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Distributor squeal while running after replacing module & coil on reman. HEI.'79

Started by Benzilla, May 13, 2013, 04:18:33 PM

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Benzilla

I'm having an issue that's completely stumped me. Here's the back story: Last Friday I was driving around when my car (1979 Coupe DeVille Phaeton) stalled, and would not restart. After determining it was not getting a spark, I had it towed home & started looking around. Started by replacing my old ignition coil, because it was due anyway. Threw on new AC Delco cap & rotor for good measure. Turned out that the electric module in my 4 month old remanufactured distributor had died. I decided rather than replacing the whole distributor under warranty, and ending up with the same (apparently cheap) parts, I'd get an AC-Delco module & replace just that, hoping for higher quality. Well, the new module got the car running again, but I instantly noticed a new problem (why I'm posting this):

Any time the car is running, there's a high pitched squeal coming from the distributor, with a random ZAP now and then... not good. Checked that everything was aligned correctly & tight, wire boots secure, coil wiring correct, etc. I read somewhere that a squealing dizzy could be caused by the shaft binding up, or not getting oil to lube it. So, I took out the whole distributor & inspected it. It spins freely & quietly by hand, good inertia once you let go... seems totally healthy.

So my question is what could the squeal possibly be? The entire distributor & related components are all brand new. It never made this noise before the new module, coil, cap & rotor I installed this weekend.

Here's a link to a video so you can hear what I'm talking about: http://www.youtube.com/watch?v=agnO4CutcC8

Can't wait to hear some ideas!

Thanks,
-Ben

Dave Shepherd

Doesn't sound like a squeal but more of a buzz, like the rotor is hitting the cap contacts, look for signs of this happening. You could put a thin layer of grease on the rotor see if it hits the cap, can always clean it off.

Benzilla

Hmm,  I wondered about that. Kinda put the thought aside originally because I bought all AC Delco parts specifically so that it would all mesh right. I still have my old cap & rotor that are in perfectly good condition, just older & a cheap brand. Might try just swapping in the old cap / rotor next & see if that eliminates it. Ran out of daylight today, lol. Didn't see any signs of them making contact yet, but it's barely been run with the new cap, so not much time to wear a mark I suppose.

Thanks Dave!

R Schroeder

I would have to agree with Dave.
Sure you have it seated in the right place ?

You didn't mess with the 8 point magnetic piece in there , did you ? It under the weight arms.

Rotor is in the correct notches ?
Roy

Benzilla

Roy,

Yeah, the cap drops dead on with no margin of error & locks down perfectly. Rotor, too. It snapped right down & tightened level. I think I've had them both on & off at least 5 times now through all the noise diagnostics. The only thing I did to the base other than change the module was test the green & white leads with an ohm meter to rule out the pickup coil. Didn't touch the magnets themselves.
???
-Ben

TJ Hopland

That is indeed a strange sound.   If there was something hitting in there I would think it would be easy to see with that much noise.  The snap is interesting too.  With that much sound there should be some evidence.   All I can think of is did you get the contact assembled correctly?  The contact goes in the cap first then the washer then the coil.   Maybe if you had the washer in first the contact is recessed enough that somehow the rotor part is somehow chattering which also could explain the occasional snap?   I have seen them put together that way but don't remember a noise.  I suppose that could be because by the time I saw them they were no longer running.

Not that it has anything to do with the noise but just a general tip, did you clean the module mounting surface and use the new white goop on the new module?   No goop or a crusty uneven mounting surface will make them not last long.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

R Schroeder

Yes , if you changed that module, you will need some dielectric grease under it.
It will over heat otherwise.
Might be the reason the other one just failed.
Roy

dadscad

I've had the carbon button in the top of the cap be loose and spin with the rotor tab. It produced a high pitched squeak, "that" took some time to figure out. See if the carbon button will turn in it's socket.

HTH, David
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

Dave Shepherd

Quote from: Roy Schroeder on May 14, 2013, 07:50:13 AM
Yes , if you changed that module, you will need some dielectric grease under it.
It will over heat otherwise.
Might be the reason the other one just failed.
Roy       Roy, actually the grease for the module is not really dielectric it is a special formula for heat transfer to the mount plate, usually comes with the module. Just clearing this up so he doesn't use that by mistake.

