: Preignition/Engine Knocking



DopeStar 156
11-10-04, 10:51 AM
Anyone have any problems with these? What are some remedies to clear this problem up. I'm convinced my Fleetwood has accumulated some Carbon on top of the pistons. I'm currently running on higher octane gasoline and am looking into a fuel system cleaner. Any other remedy I should try?

RBraczyk
11-10-04, 11:30 AM
Chill out? Its not the end of the world. Just drive her hard for a while, should clear up any problems.

Pianoman72
11-10-04, 11:34 AM
Isn't knocking, not pinging, a pretty big deal?

FASSTWOOD
11-10-04, 11:42 AM
Thats a good way to start look for chevron techron to use in the gas tank. Also look into a product called seafoam. You can find it at autozone. You disconnect the vacuum line to the brake booster and pourthe seafoam in 1/2 a can or till the car stalls then let it sit for a while while it breaks down the carbon.Check this link. (http://www.seafoamsales.com/motorTuneUpTechGas.htm)

I used it in my 85 and it really made a difference. If you are going to use it use it in an open area there will be a ot of white smoke comong out of the exhaust...

brougham
11-10-04, 12:55 PM
Did you ever get your timing checked yet or do a tune up or anything else that people suggested in your other post? If it's pining it's probably more because of things like that than anything else.

barge master
11-10-04, 07:27 PM
In addition to carbon and timing,I'd feel pretty confident your EGR could be the culprit. The EGR basically functions as a heat sink and lowers combustion chamber temps,and consequently it reduces pinging.
My own 89 pings on regular gas and I have an idea the EGR is not getting vacuum. My suspicions were confirmed yesterday when I ran it on the dyno for an unofficial emissions test. The NOx emissions were very high. That is usually something associated with old, high compression engines and it is why they dropped compression ratios to begin with. It is also a good indication there is an EGR problem, because the EGR is there to reduce NOx.

DopeStar 156
11-10-04, 08:02 PM
Actually I started this thread to sort of organize my answers from the previous thread I had. Driving hard didn't do a thing and I'm told that the carbon on top of the pistons is causing too much heat causing them to refire. I also hear that it can cause engine damage over time. All I'm doing in here is just creating a new thread to gather a wide array of suggestions since the other one was named poorly in my opinion.

cadillacdeville
11-11-04, 12:04 AM
have you tried removing the spark plugs and spraying carb cleaner on top of the pistons soak them down then fire it up does wonders also that sea foam is good stuff used it on a 79 lincoln with the 400 poured slowly down the carb smokes real bad at first but its good stuff to good luck

brougham
11-11-04, 02:50 PM
So do change the plugs, get the timing set and all that other stuff and then see what happens. If none of that is normal that could be why it's pinging.

barge master
11-11-04, 07:43 PM
It's possible it's running a little lean also which wouldn't help the situation any. If you have a dwell meter Dope it's possible to hook it to the single wire with the green plug you'll find near the carb, and actually determine if it's running at the proper mixture.
Have we all confused you enough yet??

FASSTWOOD
11-11-04, 08:03 PM
I know I'm cofused :hmm: :wacky:

DopeStar 156
11-11-04, 08:21 PM
*Crying*

RBraczyk
11-11-04, 11:01 PM
Why is his car carbed? Its an 89.

barge master
11-12-04, 04:41 AM
Especially when I have an 89 Caprice that has TBI.

RBraczyk
11-14-04, 12:56 AM
All GM switched to TBI in 87. WHy you have carb is beyond me. I don't know WHY someone would want to do that.

barge master
11-14-04, 07:12 AM
I think they weren't going to keep using the 307 so they didn't waste time developing FI for it. It's ironic that the Caddy was still carbed when it was the most expensive car they sold.

jrc520
11-14-04, 10:43 AM
yup. I have a 90, and mine is carb'ed. It's the last year for it, 91 they had a TBI cheby block.

DopeStar 156
11-15-04, 12:17 PM
I'm having the oil changed on Friday and I'm gonna have my mechanic check the timing on the car to see if it's a little off or not. Since I started mixing in higher octane fuel it's been shutting down fine but at the first start of the day the idle is still rough. We'll see what seems to be the problem here.

RBraczyk
11-15-04, 05:46 PM
The timing may need to be advanced because of the higher octane fuel.

davesdeville
11-16-04, 07:49 PM
Can't you pull a spark plug and look in with a flashlight to see if there's a ton of carbon?

I used seafoam once on my moms 286k volvo, man there was a ton of smoke.