Hi:

I have a 1983 E-100 w/a 4.9L 300 6cyl. with about 86,000 miles on it. For many years I have had a problem with a crackling noise when I accelerate from about 50mph to 60mph and above. My mechanic has told me always to use 93 octane gas, which I have for years, but even with timing adjustments I still have the problem. There is no loss of power, just that bloody noise. I was wondering if it had anything to do with the timing chain itself? Like I said, I've had this problem for years. I'm wondering also since it appears to be worse during the winter months if it had anything to do with the ethynol, (spelling?), that they add to the gas during those months. It's also happening to a 1994 Hyundai that I have with 40,000 miles on it. It never did it before. I just hope that running them like this doesn't permantly damage the engines.
Any help or advise would be appreciated, ArnieB Woodside, NY

 

The 300 is (in)famous for being a noisy engine. Most 300s have some type of tick or clack depending.

The 89 I removed gave out varous noises depending on the RPM and how hard I was using it. It always had a clack at about 3/4 throttle and while pulling a Dodge out of some sticky mud it started to remind me of a Singer sewing machine.

It ran like a champ till the day I pulled it even through the last two days of abusive driving. Most of the advice I have seen was to get used to the noise.

If you do want to take a peek at possible causes, the timing cover is fairly accessible and the 300 has the side inspection plate. The valve cover on the carbed models is easily accessible also. If you are going to pull the covers it would be advisable to use new gaskets.

Also, the 300s have timing gears, there is no chain.

 

Thanks for the advice. It's good to know that there's timing gears instead of a chain or belt. I imagine that gears last a lot longer and are more reliable. I'm wondering if hotter running plugs would help the cause, the engine always runs on the cool side of the temp gauge anyway!

Thanks again!

 

im not sure how reliable the stock gears are. i have had one shear because it got too old, and they were the stock fibre gears.

 

When it comes to the timing gears, just remember, plastic ain't fantastic, but steel is for real!

 

Is the 300 6cyl a interference type engine or a non-interference? If figured I'd ask.

 

Unless it was changed in the later years, the 300 does not have a timing chain. It has two meshed gears. That's a big advantage IMHO.

Have a great day,
Doc

 

its non interference

 

93 octane fuel is a waste in a 300. If it is helping matters it's because something is very wrong somewhere. Does the van have an EGR valve?

 

what is ur base timing set at? as SS said, does it have an EGR and is it functioning?

 

First: It's nice to know it's a non-interference engine.

Second: As far as my timing setting, I'm at a loss as of now. All I know is that over the years we have tried various settings, (mainly retarding the timing, but of course if you went too far you would get rid of knocking, but have hesitation or poor acceleration.)

I know that the original specs for gas was 87, but even when it was brand new it just didn't do the job.

Yes, it does have an EGR value, and it appears to work. When I rev the engine I see the little arm that goes inside of the distributor move. It also makes a slight sound, sort of like a grunting or a deep vibrating noise. I know it sounds crazy, it's just hard to describe!

I've had it for twenty two years now, and have tried a number of things. I never had the EGR valve replaced or the O2 Sensor. I'm wondering if a cooler plug would help, any other advice. I'm all ears!


Thanks, Arnie

 

What kinda RPM's are you at when it happens? Does it matter if you're pulling or going up hill?

Give it another 44 years and see if it still does it

Not to point fingers, BUT it seems there are'nt that many thing in common between your Ford and Hyundai beyond the mechanic(?), the gas,oil,etc., and how and where it's driven. I mean, if it were a problem between 2 300 I6's or even 2 Ford motors, I might think it was a Ford problem, but the 2 motors you mention it happening to are very different in the way they are built and really have little in common beyond how they generally function.

Since I can't be there to hear it, I wonder if your ears are just too good and your just hearing normal engine wear.

 

But the main point is, and I forgot to mention, is that the Hyundai just started with the knock about 2 years ago. It was fine and ran on 87 oct. up to that point. The van seemed to have this problem from the beginning. Plus my wife always drives that car, and I always drive my van. We buy gas from different stations also.
All I know that you get used to your vehicle riding and performing a certain way, and when it doesn't, you just know it's not right.

Do you happen to know if eythanol (10%) in the gas during the winter makes a difference?

 

You asked what rpm's it happens at etc. It starts to happen mainly at about 60mph (I don't have a tach) and above. It can happen on a relatively flat highway, of course it acts up when I have more weight in the van.

My wifes Hyundai acts up from about 35mph to 45mph and disapates from about 50mph and above.

 

Strange noises are normal for the 300. Hers mine, I had(have) a pre-ignition type of rattle at 2200 to 2400 rpm. I have: changed he timing both ways, all the way to '0' with no vacuum advance and the centrifical wired down, NO difference. All the way up to real pre-ignition and thats a different noise. I rebuilt the engine because 2 "Pros - yea right) said it was a wrist pin, wrong! still there, New Mallory Unilite dist, runs better but no change, Had the valves ground (again) this time 3 angle and new guides, no change. Recamed (Crane) and gears, and while I was there I thought well lets change out the rockers - Eureka!! It went away, but its is slowly coming back, a few folks have said it is probably a harmonic that just wont go all the way away - turn up the radio. All that and the EFI exhaust into 3" catco and cat back does make it run better. Offy DP and 4v on the bench waiting for warm weather.