Help diagnosing tapping noise...

[91boost]

98 GST 71k miles, had the car for 2 months. Today I noticed a ticking/tapping sound. It doesn't seem to be doing it at any other time except at idle. It's more like a "tapping" sound than tick. Its not coming from under the valve cover or timing belt cover from what I can tell(I did the old school screwdriver to the ear trick). It's not consistant either. Evenly spaced "Tap tap tap tap tap tap tap..." then it will stop for a few seconds, and then repeat. It is somewhat loud, but not obnoxiosly loud. It's not very fast either, IOW not at the same speed as the engine.

Any ideas? (BTW, I am new to the DSM world- but not new to cars by any means.)

Thanks in advance,

Mark
98GST
91 MR2T

 

[Glarth]

kinda sounds like 'lifter-noise', from what i understand the stock lifters are a little weak and over time will start 'ticking'.

 

[AdoreGSX]

is there a fix for this, how much is it usually...mines doin the same...

 

[Slipstream]

If indeed it is lifter tick you can try changing to a heavier weight oil like 10/40 instead of 10/30. For some people this works. You can clean the lifters. You can replace the lifters.
For oil changes or cleaning them the lifter tick almost always returns in time...and new ones only buy you more time as they too will tick after enough use.

 

[yoshimitsuspeed]

I have a fuel injector that did that for a while.

 

[91boost]

So it doesn't sound like crankwalk?

I am going to once again try to locate exactly where the noise is coming from......

On the subject of oil, about 1k ago I switched to Amsoil 5-30. Maybe I should goto 10-30?

 

[Seattle GST]

there were posts awhile ago about a product called Seafoam that was used to clean the internals and cleaned out the injectors.

I dont remember the article exactly, but try a search for it.

 

[v2ner]

seafoam and mopar combustion chamber cleaner.......these products work to clean the engine internals but it only lasts for so long. i run 10w 40 on my sixbolted 97 and 10w 30 on my 95 GSX....and they both tick now. i cleaned them both w/ MCCC but it soon again returned. no....crankwalk sounds diff.....and from my experience, there's usually bits of metal on the oil on ur dipstick.

 

[91boost]

there were posts awhile ago about a product called Seafoam that was used to clean the internals and cleaned out the injectors.

I dont remember the article exactly, but try a search for it.

I use Seafoam on my MR2 religiously, but I'm not sure it will help with this problem. I'll pick up a can and check.

Any other ideas?

Thanks again....

 

[91boost]

no....crankwalk sounds diff......

What does crankwalk sound like then? Anybody got a sound file out there of an example?

 

[FORMONTOYA]

i have a 98 gs-t and during the hottest part of the summer (in houston, tx) i also have a tapping (not ticking) sound also. i have found that this is comming from the trans area. thought it could be crankwalk and had it checked out a couple of times but no diagnosis. no other simptoms of crankwalk either. i have had the car new since nov. 97 (9 miles when i bought it, 93k on it now) and it has done this every summer since (usually around july and aug), then it goes away until next summer. probably does not help you conscience, but this is what mine does.

jim

 

[x camaro owner]

so crank walk makes a noise you guys say. interesting i have seen cars where the cranks walked 1/4 inch and still no noise hmmmmm i smell bs here

also whats the difference between a tick and a tap or a wap or clank wizzzzzz or pisssss you guys are so funny

there is an easy way to check for crank walk, try to diagnose something under the hood while your friend is dicking around with the gas cuz he thinks the exhaust sounds so cool. thats how i caught the crank on accident you will see the crank walk out or, you could be a paranoid screw ball and use a feeler gauge

 

[91boost]

so crank walk makes a noise you guys say. interesting i have seen cars where the cranks walked 1/4 inch and still no noise hmmmmm i smell bs here

also whats the difference between a tick and a tap or a wap or clank wizzzzzz or pisssss you guys are so funny

there is an easy way to check for crank walk, try to diagnose something under the hood while your friend is dicking around with the gas cuz he thinks the exhaust sounds so cool. thats how i caught the crank on accident you will see the crank walk out or, you could be a paranoid screw ball and use a feeler gauge

From the documentation I have seen, every car with crankwalk issues has made noise(from the crankshaft position sensor trigger plate rubbing on the crankshaft position sensor. No BS....

There is defintely a difference between a tick and a tap sound.

There is no way the human eye could see crankwalk. Documentation shows the allowable clearance (axial movement of the crankshaft) is .002-.007" with the max limit being .010". The distance for the trigger plate to make contact with the crank position sensor it is around .030". Feeler gauges are the best way to tell besides inspecting the actual bearing itself.

I am doubting it is crankwalk in my case, but I wanted to get all the opinions I could as I am inexperienced with DSM motors specifically.

Thanks for all the input guys, and keep the suggestions coming. They are appreciated.

 

[x camaro owner]

you think i am kidding an engine building speed shop even looked at it and yes it was about a 1/4 inch yes it does happen so much for what you read about crank walk but yes it can get that bad.

tough crap but it happens we caught it early enough before the cylinders got to far out of round and the motor was rebuildable one more time

granted the cylinders had to be bored quite a bit

 

[yoshimitsuspeed]

I run 10 w 30 Amsoil in my gsx and my lifter tick is pretty bad.
When you rev the motor it should get better or go away altogether.
My fuel injector sounded a lot like very loud lifter tick.

And I do belive it is reqired to be able ot diagnose and differenciate a
tick
knock
thump
whir
wiz
clunk
and rattle
before recieving your ASE certification

 

[Defiant]

so crank walk makes a noise you guys say. interesting i have seen cars where the cranks walked 1/4 inch and still no noise hmmmmm i smell bs here

Take a sniff of this:

http://www.roadraceengineering.com/eclipsetech/crankwalk/2gcrankwalk.wav

 

[x camaro owner]

it doesn't always have to make a noise you ###

it was a 69 barracuda should have mentioned that

 

[91boost]

Take a sniff of this:

http://www.roadraceengineering.com/eclipsetech/crankwalk/2gcrankwalk.wav

Defiant- if that really is the sound crankwalk makes in the .wav file you posted, then that is definitely NOT my problem.

It must really be lifter tick, even though it doesnt sound like it is coming from under the valve cover.

Any other suggestions?

 

[67goatpimp]

Take a sniff of this:

http://www.roadraceengineering.com/eclipsetech/crankwalk/2gcrankwalk.wav

Sounds liek a cowbell. Moo..

 

[Slipstream]

Sounds like an amature working a metal lathe :laugh:

 

[L2RTSiAWD]

it doesn't always have to make a noise you ###

it was a 69 barracuda should have mentioned that

Hmmm, openly attacking and insulting moderators, you just earned a weeks vacation.