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-   -   Loud Whistle From 94 Carburetor (https://www.fordbarn.com/forum/showthread.php?t=109483)

Tikker 06-19-2013 08:01 PM

Loud Whistle From 94 Carburetor
 

I've got a nice rebuilt 94 carb on my '52 Customline, borrowed from my brother till I rebuild mine.
Had it on before and it worked great, gave it back to him to try and determine some problems he was having on his '41 PU.
Now I've got it back and it has the loudest whistle you can imagine.
I'm sure it's a vacuum issue, it's not the line to the wiper motor, all bolts and screws are tight. I've actually had it stop whistling at initial start-up, but it quickly goes into whistle mode.
My brother mentioned the possibility of the power valve.
I can't leave it like it is, any suggestions for a solution?

ken ct 06-19-2013 08:15 PM

Re: Loud Whistle From 94 Carburetor
 

It could be the spring loaded little disc on the choke flapper is not opening when choked fully to let in some air??? ken ct. PV will not make any noise that i know of even if bad. Does it whistle when the choke plate is full open ??

Gary in La. 06-19-2013 08:24 PM

Re: Loud Whistle From 94 Carburetor
 

Could possibly be warped base of body where it mates to the carb base. I've had vacuum leaks there before on a 94 model 59 carb. Creates a very loud whistle.

OhioRick 06-19-2013 08:34 PM

Re: Loud Whistle From 94 Carburetor
 

Had this just this year and
I Traced it with a stethoscope to a hole in my cast base.

41ford1 06-19-2013 08:37 PM

Re: Loud Whistle From 94 Carburetor
 

Quote:

Originally Posted by Gary in La. (Post 673792)
Could possibly be warped base of body where it mates to the carb base. I've had vacuum leaks there before on a 94 model 59 carb. Creates a very loud whistle.

Bingo!!
Both the bottom of the bowl body and the mating surface of the throttle body must be flat. File or machine as required. Thicker gaskets there sometimes cure the whistle.

Tikker 06-19-2013 08:47 PM

Re: Loud Whistle From 94 Carburetor
 

Quote:

Originally Posted by ken ct (Post 673784)
It could be the spring loaded little disc on the choke flapper is not opening when choked fully to let in some air??? ken ct. PV will not make any noise that i know of even if bad. Does it whistle when the choke plate is full open ??

Choke full open.....

Tikker 06-19-2013 08:51 PM

Re: Loud Whistle From 94 Carburetor
 

Great information, suspect base gasket as it's not in pristine condition,
That's an easy solution to try initially.
I'll update.

Gary in La. 06-20-2013 10:01 AM

Re: Loud Whistle From 94 Carburetor
 

Suggest while you have it apart to take a piece of glass and tape a sandpaper sheet to it. Slide the 2 mating surfaces over it until have a uniform sealing surface. Sometimes using just a new gasket will still not seal good enough.

Ralph Moore 06-20-2013 11:23 AM

Re: Loud Whistle From 94 Carburetor
 

I would go with base gasket as well, a buddy's rpu was making the same noise with strombergs. We traced it to the carb base by pulling the windshield and I climbed over the engine while he drove, the sound was loudest going down the road about 35 mph.

ford38v8 06-20-2013 12:50 PM

Re: Loud Whistle From 94 Carburetor
 

Ralph, I guess no speed bumps in Alaska, or your buddy would have heard some pretty substantial thumps and bumps!

Lawson Cox 06-20-2013 01:33 PM

Re: Loud Whistle From 94 Carburetor
 

Quote:

Originally Posted by ralph moore (Post 674093)
i would go with base gasket as well, a buddy's rpu was making the same noise with strombergs. We traced it to the carb base by pulling the windshield and i climbed over the engine while he drove, the sound was loudest going down the road about 35 mph.

omg

Mike in AZ 06-20-2013 05:04 PM

Re: Loud Whistle From 94 Carburetor
 

lucky no moosie stepped out on road....yikes....the things we do, eh??....done the old ride-the-fender-and-dribble-gas-down-the-carb-while-moving thing back when....and still alive to tell about it...lol....Mike

Bluebell 06-20-2013 09:27 PM

Re: Loud Whistle From 94 Carburetor
 

Ralph, I'd have thought that whistle would have frozen solid, before it got out, at the Pole.:D

Ralph Moore 06-21-2013 08:30 AM

Re: Loud Whistle From 94 Carburetor
 

It was definitely not the proper way to do it. Don't try this at home kids. But our roads are not that crowded and it worked!

