Chasing a ticking noise!

[OldGrayII]

What it is, is a muted Tick-Tick-Tick at about 800-850 rpm ONLY after warm-up and can BEST be heard from the driver side, UNDER the car, NOT under the hood!! If you rev the motor its GONE, put it in drive (650rpm) its gone, ONLT at a steady 800ish idle can it be heard.
O.K., I figured when I bought the car that it was exhaust related as the previous owner put a full 3" ATR Stainless exhaust with high flow cat & 3" Houston downpipe and didn't band clamp the connections, I exhaust wrapped and band clamped ALL the connections, welded the driver side crack, and its STILL there - An after the motors warm Tick-tick-tick I have GOOD oil pressure (22 PSI HOT Idle) and its a pretty tight 60,000mi original motor, the previous owner had Cotton install NEW valve spings, and Cotton also did the rear main seal. I did the stephescope and its NOT valve train related- IT IS from the very back, bottom end- Almost torque converter area, and YES, I checked and tightned ALL 3 torque converter bolts!!

Now....Ideas......

 

[frankg]

Possibly in the tranny pump or convertor??? Frank

 

[OldGrayII]

Ya know, I though that for a minute, but this tranny is tight & shifts PERFECT (Full throttle & normal driving), When I changed the fluid it looked GREAT, and there was no residue on the magnet!

 

[OldGrayII]

ttt-Come on now...Ideas???

 

[FlyinGN]

the only thing I can think of is loose flexplate bolts or a broken torque converter Brian..Checl all the bolts.. The TC to the flexplate AND the flexplate to the crank..

 

[machinegun]

I would check the tranny stuff as above but would really start looking towards the exhaust. The drivers side header is well known for cracking between the number 5 and 3 cylinder. My cracked and did not make hardly any noise. Starting to go away with heat makes me think you should start to look in this area. As the metal expands it will sometimes help the sealing. Look for this and let us know what you find.

 

[OldGrayII]

Originally posted by machinegun
Starting to go away with heat ...........

Actually, as I've said above, its just the OPPOSITE!! Its VERY quiet when I first start it-or its cold-its after its warmed up that I get it!! I'm sending an oil sample to Amsoil this week, then we'll know FOR SURE!!

The previous owner before me - He bought the car off the original 72 year old owner in November of last year - A board member-Crow44- He had Cottons do the Valve Springs & WELD the Driversside header & do rear main seal - He (Crow44)ALSO put on the 3" exhaust, TH downpipe, Adjustable Wastegate - What he DID NOT DO was to put a fuel pump in it, and NO BOOST guage, and ZERO scan tool !!!!! When I drained the fuel out ogf the tank with the ORIGINAL 16 year old pump, it came out in a very slow stream(tired pump), it, OF COURSE, now has a Walpro pump in there (shoots out like a fire hose!) What I'm afraid of is that he HAMMERED this mint 66K motor- And took out a bearing or something! Its amazing that a head gasket never went, but, there ya have it! For now the Tick is "muted" so I'll leave it alone!

Anyhow....I just answered my own question!!

Thanks for listening!

 

[OldGrayII]

After Blueprinting my front cover, while off doing the Timing Chain, this noise has only gotten (slightly) worse instead of better - ie., MORE oil pressure and volume from the better gears and plate!

I was told by a local engine builder (Dave Hentz) that its the side clearance on the Piston pin(s) and that there was even a Recall on this from GM (although I could'nt find it! Under ANY kind of a load its GONE-No noise at all, comes back to an Idle and there it is Tick Tick Tick - Again, ONLY when warm, and ONly from underneath, and YES, I've checked the Converter bolts NUMEROUS times! Ideas....

 

[Jimn8or]

Put your stethascope on the cam-sensor cap, you may be pleasantly surprised.
Jim

 

[OldGrayII]

Arrrggg...Although I DO appreciate your reply Jim, this noise is, as I keep repeating in every reply.... "After the car is TOTALLY warmed up, 10 to 15 minutes at least..before the noise appears".....Cam sensor noise is JUST the opposite AND comes from the front, NOT underneath near the converter! As well as the cam sensor is new.

Sorry to sound harsh but I'm really frustrated!

 

[MSDGN]

Got the same noise on my GN which only has 34K miles...never
raced at the track...just street duty...replaced just about everything I could think of but no good...even disconnected the torque converter and ran the engine...same thing...only happens when the engine is at operating temp and idling...give it any gas and it goes away...it could be piston pin clearance but I'm more convinced it's a little rod slap...I remember reading something some time ago about rod slap in these motors...I 've had this going on for about 7 years now with no problems so I just ignore it...if it was anything major I think I would have found out by now...I run 22 PSI boost on it and have been for years...oil pressure is very good...I did try something a couple of weeks ago...put in MOBIL 1 15W-50 as opposed to 10W-30...then drove the car around to warm it up...when I got back home I couldn't
hear the tick...the fan was running on high which usually mutes it somewhat but I really couldn't make out the tick sound which I could before...I'll try it again when it cools off a little and the fan isn't running...I don't think it's a bearing going...I know mine isn't otherwise my oil pressure would have gone down over the years and there would most likely be some metal in the pan...I've had the pan off 3 or 4 times and it's clean as can be...if I were you I'd just live with it but keep an eye on the oil pressure...

 

[FJM568]

I know you said you checked the torque converter bolts and tightened them, but you might want to check and make sure that the flexpate isn't cracked...That is also a cause of ticking back there...It's more common for the bolts to be loose, but I know someone local that had a cracked flexplate...

 

[John Larkin]

I was convinced I had a lifter problem, but after replacing the stock injectors, the noise was gone. #5 injector was really loud, and like you say, only heard from the driver side, and not from under the hood. It was amazing to sit in the seat and the car be quiet. Likely not your problem but it was wierd.

 

[OldGrayII]

John,

With the Injector ticking, was it loud all the time, or ONLY after a warm-up?