Rod Knock = thrown rod :(

[Jkm3141]

when on my way to work about a week ago I noticed the car was producing slightly less power than usual, and within a min had rod knock. Obviously, I imedietly exit'ed the highway, but by the time I got to the end of the off ramp It had thrown a rod. My guess is that when the headgasket blew last year, some water got in the oil and blocked an oil passage in the crank, cauing it to spin a bearing or losen a main cap. Anyone ever experiance any sudden lowend issues after a BHG? This happened just about 600 miles after the BHG was fixed.

- John

 

[Tire Shredder]

the damage was likely done before you even knew there was a bhg. did you change the oil a couple times after repairing the BHG? the water in the oil likely damaged the the bearings at that time, it just took this long to manifest itself

 

[jdub]

http://www.supramania.com/forums/showthread.php?t=20486

 

[Jkm3141]

Yes i did change the oil. However, after the gasket "blew" i drove it about 2 miles home. The damage was probably then. Its not a huge crisis, other than the fact i put quite a bit of money into the BHG last fall. I already purchased my future planned motor about 3 weeks ago, but was planning on installing that mid to late summer, not early summer. Oh well, i guess its an excuse to do my swap earlier.

 

[Jkm3141]

Well, I pulled the motor this weekend and found the following chunks in the oilpan.



The other bolt was in there as well but I lost it. it wasn't bent or anything however. Cyl 3 was the cyl that had the rod break. I also pulled the head and fortunately there is no damage that I can see to the head. The valves are all lined up as they should, and move as they should. Lesson learned is changed the oil multiple times after a BHG, and dont drive when burning a lot of coolant.

 

[suprarx7nut]

Jesus that's scary. My motor has had 3 BHG's, and all of them were done with a full engine rebuild except the last one @ 250k miles.

I gotta try to save for/buy a motor to mildly build while I wait for the current one to crap out.

 

[AJ'S 88NA]

Yeah I have one of those custom rods around somewere, they are really expensive

 

[Jkm3141]

yea, my problem was I only did work on the top end. I did no low end work on the engine, figuring I could get away with it. It's not the end of the world, assuming I can sell the head which is in great shape.

 

[afofsupra]

Wow!!! We drove an NA that was knockin louder than normal conversation over 5 miles (at 30-50mph) and never threw a rod. It has 3 spun bearings, but the bearings were still intact.

Bummer. GL....

edit...
just pulled the pan off that motor and #6 rod nut is off and squashed with rod bolt bent...probably just a few thousand revs from being thrown. That was close!!!