Engine/Transmission (1994 - 1998) valve noise?

[Piersol]

I posted ealier this month about a noise I have. It's loudest when the engine is under load; especially when I'm on an onramp and it just shifts into overdrive. When I ease off it seems to stop. Maybe hear it a little bit. I first described it as if a screwdriver is resting on a turning shaft but it seems to have a high frequency pitch to it. Would loose valves cause this noise (worse under load). It sounds fine at idle. It sounds as if its coming from inside the dash centrally. Like maybe coming from the back cylinder. I removed the serpentine belt and all the bearings seem fine(tensioner, alternator, water pump).

 

[T-Bone]

"Sounds" like I have the same noise. Any ideas?

T-Bone

 

[Piersol]

Let me describe the noise better. It is kind of a hollow noise. Maybe as if you put a pencil in a beer bottle and rattle it around.

 

[R.E. Miller]

Hint:

Cut out your cylinders with the engine cold, and then when it is warm. Notice the change in sound and engine rpm. You might have a fuel knock. Fuel knocks can make all kinds of annoying noises, and are sometimes intermittent.



Russell

 

[Piersol]

Russell, what is a fuel knock and what do you do to fix it? It wasn't the valves. I adjusted them this am and it didn't help. The sound is barely noticable but enough to be annoying. If I so much as crack a window it hides the noise. Or even turn the radio on.

 

[R.E. Miller]

A fuel knock is a noise that is a little hard to describe, but it is caused by having one or more injectors running a tick too heavy one fuel. This is normally the result of a tired injector, but could be related to fuel pressure, quality, delivery valve condition, etc. Fuel knocks sometime sound like on cylinder running more advanced timing, most likely becausr it is running more timing by accident This could clear things up, but might make them more cloudy, let me know.



Russell

 

[Bseg]

My 97 has that same noise. When it shifts into overdrive and I lightly accelerate it picks up tempo. At one point it reminded me of the same sound I used to hear on my 66 Mustang shift linkage when it rattled and I thought maybe it was the 4WD shifter, but it wasn't that.



Would checking the fuel pressure be a good indicator to tell if this is the cause?



What should the pressure be at the line out of the filter?

 

[Bseg]

Originally posted by Piersol

Let me describe the noise better. It is kind of a hollow noise. Maybe as if you put a pencil in a beer bottle and rattle it around.

Forgot to mention, that is a great description of what it sounds like.



I never could figure out how to describe it to anyone.



Now we just need to figure out what it is.



I'm glad it's not just me, cause I thought I was the only one with that noise.

 

[Piersol]

4 wheel drive

I put mine in 4 wheel drive today and it seems to have quieted the problem 90%. As the engine shuts off I get a loud ticking around the transfer case. Maybe it needs that spring fix I have heard a little about. I will do a search and see what shows up.

 

[R.E. Miller]

Minimum fuel pressure at WOT no load is 25 PSI at the inlet of the injection pump, just FYI.



Russell

 

[Bseg]

Piersol,



I was playing around today on the freeway and put the pedal all the way to the floor at 70mph in overdrive. I can still hear the noise when I do that. Every once in awhile I hear it when I'm cruising along with no load.



Do you still hear it under full throttle?

 

[Piersol]

yes, I actually have 2 sounds. One is the tick tick sound(not the tick from the fuel pump return line) but the one we are talking about and I also have the sound when it just kicks into overdrive. I can't decide if the sounds are related

 

[WadePatton]

YES, but no!

Someone else has my condition. I think the "pencil in a beer bottle" is what I have too.



I just took over care and control of Dad's 95 auto 4x4, with 140k on the clock and ZERO BOMBs until I got it (and I'm just getting started). First we put in a Pro-Loc transmission, then I threw the stock fuel plate in a field and put in a #4. . Now under WOT I get that sound. It's sorta like a gasser with low octane gas, but not as high-pitched.



I like the tired injector theory.



I'll be checking the fuel pressure, adding injectors, KDP'ing, advancing the timing, playing with all them spring things, and fooling with the turbo and exhaust in the next few weeks. I let you know when the sound goes away.



Didn't notice the sound in the 160hp configuration, but then WOT was naptime then anyway.



Any other ideas will be explored if them don't work.

 

[illflem]

Re: YES, but no!

Originally posted by WadePatton

... I threw the stock fuel plate in a field and put in a #4.

If you can find it I'll gladly take it off your hands

 

[HBrunton]

Same sound/rattle/buzz what ever here also. tried the spring in the transfer case shifter. Didnt fix anything. Learning to live with it. The valves are not the problem in my case either.

Kinda sounded like the insert in the middle of the knob rattling around when I first noticed it. After driving I came to the conclusion that it is not the cause either. Let me know what yo do to cure it. Thanks.

 

[Hammer]

Tick,tick,tick noise may be a exhaust leak or have you checked it thoroughly. The 12 valve exhaust manifolds are well known for cracking on the underside in the center section and that noise will be there all the time but easier heard cold than warm. also they are known for stretching and pushing out the exhaust gaskets on cylinders #1 and #6. They have designed a set of metal straps to use but replacement with a better manifold is the best fix. Just a few more things to think about... ... ... . Andy

 

[illflem]

It's the 24 valve manifolds that crack in the middle. The 12s usually just bend the end bolts and may break off the ears that the end bolts pass though. Easy enough to look and see if the bolts are bent.

 

[WadePatton]

Bill, I guess I'll hang on to it.



I know what exhaust leaks sound like. This noise is only at 80%-WFO throttle. Could the new transmission have sounds I'm not familiar with?

 

[WadePatton]

noise again.

HAY, I noticed that the noise goes away after TCC lockup. Must be that juicer transmission. Do they make noises?



Whatcha gonna do with that stock plate Bill? Grind a custom?

 

[illflem]

Re: noise again.

Originally posted by WadePatton





Whatcha gonna do with that stock plate Bill? Grind a custom?

Yep, make it into a -0-