Re: [e36] Pinging problem - update

["Ron Buchalski" <rbuchals@xxxxxxxxxxx>]

Jason writes:

>
>Date: Mon, 9 Apr 2001 11:58:15 -0700
>From: Jason M Surprise <jmsurpri@domain.elided>
>Subject: [e36] Pinging problem - update
>
>A couple weeks ago I posted about a pinging problem in my 94 325i.  I
>took it into an independent mechanic specializing in BMWs and they said 
>that the spark plugs looked bad.  I told them that I recently replaced the 
>plugs about 10k miles ago, but figured maybe I got a bad set of plugs, so I 
>took the car back and replaced the plugs myself.  The pinging didn't go 
>away.  While replacing the plugs, I noticed oil in two of the spark plug 
>chambers, dripping down from the valve cover gasket and collecting at the 
>bottom where the spark plugs are screwed


Around each spark plug hole is a gasket.  If the gasket leaks, oil will seep 
out, and collect in the bottom of the spark plug holes.  If there's a 
significant amount of oil, you should have the gasket replaced.  If too much 
oil collects in there, it can short out the ignition coil for that cylinder.


>in.  I asked the mechanic if a leaking valve cover gasket could cause the 
>pinging and he said he didn't think so, but I don't agree with him.  My 
>theory is that oil is slowly seeping into the chambers and over time has 
>gummed up the cylinder walls, increasing the compression and causing the 
>pinging.  If I get the valve cover gasket


That's why he's a mechanic, and you're not...

Jason, if oil was able to seep past the spark plug threads and into the 
cylinder, in a sufficient quantity to gum up your cylinder walls, raise 
compression, and cause pinging, what kind of compression do you think you'd 
have on that cylinder?  The answer: Not Much.


>replaced, can I expect the pinging to go away?  Will I need to have the 
>engine cleaned out of any deposits to get rid of the pinging?


It's possible that you have combustion chamber deposits that are causing the 
ping, but it's not because of the oil leak in your cam cover gasket.  You 
can try some Techron, or you can take your car to a mechanic for a 
combustion chamber cleaning.  You may also want to check whether there's 
anything wrong with your knock sensor.

http://www.bonnevillemotorwerks.com/fault.html

Codes 1225 and/or 1226


By the way, do you know if your car as the stock DME chip, or does it have a 
Dinan, Conforti, or other chip?  These chips advance the ignition timing, 
and REQUIRE use of premium octane fuels.

Also, a minor, occasional ping is not a bad thing, and won't hurt your 
engine.

- -rb

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