[RESOLVED] Valve clatter after valve job

[whatturbo]

I recently performed a 6 bolt block swap on my Talon using my stock head. Of course the bolt holes in the head had to be bored larger to fit the 6 bolt head studs, and the machine shop did a valve job after to avoid metal shavings in my head. I never had problems with valve train noise before the swap. Now when I hit 3,000 RPM I have very loud valve clatter. It is loud enough to trigger my knock sensor sometimes, so I have been unable to do any performance tuning. The machine shop said all the valves were straight, and they replaced the guides and stem seals. The timing has been dead-on at 5° BTC since the first start up and remains so now. I know my valves are not adjustable because of the hydraulic lifters, but what else can I do to get my valves quiet? The car sat for 10 months while I was doing the swap and getting my transmission rebuilt. Could the lifters have gone bad from not having oil in them for so long?

 

[jpbrazill]

Does the clatter sound consistant and relavant to rpms? You could just have ticking lifters. When a lifter goes out, it is EXTREMELY loud. Its so loud that you can hear it from a good 100ft away.

Have you done a compression check? If so, what were your results?

I would also take your valve cover off, look to see if any of the rockers are not seated correctly underneith the cams.

J.P.

 

[whatturbo]

The clatter sound isn't very evident until around 3,000 RPM and then is relevant to RPM. When I started the car the first time after the rebuild the lifters were empty, so I've heard that sound. The sound it's making now is different. It's a definite clattering noise, not a ticking noise. I haven't checked my compression yet. I inspected the head real well when I got it back from the machine shop, and everything was lined up properly. This sound has been there since the first time I drove it with the new engine, and I've had the valve cover off since then. Everything looks fine.

 

[whatturbo]

I know this is old, but I wanted to update for anyone searching for the same problem to diagnose. It turned out to be a spun rod bearing. The noise was consistent until I got on it one day and it let go completely. I can't say I'm glad it happened, but when I took it out again it went back in as a 2.3 stroker. It spools my big turbo so much better and makes the car fun on the street again.

 

[talon2gbuyer]

I'm kinda having the same issue, except once my car is warmed up it goes away. Kinda an odd problem.

 

[BogusSVO]

Talon..

Depending on how may times and how much has be surfaced off your head, you may have restricted the oil flow to the head.

http://www.dsmtuners.com/forums/newbie-forum/341028-4g63t-head-oil-port-mod.html

 

[talon2gbuyer]

bogus, as far as I know the engine in the vehicle now was installed in March of 2012, not sure if it was a crate motor or a rebuild, so i really cant tell about if the head was machined or not

 

[talon2gbuyer]

I may just change from 5w30 to 10w30 synthetic oil to see if that softens up the clacking.