TJ Hopland

Yes good point, the heat transfer stuff is white 99% of the time.  Usually a small tube is included with a new module.  If you did not get it and can't get it at a parts store Radio Shack still likely has it.  Any electronic repair shop or supplier would also have it.   Dielectric (like used on spark plug boots) is usually clear.   They are 2 completely different things. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

R Schroeder

The tube that came with had some clear grease in it, but it wasn't enough to cover the bottom of module , so I added some dielectric grease to it.

Thanks for clearing that up. I will check into the correct grease for it.
Roy

TJ Hopland

Just checked online and Radio Shack still lists it as a 'in store' item.  Most likely the easiest place for the average person to find a small tube of the stuff.    $3.50 for a little tube that would likely be a lifetime supply for most people.   I do electronic work so I always have it around for other projects. 

http://www.radioshack.com/product/index.jsp?productId=2102858&locale=en_US

It would not surprise me that a vendor was including dielectric grease with modules these days, after all grease is grease right?  Why stock two types?  One size should fit all.......    I am trying to think if I have ever seen clear heat transfer stuff.  I don't think so.  The paste type has always been white as far as I can think.   There are some newer methods that are clear but they are more hard epoxy like and there are exotic 'pad' materials that go between the components that are supposed to do the same thing as the paste but I don't know much about them. 

StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

R Schroeder

T. J.,
The grease was with the NOS , 35 year old part, I installed. What was under the original looked like clear yellow stuff.
It wasn't a new one, as per say , bought this week.
But, it is a good excuse to take a ride down to get some. Caddy needs a run today anyway.

Thanks for the site .

Benzilla

YES!!! Swapped in the old cap & rotor, started it; sound GONE. I'm thrilled that we figured it out, while simultaneously horrified by such a big problem on AC Delco's part... a Brand new cap & rotor, from the same company, shouldn't clash with each other! Visually, the old & new parts look functionally identical to the naked eye, must be the slightest difference just completely messed it up.

The following, I had typed before I swapped the parts just now, but the forum was overloaded at the time, so I just copied & pasted:

It's kind of amusing how many different people all around have asked me if I knew to put the grease under the module... I though it was just common knowledge? Of course. I cleaned off the mounting surface & used the clear silicone grease that was supplied with the module itself. I hadn't seen the clear stuff before, but went with it since Delco seems to think it works for their part. It's Polysiloxane 90%, Silica 10%, and the instructions said to use it for the heat. The old one that failed came installed with the distributor, it had a thick layer of the white grease under most of it, but I discovered one end was bare from the factory... nothing like quality control!

The spring loaded "button" is installed correctly, actually pulled the ignition out yesterday to double check the alignment. I installed it in the cap without the rotor present, so that it would drop down correctly & let the washer / gasket sit down fully around it.

I'm really a bit of a perfectionist, usually if something isn't installed correctly, I catch on pretty quick. Also, since I'm still a bit green, I do all the research I can before starting a project, and usually have all the steps memorized before I start. I never put anything back together until I'm confident I've done everything in my power to  insure it's correct. However no amount of precision can account for faulty parts..

Thanks for all the great advice!

Dave Shepherd

Best part about this was that you were open to suggestions and rechecked what was recommended, not everyone does this, good work!

R Schroeder

I did change the grease on the distributor module today. I did an up date on my posting about the problem I had.

TJ Hopland

I have pretty much lost faith in new AC delco parts.   It all started with oil filters maybe 5 or so years ago.  Had one that would not thread on.  Took it back to the store and the owner and I opened up several boxes and saw crappy looking threads on many of them.   He then went in back to look at other stock and found there were apparently at least 3 different vendors for the same model filter.  All with pretty poor build quality.  Filters now I have been using Wix or Napa Gold which is made by wix.  Never had a problem with them yet.  Had a few other parts the last few years that I thought were questionable quality so I have now for the most part gave up on them.   For ignition stuff Standard Ignition brand still seems to be decent. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason