Question on sticky intake valve(s)

[spstan]

I think I have a sticky intake valve(s) on my 50 year old 440 engine. Coughs up combustion gasses through the carburetor on initial startup (haven't done a compression test). I suspect carbon build up on the valve. Watching YouTube I've seen testing on a number of products (Marvel Mystery Oil, SeaFoam, Chevron Techron. CRC Intake valve cleaner etc.) and they all show minimal improvement after one usage. (although they claim significant carbon removal on the can). My friend and another You Tuber claim the only reliable way to clean the intake valves is by mechanical cleaning which involves removal of the heads and intake manifold. For this my mechanic wants around $2500. But I'm thinking $2500 would buy around 200 to 300 bottles of the various chemical cleaners. And if keep hitting the valves (maybe every other fill up ) or keep spraying through the carburetor and brake power assist vacuum hose (maybe every other time I run the engine) I can gradually clean a majority of carbon off the valves and avoid head and intake manifold removal. Thoughts?

Also the highest rated intake valve cleaner was the CRC Intake Valve cleaner. Anyone know of one better? Paul

 

[65Port]

Get some compression numbers before you waste your money and time. Then check for timing chain slack and go from there. You'll just be guessing and hoping for results you won't get with additives.. avoid head removal? Doubtful. Crud is crud and won't easily be removed.

Try googling "intake valve buildup" to see what you are up against. That dark stuff is very hard and doesn't just flake off..

 

[Big_John]

Check your timing and spark plug wire firing order first.

 

[413]

This is ongoing, bridges have been crossed and back again.

advice on changing 440 timing chain

 

[CBODY67]

NONE of the chemical cleaners will magically work with just ONE application. The YT'r "Chris Fix" has videos on such, using a borescope to look at the tops of the pistons after each product was used. Spme helped more than others.

I'm not, personally, sure that with modern oils and fuels, if "sticking" valves is really a "thing" in modern times. Especially if the engine runs normally, as a general rule.

A "BURNT" valve CAN be, though. Always an exhaust valve. My experiences on our 383s has been that it usually is #5, for some reason. Compression check, red rag on the tail pipe, vac gauge, and "less power off-idle and under load" are ways to tell.

Does that $2500.00 quote also include a full valve job, with gaskets and labor?

NOW, I have experienced a "spit-back" when starting. Does not happen all of the time and the engine runs fine otherwise. Not sure what causes that, though, or why as things work find otherwise. That was 30 years ago.

I would suspect that WORN, but not wore-out valve guides could be an issue?

Back in the 1970s, I discovered that the best way to de-carbon an engine was to dump a bottle of Berryman's B-12 in the 25 gallon tank and drive the car on the highway for about 20 gallons worth of time. Which would be 300 miles at 70mph, cruise. Then, turn around a day or so later and repeat. I noticed that after each non-Berryman's trip, the '66 Newport ran just a bit better each time. It was not running "bad" by any means, before them, either! Others would add a gallon of diesel and then fill the tank with gas.

And THEN there was the atf+water mixture drizzled into the primary throttle bores with the engine at fast idle. Made enough noise to knock any carbon out the back! Almost as bad as starting an Olds 5.7L diesel with WD-40 spray after an inj pump change.

So . . . check the condition of the plugs, plug wires, and base timing for good measure. Then proceed and keep us posted on your progress.

----
Regarding the link in Post #4, WHY was the MSD distributor and related items installed? What were they supposed to remedy? Just curious.
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CBODY67

 

[RemCharger]

If you're going to attack the intake valve build up, pull the intake and rockers off, and pour in your favorite stuff right into the intake ports and let soak.

 

[spstan]

NONE of the chemical cleaners will magically work with just ONE application. The YT'r "Chris Fix" has videos on such, using a borescope to look at the tops of the pistons after each product was used. Spme helped more than others.

I'm not, personally, sure that with modern oils and fuels, if "sticking" valves is really a "thing" in modern times. Especially if the engine runs normally, as a general rule.

A "BURNT" valve CAN be, though. Always an exhaust valve. My experiences on our 383s has been that it usually is #5, for some reason. Compression check, red rag on the tail pipe, vac gauge, and "less power off-idle and under load" are ways to tell.

Does that $2500.00 quote also include a full valve job, with gaskets and labor?

NOW, I have experienced a "spit-back" when starting. Does not happen all of the time and the engine runs fine otherwise. Not sure what causes that, though, or why as things work find otherwise. That was 30 years ago.

I would suspect that WORN, but not wore-out valve guides could be an issue?

