TS2008

I replaced the timing belt of my 2000 civic dx, D16y7 last week. I notice, since the replacement of the timing belt, my car knocks (pre ignition) during a high load acceleration (HW acceleration ramp or overtaking another vehicle). No knocking for normal traffic acceleration though.


I verify several times the alignment of camshaft with the crankshaft (crankshaft pulley marks and with upper timing belt cover removed) and all marks are in their place.


I first thought the ecu needs to "relearn" because I disconnected the battery while I was replacing the timing belt. But so far, after a week of driving, I don't notice any improvement. I also learn that the D16Y7 engine doesn't have knock sensor. So this means the ecu has no input for engine knocking.


Anyway if you have any idea what cause the knocking, please let me know. thanks.

mac25

Did you make sure to have the right cylinder at TDC when timing?

ezone

If it is spark knock, I'd expect your timing belt is still one tooth off.
You did not touch the distributor at all in the recent past, correct?

You can verify ignition timing is 10-20 degrees off with a timing light...DO NOT try to turn the distributor...Correct the belt install and the ignition timing will go back to being correct.

The word UP on the cam gear is not a timing mark. See image below.
I sometimes use a steel ruler or mirror and flashlight to verify my cam gear marks are actually lined up with the edges of the head surfaces.

TS2008

I use the "lonely" mark in the pulley and the two camshaft white marks (front) for verifying the alignment. I didn't use a ruler for white mark though. For now, I use a timing gun to reduce 2 degree of the BTDC. The knocking decrease but it's not gone. I'm going to recheck the timing mark with a ruler tomorrow.


Edit: The distributor never been touched before the timing belt replacement. The idle timing was 12 deg BTDC (red line) when I check for the first time the timing with the timing gun.

ezone

???

Single (White?) mark on crank pulley aligns with pointer on timing cover.
Slashes on cam gear (horizontal) align with flat surface of the cylinder head.

Eyeball is almost never perfectly straight in line with the marks or head so it always looks a little bit off IMO, that's why I use other methods to make sure.


How far off was it?

One tooth off on the timing belt is equal to about 10 degrees ignition timing advance or retard. (depends on number of teeth on the cam gear and which way it's out of time)

Ignition timing--you have to insert a jumper wire in the SCS connector to stabilize computer control of the timing before trying to read it with a timing light.


Another thing, a basic OHC rule-of-thumb: The distributor has like 3 hold down bolts for a reason.
You have to make 3 mistakes in a row before you can move it.

Once correctly set, the distributor never needs to be moved for the rest of its life.
Timing variations will never be caused by the distributor.
If ignition timing is off by a significant amount, then cam timing is wrong.

TS2008

Yes, I'm talking about the two white horizontal marks on the camshaft gear. I also verify the white mark behind the camshaft gear and It aligns with the cylinder head.


For the timing adjustment, I follow the steps from the Honda Service Manual.
- insert the paper clip in the SCS connector (brown and black wire).
- the CEL stays on
- rev 3.000 rpm until the radiator fan spins.
- check the timing with the timing gun.


When I check the timing for the first time, I expected the timing will be way off. Actually, the plastic pointer was pointing near the red pulley line (+/- 12deg BTDC).


For now, my BTDC is near +/- 10 deg.

ezone

Odd you would notice something that dramatic immediately after replacing the timing belt....
Ok so cam timing should be correct if ignition timing is that close.
What else could cause spark rattle, if it really is spark rattle/preignition/detonation?

Lean?
Hot?
Hot spots/carbon deposits?
Crappy fuel?
Too much Ethanol in the fuel?
High compression?
Wrong spark plugs (heat range)?
Got codes?

TS2008

No code at all. I'm going to check the alignment again today with a ruler. I'm probably fill with higher octane fuel next time. I remember that I refilled the gas tank with ordinary fuel after the replacement the timing belt. Probably I got a crappy fuel.

TS2008

Update:

I think I found the culprit. It was the tensioner spring. To make story short, while I was verifying the timing alignment again and again, I noticed the section of the timing belt between the camshaft gear and the water pump was so slack that the belt at that section was curved. I first thought the tensioner bolt was loose but finally It was the tensioner spring which was too weak. I tried several time adjusting the timing belt tension by following the steps from Honda Service Manual, but the timing belt section between water pump and camshaft gear was still very loose. I finally push the tensioner with my hand until the tension of front section and the rear section of timing belt are both the "same". So far, I don't hear any knocking sound from any load range.

Not sure what was the relationship between slack timing belt and spark knock, but the knocking is gone for now. It took me a whole day to fix this problem. I remove and reinstall the valves cover so much time that I bought another gasket so I can always have a "clean" gasket ready for the reinstallation.

ezone

Loose belt? I wonder if you were hearing the timing belt slapping the timing cover?

Did you set the distributor back to where it was, and is the noise still gone?
Anyway, I hope that you really got the problem nailed.


