Valve Knock (?) after Timing Belt EJ25 1996

[jmickelct]

Hi,

 

Finished up my first TB (plus) job on my 1996 OBW 2.5, and the thing (miraculously) seems to run strong and very smooth (the oil leaks even seem to have abated) save for, at very low rpms, what sounds like a sticky lifter\valve kind of knock (tapping).

 

It started when I first started up, then (assuming it'd take some time for the oil pump to get primed etc...) it actually faded to just about nil. I barely notice it now, except, as I said, when I'm about to park and the engine is rev. very low.

 

I've heard that the engine will run, if I'm off a tooth (or two?), but things feel very smooth and the performance (new plugs) seems a bit peppier.

 

If this something I should have checked?

 

John

[nipper]

Hi,

 

Finished up my first TB (plus) job on my 1996 OBW 2.5, and the thing (miraculously) seems to run strong and very smooth (the oil leaks even seem to have abated) save for, at very low rpms, what sounds like a sticky lifter\valve kind of knock (tapping).

 

It started when I first started up, then (assuming it'd take some time for the oil pump to get primed etc...) it actually faded to just about nil. I barely notice it now, except, as I said, when I'm about to park and the engine is rev. very low.

 

I've heard that the engine will run, if I'm off a tooth (or two?), but things feel very smooth and the performance (new plugs) seems a bit peppier.

 

If this something I should have checked?

 

John

 

 

did you replace the tnesioner and idlers. If the noise wasnt there before the Tb change, then it is after.. thats where i would look.

Have you used a screwdriver as a stethascope to see where its coming from?

 

nipper

[jmickelct]

Hi,

 

Yes, replaced all of the idlers (except for the lower left), including the tensioner.

 

Havent researched it at all yet (just got it back on the road Monday), have some long bars that I will try and find a more precise location...

 

Still getting use to the car (just had it 2 months), so I cant say for sure how much it was doing it before; have just started paying a lot more attention since I tore it apart.

 

On the valve front, can lifters\valves\tappets "stick"

I've been cheaping out on 87 octane gas (just filled up with 93 tonight, only drove 30+ miles, havent noticed a difference.

 

I guess I'm mostly\immediately concerned that I got the belt in right.

 

I read another of your posts that suggested that knocking was pretty bad and I'm not exactly sure of the differene between A). Knocking B.) Tapping C.) Pinging. (mine sounds a lot more like a tapping, coming from, what I am assuming, is a more isolated location.

 

Will crank it up and see if I can be more precise.

 

Thanks,

 

John

 

did you replace the tnesioner and idlers. If the noise wasnt there before the Tb change, then it is after.. thats where i would look.

Have you used a screwdriver as a stethascope to see where its coming from?

 

nipper

[nipper]

are you sure its a valve tick and no piston slap?

 

 

nipper

[Manarius]

are you sure its a valve tick and no piston slap?

 

 

nipper

I certainly can't tell the difference, but I can tell you right now that valve ticking is far more common than piston slap on the 2.2's. Now, he has a 2.5 with Solid Lifters, so it's probably piston slap.

[jmickelct]

Hi,

 

OK, cranked her up.

 

Definitely an engine noise (versus belts\very front end). "Piston slap"? As I mentioned, it seems to be most noticable after a "rev", and then slow down to low RPMs. Not frighteningly loud, but, I think I would have noticed it if it was doing this before.

 

It could be an artifact of the spot(s) I was able to "listen in to" (location wise), but it appeared to be more distinct from the left (driver) side valve area.... Was touching regions around each cylinder exhaust manifold. Still hard to tell if it was valves (versus crank, piston, cams?) not even sure what it could be.

 

Am suppose to head out for a long weekend tomorrow night; any thoughts that it could be serious enough to prompt delaying the trip?

 

Has the battery out for a couple of day; (totally new to car computers), read a bit on knock sensors, etc.... can\will the car possibly have to learn how to correct for things again. What kind of time frames does this take?

 

I could probably get it in to my shop (or local dealer) for a second opinion, to see what they might think.

 

Cheers,

 

John

[nipper]

have someone else listen to it since we cant, especially since your going on a trip.

 

nipper

[jmickelct]

Hi,

 

My gut is saying piston slap (though if you put a gun to my head I couldnt give you a very detailed or rational description or cause).

 

But thats what it sounds like.

 

Very intermittent, (versus "valve chatter") though as I said, seems to come go, in between revs\slow downs.

[nipper]

let it warm up and see if it goes away. What bothers me is that you didnt notice it before the Tb change.. maybe do an oil change?

