deanbrown

Greetings,

I'm almost 1/2 way done with the TB change on my 96 LS, and I'm just not sure what's going on in this respect: With the engine at about 50 degrees past TDC, the L-CAM line is right on top of the left cam, but the R-CAM mark is way forward, on its way down to the crank - see red arrow. (The white line on the R cam is just dust, btw, nothing more).

Am I missing something here? Aren't they both supposed to be on top of the cam pulleys, or at least on them somehow? I can't see them both being on the pulleys at the same time in any orientation. See pics.

This belt was installed by Lexus 100K miles ago.

PureDrifter

iTrader: (10)

i might be mistaken (so double check in the repair manual) but doesn't it say that if the belts dont line up to rotate the who shebang 180-360* to complete the cycle and then it should (or something along those lines)??

lex2001

If you didn't move the cams after you took the belt off and you are putting the belt back on in exactly the same position as you took it off you are okay. If the cams have been moved you have to rotate them back to their starting position (see attached tutorial) The first time the belt was put on at the factory all of the marks lined up but as soon as the cams moved the marks on the belt no longer will line up. I don't know how many rotations but I think it is only a couple.
http://www.lexls.com/tutorials/engine/timingbelt.html

randal

You cannot go by the white belt markings if that is what you mean. Go only by the alignment marks on the engine and pulleys. And as mentioned, the cam marks line up every 2 revolutions of the crank. The belt markings are only useful during initial install.

I have DIY photos for a 98 LS400 that may help(note: no distributors)
http://www.flickr.com/photos/landar/...7622883357340/
http://www.flickr.com/photos/landar/...7622886015670/

BTW, sure looks like your PS pump is (or was) leaking on the alternator a lot.

deanshark

Are you talking about the old belt, the one that's 100K miles old? If so, once the engine spins it will never again line up the white lines on the belt to the timing marks on the pulleys. Even when you put a new belt on and spin the crankshaft twice around to see if the timing marks are right, the lines on the belt wont be in the same spot. The important thing is that the timing marks on the crank and cam shafts all line up. I think you should fix that PS fluid leak before you get stranded somewhere b/c it leaks on the alternator which is just gonna kill that.

billydpowe

iTrader: (1)

my 97 came OFF like this; first photo (we moved NOTHING)
and went on like this: second photo.
we lined all 3 marks up BEFORE removing the old belt,
and the new one went on the same way,
so why do you say they will never line up??
we have done 5 of these, just like this.

deanshark

Here's a tutorial from lextreme.com and it's done on a 96. It's pretty much the same as the one from lexls except for the 50* after TDC. http://www.lextreme.com/timing.htm The most important thing is to line up the timing marks before removing the old belt. And seeing how you mentioned it you already know that it needs to be 50* after TDC. Idk exactly why that is b/c I have a 93 and that doesn't apply to mine, so I never read up on that. If you're not sure about something just check out all the tutorials and directions that you can find. I don't think the 98 and up tutorials will help (the links randal posted) b/c the timing marks are different but at least ya have the rest of the tutorial as a little reference. Any other questions, just ask.

billy; Yes, if you take off the old belt and put it back on, the white lines on the belt will line up to the timing marks on the engine and pulleys. (as long as it didn't stretch) What I meant was with the belt still on, and the engine spins, those lines wont match up to the marks. But, those lines don't really mean anything anyway, as long as all the timing marks are aligned.

deanbrown

Thank you all - great support!

Those pics of mine are the old belt, I have not removed it yet.

Still don't see why the belt and marks won't line up again, sure don't make sense to me (but I have to concur that they don't line up!) but I will make my own markings before removing it.

billydpowe

iTrader: (1)

HAY, let me explain, we lined all 3 marks up BEFORE removing the old belt,
the "marks" are the marks on the cam gears and the engine, plus the crankshaft.
NOT the belt marks ..

deanshark

Correct. The white lines on the belt are only used for the 1st time you put on the new belt. This last T-belt I did on my 93 (my 2nd belt) I didn't even match up those white lines on the belt, I just made sure all the timing marks (engine and pulleys) lined up.
Dean; (it feels weird writing that name) b/c you're putting on a new belt, you don't need to make any new marks on the old belt itself b/c the new belt will have the white lines to help you line it up. Are you also changing the crank and cam seals? (recommended) Also, while you have everything off, you might as well take off and clean the IACV valve on the front of the engine, you can get to it now.

billydpowe

iTrader: (1)

YES! do the seals, even if not leaking, too cheap not to do it. (until you get a 98+)

deanbrown

Ok it must have been too late last night but it just dawned on me and makes sense (why they don't need to line up with every belt rotation).

Dean I'm not sure what is the IACV valve is - don't remember it being mentioned.

PS fluid is never going down, is it possible that the leak is somewhere else around there, like the RHS cam seal? I still gotta pull off a few things before I can see more.

deanshark

The IACV (Idle Air Control Valve) is the black cicular thing right in the front center of the intake manifold. There's usually carbon build up inside it which eventually will clog and not open correctly which will not let the car idle. Just a thought now b/c it's buried behind everything and easier to get to now. Also called an ISC; https://www.clublexus.com/forums/sc-...on-issues.html
All that fluid on the alternator looks like PS fluid. The PS pump is right above the alt and most leak. Mine leaked from an O-ring on top and toasted my alternator.

dashan

10 characters.

Kailash

I found out this means degree in timing could I get a better explanation on this and if the white mark shown is where it should be?