New Ticking Sound

[FiatRunner]

What happened to our famous ticking sound?

I completely forgot to update! I am so sorry.

The new cap and rotor arrived, but when I was installing the new cap it simply didn't fit as well as the old one. it didn't sit snugly on the distributor base, it rocked side to side and there was sliding movement, even when the screws were tightened. The old one fits much better. I decided not to use it. I couldn't see how it could be any better than the old one.

The ticking sound has, of course, persisted. I'll hopefully get time for a tappet measurement soon, but I've been quite busy putting all of the projects in storage for the winter, and wrapping up tasks before the cold really sets in. I haven't had a chance to drive or work on the Fiat.

[kilrwail]

I replaced my cap recently and the new one (from AR) fit perfectly. I wonder if your base is damaged? I guess we'll find out next year. Thanks for the update.

[FiatRunner]

I guess we'll find out next year.

Hopefully it'll be sooner than next spring. Hopefully.

I just need a bit to settle into winter, and I need to find a day where I can leave the garage heater on for a few hours to let the garage warm up. My winter break is in a few weeks, so I should have time to get some stuff done when I don't have work and school taking up all of my time.

Stay tuned. I'm planning on buying a bunch of parts as a Christmas gift for myself, and I'm sure I'll be asking lots of questions.

[FiatRunner]

Update on the ticking sound

Happy holidays everyone! Our weather on Christmas was so abnormally warm that we were able to go on a top-down ride joyride in the Fiat on Christmas eve. We drove around for about 35 or 40 minutes.

However, I barely noticed the ticking sound. I was driving around at normal speeds, and accelerating at a typical rate. Once in a while it would tick maybe 3 or 4 times, but it wouldn't happen often. I even tried to get it to make the noise by increasing or decreasing RPM's quickly, but I still barely noticed it.

I haven't had a chance to do a measurement. I also hadn't driven the car in 4 or 5 weeks, but I had started it up and let it get up to temperature a couple weeks earlier.

This has really got me confused. I'll see if I can do a valve measurement in the next few weeks. Part of me wants to say "it's stopped making the noise, it'll be fine", but I'm not sure if that would be the smartest decision. Thoughts?

[18Fiatsandcounting]

Part of me wants to say "it's stopped making the noise, it'll be fine", but I'm not sure if that would be the smartest decision. Thoughts?

Several possibilities (in no order of likelihood):
1) You've gotten used to the noise and just tune it out.
2) Whatever was causing the ticking sound has now worn down to the point that the parts aren't hitting anymore.
3) The colder weather caused parts to contract slightly so they aren't hitting anymore. Or the oil viscosity is different.
4) It fixed itself. Fiats break by themselves, so why can't they fix themselves?

The noise, while perplexing, didn't sound terribly catastrophic to me. If it were me, I'd keep an eye on it, errr, I mean keep an ear on it, and see if the noise returns. Do check the valve clearances, though.

-Bryan

[FiatRunner]

The noise, while perplexing, didn't sound terribly catastrophic to me. If it were me, I'd keep an eye on it, errr, I mean keep an ear on it, and see if the noise returns. Do check the valve clearances, though.

I'll certainly keep my ear on it, but I agree with you, it doesn't seem like a huge deal. I've driven the car probably 50 or 100 miles since the ticking noise first started to occur. (although these miles were all put on last year) I don't think I am going to seriously hurt my engine if it runs while making some noise. A friend of mine had a 1st generation Miata, and he would solve his lifter tick noises with a few seconds of rev limiter. According to him, the noise usually went away after that. If his car can fix itself, why can't mine? My truck fixes itself all the time too.

As for your suggested possibilities, I wouldn't be surprised if one (or multiple) of those things have occurred. I'm not too sure about the oil viscosity difference, as it was 55 degrees outside when I last drove it, and I've had the car out when it's been much colder than that, plus the engine was plenty warm.

I'll get to a valve clearance measurement soon, I hope. It's currently 2 degrees F outside, and that is far too cold to be working without gloves.

[FiatRunner]

Alright everyone, I've finally got an update.

After weeks of being away from my car, weeks of terribly cold weather, and incredible amounts of homework, I've finally got a chance to spend 45 minutes in the garage.

