[chevelle396]

Over the christmas break I got to drive my 2 a lot more than I have in the last year, and unfortunately I didn't keep as close an eye on the oil as I should have. I've got a significant oil leak, and after noticing a drop in pressure one night i put at least 2 fresh quarts in.

now it seems since then that I get a really rough knock when the engine is under load, generally when the SC is boosting. it sounds a lot like what I have heard described as piston slap. anyone experience something similar?

I think I'm going to drop the oil pan saturday and scope out the bottom end, and maybe cut open the oil filter and see if I find any shavings.

 

[mikeym]

yea if u run low on oil in an mr2 you fry your rod bearings...

thats what happened to my car prior to me buying it...

get prepared for the worse

~mikeym

 

[chevelle396]

guess I won't be participating in the autocross on sunday...

what extent of damage could I be looking at here? can you replace con rod bearings in the car? I might be trying out my spare GZE sooner than I thought I guess...

 

[TheAmazingDave]

worst case scenario, rod caps, bearings, rods, crankshaft, and possibly crank journals are fried.

But that is worst case scenario. I would imagine crank and bearing damage is likely.

 

[chevelle396]

if the crank and bearings have been damaged, do metal shavings ALWAYS appear? this car is my daily driver and while I don't have the time to drop the pan and check everything out after work, I can certainly pull out the oil filter and cut it open.

 

[PETC]

I just dealt with rod knock on my 5S-FE, but since the motors are so cheap it was cheaper/easier for me to just replace the entire motor.

 

[chevelle396]

wonder how long it would take me to drop out this engine and put in the other... that would practically be free.

 

[PETC]

If you've never done it before, a few days of solid work.

If you have, maybe a day.

 

[toymdngn]

if you caught it before it got bad, you could maybe replace all of the rod bearings... there may have been 1 or a few that spun without causing significant damage to the crank. i've spun 1 rod bearing in my 1st 4age and was able to replace it before it got bad (within 250 miles or so). i have also spun all 4 bearings in a datsun L20B engine, drove it for almost 5000 miles (knocking didnt start untill about 4k rpms) and was able to replace all four bearings and take some emery cloth to the crank, all was good after that.

 

[PETC]

When my #4 bearing spun on my 5S the entire motor was screwed in under 5 miles.

It all depands.

 

[mikeym]

^ i did this on my car... the 3rd journal that the bearing rides on (piston 3) was buggered up a bit, but i figured it would work... it look and felt like it would work...

put it all back together... new bearings...

shot within 20 miles...

if you are going to replace stuff, replace it all

~mikeym

 

[mikeym]

yea... and i spent a lot of work and time to do that... if you are going ot do it, do it right

 

[chevelle396]

if it was rod knock, would I always hear it at a given RPM, or only under load? When I stay off of the supercharger, I don't get the knock. it seems to coincide with the boost. I had some work done late last year and they said the SC oil was half full, so they topped it off. Could it be a noisy SC from low oil?

 

[SuperMR2]

My rod bearing only made knock under load. At steady state it was silent. If you have never dropped an engine before you can do the whole thing in 3 days(remove and replace).

 

[chevelle396]

anyone have an audio clip of rod knock?

 

[mikeym]

sounds like a hammer hitting concrete

 

[chevelle396]

well, it doesn't really sound like that. I'm leaning toward exhaust manifold leak... I'm gonna change the oil and cut open the old filter right now.

 

[chevelle396]

no metal in the oil filter, aside from what i dropped in with the hacksaw.

 

[PETC]

Make a recording of the noise. It always helps to hear it.

 

[chevelle396]

that's the plan for tomorrow, i'll post up the mpeg as soon as I get it.