32phil 06-21-2013 09:13 AM

Re: Loud Whistle From 94 Carburetor
 

Had the same problem years ago. it was the hidden screw that faces up when the carb is in place. I found it by rocking the top of the carb while the engine was running. Tightened the screw and the whistle stopped.

ken ct 06-21-2013 09:44 AM

Re: Loud Whistle From 94 Carburetor
 

That screw up from the bottom is really not long enough,use a longer one cut down to just short of the bottom of the hole.Works just fine. ken ct.

Tikker 06-21-2013 03:22 PM

Re: Loud Whistle From 94 Carburetor
 

Problem solved.
Removed the carb and didn't realize there were remnants of an old gasket on the manifold. Wire brushed that with a small wire wheel in my drill motor till clean (was surprised to discover the manifold mating surface was textured like a cheese grader). Installed a new base gasket.........no more whistle.
And nobody needed to ride under the hood.
Thanks for all the input.

Ralph Moore 06-21-2013 03:27 PM

Re: Loud Whistle From 94 Carburetor
 

Well that's no fun:(

TStiles 06-21-2013 03:47 PM

Re: Loud Whistle From 94 Carburetor
 

Darn. I'm west of you over on the peninsula and was hoping to run over for that thrill ride... ;)

dwick01 06-22-2013 07:17 AM

Re: Loud Whistle From 94 Carburetor
 

Some people pay good money to hear a whistle.........

WQ59B 10-15-2017 08:09 PM

Re: Loud Whistle From 94 Carburetor
 

REVIVAL ::
Have a rebuilt 91-99 Ford carb on a stock 59AB flathead/intake. Truck starts, idles & runs well, but have whistling vacuum leak.

3 times now have started the truck cold & timed it. Parked, it takes about 7 minutes for the truck to warm to the point the carb starts whistling, and it's quite noticeable. Wiper port is plugged.

Once the upside-down bolt was loose, turned out the threads there were partially stripped. Epoxied in a stud and used a nut. Checked all surfaces, all gaskets, replaced bottom one twice with new, sprayed exterior with carb cleaner along all seams (no effect), rocked carb by hand (tight- no effect), checked all screws... cannot find the source. If I rev the engine after the whistle starts, it's still there.

Seems logical the whistling is triggered by the heat once it warms up. Why/ where/ how? Prior to that the cab base was sweating & very cool while running. Would a phenolic spacer be prudent?

51 MERC-CT 10-15-2017 09:09 PM

Re: Loud Whistle From 94 Carburetor
 

Someone told me once that he used a propane torch to track down a carb. whistle/air leak.
With the engine idling crack open the torch without lighting it.
Pass the torch around the suspected areas of the carb.
If the idle goes up then further pinpointing should lead to the source of the leak.

Phil Gillespie 10-16-2017 01:13 AM

Re: Loud Whistle From 94 Carburetor
 

Its possible to get a small vacuum/ pressure gauge as used for checking fuel pressure and air leaks. The vacuum gauge will be a safe method for checking and with a small nozzle on end of flexi hose finding sound not be too hard.
Phil NZ

WQ59B 10-16-2017 06:46 AM

Re: Loud Whistle From 94 Carburetor
 

Tried the hose/listening method, and it is difficult. With engine/fan running and the carb so relatively small, there was nothing conclusive heard anywhere around the outside. IMO, a torch gas test would be the same thing- difficult with the fan blowing and even less targeting than carb cleaner shot via a straw. Fuel is running thru a regulator @ 2psi. There is no change in RPM pre- versus post-whistle.

I realize this sort of thing is basically impossible to diagnose remotely, but it's certainly not easy on-scene, either. I'd like to find someone local whose been around flatheads for a few decades...

Crankster 10-16-2017 07:24 AM

Re: Loud Whistle From 94 Carburetor
 

Quote:

Originally Posted by Ralph Moore (Post 674093)
I climbed over the engine while he drove, the sound was loudest going down the road about 35 mph.

Say, as long as you're up, why not put a timing light on the damper and make sure the vacuum advance is working OK at highway cruise?

