I did a timing belt on a buddy's 2002. Being the utter noob i am, i removed the vvt actuator by itself instead of taking off the access plate to the cam gear bolt. I just saw some 10mm bolts and figured "I like bolts, let's take those off."

I was frazzled at this point after finding out that RSpeed sent us the wrong 60k service set, despite the box being checked for 01-05. (Nothing like not being able to replace cam seals.)

So, long story short, i exploded the VVT actuator. I'm reasonably sure it got put together properly, and i'm 100% positive the motor is timed properly, and there's nothing else loose down there. I tore it back down the night after and checked the tensioners, water pump pulley, crank pulley, etc etc etc.



Symptom: After sitting for more than 30 minutes, the next startup has a momentary rattle that sounds pretty awful. Lasts one full second at most, usually half a second. Motor is dead quiet after that, makes good (surprising) power through the whole rev range, actually drives REALLY well. (I've never spent any real amount of time with a VVT 6spd car. I'm really impressed.)

I noticed when we were doing the whole thing that the o-rings on the VVT "Tower" were all completely hosed. Nice and flat and hard. I had him replace them after he got home in hopes that the system was just bleeding down (which... i still think it is) and it has not fixed the issue.



Thoughts? I'm thinking my next step at this point is to source another VVT actuator on my dime and see if that fixes it, but if there's something simple like "You just have to bleed the actuator dummy!" (If that's even a thing) i'd like to hear that before we replace things that aren't broken.

I know that there was a TSB for the 01s concerning a rattle from the VVT mechanism, but this being an 02, and that it didn't rattle before i touched it, i'm guessing this isn't related.


Thanks in advance.

 

You fucked up by taking the actuator apart, they are a bitch to get back together properly. Shoot me a pm if you want an actuator to test. I have a spare that I could let you borrow for a bit to figure out if that is what is actually wrong.

 

yeah, see my nightmare of a thread about vvt actuators.

then start looking for a replacement

I sold my built motor because of an issue similar to this. Luckily Dopple had a spare and replaced.

You done messed up.

 

Yeah, there sure are a lot of little pieces in there, aren't there?

We had successfully unexploded an SW20 MR2 electric power steering pump earlier that day, so i figured this would be about the same. (Hilariously similar, btw.)


Lars, i appreciate the offer, i'm sending you a PM.

 

what pisses me off, is that even when you put it back together flawlessly, and I mean literally to the tee of how it was, there's still no guarrantee that it will work like it did before.

I have no idea what wizardry mazda uses to assemble them that causes this

 

It actually goes back together somewhat easily, and it makes sense to me the way it works, but who knows what happens once that beautiful thin film of oil is lessened across all the surfaces during disassembly.

 

I've had 18psi's actuator apart, and it does make sense the way it goes together. Kinda makes me think of a rotary engine with apex seals, although I've never had one of those apart.

If you put all 8 spring clips and 8...pads(?) in, you should be fine. Don't forget the spring and pin of course.

If your friend took it apart to do the o-rings, did he damage the oil filter? If it's not seated correctly, oil could be obstructed momentarily, and the vvt actuator would be starved for oil briefly. Worth a check, the clips for those filters seem to break easily.

 

I doubt he messed it up, but i can ask. Problem was happening before the tower was removed, problem still happens after tower was removed to replace o-rings.

 

Lets give an update to this since this car is driving me insane and now costing me a bunch of money.

I got another actuator shipped to me from Lars, who is an awesome dude to 2 day ship it to me.

I installed it on Friday morning at MATG.

Started car, made tons of awful noise from the VVT area. Started to see oil seeping through the timing covers. ****.

Tore down again, investigated, saw oil pouring from VVT actuator. Why so? Because this actuator had been apart before as well, and the four 10mm bolts weren't even finger tight, and the noise was from the VVT not being filled with oil, as well as the front plate rattling around like crazy.

Tightened plate. Buttoned car back up.

Dead quiet, ran smooth. Beat the hell out of it up and down 28 from Fontana to 129 and back. Success!

Proceeded to run perfectly with no drainback symptoms it was showing before the rest of the day Friday and Saturday.

Sunday morning, the start up rattle is back, but car runs fine. Pissed at this point, i tell him to go ahead and drive it home, and i'll try to figure something out later, and make a 7 hour round trip to fix it for him then.

