I have a 2004 ls and recently in the real warm humid weather I have had some rattling at start up. This has happened twice and is like 5-6 low rattles. This am colder temps no problems.

What am I in for. I run premo most regularly and drive 80-90-120 on occasion as I know the 45 mile trip to work like the back of my hand.

Usualy some thing like this can be inadequate oiling on the top of the engine at start up? I am kinda pissed off about this. What tests can be done to assess the problem if it continues. CAr has 105 k on it. Thanks Warm

 

My guess is your valve gaps need adjusting (usually this starts around 100K mi or so). The other possibility is the timing belt tensioner is loose or going to go or the belt is going to go (bad...will cause major valve damage). BTW, the timing belt/tensioner should be replaced around 90-100K miles (Toyota conservatively specs 90K with normal driving, but you may need it sooner with your style of driving). While you are in there, have the water pump replaced, as they tend to last around 120K mi. It's only a few more minutes of work. The alternative it to wait until the pump goes bad, in which case you have to pull everything out (serp belt, radiator, timing belt) just to access the water pump.

It is NOT a timing chain rattling issue since the 3UZ engine uses a timing belt. (Timing chain vehicles often rattle for a few seconds until the chain tensioner has tightened due to increasing oil pressure from the oil pump)

 

You speed demon you... smooth isn't she? You probably don't even feel her breathing heavy at 90 mph.

 

I just like to drive er fast, I am sure they will get me some day but I am going on 50 k since i bought er without even a warning.

Options include the valve gaps beign to big, I was told they rarely have this problem.
This is not unheard of even on the new cars on occasion as the oil takes a bit to get to the valves in the heat.
And I can bring her in for diagnostic work to be done. Again i drive this best hard but mainatin it meticulously.

I was told by lexus and toyota they rarely change the tensioner, but I wish I had had it done when i did the belt at a Toyota dealer at 102,000. if it is the tensioner I would ask they go back in on their dime.

Still so much torque and extra high end even at 90-100 or more.

 

Have seen carbon build-up on valves/pistons cause that too....might try a good de-carb service first...

 

90mph is effortless in the LS. Keeping it at 120 is hardly a problem either, but not something I recommend doing. The most I ever try to travel is at 100.