231 V6 question

As the topic title says, I have a question about my 231 V6 engine. I know this is the small block section, but I don't know where else to go with this V6 question hehe (it sure isn't a big block or a race engine).

My question is about a certain sound when the engine is running. You can really hear something 'tick' when she is running. Even with the hood closed and just standing next to the car. When you rev the engine the sound goes away. This 'ticking' sound can best be heard when the engine is cold. And it seems to pretty much go away when the engine is warmed up. Idling you can still hear it but just a little. What could this be? Lifters? Valves?

At the left side (passenger side) of the block I have a tiny exaust leak, right where the exaust manifold meets the tailpipe (I need to tighten those bolts a little better). Could this be the reason? I once read something about leaky exaust manifolds/headers causing an engine to make a ticking sound.

I don't know if 'ticking' is the best word to describe the sound. I think it sounds pretty much like an old steam engine. You know, that kind of ticking/knocking sound.

It is a 1975 'odd fire' 231 V6. Do these things have hydraulic lifters? How can I check (and maybe adjust) the valve clearance?

I hope someone can help me in the right direction.

 

Fix the exhaust leak first so you can pin point where the noise ( if other than the exhaust leak is) is coming from. Its not unusual for the old V/6 motors to have lifter tick. Sometimes you can get it to go away by just changing the oil if its been in there for some time. Yes, these motors had hydraulic lifters.

 

Yes, your motor has hyd lifters and this could be your problem.

What you need to do is:

find a 1-2 foot long peice of garden hose or similar
stick an ear plug in one ear
hold the hose to the other ear and poke the end of the hose around the motor while its running.

Try to narrow down the sound to either front/back and or side to side. If the sound seems the same from everywhere on the top of the motor than it is likely a bottom end bearing but lets hope you can narrow it down...

Oh and make sure it isn't you heat riser flapping around, that it common and annoying.

 

Thanks for the replys!

Yeah, I will defenetly fix that little exaust leak first. I was already planning on doing that tomorrow.

Thanks Sean, for that advice. I'll try to locate where the sound is exactly coming from that way. What your saying about the heat riser sounds interesting. I've come across this term before, but don't know exactly what is it and where I can find it. It's connected to/on the exaust manifold right? Passenger side? What exaclty would be flapping around? And how can I check this and fix it.

Come to think of it, I believe the sound is mostly coming from the passenger side of the block. But not totally sure though. I will check some stuff out tomorrow. I don't use that car that much (yet) actually, she also does a lot of sitting. Therefor I can't tell exactly from the top of my head.

 

The heat riser has been on the drivers side of my car which would be the pasenger side of your car HAHHAHAAHH!!!!!

It is a butterfly type valve that goes between the exhaust manifold and the exhaust tube. I usually wire them open since the heat activated metal coil that is supposed to open them after warmed up usually craps out.

 

Oh, and just a side note:

The 231 Buick v6 is a essentially a Buick 350 with 2 less cylinders so we can help you with most of your needs!

 

ou: of course I meant drivers side! My bad Also what I said about where the sound is mostly coming from...drivers side.

I'll look into the heat riser thing tomorrow. I heard about keeping the valve stuck open with a steel wire or something. I might do that too.

Yeah, I know the 231 and the 350 are pretty much the same. Same motormounts too.

 

when changing oil, do NOT use a Fram filter. use something reputable like a Wix, AC-Delco, Bosch or something.

use Shell Rotella oil or some other diesel rated oil as well.

 

Well, I checked the heat riser today (yes, on the drivers side lol!). But it seems to be stuck. My manual says it should move freely, and can be moved by hand. Mine is completely stuck, I can't make it move what so ever. I think it's stuck in open position. There's a rod on it, wich can be pushed away or retracted by some canister (I have no idea how it is actually called, or how I should describe it in english, and I'm new to heat risers anyway, hell I didn't even know I had one ). But it looks like it pushed the rod away. I think that means the valve is in open position. Please, correct me if I'm wrong.

But since the heat riser is stuck, I really can't imagine how this could make a sound. If a heat riser is ticking, what part is actually doing that? Is is the valve, moving a little too freely? Anyway, mine is as stuck as can be, so it can't be the heat riser I'm hearing. Oh and I also got that exaust leak fixed, so that can't be it either. I tried to locate the sound with a piece of garden hose. To me it sounded like it's coming from the passenger side of the engine. And right at the front of the engine, wich means it would be cylinder #1. I really think this is a lifter issue. When I moved further down I couldn't really hear the sound. So, it's not some bottom end bearing. It is defenetly not the same from everywhere around the engine. Cylinder #1 for sure. I paid attention to it today, and it turns out the ticking goes faster when I rev the engine. It doesn't go away. Only when the engine is warmed up the sound gets less.
I think it would be best to replace all lifters right? I mean, while I'm at it anyway.

Oh one more thing, can it hurt an engine to drive with a ticking lifter? It is annoying, yes. But I'm wondering if I could cause serious engine damage to keep driving it this way?

 

If this is a stuck lifter:

It is best to replace the cam and lifters at the same time since they work together it is not good to use old and new parts mixed up.

Yes the ticking is causing damage and will eventually lead to a worn out cam lobe ect.

But since it has been ticking for a while already theres not to much worry about damage since its allready damaged.

 

There are some bottles of oil addative that may help free a stuck lifter.

 

Have you changed the oil yet? I have had engines that had a lifter tick and changed the oil and the tick went away (well almost). I have also driven them with a slight lifter tick for thousands of miles and the car wore out before the motor. Its your call but I would change the oil first and see if the ticking goes away.

 

I did change the oil recently. And filter too. Filter is AC-Delco and the oil is 10W40 Halvoline (half synthetic). But I might try one of those additives and see if that helps. I'm not sure but maybeI can make some valve train adjustments, I mean to the push rod and rockers. I'll look into my manual, maybe it says something about that. I want to try these options first, before I take the top of the engine apart and change lifters.

 

does it sound like a rattle at idle?
i would check the timing chain as have seen it many times,
my 65 v6 sounds like a popcorn machine right now
but the turbo v6 it shaping up

 

Thanks for the tip Alec! I will check the timing chain!

If it is the timing chain, what exacly would be the cause? Would it be too loose?

 

those had plastic teeth if original and the get weak and break
there is a tensioner on them which will help them from jumping but breake enuff teeth and you will have a problem

 

Alright, well I will check tomorrow. With the garden hose it really sounded like it is a lifter making the noise. But I will try it near the timing chain cover. Maybe it is the timing chain.

 

Thare are no adjustments for the valvetrain on these motors. What I would do is remove that one valvecover and run the motor for a few seconds (not too long or oil will start shooting out of the pushrod tips), Watch for a pushrod thats not spinning around as it goes up and down. That will be your stuck one.

 

The "tick" is probably from the exhaust leak. It is pretty common on these cars to mistake an exhaust leak for a valve tap, the V6 engines are also notorious for cracking the exhaust manifold (which will cause the ticking sound). On top of that a leaking exhaust is most prevalent when cold, when the engine warms the maniflds expand. the leak closes and the noise goes away. That sounds like what you have. Since you already know you have an exhaust leak I would be surprised if it was something else.

That said, other less likely possibilities include:
collapsed lifter
bad valve/seat/guide
low oil pressure
bad rocker, bent rocker shaft or loose rocker shaft