Valve clatter from 5000-5500 RPM under hard accel in 3.4L?!
#1
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Valve clatter from 5000-5500 RPM under hard accel in 3.4L?!
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?
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?
#3
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 $$)
- Headers accentuate the noise vs. the cast iron manifolds
- I run 5W-30 full synthetic
Do you have the stock airbox? If so, try putting it back on and see if the noise is as bad. Seems like when I had intake on my 98 Taco it really screamed around redline.
The noise I think you're describing is really "bad" when you have the window down and are at WOT next to a concrete barrier. Same noise?
It's really hard to diagnose things like this over the 'Net.
FWIW, my 96 makes a "racket" at higher rpm. My 97, 98 4R and 98 Taco did it too. I attribute it to a few things on my 96:
- Probably needs a valve adjustment at 110K miles (yes, they can be adjusted $$)
- 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?
#4
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Thread Starter
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.
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.
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#8
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#11
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.
I say follow the FSM recommendation.
#13
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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?
#14
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.
#16
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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.
#19
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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.
While this could happen, I don't think it likely on this motor in this application.