LuminoZ

I've noticed that when I really stand on it, and tap out (to the redline) 1st and second gear that I get what sounds like valve clatter over 5000 RPM. If the vehicle isn't moving and I just rev it up to the redline, I hit the limiter and there is no valve clatter noise.

Has anyone else experienced this?

I know I've got plenty of clean oil in my motor. So am I just starving my front valves/rockers for oil under a hard launch? Or is something else going on?

Elton

could it be ping ? u no mine makes some clatter once and awhile

rimpainter.com

It better not be ping at 5K+ RPM or you're in trouble!

It's really hard to diagnose things like this over the 'Net.

FWIW, my 96 makes a "racket" at higher rpm. My 97, 98 4R and 98 Taco did it too. I attribute it to a few things on my 96:

- Probably needs a valve adjustment at 110K miles (yes, they can be adjusted $$)
- Headers accentuate the noise vs. the cast iron manifolds
- I run 5W-30 full synthetic

Do you have the stock airbox? If so, try putting it back on and see if the noise is as bad. Seems like when I had intake on my 98 Taco it really screamed around redline.

The noise I think you're describing is really "bad" when you have the window down and are at WOT next to a concrete barrier. Same noise?

LuminoZ

Yeah I probably should get my valves adjusted/checked. I've got the stock headers, and a cold air setup so I can't toss the stock one back on.

I run mobil 15w-30 and BG stuff when I can get a hold of it.

I only notice it under hard acceleration, if the vehicle is stationary and I go WOT all is get the sputtering from the rev limiter, hence why I thought it was the valves getting starved for oil.

I notice the sound out in the open with the windows up too.

rimpainter.com

Can you post a vid sometime?

LuminoZ

Yeah, I'll get one up tomorrow night...
Anyone have any other ideas?

Teuf

Why would 5/30 syn make it make noise

xcmountain80

Don't drive near 5k? My God you must be standing on it, you know this thing is not a Supra right?

A

Teuf

Dang I could crack walnuts in mah butt cheeks every time I even get near 4k rpm.

j-money$$$

just had my valves adjusted after 220k miles. i had one cylinder at 25 psi of compression and it cost me about $800 good luck

rimpainter.com

On a higher mileage engine lighter weight oils tend to make more noise (tolerances have expanded). That's why you'll often hear people recommending "straight 30" or even 40 if you get valve clatter at start-up or increased noise in general. I think that's a bit excessive, but it did work on my old 88 Mazda truck.

I say follow the FSM recommendation.

Teuf

i think Syn 30 is the same as dino 30, even 40. At engine opp temp most oils are near the same protection level.

LuminoZ

Exactly. The torque peak of the stock motor is 3600 RPM I've been told, and the HP peak is at 4800, so I guess I'll stop there.

Hell I'm never over 3600 in daily driving, but it was just something that didn't sound right so I wanted to know what was going on.

I'll still try and get a video up tomorrow night.

I know how to tell if valves are going on a MX bike by paying attention to the way it runs... do V-6's give any indications that the valves are out of tolerance?

rimpainter.com

I agree that weights are weights. However, 30 is different than 40. Anyway, I don't want to split hairs...the properties of full synthetic, even if the same weight as dino, can sometimes create issues for higher mileage engines. I've seen oil lights come on with full synthetic, more noise when cold and hot, and oil seeping past valve seals when sitting, then burning at start-up. All issues were reversed when switching back to dino. So I guess what I should have said was that full synthetic can sometime create previously unheard noises. Just thought it might be a factor to add in to this particular question.

Teuf

Valves on an mx bike, I Never,,,,,,,,, Maico 501, now there was n mx bike.

Teuf

Look up, (sorry no link) Ferrarichat.com Motor oil article, Dr Ali E Haas, AEHAAS, its a long read but interesting, from what i saw its all about flow and start up oil weight.

hross14

valve float

LuminoZ

Can I trouble you to elaborate on that one?

Man4God

Same thing as valve toss? Basically that with the engine spinning high under load the valves can be "tossed" away from the cam lobes (or push rods) and then clank back to the cam/rods.

While this could happen, I don't think it likely on this motor in this application.

etan

"if it don't pull anymore, theres no need to push it anymore."