WQ59B 10-18-2017 08:12 AM

Re: Loud Whistle From 94 Carburetor
 

SO this HAS to be related to something heating up if it consistantly takes about 7 mins of run time to happen. The aluminum sections of the carb never get this warm, and I believe the cast base of the carb never got 'hot'- it was sweating & cool for most of that time.

Unless it's the intake that somehow is sucking air, but I've not disturbed that and by looks, no one else has since FoMoCo bolted it down.

If I install a phenolic spacer- that still needs a gasket on both sides, correct? I'm not driving this in really cold weather (no heat anyway)- icing shouldn't be any issue.

Oh- the mechanical fuel pump is still there- I covered all 3 ports while running- no change. Should I plug those ports for any reason?

revkev6 10-18-2017 08:59 AM

Re: Loud Whistle From 94 Carburetor
 

since you say you had a stripped out stud, that would be my first place to start. I'm guessing your carb is leaking between the carb flange and the intake. epoxy is nowhere near as strong as metal....

RalphM 10-18-2017 10:03 AM

Re: Loud Whistle From 94 Carburetor
 

Quote:

Originally Posted by Crankster (Post 1540033)
Say, as long as you're up, why not put a timing light on the damper and make sure the vacuum advance is working OK at highway cruise?

I was going to try that, but I couldn't find a timing light small enough to hold in my teeth!

Reminds me of the guys that drove non stop across the country back in the fifttys I think. They had running boards all around the car and could walk around and fill gas, check the engine. I think they even had a set up where they could change a tire while going down the road.

WQ59B 10-18-2017 05:58 PM

Re: Loud Whistle From 94 Carburetor
 

(Partially) stripped threads were at the upside down screw, between the bottom & center sections. I JB Welded a stud into the upper section so the sections tightened down with a nut instead of turning threads in the aluminum.

I've read mention of 'thicker copper' gaskets- where are these available?

oldredford 10-18-2017 06:09 PM

Re: Loud Whistle From 94 Carburetor
 

I bet the vacuum was loudest at idle. Goes away when you speed up. Figure that....

RalphM 10-18-2017 06:17 PM

Re: Loud Whistle From 94 Carburetor
 

Only ever heard of copper head gaskets, not carb gaskets.

WQ59B 10-18-2017 10:22 PM

Re: Loud Whistle From 94 Carburetor
 

Whistle remains when revving motor. Only variable it the truck has to warm up first (7 mins of idling), that's when it starts. One of these clues has to be tell-tale (7 mins, still there when revving)....

slowforty 10-19-2017 07:47 AM

Re: Loud Whistle From 94 Carburetor
 

Had anyone mentioned a leak around the Throttle shaft? Did you try spraying WD 40 or carb cleaner around the carb?

WQ59B 10-19-2017 04:25 PM

Re: Loud Whistle From 94 Carburetor
 

Sprayed the outside all over- no difference in RPM.

UPDATE :: Took carb off (Ford script 91-99). Tilting it in mid-air and fuel was running out the throttle shaft. This is a 'truck' carb with the manual throttle on the other end of the throttle shaft- that's where it was dripping. I have an 8BA carb, so swapped bases.

Put everything back together, truck ran a good 12 mins with no whistle. Problem now is I lost a really smooth idle- it would not idle without throttle and even then ran rough.

Adjusted mixture screws for some time with not much in the way of results. Can't drive it this way. Any issue in swapping the bases as far as idle quality?

I'm not above sending both out in a box to a reputable rebuilder....

JSeery 10-19-2017 04:40 PM

Re: Loud Whistle From 94 Carburetor
 

Looks like time for the rebuild.

WQ59B 10-19-2017 05:18 PM

Re: Loud Whistle From 94 Carburetor
 

I did rebuild the carb that was on the truck- cleaned the swapper base but of course there's not much to that. Idled so nicely before, feels like a bit of a sucker punch.

I read someone recommending a carb rebuilder on this board somewhere - anyone recommend anyone?

JSeery 10-19-2017 08:37 PM

Re: Loud Whistle From 94 Carburetor
 

There is a big difference between cleaning up a carb and installing new part and having it completely rebuilt. All the surfaces will be squared up and all the rod holes resized, etc. There is NY Charley and Uncle Max. One specializes in 94s, but don't remember which one. A quick search of the Barn should tell you all you need to know.

flatjack9 10-19-2017 10:52 PM

Re: Loud Whistle From 94 Carburetor
 

Charlie NY is the man you want to talk to.


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