i just changed my plugs and i noticed the little ticking sound i thought the plugs werent gapped right so i took them all back out made sure and tightened everything back up but the ticking remains. so i just chalked it up to the injectors or the plugs firing b/c thats what it sunds like. icant really tell with the exhaust making noise also in the engine compartment. i know im not paying anyone to do a valve job b/c i can only hear it if i pop the hood and listen

 

Lex ,i am not being sarcastic unless you were the person who did not tighten the plugs in the first place.
I am just making a factual statement, there are tons of possibilities of the ticking and a plug being loose is not one of them that pays very high odds.
Changing your oil has more significant impact than this can make to every LS400 owner.
Would you come to the assumption that everyone driving a car has a loose plug in there car?
The answer would be no just like the only reason you had a loose plug was because some moron forgot to torque them properly.
If everyone had a thread that had very little pertaining to the actual root reason for posting the forum would be filled with stickies and no real posts .
It is an idea to look at but like i said ,it should have been looked after before not at the same point.

A guaranteed way to reduce noise is to use an engine flush before changing oil, then follow up with a thin 0w-30 synthetic oil until the next change.Then filling it with a higher viscosity like 20w-50 which would reduce the valve slap noise associated with the noise. It then makes it much easier to narrow down where exactly it may be. This is done by less ambient background noises from the valves or point right to the valves .

 

You're right there could be a number of reasons why the ticking exists, but if someone comes across one solution that has not been listed before in any of the forums don't try to knock it. It's just one added step to a possible fix. I don't see anything wrong with that. I did it and it worked for me and maybe someone else may have a similar problem. It could be one in a million chance but at least it helped.

 

Same problem on a 96 I'm buying. Ticks with acceleration after a cold start. Goes away when it warms up. Otherwise smooth. Told the Lexus dealer I'm having it inspected at to check the EGR pipe. Sure enough. Should go away after I get it fixed for $500.

 

I agree.
The ticking is typically caused by lifters or by EGR pipe crack. LIfters are the most common culprits. EGR crack can sound like ticking when it is relatively "young". By the time you hear an exhaust leak sound, your EGR pipe is far gone.

The loose plug is a very rare thing to happen. Plugs never come loose if torqued correctly. Lex's case is pretty unique and does not deserve to be stickied.

 

Cost me $70 for the pipe and $50 for the replacement + $20 tip I gave to the guy for not removing tranny to do this. Total: $140 for EGR pipe replacement.

IT CAN BE DONE W/O removing tranny or any other major removals! Don't let your mechanics swindle you out of $500!

 

Too late for me! I think I paid around the same price for mine ($500) from this rip-off mechanic in Brooklyn 2 years ago. Yeah all you have to is drop the exhaust.

 

I have a 97 ls 400, 111,500 miles. I purchased the car last Jan with 101k miles. Since ownership, I have replaced the ps pump...faithfully change the oil every 3k. When I purchased the car from the Lexus dealership, they said the 'ticking' was common among these cars. How can I find out the cause. I really notice the ticking when I drive thru a fast food..like mcdonalds, burger king...or in the garage...when I am in the open, I hear the ticking but not as profoundly...pls advise...also, i get a vibration around 60 mph, in which I have simply decided to ignore...any feedback you can give on these problems would be highly appreciated. The car doesn't appear to be out of balance, and the harmony michelins have plenty of thread on them..

Thanks,

Gwen
c

 

There are two most common causes for ticking:
1. Valves need to be adjusted. I have not experienced this first hand. I also have a 97, but with 160K on the clock. Do a search of this forum for valve adjustment and you will find lots of good info.
2. EGR pipe cracked. This is detected by lifting the car and listening to exhaust near Catalytic on the passenger side. In the later stages,as the crack grows, you will notice the ticking being loud when the engine iscold and deminish when it worms up.

Good luck with it.

 

Does anyone have experience with changing the EGR pipe diy? Or is this something better off for a mechanic?

 

its not hard just a pain to get to the bottom part.

remove air box and tubes.
i think its a 12mm or 10mm more likly.
need wrench
extention
let me know if u have any other problems

 

I recommend to take it to the mechanic.
It's hard to get to even with a lift. Without, you will kill youself...
Also, if you break a bolt, you will need to take it to mechanic any way. Those bolts are pretty rusty, since it is exhaust and it gets corroded a lot.
Don't take chances...

 

u actually dont need a lift

 

If you dont have to worry about some emissions testing, you can always block it off....

 

I had similar problem. Harder to start than normal and noticable loss of power when excellerating. Went to change spark plugs and found #5 plug very loose. Happens to be on side were oil is filled. Had oil residue around plug and carbon fouling of plug. Considering how loose the plug was, suprised the engine ran as well as it did. Plug and wire change fixed problem.