Update is the exhaust camshaft scissor gear backlash was not properly set after the camshaft seals were replaced. Sound legit?

Compression test had everything around the 150 psi mark. All but one were within a few psi of 150. That one was around 160 psi.

 

That's a possibility.
If you look at this video, starting at 17:30, you can see that the exhaust camshaft uses a split gear to prevent noise, and ensure the teeth engage consistently. There is a spring in there and when you replace the camshaft you have to get the gear in the right position.


Chip H.

 

Picked up the GX this evening and still detect a slight clacking sound...particularly on the drivers side. The mechanic said it was the injectors. It sounded loud at the shop but was hard to compare to the first 'Before' vid until I was able to record another and put them side by side.
Thoughts?

 

Duplicate post

 

...yes that does not sound right.
The scissor gear, (one on each bank) should of had a service bolt in place for the cam assembly removal and install.
sound like the service bolt may not have been removed on bank one.
Below is a link on this discussion...
https://www.clublexus.com/forums/ls-...vice-bolt.html

 

Thanks! I think this is exactly what the problem is.

 

For your sake I hope that's what it is.
It sounds like it.

Definitely pull the valve covers, or maybe have the shop do it if you still trust them.

Btw there is no adjustment for that gear.
It can also be that a service bolt was never used and the scissor gear was not correctly lined up. If that's the case the cams need to come out again.

GOod luck

 

so I just purchased an 06 GX with 169k miles and looked through the carfax history and on the lexus owners website and couldnt find the timing belt service on there
I took some pictures of the timing belt with the cover slightly removed would you be able to tell if the timing belt is original or has been replaced ?

 

That looks original.

 

I agree. Plus, if there's no documentation (receipts for the labor + parts, sticker on the housing, tool marks on the bolts) you should assume it hasn't been done.

I have a non-VVT-i so I don't have the label with the Japanese printed on it.

Chip H.

 

Even if the original was changed at the service interval (90K miles) and you are at 169k miles, that puts you at 79K miles on your current belt which means you are due for a belt change in 11k miles anyway.

 

yeah thats true would the timing marks with the marker still be there even if they didnt change it?

 

Timing marks are really not needed to swap the belt.

You mark belt tooth on cam and crank gears, mark the mating neg-tooth on gears. On the belt marks add a label "LC" for left cam near that mark, and then put an arrow facing fwd or rear for positional reference.

Layout old to new belt tooth for tooth, transfer all the marks with arrow. Check and recheck marks against the old belt marks just to make sure they are 100% correct.

Install new belt by aligning marks to gear marks with arrow the correct way. If the gears moved slightly then you can easily move it back to match the belt marks, etc.

 

I have no idea if the factory marks timing marks with a marker when the belt is put on a newly assembled engine. That would be a good thing to know so if the factory does not mark timing marks with a marker and you see timing marks, you know the belt was changed at least once. Now I understand you were identifying the yellow markings in some of your pics.

 

I’m glad I ran across this, was wondering about my timing belt also. I bought my truck used at 55,000 miles in 2012 and it has been the Best vehicle I ever purchased against my 2014 Mercedes GX550 that I recently sold. Mercedes looks great and are known as one of the top luxury vehicles well built, but I put more money into Service A and B than I ever put into my Lexus. Unfortunately, I have yet to change the timing belt because it has been such a reliable SUV. I’m currently at 246,000 miles I have been using regular gas in it since I bought it with zero incidents, and the most I spent on this SUB were for brand new tores which cost me back in 2018 $1200 for all four mid grade tires. Although, I had a loaded Mercedes HX 550 with heated seats front back full package including both headrest individual playing DVD players third row seats automatically trunk, and automatic back seats that folded at the push of a button, I put over $8000 into fixing problems from the previous owner who just bought it off the lot and drove it 55,000 miles without changing anything in it under the hood. I also had to purchase new tires costing $1500 I only had it a year and put over $10,000 into maintenance not including my down payment of $2500 all in one year of owning it.
I refuse to take a free Mercedes from anyone over my 2003 Lexus any day. The most reliable SUV even at the age. I hope this helps someone.
Finally, I will be looking into a new timing belt soon, since I have been pushing it. 245,000 miles down and still rolling!!!