VVT Actuator replacement

[onion86]

I've been putting this off forever, but it's time!

Can you get the VVT actuator off by just removing the chain tensioner + rocker cover (as per stolen pic), or do I need to take the timing cover off the side too?

On a scale of 1-10 how difficult is it to do myself without getting it wrong? I've done everything on my car myself since I bought it - from bulbs (1), brakes (3), to a full turbo install (I'll give that an 8/10)... but this has always worried me for some reason and I've put it off.

Car is on 82k, if I'm going to do this and I do need to take the side off, should I just replace the whole timing assembly / chain too?

I guess if it's going to take me a weekend and the worst I need to worry about is aligning chain / sprokets then I'll do it myself. If I'm likely to kill my engine then I'll pay Toyota the £800 odd to do it for me and I'll just have to feel like a failure

[shnazzle]

This has a how-to written all over it

From what I remember when I watched a video many moons ago, the only thing that seemed tricky was using compressed air to engage (or disengage?) vvt so you could take it apart.
Something to do with compressed air. And I have no compressor so I stopped reading haha

Guy on the video used compressed air as well

[paulj]

Share your concern at anything which involves the timing chain, have the same issue with worry at doing something which could cripple the engine in one go.

Mine probably needs a tensioner replacement but haven't plucked up the courage yet.....

[Carolyn]

If you are wanting to simply replace the hub, there is no need to remove the timing cover. 

See the 'how to' on adjusting valves, in the how to section.  It tells you how to time the cams and get the chain off the sprockets.  You don't really need to lift the cam to change the hub.  Just hold the cam steady as describes in the how to and remove the bolt that holds the hub to the front of the cam.  Then the hub will come off.  If you find that difficult, follow the procedure for lifting the cam, then you can do the hub replacement on the bench.

With your level of skill, I would not recommend dismantling the hub once you've got it off.  I've had a couple apart and they are quite fiddly things to work on.

Everything you need to know is covered in the 'how to' on 'valve clearance adjustment'..

Paulj:  Read the 'how to' on the chain tensioner and go for it. It's really not to hard or scary.  Honest!!

[onion86]

If you are wanting to simply replace the hub, there is no need to remove the timing cover. 

See the 'how to' on adjusting valves, in the how to section.  It tells you how to time the cams and get the chain off the sprockets.  You don't really need to lift the cam to change the hub.  Just hold the cam steady as describes in the how to and remove the bolt that holds the hub to the front of the cam.  Then the hub will come off.  If you find that difficult, follow the procedure for lifting the cam, then you can do the hub replacement on the bench.

With your level of skill, I would not recommend dismantling the hub once you've got it off.  I've had a couple apart and they are quite fiddly things to work on.

Thanks Carolyn, got it - https://www.mr2roc.org/forum/index.php?topic=65009.0 That's perfect, thanks... sorry I hadn't noticed the new 'How To' in there! That pic easily shows that you can get to the bolt on the end of the hub without too much bother

Sounds like it's easily doable for me, I just need to not drop the bolt down behind the timing cover and it's good to know I can't lose position on the bottom sprocket. Definitely getting new from Mr T, so wouldn't be taking it apart to refurb or anything like that. Do you think it's worth replacing the exhaust sprocket too whilst I'm in there?

From what I remember when I watched a video many moons ago, the only thing that seemed tricky was using compressed air to engage (or disengage?) vvt so you could take it apart.
Something to do with compressed air. And I have no compressor so I stopped reading haha

Yeah, I've watched a lot of videos on the subject too. If the hub is locked you have to fire 20PSI into a little hole to unlock it. Might be that they all come like locked... so I might have to find a compressor!

[Carolyn]

I must confess, I'm curious as to why you want to change the hub.  I'm not saying they don't go defective, but it is quite unusual.
More often VVTI issues are down to a sticky VVTI valve (also known and the oil control valve) or a blocked-up VVTI filter.

