Koko4

I was in the middle of doing my timing belt job - I had installed the new timing belt, tensioned it per the FSM, and double-checked the marks by turning the engine by hand. Then, before putting back on the accessory belts, etc, I decided to put the valve cover on and crank it up. Almost immediately, it had what sounded like a BAD knock / rattle from the bottom end. I thought it could be the crank position sensor rubbing on the crank sprocket, so I checked that, it was close but not hitting. Then I took off the harmonic balancer and cranked it with just the crank sprocket on (just for a second). Sound was still there.

I had coolant, I also had oil. I decided to put the car back together (after TRIPLE checking the cam / crank sprocket markings) and also turned the engine by hand - nothing seemed to bind or rattle.

Put the car together, put it on the ground, and cranked it up. Started and had NO more bottom-end noise. My question is: could I have f#*ked up the engine by doing this? Could I just have reduced my engine's lifespan or increased my likelihood of spinning a bearing? Did I deprive the bottom half of the engine of oil?

When I was doing this, the driver's side mounts were not hooked on, BUT the engine was level-enough (I thought) to be running.

Thanks for any suggestions. Timing belt and water pump was a success, though! No more water pump leak!

**This noise was present for three times that I started the car (all before putting EVERYTHING back together), and was a total of about 40 seconds, if I had to put a time to it.

White_EG1

All of the above.... Especially on a y8

Koko4

It's actually a Y7, BUT I am interested in knowing how what I did was harmful. The coolant was full, and the engine was also full (did not drain it or anything to do this job). The last time it was started was on Saturday morning, so I don't see how / if the bearings and galleys were dry. The angle of the engine was not excessive - actually it was tilting downwards a few inches lower than it normally sits (tilting towards the drivers side) because I needed to be able to access the harmonic balancer easier.

But once everything was hooked up and back in place, and it was on the ground (and after adding about 2 CUPS of oil), I started it and it was fine.



It's not like I started it bone dry, or even lower than it could get with normal driving and use. I check my oil every fill-up so generally it doesn't get lower than 1/8qt or so (IF that) at a time.

2LEM1

iTrader: (1)

Bingo.

White_EG1

^You don't see anything wrong with this?

Only time will tell, you did not take a video of the noise so we are kinda shooting in the dark here. If it's gone it's gone, if it comes back post a video.

TomCat39

Also we are assuming you shut it off immediately after starting and hearing the noise.

The disparaging part is you did this 3 times?

Like was said, only time will tell if anything is seriously wrong.

Hondaciv866

did you leave the ratchet on the crank bolt lol?? i ve done this before as was like fuaaarrkkkkkkkkkkkkkkkkk

Koko4

You have a good point, and now I'm going to be even more paranoid of every little engine noise

I did it three times because I thought I'd be able to locate the source of the noise each time. I didn't want to NOT figure out what the source was, button it all back together, and hope for the best (which is ironically, what I ended up doing).

Would having the mounts off, and having it jacked up by the oil pan (with a piece of wood) really make that much clatter?!

I suppose if it was about to spin a bearing (or do something else bad because of oil deprivation), then a compression test of the cylinders wouldn't be of much assistance.

If it makes the noise again, I will definitely post a video. I just didn't know if anyone else had experienced the same issue, and if it was blatantly obvious as to what could have caused this. I'll also mention that the oil dipstick tube was NOT inserted, resulting in about a cup of lost oil on my garage floor. Also a dumb mistake.

You live and you learn, I guess!

Caoboy

You're making miniature explosions and you don't have the engine mounted. Of course it's going to jump around a bit.

Theres your problem. I bet you it was the intake manifold knocking back against the firewall.

If it isn't running poorly, just chalk it up to stupidity and don't start a car before completely finishing the job again.

TomCat39

More than likely nothing serious was done but mounts and torsional dampers are there to reduce stresses on the motor.

Without the mount the motor can move abnormally and also have unusual vibrational stresses that are normally absorbed by the mounts and dampers.

This can cause problems but it's not going to happen in a few moments of running.

It's like people with a v-tec motor (has a dampened crank pulley) that put on a lightened crank pulley "for the added performance". None of the lightened pulleys are dampened and so certain vibrational stresses start attacking the crank at certain rpm's. At some point it breaks something, it doesn't happen right after the pulley is changed, it's going to run like a banshee for awhile and break on the fly.

This is more like that. You didn't keep running it so more than likely you will be just fine. And the topper, I highly doubt you even revved it much with it happening so the stresses that may have been present were relatively low as well as very short lived.

You should be fine. Just don't make it a habit.