Knock/tap after valve cover gasket change (with video)

[EatonKyleH]

You're on the right track and have some good guidance/suggestions from the guys above.

One thing I'd suggest is to check your valve clearance BEFORE you take the caps off and see if you can confirm a clearance issue especially on the rear valves you suspect problems around. Right them down and recheck again after the cam has been reinstalled with the correct sequence and torque values. This may help you to see the potential problem and then see the positive (hopefully) change in clearance you make and a chance to change shims/correct clearances as needed. Also would just suck to take it apart, put it all back together again only to have the same problem and only be able to guess if any of the clearances were changed haha.

Anywhoo just a suggestion and something I like to do...before and after measurements.

 

[T4R2014]

Your really not going to want to hear this, and I'm not saying this is what happened only a possibility.

My mentor of sorts (a ASE and Toyota certified Tech, worked for Toyota dealers exclusively for 35yrs) smacked the wrench out of my hand for touching the cam caps when I was doing a head gasket on an old MR2. He said by loosening one cap (especially and end cap) you can bend the cams ever so microscopicly but it adds enough wobble to "slap" the valve lifter when the lobe comes around. You might have a bent cam.

Anther thought is that you over tightened that cap which could definitely cause the tick. I watched a guy tune his 94 ford ranger WHILE IT WAS RUNNING, (crazy some ***** but it was his truck) by tightening the cam caps until the valves started to tick and then backing off one point/flat.

Lastly the cam has worn into the cap in a certain rotational direction by installing it backwards the cam is rubbing the cap the wrong way, (like petting a microscopic cat from tail to snout) it could even be trying to walk forward or backwords and your hearing a snapping as it pops back into place, kindof like when you cut your rear drums too fast and it leaves a slight spiral vs a smooth surface.

In any matter, I personally would pull that valve cover off again, back all the cam caps off in the FSM stated order, and makeing sure all are in the correct direction torque them to the (as another member stated) specified 12ft lbs in the order the FSM states.

Be forewarned, our cams are contra rotating and will have a biparted cam gear that drives the opposite cam that is spring loaded There are little indents in the gear to show where the spring loaded bit aligns, pay close attention and keep the spring gear compressed so it doesn't unload when you take all the caps off or you WILL have a very bad tick.

Best of luck and I pray for your sake the cam didn't bend!

Would the same issue apply to the cap that goes over the cam plug?

 

[hour]

You're on the right track and have some good guidance/suggestions from the guys above.

One thing I'd suggest is to check your valve clearance BEFORE you take the caps off and see if you can confirm a clearance issue especially on the rear valves you suspect problems around. Right them down and recheck again after the cam has been reinstalled with the correct sequence and torque values. This may help you to see the potential problem and then see the positive (hopefully) change in clearance you make and a chance to change shims/correct clearances as needed. Also would just suck to take it apart, put it all back together again only to have the same problem and only be able to guess if any of the clearances were changed haha.

Anywhoo just a suggestion and something I like to do...before and after measurements.

That's an excellent point. Honestly I was trying to avoid ordering the shim related materials and having yet another thing to try and DIY, potentially screwing up again - but no harm in measuring. I'd definitely feel better with a confirmation of values changing. May as well purchase everything I need just in case I do need to do a valve adjustment should the retorquing not do the trick. I guess however that I'd hit a fork in the road of wondering if a valve adjustment is needed or if I bent the cam shaft.

And in the event that anyone stumbles upon this trying to fix their own problems, or does something stupid like me, torque sequence for caps is on pg 866(intake cam, exhaust cam is 867) of the giant FSM .pdf file, or section EM-52 if you have a paper copy.

 

[Troybylt]

Would the same issue apply to the cap that goes over the cam plug?

If you're talking about the cap that just holds the round plug on the outer wall of the head (the cam shaft does not pass through) then I wouldn't worry too much about it if you didn't break the bolts off leave it however tight you made it. Your really only worried about what actually contacts and puts pressure on the cam. Now if it's the cap that that cam passes through the head/valve cover to the cam gear driven by the timeing belt, then yes The fsm (Factory Service Manual, I have a digital copy of one if you need it but it's not too hard to find on here either) should state when and how to remove it.

That said looks like your working on your exhaust cam from the pictures you provided, as I recall the exhaust cams do not leave the head or valave cover so it shouldn't be difficult to fix, just make sure the dots on the intake came line up with the dots on the exhaust cam. You may need to bump the motor or turn the crank shaft with a socket and breaker bar to get the dots to align. This step is important so you don't end up with your exhaust cam one tooth off. I wouldn't touch your intake came if you didn't when you did your valve cover gaskets.