I unfortunately only got enough time to measure the tolerances on the exhaust side tappets, as the stock air filter housing is a pain to remove when you don't have a correctly sized socket. However, I did come up with some interesting results. The exhaust tappet clearances for cylinders 2, 3, and 4 are all within a thou of 0.019". But tappet 1, was about 0.013". It was kinda halfway between .013 and .014, as 0.13 fit somewhat easily but .014 wouldn't fit.

At first, I had assumed that this was the source of the ticking sound, but that doesn't make sense. Wouldn't a ticking noise occur with a loose or worn tappet? The #1 tappet is generally where the noise occurred.

[18Fiatsandcounting]

Wouldn't a ticking noise occur with a loose or worn tappet?

That's what I would have thought, but stranger things have happened. I'd still check the intake side clearances, and then you could get new shims for any that are out of tolerance like the #1Ex. is, and see if that helps with the ticking sound. The shims can be replaced with the cam boxes where they are, but it is a little tricky.

Most of the Fiat engines that I've run across do have a bit of a ticking sound, so it also might just be normal.

-Bryan

[FiatRunner]

Most of the Fiat engines that I've run across do have a bit of a ticking sound, so it also might just be normal.

This is definitely something that I can agree with. After spending so much time trying to diagnose this noise, I've realized that it's never going to be as smooth as my modern engines that I've been comparing the Twin Cam to. Not that it can't be smooth, but it's never going to be like my old Lexus.

My plan is to replace the tappet shim, and drive it. I'm not going to let the noise bother me too much. From what I've been told, these engines are tough, and a tick isn't the end of the world.

[Nut124]

I would not bother messing with the #1 EX shim. The noise is more likely to come from cyls 2-4. Replacing the shims w/o removing the cam box can be a major pain unless you have the tools and know the tricks.

I would check the intakes though.

Cam clearance specs have changed since these Fiats first came out. New performance cams for these engines often call for 0.008" clearance.

[FiatRunner]

I would not bother messing with the #1 EX shim. The noise is more likely to come from cyls 2-4.

Cam clearance specs have changed since these Fiats first came out. New performance cams for these engines often call for 0.008" clearance.

Why would the noise be more likely on 2-4? More heat further back in the motor?

Also, I was told that the car has a "high performance cylinder head". Don't know what this means... more compression? Bigger cams? Stiffer springs? Who knows. I've never driven another spider, at least not on the road, so I'm not sure how my car compares to a stock one.

This "high performance head" was installed by the car's first owner 10k miles ago. I am the third owner, so the second owner, (previous to me) didn't have any specifics. This could maybe explain the tight clearance.

[Nut124]

Hello FiatRunner,

Larger valve lash gaps make more noise. The larger the gaps, the louder.

Sorry, can't help with the perf head questions.

[FiatRunner]

Hello FiatRunner,

Larger valve lash gaps make more noise. The larger the gaps, the louder.

Sorry, can't help with the perf head questions.

Oh! I completely misinterpreted what you wrote. I get what you mean, my apologies.

As for the questions about the head, I wasn't specifically asking you or anyone else, just attempting to show how little information I have on my engine. I am planning on doing a fairly extensive rebuild in a couple years, and then I'll be able to get all the specific information that I need.

[peteshack]

Hey FiatRunner,

I've got the exact same sound.
Stethoscope seems to indicate it's coming from the distributor shaft or the top of the exhaust cam box.

Did you ever discover the cause, or have you just been living with it?

[FiatRunner]

Hey FiatRunner,

I've got the exact same sound.
Stethoscope seems to indicate it's coming from the distributor shaft or the top of the exhaust cam box.

Did you ever discover the cause, or have you just been living with it?

The ticking noise slowly got worse, and eventually it was obvious that it was rod knock. Looking back on this thread, the instances where I wasn't able to hear the noise was simply because the oil was cold and thick.

I ended up replacing just the rod bearings with the engine in the car. I posted about it in this thread here: viewtopic.php?t=40925 I updated this thread today. If you end up deciding to do this, let me know. I'll post a write-up on how to do it.