Camshaft position sensor location

What kind of filter is on your engine? Is it a Toyota OEM? Have you ever had the engine worked in anyway requiring removing the timing chain cover?

 

The heads cannot be mulled on the 1GR. Service manual states to replace if warped out of spec, no resurfacing allowed. It could be that the angle of the cams and crank is changed too much and there is slack in the chain causing timing to be out spec.

 

Yeah its oem. And the first time I pulled it (last week), oil did in fact come out, I had even placed rag under it to catch it as someone mentioned the fact in another thread here.

And here's the thing, the original valve was in fact bad. It had no movement at all when voltage was applied.What are the odds 2 things could be wrong. 137K on the truck. It runs smooth.

To answer your last question, no, no one has touched the truck but me and this is the extent of my work up top.
I'm stumped.

 

They can. Just get a head gasket from Cometic with the thickness to make up for the difference.

I've had plenty of head resurfaced.

 

How many of your engines are still going with those custom head gaskets? Technically the sealing surface is more exposed and the head bolt torque will need to be higher.

 

Three.

They all have ARP head studs.

 

Also, Toyota will sometimes send them out to be machined as well. The one local to me did it all of the time.

 

Anyone know what connects these two? Is it a channel in the casting(my guess), or is it a tube of some sort?



The reason I ask is, I wonder if when I changed the bad OCV, if it died closed, when the new one was installed.... oil then flowed from the filter to the valve and perhaps that oil (the oil that was trapped between the filter and the valve for a long time) had sludge in it and now as fresh oil was allowed to flow, it pushed the sludge and perhaps the sludge reached a turn or something in the channel, built up there, and is now clogging the path between the filter and the valve.

I was thinking trying to run a wire or something, like you'd use a snake on plumbing from the filter hole, but if its got bends or something where say it makes a 90, that won't work.

I'm gonna try to blow air through there and see what happens. Maybe blow out the clog, if it exists. Worth a try, I don't think I'll mess anything up.

 

Worthy of a shot. Have you yet tested the new OCV?

 

Yes, it works fine as far I can tell.

 

Awesome.

 

The oil passage is cast into the cylinder head. It's a tough decision regarding using compressed air to test flow and/or dislodge a blockage, as the discharge from the oil control valve when opened flows oil into the intake camshaft #1 (front) bearing shell, then through the camshaft and into the VVT actuator.

If the VVT filter basket is clean, and the engine interior under the valve cover is clean, it is unlikely there is a blockage downstream of the filter. How do they look?

This is a difficult troubleshoot...I'm speculating that the lock pin in the VVT actuator (big intake cam sprocket & canister) may be stuck. If things are clean as described above, and you've verified you are getting voltage to the VVT oil control valve as described in the diagnostic procedure, I'd swap the VVT actuator (expensive at $170 for Toyota part).

 

EDIT: my next steps would be:

1.) Re-verify both intake and exhaust cam timing on bank 1 after checking the spec diagram attached. Intake cam timing mark placement is different on bank 1 versus bank 2, threw me off the first time...the sprocket timing mark aligns with the *indented* timing mark on the intake cam bearing cap, not the raised timing mark like bank 2.

2.) Reassemble valve cover and whatnot, apply 12VDC to the oil control valve w/ engine running, similar to what's in the diagnostic procedure. If engine runs rough w/ 12VDC applied to the valve, the VVT system is working properly and you move to electrical problem between the ECM and oil control valve.

 

Hi Craig,

Thank you for that post. That is too funny, I was just logging on to start a new thread and ask how the VVT actuator (the cam gear assembly) actually works... mechanically that is. Its intrigued me and I can't find anywhere on google that explains the mechanics behind how it actually varies the timing using oil pressure. Reason being, that is exactly my next target. I am having a hell of (but fun) time with this thing. Let me tell you what I have done in the last two days for your amusement....

First I did in fact pull out the filter and solenoid valve and blew compressed air from the valve hole towards the filter. I placed a rag on the filter side to see if anything came out and sure enough, there were several "tar balls". About the size of a bee-bee. Now let me point out, I had let my gf use the truck quite a bit, and the oil did not get changed. It was my bad, I just didn't think about it. Dumb I know, but when I did check the oil, to my horror it didn't even register on the dip-stick. It was low as all get out. When I drained it, it was very thick too. It was synthetic, but it was the worst looking oil I have ever seen. I added Sea-Foam with the new oil. Soooo.... the tar-balls did not surprise me. I was sure however I found my problem and had it fixed.

No such luck. P0012 came right back as advertised on the second drive cycle. I thought ok, maybe there's some more tar balls in there. Took it apart again. Blew the air. This time not only did I blow the air from each side, but I also plugged one side at a time since I wasn't sure as to where the oil actually comes from or goes once it leaves the valve... I figured maybe those channels had some sludge. So I put the valve in and blew air into the filter hole (I removed the oil filler cap to let the air go somewhere), and then I did it the other way, I put the filter plug in, without the filter (just to stop up that hole), and blew air into the hole that the valve slides into. I figured this might clear a channel that could be blocked heading for the VVT actuator. I put it all back together, and you guessed it, good ol' P0012 comes right back.