After 300 miles, i get a call saying the car is now throwing P0012. He clears the code, car is still running fine, he beats on it on the rest of the way home, never skips a beat.

Still doing gross-sounding cold start rattle.


In looking into P0012, i'm not entirely convinced that it's related to the VVT at this point. It was hot as ***** on Sunday on the drive back, and the car has 65-70k miles on it, which sounds like it's about time for a heavily heat-soaked CPS to act up.

However.... this VVT drainback thing is infuriating. I'm not passing anything on Lars at all, it's my own damn fault for not noticing that the actuator had been opened before, and i probably shouldn't have bothered to install it anyways. I have no problem with him, nor should anyone else.


NOW.

What the **** do i do? I'm at a loss. I've double and triple-checked my work, and the only three things i can think of that would be causing the rattle are:

1) Another opened and failed VVT actuator
2) Homeboy didn't properly install the VVT "tower" o-rings. (I should have checked this, but i'm not thinking it's real likely. They aren't exactly hard to do.)
3) copper o-rings on the big 19mm banjo bolt on the back of the valve cover maybe worn out after 4-5 cycles in the last 2 weeks? No visible leaks from that area, however.

 

I get some rattle on start up after replacing my VVT actuator with a known good unit(I had previously opened my original one, but I am not convinced it is bad). I thought it was just the valve opening and closing before the feed tube filled with oil. If you find a solution I am interested, but I felt it was more of an annoyance than anything else.


I was getting P0012 when my timing was off a touch, It would trigger at low rpm with high load. If I cleared the code and drove without loading the engine up below 3500 it would not set. I finally ditched the FM "timing ninja" tool and set the timing manually and it went away for good.

not sure if your symptoms are the same, but I thought I'd offer my experiences.

 

I used the FM Ninja tool the first time after i exploded his original VVT actuator.

Did not use it the second time, as i found the tool to be maddening to use in the first place, and i've done a BP timing belt or 7 in my time without it just fine.

Each time the timing was set, i rotated the motor two times to ensure that all marks were still spot on. The way the car is running also points to a correctly timed motor.

I'm finding now in more research that this rattle isn't exactly uncommon (Was even a TSB on it in the earlier cars) and probably doesn't hurt anything, but it bothers me to no end (and imagine how much it bothers him) that the car didn't rattle before i touched it.

 

Sorry about the VVT actuator I sent you having those loose bolts. I honestly did not ever look at that one and assumed it had never been apart., I picked it up on here for cheap as a spare and it sat on a shelf for the past couple of years.

 

In for answers.

IIRC with this style VVT actuator rattle only at startup means that the locking pin is not fully engaging. Maybe the spring is toast or something. Which may or maynot be the plastic plunger thingy. From what I can tell you have to make sure that plunger doesnt fall out when putting the 4 bolt cover back on or the locking pin wont be able to lock into the hole.

 

No worries, i wasn't trying to call you yesterday to bitch you out or anything.

I'm completely ******* flabbergasted that the car was dead quiet on start up for 2 days though...


Definitely possibru, but... i still can't explain why it was quiet on Friday and Saturday.

Bad locking pin = drainback problems with sitting, yes?

 

I took the VVT actuator apart on a car earlier this year because I just wanted to finally see for myself how the little guy worked. It went back together fine, no rattles. It was a bit of a pain to hold all 8 components in alignment while a I slipped it all back together, but nothing impossible.

Sorry I don't have anything to add, it's just after reading this thread and then some others about people getting the rattle even after proper installation I feel really ******* lucky.

Sorry this thing is being such a nightmare. Is that little plastic plunger piece directional? I mean should one side face out and the other face in? Would that even somehow affect drain back? I know if it gets smashed it may cause p0012 (at least that's what I've read), but I wonder about direction.

 

What I really dislike abut the VVT gear thing is that Mazda does not sell parts for the insides as far as I have found. They only sell the completed assembly for $400+ or something crazy.

 

I don't know.... :( Anyone else have a known good one laying around? Or want to dissect the original one off the car that i probably put back together slightly wrong?

 

If you put it back together wrong the little plastic cup is broken. What we need is someone with a lathe and some plastic to have a non-broken plastic cup put in their hand so that they can make some new ones.

 

I wonder if you could 3d print the piece we need.

 

Depends on if you could get the surface finish sufficient on it. I think its a sealing surface. These shouldnt be too hard to just whip up on a lathe quick.