[PickNick]

Hello,
I have a 1967 Impala, 350 small block engine, attached are pictures of my distributor. A few months ago I noticed some ticking when I accelerate so I checked with my mechanic, he said it was my distributor making adjustments and the ticking isn't/wouldn't affect anything. He stated the change in weather is what causes the distributor to make it's adjustments. A few months passed and I noticed the ticking happened every time i accelerate regardless of the weather (cold or hot). I couldn't find anything online stating this is normal, however I took my car back to the mechanic, we went on a drive and he said the ticking is the distributor making and adjustment due to the weather. He mentioned that we could adjust the distributor and get rid of the ticking, however it would have to be re-adjusted again when summer comes around. He mentioned that the ticking wouldn't affect anything so if i leave it as is then there wouldn't be any issues.

My problem is that it doesn't make sense to me - we live in California so the weather is pretty much the same year round. The ticking noise is happening whenever I accelerate regardless of the weather (cold or not). It doesn't happen when I accelerate in neutral or park. If this is normal and won't affect anything I rather not make any changes, however my gut tells me this doesn't make sense as it never happened when I first built the engine. I have about 25K miles on these spark plugs (and engine) so I thought maybe i should change the plugs, distributor cap, rotor and ignition wires to give it a tune up and hopefully fix the problem. Any input would be appreciated. Attached are pictures of my distributor. I'm just wondering if this is a normal noise like my mechanic said; if it is can I leave it as is (keep driving my car daily) without any issues, or should I be worried? I've taken 2 trips cross country with this noise and had no issues with performance or gas mileage.

p.s. wanted to mention that the more I accelerate (higher RPM's) the faster the ticking gets - and if I leave it on a steady pace of acceleration the ticking goes away, however if I increase acceleration (RPM's) it ticks again until I leave it at a steady pace.

Thank You.

 

[Big Dave]

Time for a new mechanic. Your HEI isn't making the ticking sound. It is most likely in your valve train, or detonation but I haven't heard your ticking noise. This is the problem with diagnosing a problem over the web. Things that also make a ticking noise are a cracked fan belt, a cracked flex plate, a bad or flat lobe on your cam, piston pins, worn rod bearings, something touching the driveline because a of a broken motor mount or a broken transmission mount, a bad universal joint. The list goes on and on and it will take an experience mechanic who knows it isn't the weights in the distributor making the noise. If the distributor is in some way ticking and still running it is because it is worn out and the rotor is contacting the electrical terminals in the plastic cap.


If the guy thinks the distributor ticks advanced your initial timing too far it will be setting off the ignition sequence too soon and the explosion in the chamber is trying to push the piston back down the cylinder as the crankshaft is trying to push it back up. This causes the piston to be hammered which makes a sound that is loud enough to be heard inside your car while driving. Detonation breaks pistons which leads to holes poked through your engine block.

Big Dave

 

[dadstoy]

If the distributor is making the noise, It needs to be dissembled and inspected and possible rebuild. Like Big Dave said, Lots of things can make a ticking noise. Have it checked out by a REAL mechanic, Not someone that thinks a ticking sound in a engine changes with the season. I say its the season for a new good mechanic.

 

[PickNick]

haha... Thanks all, appreciate all the info. I took your advice and took the car in this morning to a local shop to get a 2nd opinion and 2 different mechanics said it's not the distributor or I would have other problems. They are convinced it's an exhaust leak. The owner of the shop said he bets it's the gaskets on my headers (ones that go between the headers and engine block) since they looked burned (that I should change them every 6 months - that doesn't make sense to me), however they could run a smoke test for $60.00 to confirm (which I didn't do). He said it would cost $400.00 to replace the gaskets on my headers! I went back over to my regular mechanic and we pin pointed the leak to the one of the gaskets on my exhaust system (not the header gaskets - it's the one on the bottom of the car that connects my headers to my exhaust system). You can feel the air coming out from the exhaust if you put your hand under the bad gasket when you plug the exhaust pipes in the back. I'll be swapping out the gaskets this week and we'll run a smoke test (for free! at my regular mechanic) to see if there are any other leaks. Slowly, but surely we'll find the ticking noise - but all 3 of the mechanics that have looked at it said it's not something that will leave me stranded anywhere.

Regarding getting a new mechanic; all my family has been going to this guy for 20+ years and never had any issues. He's a good dude and doesn't even charge me for certain things. Nonetheless, it's just hard to get a good mechanic that REALLY knows (and has the time to deal with) older cars, plus I just get really uneasy when I think of anyone except myself or him working on my car cuz people never take their time and put **** back together right on an old car that has it's own home made mods (last time I went to another shop I ended up re-doing the job myself outside my hotel room cuz the shop didn't secure anything properly). You just get a feeling when you talk to someone how they're gonna treat your car; I don't even know any of you and I can honestly say I'd trust you more on my car than any of the mechanics around here! Sorry about the long post and thanks for the help!

Thanks!

 

[PickNick]

Time for a new mechanic. Your HEI isn't making the ticking sound. It is most likely in your valve train, or detonation but I haven't heard your ticking noise. This is the problem with diagnosing a problem over the web. Things that also make a ticking noise are a cracked fan belt, a cracked flex plate, a bad or flat lobe on your cam, piston pins, worn rod bearings, something touching the driveline because a of a broken motor mount or a broken transmission mount, a bad universal joint. The list goes on and on and it will take an experience mechanic who knows it isn't the weights in the distributor making the noise. If the distributor is in some way ticking and still running it is because it is worn out and the rotor is contacting the electrical terminals in the plastic cap.


If the guy thinks the distributor ticks advanced your initial timing too far it will be setting off the ignition sequence too soon and the explosion in the chamber is trying to push the piston back down the cylinder as the crankshaft is trying to push it back up. This causes the piston to be hammered which makes a sound that is loud enough to be heard inside your car while driving. Detonation breaks pistons which leads to holes poked through your engine block.

Big Dave

Dave, just curious for my own knowledge... How can you tell I have an HEI distributor? Also, based off of the picture could you tell whether I have an electronic ignition?

 

[Big Dave]

Dave, just curious for my own knowledge... How can you tell I have an HEI distributor? Also, based off of the picture could you tell whether I have an electronic ignition?

You have the "Big Cap" coil in cap HEI distributor in use from 1977 up through 1992. If you have an Ignition Box you could follow the wires from the coils back to a box (it could be a Red MSD ignition box if it is a six or seven series, Black if an Accel/Mallory six series ignition box or blue if a repackaged GM ignition box That buy their parts from MSD).

Not all high energy ignitions (HEI) distributors use an ignition box (in fact few do). An ignition box makes starting easier, removes high speed misses, and offers a lot of capabilities to control or custom tailor your ignition needs. But they are expensive and require a little bit of electrical knowledge to wire one into your ignition without blowing up the ignition box.

Big Dave

 

[PickNick]

Dave... thanks for the info...

I swapped out both gaskets that connect my headers to my exhaust pipes and the ticking noise went away. Thanks, everyone, for your help!

 

[Scott Liggett]

An easy way to check for where you have an exhaust leak is using a 3 foot section of vacuum line like a stethoscope. Put one end your ear, then run the other end around the headers at the heads and the collectors (where yours were leaking). No putting your hands right next to very hot pipes to get burnt trying to feel the exhaust pumping out of the leaking area. The noise in your ear will get louder the closer to get to the source.

Your neighbors may look at you like you are some kind of nut doing this, but you will be saving money paying a mechanic to do a "smoke test".

Yes, a good mechanic is hard to find.