Lastly yes, although they only get torqued to 12ft lbs (be sure to double check that with the fsm values) heat vibration and time as well as oil that bakes into the threads can all seal it up and make it feel a lot tighter when you take things apart. That's why knowing the torque and haveing a torque wrench are so important. Forearm torque wrenches aren't all calibrated the same nor do they "keep their memory" and stay set to value like an iron one does.

I'm guilty of relying on my forearm torque wrench however.

Like you said glad it was on the passenger side!

 

[hour]

If you're talking about the cap that just holds the round plug on the outer wall of the head (the cam shaft does not pass through) then I wouldn't worry too much about it if you didn't break the bolts off leave it however tight you made it. Your really only worried about what actually contacts and puts pressure on the cam. Now if it's the cap that that cam passes through the head/valve cover to the cam gear driven by the timeing belt, then yes The fsm (Factory Service Manual, I have a digital copy of one if you need it but it's not too hard to find on here either) should state when and how to remove it.

That said looks like your working on your exhaust cam from the pictures you provided, as I recall the exhaust cams do not leave the head or valave cover so it shouldn't be difficult to fix, just make sure the dots on the intake came line up with the dots on the exhaust cam. You may need to bump the motor or turn the crank shaft with a socket and breaker bar to get the dots to align. This step is important so you don't end up with your exhaust cam one tooth off. I wouldn't touch your intake came if you didn't when you did your valve cover gaskets.

Lastly yes, although they only get torqued to 12ft lbs (be sure to double check that with the fsm values) heat vibration and time as well as oil that bakes into the threads can all seal it up and make it feel a lot tighter when you take things apart. That's why knowing the torque and haveing a torque wrench are so important. Forearm torque wrenches aren't all calibrated the same nor do they "keep their memory" and stay set to value like an iron one does.

I'm guilty of relying on my forearm torque wrench however.

Like you said glad it was on the passenger side!

Yeah, double checked FSM, definitely states 12 ftlbs. Also instructs to apply oil to the threads and contacting surface of the bolt head, so that explains being ehh.. baked on.

And yes, I only made my mistake on the one cam. I'll update this thread when I get it all buttoned up again and hopefully running beautifully, ready for some winter shenanigans.

 

[Troybylt]

Yeah, double checked FSM, definitely states 12 ftlbs. Also instructs to apply oil to the threads and contacting surface of the bolt head, so that explains being ehh.. baked on.

And yes, I only made my mistake on the one cam. I'll update this thread when I get it all buttoned up again and hopefully running beautifully, ready for some winter shenanigans.

Awsome! Really hope she gets back to being right! Looking forward to good news in the update.

 

[hour]

Got it done this morning. Took maybe 10 minutes to remove the passenger side valve cover, so that was nice. Had to remove bolts for the upper plenum and shift it towards driver side a little bit but that took <1 minute.

Anyway, after getting it open I had intentions of checking valve clearance and had received the feeler gauges I had ordered, but I didn't want to fart around with rotating engine to TDC and yadaya. If the whole disassembly had taken longer, I would have been able to justify it - but instead, I just flipped that cap I put on upside down, loosened all the caps on exhaust cam and then retorqued to appropriate 12ftlbs in correct sequence.

Buttoned everything up, battery dead I guess two weeks of sitting with near freezing temperatures at night didn't help. Also, last weekend, I had started it twice but barely run it due to the noise, so that took some juice that wasn't replenished by driving. Anyway, jumped with truck and took it for a spin to Walmart (15 min drive) with some tools, in case I came back out of the store and the battery was dead I could just get a new one inside. But battery is ok now.

The noise, it's still there - but greatly reduced. I'd wager it was always at the volume it is now, so maybe I could stand for a valve adjustment but if this gets me 40k miles (that's like 5 years) then I'm cool with whatever happens next. I'll be nearing 300k at that point anyway. Can't hear anything with hood closed unless you're standing on passenger side with your head a foot away from the hood. No noise at stop lights from in cab, no CEL, feels smooth, drives great. Best of all, the original goal of stopping oil dripping on the exhaust and smoking me out was achieved. So, back to building. Thanks for everyone's input - glad it didn't turn out any worse!

 

[Troybylt]

Outstanding man, glad you got her all figured with minimal issues, if you wanted you could always post a video of how it sounds now, it may just be the "Toyota Tick" you're hearing.

Glad she's back on the road.

 

[LittleCaesar]

Always good to hear a success DIY repair, especially after being the one who made the mistake.

I have the tools to adjust my valves, but probably not until Spring 2015 when I will have some shims if needed. I'll post some pics and procedure, but if you beat me to it, take a couple of pics and post them.

 

[repo]

Just found this thread after making the same mistake, although I haven't put it back together or run the engine. If you wipe off the top of the cap there is actually a tiny arrow marking that should point to the front so you know which way round it goes. Hope I haven't busted anything by messing with it.