You can change the exhaust sprocket if you want, it's not an expensive item, though you might also want to check for chain stretch at the same time.  If the chain is well within spec, you're good.  Meaure the length of 16 links it should me no more than 122.6 mm.

You don't need any compressed air if all you're doing is swapping the hub.

Have fun

[onion86]

I must confess, I'm curious as to why you want to change the hub.  I'm not saying they don't go defective, but it is quite unusual.
More often VVTI issues are down to a sticky VVTI valve (also known and the oil control valve) or a blocked-up VVTI filter.

You can change the exhaust sprocket if you want, it's not an expensive item, though you might also want to check for chain stretch at the same time.  If the chain is well within spec, you're good.  Meaure the length of 16 links it should me no more than 122.6 mm.

Basically P1349... It's been an on-going issue for 6 years: http://www.mr2roc.org/forum/index.php?topic=38104.

The code came up a couple of months after a I bought the car, with the little use it got I was seeing it every few months maybe every 400 miles or so, reset and it went away again for another few months. Now I'm using it as my daily it's actually coming on
twice a week or more now.

I think the car was pretty badly treated before I got it as you can see from the pics on Page 2 of the above thread of engine/oil that came out.

- I replaced the OCV a few years ago with a genuine new part. Both the new and old work perfectly well when I put 12v on them with no sticking. Also when they're in the car and I've done the test at idle, it stalls like it is supposed to.
- I've cleaned the filter a couple of times and also replaced it; at no point was it 'clogged' like some I've seen, but did it anyway.
- Last year cleaned off the Cam position sensor.
- I still haven't got round to checking the Crack position sensor as I'm worried I'll break the bolt on it, did clean up the Earth wires on it though.

So basically I'm out of ideas and in my mind this is the only thing left to finally try. Unless you have any more advice for what to look at first
Will make sure to check chain stretch when I'm in there, engine isn't especially noisy so hopefully OK.

[Carolyn]

You seem to have covered most of it.

[onion86]

If you are wanting to simply replace the hub, there is no need to remove the timing cover. 

See the 'how to' on adjusting valves, in the how to section.  It tells you how to time the cams and get the chain off the sprockets.  You don't really need to lift the cam to change the hub.  Just hold the cam steady as describes in the how to and remove the bolt that holds the hub to the front of the cam.  Then the hub will come off.  If you find that difficult, follow the procedure for lifting the cam, then you can do the hub replacement on the bench.

Finally got some time to actually do something today as need to replace my timing cam cover gasket anyway... Don't think that's possible without lifting the cam, bolt is too long and not enough clearance:(



got this far, then the rain started 


Still got to remove exhaust cam sprocket, lift intake cam and then replace VVT hub; have put timing cam cover back on with some plastic sheeting over the top (just in case) until it stops...

[Carolyn]

I take it by 'timing cover', you mean cam cover?

Yes, I see you DO have to lift the inlet cam.  No big deal.  you've done the hard part.  If you're worried about the chain position, mark the chain where it lines up with the slot on the hub.  Line them up when you put the camshaft with the new hub back in.

If you drop the chain - no big deal.  It can't move on the bottom sprocket and you can fish it back up with a magnet.

Have you removed the chain tensioner?  You should...

Tip: the gasket goes on the cover - not the head.  Wipe all the oil off the sealing surface when re-assembling.

P.S.  Engine looks quite clean inside.  Someone DID look after it!

[onion86]

I take it by 'timing cover', you mean cam cover?

Yes, I see you DO have to lift the inlet cam.  No big deal.  you've done the hard part.  If you're worried about the chain position, mark the chain where it lines up with the slot on the hub.  Line them up when you put the camhsaft with the new hub back in.

If you drop the chain = no big deal.  It can't move on the bottom sprocket and you can fish it back up with a magnet.

Have you removed the chain tensioner?  You should...

Tip: the gasket goes on the cover - not the head.  wipe all the oil off the sealing surface when re-assemble.

Yes, sorry I meant cam cover; I usually call it 'rocker' then decided against it and edited it to the wrong thing! (will edit previous post)...

