I adjusted the timing on my car because it was idling rough. Now it idles great but when the engine is under load it sounds like it has a leaky exhaust manifold. Could it be pinging? Would higher octane definitely solve the problem or should i retard it a bit?

 

[updated:LAST EDITED ON 28-Jan-02 AT 05:48 PM (EST)]Pinging sounds something like a Rattle Snake's Rattle.

Exhaust POP sounds different.

Dennis

"Please Don't Ask Me Any Tough Questions As I'm Saving My memory For When I Develop Alzheimer's"
78 F-150 429CJ,Silver w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

The best answer is to retard your timing a little. Yes, higher octane gas will help reduce the pinging.

 

If you are running a stock set-up/carb, make sure your egr is hooked up and working. If it's not working, it will cause it to ping too.

 

Easy way to find out what pinging sounds like, start your car up, and before it even has a chance to run for a minute, pull out on the street and just drop the gas pedal. If you've got a small V6 or bigger then you should definately be able to hear it pinging when you do this. But most good engines I've seen, will ping when cold like that but after about a minute or two of running it goes away.

My experience has always been that if there is pinging either run a higher octane gasoline or get a octane boost additive and dump it in with the fuel and the problem goes away. I honestly do not know if its truly fixing what is or can become a problem, but it does help eliminate the pinging.

Depending on what size engine you have though it could be other problems. Pretty much the only engines I've ever experienced pinging in where the bigger ones and high performance engines. I know for a while driving a Crown Victoria (4.6L V8), we ran premium gasoline only and then cause of prices going up switched to the cheap regular and then it was ping city. Didn't matter if the engine was hot or cold, just drop the gas pedal and all you could hear was pinging (ran the cheapest brand possible). Monte Carlo (3.4L V6), only time ever hear the pinging was when it was a cold engine. After warming up, drop the gas pedal and it would just fly with no pinging and that was with cheap gas too (only ran Chevron in it though). Tacoma (3.4L V6), never had any pinging with any kind of gas used (all brands and grades). Ranger (2.3L V4), still haven't had any pinging and all I use is the cheap Chevron in it.

So basically I'd say go to a Chevron or Texaco station (not some 7-11 store or something) and spend a few extra dollars and run a few tanks of premium gasoline through your engine and see how it runs. Hope this helps you out some. Goodluck.

James

 

To avoid pinging ,make sure you have the recommended
octane rating gasoline in your tank.Read your owner's manual,the info is in there.
The rest is in *the timing of the engine*.
Make sure it's AT SPECS or tuned to perfection.
Putting lower grade gas into an engine that's been tuned to a higher octane will Naturally make an engine ping,until it's re-tuned to the new grade of gas.

Putting a higher octane in an engine that require it is a waste of money.

Putting in a lower grade(octane rating) can do damage to the engine with sustained use.


Dennis



Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"


78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

On the subject of gas and engine performance. Should I run mid grade or premium in my '86 F150? Or is cheap(?!) gas ok. The only time it runs crappy is on cold mornings. It sounds like a rock in a blender then. Also, if I want to change from one grade of gas to another, should I try to run the tank close to empty first, to get rid of what kind is already in there? Also I have a question about my teeny weenie gas tank on here somewhere, will someone please check it out? I need you guys, I'm just a girl ya know! HAHA. :*

 

>I adjusted the timing on my car because it was idling rough.

With a timing light, or by ear?? Did you change the plugs,
cap and rotor??

>Now it idles great but when the engine is under load it
>sounds like it has a leaky exhaust manifold. Could it be
>pinging?

Yes, it's talking to you, the timing is too far
advanced, it probably is pinging (pinking for the brits)
first thing I'd have done is check the timing with
a timing light. Then I'd be looking at all the vacuum
hoses, then checking that the EGR valve is functioning
properly, then checking the cap and rotor, then the
plug wires. Randomly resetting the timing is a waste
of time if it's set right to begin with...but thats just
me, because I've spent more than 10 minutes trying
to figure out *WHY* it's running badly, rather that
ASSuming the timing is wrong...

>Would higher octane definitely solve the problem or
>should i retard it a bit?

No, setting the timing properly and looking for other
causes of the rough idle is the right way to approach
the problem.

Steve & the Rockette

 

>On the subject of gas and engine performance. Should I run
>mid grade or premium in my '86 F150? Or is cheap(?!) gas ok.

Of the 3 engines available in '86, which one do you have??

>The only time it runs crappy is on cold mornings. It sounds
>like a rock in a blender then.

You're rig is pinging...in open loop mind you...

>Also, if I want to change
>from one grade of gas to another, should I try to run the
>tank close to empty first, to get rid of what kind is
>already in there?

When was the last time it had a tune up?? A tune up will
cost less than running more expensive fuel through it.

>I need you guys, I'm just a girl ya know! HAHA. :*

That's no excuse, SWMBO has rebuilt her own engines
for about 6 years now...no reason you cant...

Steve & the Rockette

 

The engine is a 351HO. Were Windsors the only HO's then or were Cleve's HO's too? The last tune up only the Lord and maybe the previous owner know. It is about to get one tho if I have to do it. As for me rebuilding, well, since that is my only ride and I would have to learn as I go, well, I wouldn't want to ruin it. Maybe some day I can buy and old clunker to tinker with and learn on. Right now, that money has got to go into what I have. I would love to attend college or vocational school to learn mechanics, but I really don't see that happening. Would tickle me pink to learn to rebuild my own engine tho.

 

[updated:LAST EDITED ON 12-Feb-02 AT 09:49 PM (EST)]I wasn't aware of a 351W HO(High Output)in 86.

AFAIK ,There was only 351W Carb. & a 351W FI.
OHV engines (Overhead Valve engines)

Dennis



Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"


78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

 

A "ping" sounds nothing like the word "Ping". Whoever named it that really screwed up BIG time! If your car is pinging, the time you usually notice it is when you are drivng beside a concrete freway barrier or cement wall, etc, for the sound to bounce off of. It is more of a loud clattery or "fluttering" sound sort of, and makes your engine sound sort of like an idling diesel truck. THAT is "ping". As far as waiting until your tank is very very low, NO, that is a mistake a lot of women (and men) make, running around with a perpetual 1/4 tank or less. Two very good reasons to NOT do this: 1. Your fuel pump will be sucking up a larger amount of crud from your tank, because all the crud sits in the bottom of the tank, and wear out LOTS faster 2,because ALL gas tanks get moisture in them just out of the air on a normal day. If your tank is almost always close to empty, it acts like a big solar still, and the moisture evaporates up to the top of the tank, where it condenses at night, and over the weeks and years, rusts the heck out of the top of your tank. This rust flakes off and falls to the bottom of the tank, where it gets sucked into your carburetor and keeps carburetor rebuilding businesses in business. Ask most any carb rebuilder, and he will tell you that varnish and gum from old/bad gas, and RUST kill a LOT more carbs than old age or wear and tear. I know, I've seen it many many times.