I was thinking about this thread today..... sometimes an engine can benefit from being run hard, to "blow the cobs out", because carbon buildup on the pistons and in the combustion chambers can lead to spark rattle. Even with knock sensor controls they can still have the rattle.

TS2008

Yes, I set the distributor back to the pulley red line (12 deg BTDC).


The Knocking sounds were definitively spark knock, because there were no knocking sound if I rev the engine without load.


I have only one picture of the loose timing belt. I took this picture while I was verifying the timing alignment. You can see the timing belt was curved. What makes me mad is I paid higher price for the "best" quality timing kit, but they give me a shitty spring.

Wankenstein

When you tensioned the belt did you do it similar to shown in video starting at 7:20 time mark?:


and per FSM after afterwards spin crankshaft 6 full revolutions to check for slippage or loosening.
If, loosens too much during 6-spins then must retension. I bought the same kit as yours a year and 10K miles ago and no issues to this point. I followed ETCG's method which is not shown in FSM.

TS2008

No I didn't do the ETCG's tricks but I follow religiously the FSM for the timing belt tension adjustment. As you can see in the ETCG's video his tensioner spring was stiff enough to give a good tension at the rear side of timing belt even before the tension adjustment. Mine was slack and was curved at the section of camshaft gear and water pump. I need to push the tensioner arm in order to have more tension. But if I need to redo the timing belt tension adjustment, I'm not sure I can do the ETCG's trick alone.

Wankenstein

I tried per FSM way first and belt just kept slipping. Did it ETCG way and got it sorted properly. Remove the top TB cover and black plastic tensioner cover from lower TB cover and try 'er again. Proper tension is when you can flip belt roughly 90 degrees at the halfway point of longest portion of belt. Of course, it's an auto-tensioner and it knows best..lol. When you get 'er dicked report back.

ezone

I thought he did this in post #9?

As long as the belt doesn't whine from being too tight, it'll probably be ok that way.

TS2008

So far so good. No whining nor knocking sounds. But I need to check my cylinders compression this weekend because while I was rotating the crankshaft for the timing belt adjustment, I noticed the cylinder 1 didn't have much compression resistance and I heard the air leaking when I was close to the TDC. Anyway this is another story. For the moment, I'm very happy the knocking sound is gone and I didn't make too much mess for my first DIY timing belt replacement. This job is actually not hard if you know where to go. I think I'm going to buy an another used car just for the sake of changing another timing belt.

ezone

There's a self help group for this problem, I'm sure.
12 steps.

TS2008

Who says I have a problem ? I can stop thinking about timing belt anytime I want, but just not now.

ezone

Oh no, it's more serious than we first thought.

Wankenstein

My mom's granny-mobile ('04 value package) has 70K original miles on it. I'll give it another 10K before it gets changed out. However, if you're jonesing to do another TB repalcement.. you're welcome to have at it.

TS2008

70K!!! you should replace TB every 20K!!! Where your mom lives ?

Wankenstein

20K? hope you're joking. FSM states up to 100K depending on climate. We are in Florida.

TS2008

I always serious regarding TB replacement. I change mine every 15K or every 3 oil change.




But seriously, lots of people can reach 200K without problem. I found in the web, some "unlucky" dudes who live in a hostile environment (salt belt ) broke their TB at 160K. My old TB, with 100K, is still in great shape. There are even some letterings left on the belt. I changed my TB, because the previous owner, an old lady, have no idea what is a timing belt and I don't trust a 16 year olds TB even with a low mileage.

ezone

For anyone else reading this exchange and trying to take it seriously:
Owners manuals state replacement intervals by mileage and time, whichever occurs first.

Random samples
1990 Civic, 90k miles/144k km/6 years
1995 Civic, 90k miles/144k km/6 years
2000 Civic, 105k miles/168k km/7 years
2005 Civic, 110k miles/176k km/7 years

Then there is the climate stipulation that overrides the above info
For example, a 1998 owners manual says
The timing belt should normally be replaced at the intervals shown in the maintenance schedule.
Replace this belt at 60,000 miles (U.S.) or 100,000 km (Canada) if you regularly drive your vehicle in one or more of these conditions:
In very high temperatures (over 110° F, 43°C).
In very low temperatures (under — 20°F, — 29°C).

TS2008

Ha Ha Ha. I don't want to be smartass but for those who take our discussion as face value are not deserve to touch anything inside of car hood.


* Update for the compression test*
Just finish the cylinder compression test with a cold engine. Everything is fine (165, 170, 170,180). Too lazy for warming up the engine and for the wet test.

ezone

You apparently haven't read some of the stuff I've written around here LOL...

You've read some of the posts people write in this forum?

TS2008

Someone will ask you soon the contact number of the self help group and they need more details about the 12 steps

Wankenstein

Mom's car has 12 years on TB.. guess it's a "bit" overdue.

ezone

You horrible child!

You can redeem yourself....make sure Mom has a set of comfortable decent quality walking shoes

TS2008

This Sunday is mother's day




Just for your curiosity about my old timing belt. It still looks great for its age. No crack, no tear, some discoloration that's all.