Hello to all I need help identifying a ticking noise in my engine and exhaust system. I have a 65 Riviera GS with the original 425 engine and dual exhaust (no crossover muffler). When I rev the engine I hear nothing...when I let off of the throttle I hear a ticking that may be a lifter or a valve and it is in time with the engine RPM. The ticking sounds as if its coming from the passenger exhaust pipe and not the engine. Is the ticking being propagated by the exhaust pipe? No ticking at idle...only at 1500 RPM plus...sometimes there and sometimes not. Strangely, i had the SAME problem wtih a 63 401 Riviera I had a few years ago. I'm thinking its a lifter or an exhaust valve...any ideas or tricks to try? thanks in advance for any help Carl
Use a 4 ft. piece of heater hose and listen to the engine thru it to pin down the area that the noise is coming from....moving the end around from area to area....untill you find where the noise is.... if it is a lifter collapsed, the noise will be one one head or the other and at the rocker arm cover... if it is a leaking exhaust manifold it will be on one side or the other at the exhaust manifold area....naturally you will have to get some one else to slowly rev the engine up and down for you while you do this.... Then you will know how to proceed....if it is a lifter, the first thing I would do is install a qt. of atf in the engine oil and then run it to see if it will get quiet....
Some Riv's were known to have a knock from the return fuel line. Mine does it occasionally. Best to search the Riv forum @ BCA website for more info. Just throwing it out there!
Thanks for all of the input guys. My mechanic suggested Rislone or ATF to see if would do anything...I'll be trying that tonight. The stethoscope idea is a good one too. For some clarity...the car can be sitting still and it ticks with engine RPM. The torque converter bolt issue would seem to make sense as the noise stops ticking when the engine RPMs drop down to less than 1000rpm. Also, the noise doesnt seem to be coming from the top of the engine like a lifter or valve but rather I am hearing it under the car, specifically under the passenger seat. The investigation continues tonight.
Does the car still have the original exhaust damper on it at the pipe to manifold? If so check to make sure the spring is there and complete. When the engine is cold check to see that the plate is operating by moving it with your hand.
I'll check into the heat riser valve tonight and report any progress tomorrow. I'm eager to get the heater hose out to do some sniffing around!
Commonly referred to as the "Riviera Rattle." My dad taught me to use the breaker bar from my socket set to listen for noises. The sound travels through the solid metal much better than through air, and you can more easily identify what the sound actually is - lifter, pushrod, piston slap, what ever. Each has a unique sound.
Years ago; the Roadmaster had a strange ringing, (like a bell) after; riding over a bump. Turned out; it was, the parking brake cable bouncing against the torque tube.
I`d check for an exhaust leak at the heatriser valve. Or, an exhaust leak at the exhaust manifold coming from just one cylinder. Short each of the plugs one at a time to see if the tick goes away. If you pull a plug wire and it goes away the exhaust leak is at that cylinder. Sometimes a single cylinder exhaust leak can sound like a tick. Sometimes even a fan belt can sound metallic in nature. To eliminate that possibility spray some water on the belts one at a time. If the sound disappears the belt could be the culprit. The fuel hammering sounds more like a piston slap, like hitting a hollow coconut. Be careful if you are diluting the oil with an additive. Good luck! Tom Mooney P.S. If your Riv no longer has the dual quads and is equipped with a single four, there is a core plug in the bottom of the intake manifold exhaust crossover passage that sometimes leaks.
