mkmbt

Hello. New to the forum and have a 1993 SC400 with 36,000 miles. I have noticed an irritating ticking coming from the engine ( near the valve cover as best as I can tell) at idle that increases with RPM. Additionally, when I am driving the car I can hear this fluttering noise that increases with engine speed. I do not know if these are the same sounds. If I have the window open, I cannot really hear either of the sounds. Lastly, when I accelerate quickly, near WOT I can hear this rattling noise that I initially believed to be pinging, but now I'm not so sure.

Has anyone else experienced these types of noises with their SC400? The noises do not seem normal and I would think a car of this caliber and with so few miles would sound like a well oiled, quiet machine. Any help would be greatly appreciated. Thanks!

JBrady

WOW, only 36,000 miles on a 93!!! that is only 4500 miles a year. Regarding the noise, could be many things, exhaust leak, hydraulic valve lifter/bucket, loose spark plug, arcing plug wire, bad accessory bearing, bad belt tensioner, debri, etc. If you do in fact have detonation under load you need to have the car professionally serviced and diagnosed. You are running premium, right? Good luck and let us know the problem when you do get it diagnosed.

SuperSoarer

Does the sound leave after the car warms up?

I used to have a similar problem with my old car (97 Grand Am V-6) Apparently some of the oil gunked up and was causing the lifters to stick. A 120 dollar engine flush cleared the problem.

mkmbt

Thanks for the response.

Yeah, the previous owner (my pops) had a roundtrip commute of about 1 mile everyday from 1993 to October of last year. I actually have put 5,000 on it in the past 6 months.

I am running premium (93 octane) and I have had the car looked at by a couple of Lexus dealers and an independant place. No luck so far in determining the problem.

There doesn't seem to be any reduction in performance, as the engine pulls strongly without hesitation. If it was the valve/ lifters, would there be a corresponding reduction in performance of the engine, or would that be manifest as merely an irritating noise? Again, thansk for your help and suggestions.

mkmbt

Supersoarer,

Actually the sound is constant cold engine or warm. I am going to have it looked at again tomorrow morning and hopefully get to the bottom of this. Thanks for your help!

FastSC300

no the tick will not hurt the cars performance at all, just annoying as hell.
Could be expensive to fix though, I remember the part for my 300zx was approximately $20 and the labor was $800!!

needless to say I tolerated the tick!

Scot Hail

JULIAN

Actually what you may be hearing especially if the ticking increases as the rpm increases is the fuel injector cycles open and close. If that is what it is, it is normal, the Lexus engine is probably so quiet and smooth that something has to make noise.

FastSC300

True injectors will tick but they will not tick loud enough to be pronounced, over the normal engine noise. If the tick is very loud and sounds like a tap tap tap then it is something else. It is hard to diagnose this problem since it is internal and does not hurt performance in any way.

Whats weird is the fact that the motor only has 35,000 miles on it. And toyota motors aren't known for tappet or lifter problems...weird, maybe it's because the car has not been drivin enough!


Scot Hail

SQ-LS

I have a tickin' noise on my LS4 and the guy at the dealer said it is most likely my header or exhaust has a small leak. It gets louder the harder I rev. I figure no biggy in fixing it right now so I let it be.

mkmbt

Thanks to all of you for your assistance and suggestions. I know I should probably just live with it, but I find it difficult to ignore the sound. The car is really quiet otherwise, so I think that makes the ticking sound seem more pronouced. I also have a 1998 Nissan Maxima with an engine that is nearly silent when idling and makes a lovely ripping silk noise when accelerated hard. My SC400 engine would sound great if not for the ticking. I wonder, if because the previous owner had such a short commute, that the engine rarely had an opportunity to fully warm up, thereby sludging the engine or injectors. Any thoughts?

MISURA

My '92 SC400 has been ticking ever since I bought it. I had Lexus check the engine before I bought it and they said it was OK. Since then I have had 2 other dealerships tell me not to worry about it, although one said to consider a valve adjustment in the future.

I have driven 45000 miles since purchasing the SC400. It annoys me everyday but I just put my right foot down and ... .