, sticking valves, wrong/bad valvesprings, bad oil, errant machining of the cam saddles, improper clearances around the adjusters resulting in problems with oil control, defective adjuster assy., bent followers, bent valves, plugged oil passages, I dont know, I'm probably forgetting something.
Q; cam bearings?
A; I dont know if this engine has them or not. Many engines with aluminum heads run the cams right in the head with no bearings at all. I don't know about ours.
Q;are you crazy?
A;yes
Q;do you deserve this?
A;no
I hope they figure it out, I know you got other things to worry about.

 

Well Im gonna take the valve cover off and make sure the bearings(caps) are champhered or however the hell you spell it, according to the TSB...Ill take some pictures while Im in there, and maybe those who know more than I do can help me out. []

 

WOW Pressure!

A logical, honest, and well balanced approach. I love that (not in a brokeback mountain sort of way...)

LSP, your car is doggy?? So sorry to hear this. Wanna race??

LOL

Scott

BTW LSP.. We used to get a better feel of where the noise was coming from by using a hard shaft of some sort (yeah, yeah, bring on the jokes). Seriously, something like a long socket extension or even a tire iron placed on the valve cover and held to the ear can be a great "back yard" stethescope (SP?). It alows you to pinpoint where the noise is coming from, and also isolates the noise from the other perifferal (once again, sp?) noises. Just an idea.

 

Yeah I used a screwdriver too.....its the exhaust side for sure, but ill be damned if I know why.

 

Hows your engine running? Like at idle. Is it rough? Popping, spitting, stumbling? What is your vacuum? The noise you describe sounds like collapsed adjuster/s or excessive lash. How collapsing happens is usually from a lack of oil pressure while running at higher rpms. What happens is the oil pressure inside the adjuster is not there to keep it pumped up and a few hundred beatings by the cam lob later, internal damage results and the adjuster fails to pump back up even after the oil pressure has returned. This does not usually happen gradually. You should be able to pin point a very specific event when it just started. I.E. "I knew my engine was 3 qts low on oil, when I took that high speed sweeper at 140 turning 4000 rpm while pulling 1.0 g's lateral when the idiot light came on for oil pressure, so I backed out of it and when I slowed down I heard this racket" This does not seem a likely scenario for you, plus, this is the second set. This is strange, but seems to indicate an ongoing problem with oil pressure or some kind of machining or mechanical dimension problem like if the cam perches were machined at a dimension too close to or too far from the valve and were putting either undue pressure (crush) on the adjuster, or, the adjuster has expanded to its max and can no longer keep the lash gap controlled. The second part being the more likely. Even if the cam is properly positioned in the perch, but you have excessive wear to the lobes and followers then the new adjusters may have expanded to their max already and are maxed out. Now and you are running with too much lash, causing the noise. This is the most likely I fear. The other thing I thought about was if these adjusters sit down in wells and the wells have drilled passages through them for adjuster oiling and the adjuster to well wall side clearance is too great, your adjuster may be bleeding down too easily. Not very likely.
If I were to bet, I'd go with the excessive gap due to worn cam lobes and followers.
Remember, too much lash (large air gap) will cause noise but the engine will generally run good and have good vacuum. Too little lash will hang the valves slightly opened all the time and you will have crappy/unsteady vacuum, hard starting, spitting, stumbling etc. This condition, if marginal, will be worse when the cyl head is cold and will go away when the head warms up due to the different rate of expansion in the head of aluminum (head) vs. steel (valves) so the valves will seat better when the head has fully expanded from heat.
Also, being this is a hydraulic valvtrain, ideally, there is never an air gap. The adjusters job is to keep the gap at zero to keep the engine quiet as well as compensate for wear (within limits).
Keep your chin up Kiddo!
Could be worse I guess.....