Clicking or Ticking from Engine?

[Nightsabre]

When I start up my 1994 SC400 there is a continually ticking or clicking sound from the engine when I open up the hood. It is a rather quick and to me it sounds as if a specific component is rotating and tapping on something. But when you rev it the sound just seems to disappear completely and when you let it idle the sound returns. I have used a mechanics stethoscope to determine where it is loudest. Unfortunately I am not too familiar with engine terminology. I have seen a full diagram of the engine but cannot find it now. If someone would be able to locate a diagram for me I can point out the part. Does anyone have any ideas?

 

[stevechumo]

There're many reasons for the ticking sound. They could be the belts, starter, alternator...etc. It's very hard to tell the exact problem by not hearing it or looking at it, unless the problem is so common that we've all had before. Take your car to a shop and let them find out.

 

[Glen75]

More than likely injectors or tappets.

 

[Peewee]

Most likely shim gap that is now out of spec.

But it could also be waterpump and/or timing belt idler bearings.
Thats what I suspect is the main cause of the noise on my motor.

 

[Nightsabre]

I'm attempting to gather as many suggestions as possible in order to draw a valid conclusion at the moment and I appreciate all the responses. I will check into some of the not-so-complicated things. At the moment, I will check the timing belts and waterpump first as it seems Lexus tends to have those problems most often as with the other ones we have as well. Also, the engine has 220,000 kms on it.

 

[Lextech]

It is not possible to diagnose noises on a forum but,---The older V8 engines seem to get wear under the lifter buckets on the drivers side on the rear cylinders. If this seems to be where the noise is coming from then you will need to replace the bucket and adjust the valves. PS your drivers side might not be my drivers side--so I mean the side with the EGR valve,left side.

 

[Nightsabre]

I understand it is quite difficult to diagnose sounds, especially with text. I believe I may have heard the same sound on many other vehicles as well, older vehicles to be exact. Would there be any correlation? Any common problems that would arise in all vehicles? In the meantime, I will ask someone to take a look at the suggestions posted here and perhaps they would be able to determine something. Thanks a lot to all of you.

 

[stevechumo]

I understand it is quite difficult to diagnose sounds, especially with text. I believe I may have heard the same sound on many other vehicles as well, older vehicles to be exact. Would there be any correlation? Any common problems that would arise in all vehicles? In the meantime, I will ask someone to take a look at the suggestions posted here and perhaps they would be able to determine something. Thanks a lot to all of you.

You're quite right that diagnosing a noise problem is hard just from text. As I've mentioned, there're many reasons and parts where the noises come from. To help answering your question, you should at least narrow down to a particular area where the noise is likely to come from.

 

[Nightsabre]

would anyone be able to provide a diagram of just the 1UZ-FE engine? I remember seeing one somewhere on the net but can no longer locate it. If so, I will be able to circle the area in which the sound seems to be originating which I used a mechanic's stethoscope to determine.

 

[Nightsabre]

I've figured it out! That sound would happen to be some worn valve shims. Too bad its no DIY job for me. Thanks for all the replies.

 

[Lextech]

The shims typically don't wear. If there is excessive valve clearance, have your mechanic check the bottom side of the lifter bucket for wear where the valve tip contacts the bucket.

 

[Toyotasup]

clicking and ticking noise can come from alots of engine parts on my truck i had the same problem making ticking sound when idleing i got underneath the car listen to the sound was coming very close to where torque coverter and flexplate are mounted so i opened the flexplate cover and rotated the crank pulley and found that flexplate is crack. replaced the flexplate never had the problem again. you can have similar problem or something complete different

Just my 2 cents