horrid knocking noise upon startup

[Alex C]

OK, I think I have rod knock. All that water must have done something to my bearings. I used to get a couple knocks upon starting the car up cold in the mornings prior to my recent headgasket failure. This was probably due to my previous major headgasket failure three years ago. Anyway, it use to only occasionly knock, and only once or twice, It could have just been something loose you know? Also, it only does it when the car has been sitting overnight, and the oil pressure is still climbing at startup.

 

So this morning I get it started, its idling on the choke at about 1200 RPM and its knocking every second or so, did it maybe 15 times, until the oil pressure reached 40 psi or so. Then it went away and I didnt hear it the rest of the day.

 

I guess Ill find out tomorrow morning if it happens again or not.

 

What is the life expectancy with different forms of rod knock?

 

thanks,

 

Alex

[Ross]

 

What is the life expectancy with different forms of rod knock?

 

 

 

I'm not sure, depends on how bad it is. Best not to wait and see though, a rod through the crankcase would probably ruin your day!

Perhaps you should find another motor to put in while you have a good look inside yours?

[Alex C]

OK, this morning it knocked about 8-10 times, aproximately every second or so, and it started when the oil pressure passed 30 psi and stopped when it passed 40 psi.

 

It still makes no other bad noises for the rest of the day.

 

 

Alex

[Ross]

That might be ok, if there are no other signs of significant wear. It's realy a gamble though, the fatigue life of the rod depends on too many factors (severity of knock, presence of stress raisers etc.) to be able to say anything for certain.

All I can say, is that if it is going to fail, it will probably do so within the next million or so knocks! After that, you should be fine!