All thanks for the interesting input. I've been involved with other non-Buick stuff (gasp) and havent been able to check the operation of the heat riser valve or isolating each cylinder yet. I did put a quart of Rislone into the engine and ran it up on the jack stands for 10 minutes or so. More time with this addititive when I get the rear brake drums back from the machinist and I can get it out on the road. While the rear drums were off and the car immobile, I took the opportunity to pull the rear bumper and the rear wiring harness. The left side bulbs were not working and found to be rusted into the sockets. The sockets were replaced with replacements from NAPA that seemed to be the closest to the originals. The rest of the harness was refurbished and reinstalled and the lights work great now with all new 1157 bulbs. I suggest that everyone checks the voltage at the bulb sockets to see if there is any difference in voltage between them. I found two sockets that were 2 volts down from the others. Corroded splicing was found to be the culprit and new solder joints fixed this problem allowing all of the lights to exhibit the same brightness. More on the engine ticking later. carl
Tom thanks for the information. The car has the original dual quads and runs great. One thing I didnt mention is that the car does NOT have the single cross over muffler...it has true duals all the way back with mufflers at the rear. The ticking sounds like a lifter, valve or maybe the loose bolt on the torque converter as was suggested. I can fire the car and it would have no ticking until I bought up the rpm and let it drop back down. I hear the ticking under normal cruising conditions. Rolling along at 50mph and letting off the throttle gets the ticking started...it will slow with declining engine rpm and then totally disappears shortly before the car comes to a stop. It never ticks in gear sitting at a traffic light. It almost seems like something spinning at engine rpm within the transmission...like the torque converter or maybe a loose bolt on the flywheel. more later
Doc the heat valve is intact but missing the large heat spring that rotates the shaft and the valve. I can replace it or have the rest of the guts removed and have the shaft holes welded shut. Here in San Diego the cars warm up pretty quickly. My other Riviera had the same set up with a gutted valve and welded shaft holes. I will continue to see if I can pinpoint where the ticking is coming from and report any findings. The ticking noise sounds like a small ball pein hammer rapping the exhaust pipe in time with the engine rpm. Could a recessed valve seat cause this type of ticking? I've heard that these heads have valve seats that wear pretty quickly without the lead. thanks
Carl,,,, the valve seats on a nailhead dont wear any more or quicker than any other engine....urban myth.... I am begining to think that... you may have some unusual thing , like a loose baffle in a muffler, or a double pipe that has come loose on the inside.... what did you find when you listened thru the piece of heater hose?????
Hi Carl, I have a similar case with my 455 Ive never been able to figure it out but I have excluded a few things though. http://www.v8buick.com/showthread.php?t=164428
Havent tried the heater hose yet. Robroy sounds as if he's run the gamut of possibilities too. As I said in my previous post the heat riser valve has been gutted and the temp spring removed. I'd like to find another valve to be sure its as original as possible. Anyone know of a source for one? I cant do much with the car until I get the rear drums back from the machinist tomorrow but I may fire it up tonight to let the quart of Rislone circulate through the lifters.
have you crawled under the car and with your fist or rubber mallet give nice firm taps to the exaust and listen for any tinging noises. At the shop i swore i saw one a week from everything from broken baffels to cracked exhaust manifolds. dont overlook the simple things. Paul 66larkgs 401 turbo nailhead
My Riv makes all kinds of ticking noises. I know it has some nasty exhaust leaks, (thanks Midas) and I was looking at the engine and it has no exhaust manifold gaskets or french locks!!!!! Sooo... Keep it simple, look at your exhaust and like doc says, Listen.
Guys Yesterday I had a chance to get the car out into the sunshine and get a new perspective on the problem. My mechanic and I both feel that the ticking is a lifter, a rocker arm or a valce slap of some kind. I did put a quart of Rislone into the engine and ran it about 15 miles yesterday. At about 7 miles into the trip the tick stopped altogether and stayed that way all the way back home...another 8 miles or so. Once there I listened to the engine with a heater hose and could her no discernable noise coming from the engine or enhaust manifold. Afterward, I left the hood open and let the engine cool down for about an hour then fired it back up again and took it for another ride. The ticking returned and was present for the whole 5 mile drive. I'm draining the Castrol SynTec 20W50 with one quart of Rislone tonight and replacing it with new. I'm eager to see if any crap comes out of the crankcase. I'll also pull the plugs to determine if anything is different between cylinders and may pull a compression test on it too. While out on the drive I was able to confirm that the ticking disappears under load and shows up when I let off of the throttle and the ticking is a metal ticking as if someone is tapping on the passenger side exhasut pipe with a metal wrench. more later
