|
First. I thoroughly enjoyed reading the two previous responses. I don't hesitate to respond, even though I am fully aware my knowledge of cause and effect in this arena is minuscule.
It is interesting to me to hear this is a '92, which is by my understanding the last year before squirters were added to the B230 to take care of piston slap. The add-on nature of the squirters has come to cause me to speculate why it seems so many '93 owners have problems which seem to possibly be related to cam oiling, as if diverting some oil flow from the upper regions created a more critical need to keep it clean and unblocked. Every time I hear of another head gasket failure or stripped timing belt on a squirter block, I think of this. But, our only 93, fairly new to us, and hardly ever seen by me, is quiet.
Two of ours, an 89 and a 91 came to us with what I believe is piston slap. Both in the mid-300K range. Now, Ted mentions being able to hear this 20 feet behind the '92. I can definitely say I hear this "piston slap" from that distance easily, despite my hearing loss. The 89 is so pronounced, it sounds no different to me from a Diesel, and invites admonishing remarks from those reminiscing about their own dealings with clogged hydraulic lifters. But it goes away, entirely, after it warms up. And these cars have been making this imitation of an MB 240D ever since we first acquired them in 2003 with no change. Yes, the valve clearance was one thing I checked on both cars, so I believe this is "piston slap."
I have heard rod knock. But the memory is old - at least 30 years. And for Oldduke's benefit, I'll mention it was a 73 Dart with a slant six owned by a neighbor. It was never run long enough to learn whether it would "go away" with warmup. One thing I believe about rod knock is the condition will quickly grow worse with miles. Maybe just feet. No rod knock heard outside the car would survive a month of driving?
As regards the knock sensor, I don't believe it can be a cause of knocks. It is a microphone, and it retards timing if detonation occurs within a narrow, per cylinder window of time, decreasing fuel economy. If the microphone does not sense the detonations in the correct time windows, per cylinder, the EZK will know it is not working and set a code, and keep the spark timing in a safe region.
--
Art Benstein near Baltimore
Men can read smaller print than women can; women can hear better.
|
