Bad Knock and Vibration at start up

[Eric B]

I searched and did not find anything like this.

When I started the car this morning there was a bad KNOCK and a bad engine VIBRATION for the first couple revolutions and then quickly went away. I don't know what the knock was, I thought maybe an engine mount broke that would explain the knock and vibration. Could have been a rod knock. I started it again and drove it to work and it was fine. Could this have been hydro-lock. Maybe a leaking injector overnight or bad head gasket. I washed the car on Saturday and pulled it in the garage but I didn't use a pressure washer and I don't see how water vapor could get past the air filter, shouldn't be any worse than parking it after driving in the rain.

I've heard of knocking noise at start up due to timing belt tensioner. I replaced the timing belt a few weeks ago and the tensioner was fine, it only has 15,000 miles on it so I think that's unlikely.

It is a 1993 3.0L MTX with 147,000 miles and I bought this car new in 1993.

I guess I'll find out soon enough if it does it again. I'll update tomorrow.

 

[Eric B]

This issue has not happened again. I am hoping it never happens again and there was no damage to the engine. :swing:

Thanks to everyone who read this.

 

[trainguy1989]

If you washed the engine you might have gotten water in the spark plug holes which could miss and sound like an engine knock. The reason it probably has not done it since is the water has finally dried out of the holes.

 

[NovaSS]

If you washed the engine you might have gotten water in the spark plug holes which could miss and sound like an engine knock. The reason it probably has not done it since is the water has finally dried out of the holes.

yep has happened to me once or twice.

 

[Eric B]

If you washed the engine you might have gotten water in the spark plug holes which could miss and sound like an engine knock. The reason it probably has not done it since is the water has finally dried out of the holes.

Maybe, thanks. It was like a dieseling sound.