Chain tensioner out already and chain marked up with marks on sprocket and vvt hub (and crank pulley as I followed your guide more than I probably needed to in case I screwed something up). Only a couple of extra steps really, I had thought maybe I could get the hub off without removing the exhaust cam sprocket, but don't think the chain will allow it without moving the cams.

Was planning to put new gasket into the cam cover cheers, that's still the old one sitting there so not cleaned it up yet either.

Thanks for all the help and advice

[Carolyn]

Fear not.  You're doing really well.

Just whip out the exhaust cam sprocket (I see it's already loose) and put it to one side.  Then you can lift the inlet cam free of the chain.

Fun innit?

[Ardent]

Onion86

Sorry a bit late to the party. Whilst researching the fault code. came across this.
*: DTC P1349 is also output after the foreign object is caught
in some part of the system in the engine oil and the system returns
to normal in a short time. As ECM controls so that foreign
objects are ejected, there is no problem about VVT. There is
also no problem since the oil filter should get the foreign object
in the engine oil.

Clearly if happening a lot may not simply be gunk. As you suspect poor maintence previously.
Obviously you are committed now, but when things back together, do you have the means to check wave forms for checking signals to a from various controls?

I could send you a vvt diagnostic pdf if it helps.
drop me your E via PM if you would like it.

J

[onion86]

Had to abandon ship again (:< > Got my new hub installed on the cam (then locked), chain back with the marks I made lined up, but  the chain was too tight to get the exhaust sprocket back on so it cranked the VVT / pulley back (anti-clockwise) a bit and now can't get timing marks on cams and crank pulley to line up. Hoping some words of wisdom @Carolyn ? As you've said chain can't move on the bottom sprocket I'm not sure what could've happened? All good fun isn't it I'm hoping it's something I've been a bit stupid with which I can easily fix tomorrow.

Crank pulley grove lined up with mark on timing cover:


With pulley in the above position, timing marks now miles out...:

[Carolyn]

As per PM.  Inlet cam is a bit wrong and crank timing is using the wrong mark on timing cover - use the one to the right.  I think I might have said 'left ' in my PM.  It's the last mark the notch comes to as you crank the engine clockwise.

The inlet cam looks like it will be right if you line up with the yellow link and get the crank in position. Don't know how you got the mark a tooth off....

You'll probably have to lift the inlet cam again...  It's one tooth off plus not timed properly to the crank.  As per PM I'll try to assist by phone as you do it.  Exhaust cam looks good.....

Nearly there

[onion86]

Thanks very much Carolyn, will let you know how I get on tomorrow.

The inlet cam looks like it will be right if you line up with the yellow link and get the crank in position. Don't know how you got the mark a tooth off....

...also no idea how it ended up being one off, this was what it looked like last week when I made the marks, maybe I did something wrong on the crank pulley end last week:

[Carolyn]

Looks like too much slack in the chain between the crank and the inlet cam.  Should be taught when in position.  Use an adjustable on the hexagon on the cam to hold it in position.   

I just keep looking at this.  Looking at the 'before' pic and seeing how the camera angle is working and then your pic, it just looks like the crank position might explain all.  It only has to be pulled round one tooth's worth of rotation to be right.

Edit:  Just noticed that it's an aftermarket VVTI hub.  Are you sure it's installed correctly? 

[Carolyn]

Damn... I just keep on thinking about this one!  Can't get it out of my head. 

AS per PM, I understand that the hub is Toyota and that they've moved away from the silly pentagon bolts, and I understand you won't be re-visiting this till next weekend.  But I just had to write this to get it off my mind!!

As the camshafts turn at half the rotation speed of the crank, and as the timing is obviously ten degrees out at the camshaft, the crank timing would have to be 20 degrees out to explain this. And it DOES look like you did a good job of marking the chain.  The line markings on the hub indicate the locked position too.

That only leaves (I think) the possibility that you have the pin in the end of the camshaft located in the wrong slot on the back of the hub. This is possible (and easy) to do.  I know you have been very careful and methodical, but I can't think how else it could be 10 degrees (One full tooth) out.

