Re: MP SBEC, bad pinging problem, please help!

From: Jon Steiger (stei0302@cs.fredonia.edu)
Date: Thu Dec 17 1998 - 19:33:07 EST


At 06:57 PM 12/17/98 -0500, you wrote:
>DML,
> I just installed the Mopar Performance computer in my '95 V8 auto. After
>installation I took it for a test spin. The first time that I got on the gas
>from a dead stop I thought I heard 2 or 3 tapping sounds, but I wasn't quite
>sure. These occured around 4000 rpm. I drove it around another 5 minutes or
>so, and got on it again from about 45mph. I immediately heard what sounded
>like a drum solo of pinging coming from my beloved 318.
> What's the story with this? I thought that running 93 octane (Mopar says the
>computer requires 92) would satisfy the computer's needs. I can't see that
>anything I've done to the truck so far (headers, MSD, cat-back, pulleys, K&N)
>could even contribute much less cause this problem.
> The only possible solution that I can think of would be to install a lower
>temp thermostat, but what temp should I go with? I know that running the
>engine at too low an operating temp can result in as much damage to the
>engine as the pinging and detonation. Has anyone else had this problem? If so,
>please tell me how you dealt with it. Thanks in advance.

  That sounds all too familiar. :-) I had the same thing with my '96.
Fortunately, I had heard about others having the same problem and I was
planning on changing the thermostat anyway, so I had the thermostat handy.
I was getting pinging on 93 octane, but after I dropped the 180 degree t-stat
in, problem solved.

   Some people on the list are running 160 degree thermostats. Personally,
that's lower than I'm comfortable going; you should be OK with a 180. The
stock t-stat is 195. From what I've heard, the "normal operating temp" of
the engine is 180 degrees.

  Do you have header wrap or anything like that on your headers? Generally,
a set of headers will help to reduce pinging... ?

  I don't know if it will help at all, but I detailed my t-stat install on the
DML home page at:

http://www.cs.fredonia.edu/~stei0302/WWW/DAKOTA/UPGRADES/TSTAT/index.html

  If you know what you're doing already, it probably won't be of much help,
although the part numbers for the t-stat gasket and a 180 degree thermostat
from Stant are listed there too.

                                               -Jon-

  .--- stei0302@cs.fredonia.edu ------------------------------------.
  | Affiliations: DoD, EAA, MP Race Team, NMA, SPA, USUA. RP-SEL |
  | '96 Dodge Dakota v8 SLT CC (14.58@93.55), '96 Kolb FireFly 447 |
  `----------------------- http://www.cs.fredonia.edu/~stei0302/ ---'



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