So, I had already meticulously read through every troubleshooting step in the service manual (that someone here has kindly posted the link to for all to share) its for a 2005/2006, but in this case it works for my 11... so I was aware of the test for sending power to the valve and seeing if the engine ran rough. The dealership has the ability to do that via their super-tester or whatever they call it, but I did it using safety-pins poked in the wires, alligator clips, and wires to the battery. Before I tried it with engine running, I did it with engine off just to make sure I could hear the valve clicking. It did, so I tried it with the engine running. **Now, this may impress you lol... I actually thought about this before I tried it because somewhere in that service manual, not in this section, but the section for circuit troubleshooting, they hook up an oscilloscope to check the waveform of the signal generated by the ECM that is sent to the control valve. They don't specify the voltage coming from the computer, but they show a picture of the waveform and its a +/- 5V squared off sine-wave. I wasn't afraid to send 12V to the valve, but I was worried about that 12V returning back through the ground to the ECM. I certainly didn't want to fry the ECM. Not sure why they just don't ground the thing right there, but it is in fact grounded back to a terminal on the ECM. Probably for pureness of signal would be my guess. So I disconnected the plug, and used alligator clips directly on the valve with the engine running. No difference whatsoever. It ran smooth as it always does. Frustrated, I plugged it back in, inserted my saftey pins in the wires and gave it a shot, ECM be damned. Well thankfully it didn't fry the ECM, but the results were the same. No difference whatsoever in the engine's smoothness or rpm's.

So here we are. Your post read my mind and that was the next thing I wanted to check. The VVT actuator. And you further read my mind by mentioning "the lock pin". I don't know what it looks like or where its at on the assembly however. Is this something I can actually get to? There's no telling what that bad oil clogged, but simply by looking at the tiny pin hole where oil enters the bottom of the control valve tells me it wouldn't take much to clog up something after the valve, ie a port in the controller that goes to the locking pin(?).

I'm tempted to wait until you read this on the chance you happen to log in today before I proceed... but since there's not a whole lot to do since we're all supposed to quarantine ourselves, I'm chomping at the bit to tear this thing apart again and see what's up. Its driving me crazy. I will fix this thing if its the last thing I ever do. If Corona gets me, I'll be doing it with a fever. This is the first thing in 40 plus years of selectively fixing mine and friends' cars that has taken me this long to nail. Gotta admit though, I do kinda enjoy it. In a way at least. Keeps the brain nimble. -Thanks Craig.

 

I'd pull the valve cover and check the intake cam timing, crank on the zero TDC mark, before going after the VVT actuator. Here are pics from the one I pulled off mine early in the project, to give you an idea of what's inside. Lock pin moved freely against spring pressure and no signs of mechanical damage (the chain was stretched).

 

Good pictures, thanks.
Ok, I'll pull her apart again and keep ya posted... more to follow.
-thanks Craig.

 

Here ya go Craig. Half tooth off?



Assuming it is, one question. Why when I applied 12V to the OCV, why did it still not make the engine run rough?
It seems like it should have done that regardless if I'm a half link off. Right? It should have done something I would think. As I've said, the truck runs smooth as silk. Hmph.

My tensioner was extended too, about 4 of those little lines. I didn't take off the inspection plate, but I tried to take a decent pic from above... Not sure if that matters.



I guess my next question is... please tell me I don't need to replace the timing chain if this is in fact the case.

 

Also, note the sludge in the first pic near the bottom.
Again, lock pin (maybe?)

 

Sludge isn't too bad, and not nearly as bad as mine was. Are you absolutely certain the crank pulley timing mark was exactly on the zero (0) timing tab mark when the pic was taken?

Your tensioner shows the tell-tale rings which accumulate after each click of the tensioner plunger ratchet as the chain elongates. Can't tell from the angle how far it's extended, but I count 4 rings just on the visible portion of the plunger. Next move is to unbolt the small 4-bolt tensioner cover and get a straight-on pic of the plunger.

 

Yeah the saga continues. As I said, this is war, its me or P0012. One of us is gonna die.
Allow me to update.

Yes, I got down there with a mirror and got it right on zero. From above its hard to tell, even though it looks like its on zero. In aviation, on old-school steam gauges we used to call that parallax. IE, you have to look at your needles head on (straight) or you'll get a false reading. But yeah, timing is cool.I triple checked.

So for fun I decided to flush the engine. Drained two quarts, put in a quart of motor flush and topped it off with Kerosene. Ran it for quite a bit. Drained it, took the two quarts I drained to start with, put them back in, topped it off with kerosene, ran it, drained it again.

I looked at the oil pan, and it seemed pretty easy to drop so I figured what the heck.
Glad I did. Quite a bit of tar in there. Had the consistency of that stuff you seal your blacktop driveway with.

The pick-up screen looked horrible.

Cleaned it all up... put it all back together, fresh 5W-30 Synth, new Purolator Boss filter.... cleared all the codes.... ran it down the road, pulled over, shut it down (to get in the 2nd drive-cycle which is required to get the CEL).... Got it up to 40MPH.... bam... CEL.
P0012.

Remember the episode of Seinfeld where Cramer passed the kidney stone and screamed so loud all of NYC heard him. Pretty sure my "F***" was heard by anyone within two miles.

Undaunted... I press on.
Its gotta be the actuator gear. So all yesterday, I worked to get that thing off. I got both cams out of there, as I could see no other way to pull it off.

Its definitely locked up. Those 3 bolts holding that thing together... pfff.... they are on there. The only thing that would work was the right tool. I had to go all over town to get one of those 5 sided torx (tamper-proof) or whatever they're called. Even Harbor Freight didn't have them. No one did. Ended up going to a specialty tool place, $29 for a whole set. Whatever. I used an impact hammer and got em out. The spring was jammed.

Cleaned it all up and called it a day... so we'll put it all back together and see what happens. I hope that timing chain doesn't jump any links down there while I mess around putting these cams back. I think I've got it secured. We'll see .

Here's some pics. Oh yeah, I took out the tensioner too.

More to follow.

No cams:



Tensioner



That stupid actuator, after the wild goose chase for the 5 sided tamper proof tool. :