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Discussion Starter #1
Hello, I came off the freeway and I noticed this noise, it only seems to happen around 3000rpm you cant hear it at idle

I can't pinpoint the source as to whether it is in the top or the bottom of the engine

has anyone had a similar issue that might help me diagnose it?

I have had the valve cover off and checked all the clearances there and they all look fine.

Thanks..



Zetec Noise
 

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Possible dead connecting rod bearing, allowing piston to strike head at revving it up. Drain oil and look for bits of bearing material in it.
 

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Discussion Starter #3 (Edited)
I was afraid of that, I must have screwed something up somewhere, however over 3500 the noise goes away
the bottom end was all new 5000K ago and all the new bearings were plastiguaged new eagle rods, and JE pistons and pins. and the crank was polished and checked at a machine shop.

Ok, Its been parked since last summer as I had a few home reno projects to finish but now they are done its back to cars again :)
anyway since I couldn't remember all the details about it i just spent the last 2 hours looking at it and here's the symptoms

the noise starts at around 3000rpm and doesn't go away over 3500
I drained the oil and it looked clean maybe 2 tiny silvery bits but there is only 3500km on that engine and its on its second oil fill, I put the oil back in through a filter and nothing on the filter.
when I push in the clutch after it warms up the load goes up and the engine sometimes stalls, the clutch is also extremely grabby, more than any I've ever driven and I seem to remember i used to stall it on a regular basis but i just assumed that's how the stage 4 clutch was, now I'm starting to wonder
if i use a stethoscope I seem to hear that same noise that i can't hear at idle on the transmission and not really on the engine block or the head
could it be something in the transmission?
the fact that the engine rpm dips when I push in the clutch is pointing me that way, or am i out to lunch :)
 

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I would get a hose like a heater hose or garden hose , use it as a stethoscope one end to your ear the other around the engine , you can hold it right up against the block , oil pan , valve cover and pin point the noise

Tom
 

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I would play with the clutch a little more. Engage and disengage it at different RPM and keep a log of what happens. Both while driving and in the driveway. It sounds like you may need a clutch adjustment.
 

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You gotta be freakin' kidding me. Besides that the clutches adjust themselves. Clutch could be broken of course. But it would show in working it.

Re: posts #5 & 6.............if the bearing is rotating in its' space the noise could easily change. I've heard them even shut up suddenly........until they blow up.

I'd be cool running it any more than needed checking for noise location, if smacking the head it will not run long at all before it comes apart bigtime. The piston will break into pieces, even forged ones can do it under those circumstances. .
 

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Discussion Starter #9
You gotta be freakin' kidding me. Besides that the clutches adjust themselves. Clutch could be broken of course. But it would show in working it.

Re: posts #5 & 6.............if the bearing is rotating in its' space the noise could easily change. I've heard them even shut up suddenly........until they blow up.

I'd be cool running it any more than needed checking for noise location, if smacking the head it will not run long at all before it comes apart bigtime. The piston will break into pieces, even forged ones can do it under those circumstances. .
Yes I know, no adjusters on a zetec clutch that I've ever seen and, I'm quite opposed to driving it anywhere :), the throw-out bearing was always noisy but Tom tells me that's more than likely the bearing in the front of the transmission and if I put a stethoscope right on the clutch slave check valve I hear the noise at idle which I am hoping is a clutch or transmission issue and since I was extremely careful when I put that engine together, and since it so far has never been over 15LBS of boost I haven't yet put too much power through it as I'm still in the tuning phase.

the clutch and transmission came from the stock engine,(clutchmaster FX400 that i installed a year earlier) which I did break from too much boost, so maybe there was something I broke then that i didn't see when i put the new engine in.
anyhow the transmission has to come out as I have a LSD to install
no parts from the stock bottom end were used in the rebuild except the oil pan that i had to fix as it has the oil return for the turbo
 

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Went back and listened again and I don't get clutch issue out of that at all. The rattle matches power impulses of the engine perfectly. You could try removing a plug wire at a time to see if the noise changes, that might tell you something. If a rod bearing the oil will be full of shrapnel by now. Pull your smaller bottom cover. Use a clean drain pan and you can even reuse the oil if careful, I've done it when needed before.

I could always be full of crap but not very often. You will hear noises at listening to clutch parts, there are a lot of parts that normally make noise at idle rollover. If the noise began at a shift then maybe, if the noise began in the middle of a gear pulling though, not likely.

Dunno what your exhaust setup is there but look it over, maybe a huge crack somewhere?
 

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Discussion Starter #11
Went back and listened again and I don't get clutch issue out of that at all. The rattle matches power impulses of the engine perfectly. You could try removing a plug wire at a time to see if the noise changes, that might tell you something. If a rod bearing the oil will be full of shrapnel by now. Pull your smaller bottom cover. Use a clean drain pan and you can even reuse the oil if careful, I've done it when needed before.

I could always be full of crap but not very often. You will hear noises at listening to clutch parts, there are a lot of parts that normally make noise at idle rollover. If the noise began at a shift then maybe, if the noise began in the middle of a gear pulling though, not likely.

Dunno what your exhaust setup is there but look it over, maybe a huge crack somewhere?
Thanks for the advice, in the video I was specifically holding it at that rpm to make the noise, I have listened to the car more than 20 times and the first 19 I was convinced it was engine noise, and if like someone said it was a rod bearing and the piston was hitting the head i think i would surely feel that when the noise comes on and i don't
the oil came out and went back in through a filter 2 days ago and its clean. and the exhaust is new and undamaged.
and the stage 4 clutch has always been a concern as I don't think it should be as grabby as it is its basically a switch either fully engaged or disengaged and i don't think that right,
 

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You're jogging my brain..........if that clutch lining has like ceramic pieces riveted to it one could have cracked through a rivet to come loose and swinging erratically to strike things. You should likely feel some sort of change in the way the clutch works but not guaranteed.

You really won't feel a piston striking the head, I never have on countless bad rod bearings through the years.
 

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Discussion Starter #13
Well I guess I'll find out soon enough :)

I have my other transmission ready to go in, just installed the torsen LSD but i have a question on preload, on the diff preload I measure it at 0.3mm instead of 0.2 mm with a dial indicator I have a 1.7 shim with a 1.4 gap since I only have the 1 shim I had to remove it to check it. is that too tight?
 

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Discussion Starter #14
You're jogging my brain..........if that clutch lining has like ceramic pieces riveted to it one could have cracked through a rivet to come loose and swinging erratically to strike things. You should likely feel some sort of change in the way the clutch works but not guaranteed.

You really won't feel a piston striking the head, I never have on countless bad rod bearings through the years.
yup you were right :(
 

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Bummer, always hoping I am wrong when giving the bad news. But it's the pessimist in me. Then when I'm wrong it's still a good thing.
 

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Discussion Starter #16
yes all 4 pistons were clicking up and down as all the rod bearings were destroyed I'm assuming that it was endplay that killed everything but I have no idea how it happened other than I have a stage 4 clutch pushing it forward Did you see the pics? any idea what could be the cause, I don't really want to put it back together and have this happen a second time because i don't know the root cause.
 

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Well stage 'three' or four' clutch doesn't mean literally anything to me but gibberish, but if you by some means knew exactly how much poundage was in the pressure plate that may tell the tale. Both spring rate and any centrifugal assist there.

Take for instance the dynamite twin disc clutch we used off 454 Vettes on our AMC race cars. 1950 lbs. of pedal pressure at 7000 rpm X2 discs = 3900 lbs. clutch capacity. That of course would dwarf anything you have there. The higher the number the more stress the crank thrust bearing goes through.

Yes, I saw the pics.
 
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