UserX826

???

I have a knock on a freshly rebuilt y7. I've eliminated the possilbilies that it's a rod knock, spun bearing, or bad rings.

I'm wondering if my timing is off, can it cause a knock?

hoya_10fintec

yes

98vtec

its called detonation.

UserX826

care to explain a bit please? how can it be that far off and still be starting?

hoya_10fintec

timing might not affect much when idling(15~18) unless you start noticing something like missfiring or hick-ups.

It also could be the timing belt being off.

It would help if you be more specific about the symptoms.


Who did the work?

Jdmglenn

Retard your timing asap

UserX826

I did the work, other than what had to be done at the machine shop(pistons put on rods, cylinder hone). And yeah it's the first time i've done that much, but i was careful to get everything done right, torqued down to spec, bearings lubed, etc.. Timing I just don't have much experience with in the past. Still quite the newbie.

I have seen some hick-ups..

If there's anything else you need to know let me know.. Not sure what else i could tell you other than what you know.

1grex

only happens under load or all the time?

keving85

you need to check your timing quick.....

spark knock.... sounds like it to me.... (basically pre-detonates and rattle's the valves)

did you adjust your valves before you started the motor?


kev

JDM EJ2

I think its called valve tic. Its when the timing on the valves is off slightly and it gets smacked by the pistons. You gotta make sure to adjust your valves. My brother just blew his Y8 because he beat the **** outta it like a jackass for a solid 40,000 miles (From about 127,000 to 170,000). **** loosens up over time, especially with excessive vibrations due to revving it out. Anyone agree with that theory?

Former User

Read this.

JDM EJ2

What is it when a piston just touches the valves without bending them? I swear there is something like that...

hoya_10fintec

valve-to-piston slap. B20/vtec with CTR cams could do this. Well, any engine could do this I guess. =P

I would check the timing/timing belt definately first. Do you not have a timing gun?

UserX826

all the time

and no. no timing gun.

haven't adjusted the valves.. i'll have to get a gauge and check em out.

I adjusted the timing last night, and I swear to god the knock was very very faint. Let it run for a few minutes, no hick-ups. Lighter knock. Then I cut it off, let it cool off(cracked radiator, haven't put the new one in yet), start it up again and the knock was about back to where it started.

hoya_10fintec

you did all that work and didn't even check the timing or adjusted the valves???

-common mistake for noobs:

Do you know which line is TDC on the crank pulley? no, I'm not being sarcastic.
-take the timing belt cover off and double check and see if you skipped the tooth anywhere THEN get a timing gun and make sure it's within the spec. Make sure the tension on the timing belt is good as well. And reaplace the rad.,fuel filter...

...and go from there...

UserX826

thanks for being nice about that haha. Crank pulley only has the two yellow marks. No white mark anywhere. However, now it looks like the belt tension could be the cause of the knocking.. although the cover is off so it's not slapping that. Just one side of the belt is slapping around quite a bit. But i don't know how i could've taken the belt off so many times and put it back on with too much slack on one side that many times. I'll post a video of it tonight.

trustdestruction

The belt slapping around is your timing belt tensioner. You either didn't tension it properly or you need a new one.

remember this thread? https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/knocking-w-video-2507013/


when you put the timing belt on, did you use the mark on the oil pump and the marks on the cam gear like you're suppose to and then put the timing belt on?

UserX826

yes. problem in that thread is fixed. and yes.

trustdestruction

i think your tensioner is bad then.

hoya_10fintec

Now it sounds like the problem is all in the timing belt (= affecting ignition timing as well).

SEARCH and find out how to tension the T-belt and make sure the tensioner is good like the other guy said(get a new one i you didn't). I could tell you how right now but I want you to search.

let us know

hoya_10fintec

Oh, almost forgot... for you to read timing mark.. you should see 4 marks on the crank pulley:

- <-----TDC





-
- <-----with a timing gun, this is what you should see.. within those three marks is fine.
-

..and hopefully you fixed the timing belt problem.. I watched the video.

93wip

if the timing is off you need to pull the head and check the valves if the pistons were slapping the valves i can garrantee the they are bent even if they were lightly hitting they arent ment for that

UserX826

yeah i've read that before.. but mine just has 2 on it somehow.

and the tensioner is new, came in the rebuild kit.

and i'll search on tensioning. thanks for all the help guys. i'll let you know how it goes

Former User

This may help:

UserX826

So I finally got to fix the timing.. the right way. I took off the crank pulley, took off the belt, lined up the mark on the crank gear with the arrow on the oil pump. I rotated the cam til UP was up, moving everything CCW. I install the belt, loosen the tensioner, turn the crank, tighten the tensioner. No tension in the belt anymore.

Now, the problem seemed that it was just belt slap before right? I figure.. can't be doing that now. It should finally be ready to go.. So I start it.. and hear the horrifically loud knock.

So.. I started with a not so terrible knock, fixed the timing, and now have a pretty terrible knock.. WTF