valve rattle

1958 Views 11 Replies 9 Participants Last post by rainman, Dec 2, 2005

ultraclyde

Discussion Starter · Oct 20, 2005

now that it's finally cooling off in the deep south, I've been driving with the windows down and the air off a good bit, and I've noticed something

when I shift up while running moderate acceleation - the valves rasp just a little as the clutch comes out the last bit and the engine and drivetrain sync up. It does this if I'm revved a little higher and the drivetrain slows the engine slightly as it locks up - which is fairly often since it tends to hold the revs up a little as you shift. I don't hear it all the time under the same conditions, either. If I'm slow and careful in shifting, it's fine, and if I speed-shift it, it's fine.

I know some of the new comp-run engines are set up so that a little valve rattle under certain conditions is normal (Chevy trucks for example), but it grates on my nerves a little. Anyone else hearing this?????

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kj_cinci

· #2 · Oct 20, 2005

I don't hear anything abnormal from my engine, ever...

I guess you're sure it's from the engine/heads area? Otherwise it could be the tranny noises we all have... which is a Ford (Stang) thing, and part of that strong tranny...

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pbatour

· #3 · Oct 20, 2005

Could it be spark rattle? If you shift into a gear that is too high for a hill does it do it until you get up to speed?

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ultraclyde

Discussion Starter · #4 · Oct 20, 2005

Could be spark rattle....but I don't have the problem when it lugs down, and I cruise slow in 5th a good bit.

It sounds like it's coming from the engine, but it's a split second and I have to be near something to reflect the sound to catch it, so it might be elsewhere.

I'm not overly worried, but I hate to think that it sounds like that as I drive by someone!!

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Gig4Fun

· #5 · Oct 20, 2005

ultraclyde said:
now that it's finally cooling off in the deep south, I've been driving with the windows down and the air off a good bit, and I've noticed something

when I shift up while running moderate acceleation - the valves rasp just a little as the clutch comes out the last bit and the engine and drivetrain sync up. It does this if I'm revved a little higher and the drivetrain slows the engine slightly as it locks up - which is fairly often since it tends to hold the revs up a little as you shift. I don't hear it all the time under the same conditions, either. If I'm slow and careful in shifting, it's fine, and if I speed-shift it, it's fine.

I know some of the new comp-run engines are set up so that a little valve rattle under certain conditions is normal (Chevy trucks for example), but it grates on my nerves a little. Anyone else hearing this?????

Do you mean detonation... or preignition? Is it pinging? When I was a kid I can remember my Dad referring to pinging as "rattling the valves"...
got it when he ran the HiPo cars with "cheap gas".

http://www.hastingsmfg.com/Service%20Tips/detonation_and_preignition.htm

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pcfrisch

· #6 · Oct 20, 2005

How about the fuel injectors, I have a pickup that was as quiet as could be for the first year, after that it developed a knocking sound, took it in, they said it was the fuel injectors, nothing to worry about they said, except now it sounds like a diesel idleing.

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Stoenr

· #7 · Oct 21, 2005

I think I know what your talking about, I kind of hear is sometimes starting out. I think its normal, but then again, im not normal!

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htownStang

· #8 · Oct 22, 2005

I have the exact problem at around 5000 mile and i still hear it every now and then? I was thinking put the TT in but with this I have to think it over.

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zman99

· #9 · Oct 27, 2005

I'm in the same boat!

My 2005 Mustang GT is making the same sound you are hearing. Sounds like pinging. The pinging is very noticeable on upshifts @ revs above 2500. It also happens at highway cruising speed when you lightly depress the gas pedal. It never happens before the engine has reached normal operating temp. It is very bad on 87 octane. Not quite as bad on 89. It can even be heard on 93 octane, but rarely. I have had my knock sensors replaced. Did nothing. I have had the processor reflashed. Did nothing. Ford has taken recordings of this engine noise. I'm waiting to hear what they have to say about this annoying, and sometimes embarrassing phenomenon. Other than this, the car is really fantastic.

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zman99

· #10 · Dec 2, 2005

Ford sent an engineer out to listen to my spark knock problem. The engineer also happens to be an expert witness for Ford. Not a good sign. We took a nice long drive and he acknowledged the pinging I was hearing, but dismissed it as normal spark knock. He stressed over and over that I was NOT to use a higher octane rating than 87 in my car, even though 93 octane cuts the pinging down to almost nothing. I have now had two spark plugs and one coil replaced. They scoped my cylinders and already have noted carbon buildup on the pistons even though I only ran a tank or two of 93 octane through the thing. The car only has 7000 miles on it. I cannot stand the constant pinging every time I upshift and/or accelerate. I'm considering selling it. If what is happening to my car is normal, it's not half the car my 1989 5.0 was.

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kj_cinci

· #11 · Dec 2, 2005

Don't sell it!

It is NOT normal and they need to fix it!

I guess they and you have seen this: http://www.allfordmustangs.com/forums/attachment.php?attachmentid=12514

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rainman

· #12 · Dec 2, 2005

Ultraclyde,
Mine's doing the same thing, as I attempted to explain in this thread:

http://www.allfordmustangs.com/forums/showthread.php?t=50971

You did a little better at describing it than I did. At first I thought it was clutch related, since as you've noticed, it does it on spirited upshifts. However, as I mentioned further down in the thread, it also happens when simply jabbing the throttle suddenly. It may well be pinging, especially with what zman99 has said. To me, it just doesn't sound quite like pinging I've heard in other cars.

Like you, I've only noticed it lately, now that I can drive with the windows down and A/C off. I have no idea if it was doing it before and I couldn't hear it, or if it's suddenly started doing it. I could live with it as long as it's not doing damage, but if it is indeed spark knock, I have to wonder what damage to valves and such could occur over time.

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