[onion86]

Sorry that you can't get it out of your head; I appreciate all of the input so let's hope next weekend I figure it out!

As the camshafts turn at half the rotation speed of the crank, and as the timing is obviously ten degrees out at the camshaft, the crank timing would have to be 20 degrees out to explain this. And it DOES look like you did a good job of marking the chain.  The line markings on the hub indicate the locked position too.

That only leaves (I think) the possibility that you have the pin in the end of the camshaft located in the wrong slot on the back of the hub. This is possible (and easy) to do.  I know you have been very careful and methodical, but I can't think how else it could be 10 degrees (One full tooth) out.

I'm certain that I checked the pin/slot by looking in the end prior to installing the bolt. But, if that was installed in the incorrect hole, when the sprocket timing marks are lined up then the TDC on #1 would be out on the inlet cam? The install position of the hub on the camshaft would not make a difference to the position of the timing mark in relation to the chain marks that I made, or the crank pulley (I think?).

Equally, I think the same would be the case if the hub were locked / unlocked, as the inlet timing would retard/advance, but the chain / outer hub still turn at the same rate. It doesn't look like the line marks / grooves on the outer side of the hub move when locked/unlocked based on pics I sent last night of the old/new next to each other.

Is there any possible chance that the crank pulley notch is not in line with the actual crankshaft? I know that also has a pin on the shaft, but having not touched the pulley, and not actually having a picture of whether the notch lined up last week - just my luck as I took pictures of everything else! - could it be out? Anything I could see / check by looking down spark plug holes at the pistons? Or should I just ignore that train of thought completely?

[Carolyn]

No chance the crank pulley is out.  It's on a massive Woodruff key.

Concentrate on the bits that have  been disturbed.

It's really hard to assist when the thing is not in front of me!

You've lined up the chain ok, so long as the thing was properly timed when the marks were made. (which it was).

The outer part of the hub moves in relation to the sprocket part of the hub - that's how it works.  If you look carefully at your pic one set of lines IS slightly misaligned (the ones to the left).  The other line is only on the outer part of the hub.  But. as you say, that will only affect the actual cam position, not the sprocket in relation to the crankshaft.

There is a casting partially surrounding the sprocket on the crankshaft.  That holds the chain in position on the sprocket.  It is remotely possible that is has been damaged (it's quite thin) and the chain has been able to jump a tooth. 

You should already have the plugs out, so a screwdriver gently down #1 plug hole will confirm TDC. 

We'd better wait 'till you're working on it again and then you can get the crank positioned properly and send me pics of the cam lobe position.  Then we'll just do it from first principles.

[onion86]

After a few weeks of wind, rain and early darkness I've finally managed to get the work finished and the car back running It was sorted out on the weekend, along with changing the front brakes but only started it up tonight.

Massive thanks for Carolyn for all of the help, turns out the sprockets somehow ended up being 1 link out from the marks I made at the start, so if I'd just left it how I had it on the 3rd Nov before I took the cam back off and moved the sprockets to the chain marks it would've been fine. Oh well, very strange!

I'll put my pics together and make a how-to when I get some time.

[onion86]

Resurrecting an old thread, but so far had 500 EML free miles, which based on how I was going before the replacement is a lot to go without an issue! 

[magic_alex]

Digging up an old thread I know but curious to know if this did solve the problem once & for all? I'm having the same off again on again P1349 fault code mainly when doing motorway cruising speeds for longer than 30mins. No apparent effects to performance or fuel economy so not hugely worried just annoyed at the EML!

[onion86]

Digging this back out, it's been 5 years now... But! I've actually had my 'Trip B' tracking ever since the work, this weekend it just ticked over the 9,999 and back to counting up from 0, no EMLs since it started. So, I think I'll finally say this is fixed now

[paulj]

I used your "how to" on this as a reference when i changed my cam cover gasket.  It gave me the confidence so thanks very much.  Really glad the full fix has worked for you