I drove to CA to pick up my new Stage II heads and on my why home, I started to hear a tapping noise. It sounds just like my valve train noise except it is a little louder. As the rpm climbs, so is the frequency of the tapping sound. My first thought is broken valve springs. So I pulled over, turn off the engine, and started looking for something wrongs. The oil level was fine, the oil looked clean and no metal shavings. I started the and cannot hear it anymore. So I slowly eased back on the freeway, keeping the rpm below 3000 at all times. In about 5 minutes, it came back and I pulled over again. This time I can hear the taping noise in the cabin but not clearly outside the car. To much wind & traffic noise. So I got back in and started calling people for help.

They have the following theories:
1. Bent push rod.
2. Crud in one of the lifters, it will go sway.
3. Broken Valve spring.

It persisted for another 1 1/2 hours and there was no lost in power, no errors. Oil pressure was fine. Finally I reached Nevada and stopped for a break. As soon as I turn the car back on 5 minutes later, the sound is gone. I slowly worked up the courage to do some some WOT runs and it was fine. So what happened? The sound is like a Heads & cam valve train noise but louder and sharper. Metallic sound. It raises in frequency with the engine rev, also it get slightly louder.

I have a MMS 224 cam with A&A stage 1 heads, REV dual springs and REV valves. Never had a problem with the car and there was no Error codes...


[Modified by benelliwang, 3:01 PM 11/23/2002]

 

Anyone :confused:

 

Well....
One of my kids drive a 1989 Ford (Aka MAZDA) Probe that I totally disassembled to the chassis and restored (she loved the car and wanted to keep it :U ). One of the items that I had a little trouble over - due to the OHC - was getting valve lash set correctly. I was re-using the same lash adjusters that came off the head when I rebuilt everything - big mistake :mad .

Point is, I had a loud tapping noise that I could not seem to get rid of. After replacing the lash adjusters everything settled down and got real quiet. The engine rev'd fine, would idle fine and accelerated great, just had a lot of tapping noise. After checking them, the old lash adjusters were only worn .003" below spec but apparently that's all it took.

I'd guess :crazy: you have a hydraulic lifter issue and need to take a look. Could be the seal, or seals, are worn enough that you're getting the tapping noise from inadequate lift due to pressure loss. I would be really supprised if it's anything more serious. Try running some 10W Mobil 1 in the car. It won't void your warranty and the car runs quieter in hot conditions (I live in Texas so I run 10W year round).

Good luck :cheers: :cool:

SAVE THE WAVE :seeya

 

Its easy enough to check for a bent pushrod/broken valve spring when you get home. I have seen stock, used LS1 lifters get pretty noisy after a cam install and then go away for a while and come back and go away..

If it keeps up you are going to have to take it apart and look (I would look anyhow since its pretty easy to get the valve covers off these cars) - one of your rockers may have lost its bearings as well..

It may also be a header leak, sometimes they sound amazingly like a lifter buy you can usually hear it the most at lower rpm/high load.

 

I just had h/c work done and I have a tapping noise also. I only hear ii in the cabin. It goes away when I shift but comes right back. I am going back to the performance shop this week. I hope it is something minor.

 

I always have the valvetrain noise since the cam install, this one just got louder all of suddent. Then it went away after a few hours. The idle seems to run rougher but I could be my imagination.

I latest theory is exhaust leak... What do you guys think? The good new is that I was going to take off the heads next week anyway.