 

nipper

[jmickelct]

Hi,

 

Yes, am 1kmi overdue for oil change, so will do that tomorrow (will STP or any oil treatment do anything of value?

 

On the TB front I guess I have two fears:

 

I'm 89% sure that I got TDC (had the valve covers off, saw the cams, saw pictures of where they were suppose to be, etc...) all everything lined up well, and the left (drivers) cams did spin when I took the belt off.

 

I also (in getting the crank bolt off ) rotated it maybe a few degrees (counter clock wise) but not a whole lot.

 

So if I had bunged up the valves, could that cause something like this? (versus a bent valve which I am assuming would be a bit more obvious... also assuming that, since the motor wasnt running and I didnt go all that far in any one direction with anything, that (having seen the pics of where the pistons are @ TDC, assume that I'm probably good there).

 

#2 is that, even though I checked 6-8 times putting the belt on and am 94.6% sure that I got it dead nuts on, that, hey, I could have been having a 70's flash back and I've screwed up a lot more obvious stuff than that. So am wondering what the symptoms of a 1-2tooth off belt would act\sound like.

 

John

 

let it warm up and see if it goes away. What bothers me is that you didnt notice it before the Tb change.. maybe do an oil change?

 

nipper

[nipper]

If the timing was off the car would not run or you would have no power, so i think your fine.

 

The only thing i would worry about is make sure that crank bolt is properly torqued.

 

Also there is no way you can do damage by being even three teeth off.

 

nipper

[jmickelct]

Wow, thanks (*thats* what I wanted to hear...).

 

I have been paying very close attention to the crank bolt (laid it in to 130 Ft. Lbs and lathered it up good with loctite (blue) and have been checking it a.m. and p.m. every day so far (have paid attention to folks who said the same thing only to have it rattle off)

 

Will do the oil, (whats the heaviest you tend to use?) and say a prayer (and will be bringing my tools on the trip!).

 

Thanks again,

 

John

 

If the timing was off the car would not run or you would have no power, so i think your fine.

 

The only thing i would worry about is make sure that crank bolt is properly torqued.

 

Also there is no way you can do damage by being even three teeth off.

 

nipper

[nipper]

i keep out of the oil arguments, its safer to talk religon and politics. Use whatever oil you want. If you use synthetic you still have to change the filter at the recomended intervals.

Dont go crazy on tools. Personally aside from hand tools, the only tools i carry on a long trip is my AAA gold card and mastercard.

Odds are the car will breakdown miles from a parts store, so the tools do no good anyway (murphies law volume 6 paragraph 27 section 6 line f).

 

nipper

[johnceggleston]

(murphies law volume 6 paragraph 27 section 6 line f).

 

nipper

 

sub-sections U, C, K, E, D

[Prwa101]

Okay same exact thing is goin on with my car right now! I did the TB, fired it up to make sure it ran right, really back knocking/ticking then faded away... It's still running strong, no loss of power, (other than the clutch acting weird, and shaking the car running at 2k rpms in any gear) other than it having really low rpms at a stop and it wanting to die. It's doing good.

 

Did you guys figure out what it was? And any advice for me?

 

Thanks!

[Fairtax4me]

If you removed the oil pump to reseal it then the valve train is pretty much dry when you first start the engine. It takes a few seconds for the oil pump to prime and oil pressure to reach the tappets, so you get a lot of noise for a few seconds then it goes away. But paranoia kicks in and you start listening hard to sounds that are of no consequence. Things you thought weren't there before, when in fact they were, and are normal sounds for pretty much any engine.

 

The clutch, shaking shuddering is typical of a glazed and/or warped flywheel and/or pressure plate. There are ways to "fix" it temporarily, but in the end you just need to replace the clutch and have the flywheel machined so it's nice and flat. GripForce on Ebay sells Exedy clutch kits for about $125, maybe a bit more for the 2.5, but still possibly the best deal that you'll find anywhere on an O.E. quality clutch kit.

 

Your low idle RPM could be a loose vacuum line or PCV/breather hose. Chances are the ECU had compensated for the issue before and when the battery was disconnected it lost the data it had stored for air/fuel mixture and spark profiles. It has to re-learn that information as the car runs, and it can take several drive cycles to complete the process.

Edited January 7, 2012 by Fairtax4me

[bork]

This new to me 2.2 has the same slight knock at idle, especially in gear (lower rpm) But I changed everything at once. Oil/filter, TB and pulleys & waterpump, thermostat, drive belts, and flushed AT tranny last. I didn't notice mine either before all the work. But I still wander if the guy I bought it from had a bunch of additives in oil to silence it? Other than that it runs great!