Back in the 1970s, I discovered that the best way to de-carbon an engine was to dump a bottle of Berryman's B-12 in the 25 gallon tank and drive the car on the highway for about 20 gallons worth of time. Which would be 300 miles at 70mph, cruise. Then, turn around a day or so later and repeat. I noticed that after each non-Berryman's trip, the '66 Newport ran just a bit better each time. It was not running "bad" by any means, before them, either! Others would add a gallon of diesel and then fill the tank with gas.

And THEN there was the atf+water mixture drizzled into the primary throttle bores with the engine at fast idle. Made enough noise to knock any carbon out the back! Almost as bad as starting an Olds 5.7L diesel with WD-40 spray after an inj pump change.

So . . . check the condition of the plugs, plug wires, and base timing for good measure. Then proceed and keep us posted on your progress.

----
Regarding the link in Post #4, WHY was the MSD distributor and related items installed? What were they supposed to remedy? Just curious.
----

CBODY67

To all respondents; thanks, with the help of the board I (and my neighbor ) I replaced the timing chain about a year ago. Starting improved dramatically. Car almost jumps to start once I turn the key. I can't understand why some board members don't believe its carbon buildup on the valve thats causing the smoke issue. Afterall the car is a 1975 and 50 years is long time for carbon buildup to occur.
As I said I did not do a compression test but I have used a vacuum gauge on the car to check the air bleeds.

How would a vacuum gauge diagnose a stuck valve? Would the needle flutter? Cause I saw on You Tube where a guy holds a piece of paper against the exhaust and the paper is alternatively sucked in and blown out (i.e. the paper flutters) and he claims this is indicative of a stuck valve. Also watched Mortske on YouTube (he's pretty good) and he was working on a 40's Ford flathead and he claimed white smoke coming back through the carb was indicative of a stuck intake valve. I'm going to try some CRC intake valve cleaner and see if that doesn't help. Like I say, once the car is started it runs beautifully and I hate the idea of trying to remove the heads and the intake manifold on a 50 year old engine. I'd probably break a bolt or some thing. Paul

 

[CBODY67]

The fluttering of the paper at the end of the tail pipe is due to the reverse pressure spike when an exhaust valve is closed, but leaking, on the intake stroke. NO white smoke anywhere. White "smoke" is from a coolant leak, as in head gasket blown (which also causes other things to happen, too).

IF there is a lot of build-up on the backside of the intake valve head, any cleaner will not remove it in SMALL chunks. Those chunks must go through the combustion chamber and probably get caught by a valve's edge, which means instant misfires . . . which only get worse, not better, by observation.

Back in the later 1980s, my late machine shop operative showed me a valve out of a Chrysler 383. Seems that a guy and his family had moved down to DFW from Chicagoland. They rented a UHaul trailer and towed it with their 1970s Plymouth Fury III. The engine started to miss, which got worse the farther they drove. HAD to get it fixed. So he pulled the heads and brought them to my machine shop guy.

ONE of the intake valves had a really pretty black CONE of oil deposits on it. They'd been there for a good while. Smoothed/compacted by the air flowing past them. The heat and load of the engine started to fissure one of the cones, some of which got wedged between the intake valve and the valve seat. Do the guides, new valve seals and head gaskets, etc., plus new intake valves. DONE!

Do NOT expect ANY oil or gas additive to work in "one tank", for a complete cleaning. The best ones will take longer than that and do a better job of not breaking something inside the motor. Sure, with a -.125" deck height and the larger combustion chambers, that seems like a huge area, BUT consider there are some big valves which are going up and down, too! Not a safe place for .125" chunks of deposits to be "floating" around at 2000rpm without getting hurt. Them AND the engine!

IF the timing chain is really getting worn, you might hear it hitting the cover surrounding it. On a Chrysler, if it does that, you are in "deep stuff" anyway.

ALWAYS think about what people on YT say. Listen with a bit of skepticism, then verify what they say with other corroborating evidence. Just like one should be doing anyway. Do not consider the condensate cloud you see out the rear of the tail pipe during warm-up or cold weather as "smoke".

For the past few months, Hertz has been purging their rental fleets of EVs. In the near future, the General Services Admn will be doing similar with their EVs. MIGHT be the time to get one!

Otherwise, head out and buy a 1/2" drive clicker torque wrench and a 1/2" to 3/8" adapter for it. If I can change an intake manifold, you can change a pair of cyl heads.

CBODY67

 

[413]

Your last statement about the car sum it all up.

"Once the car is started it runs beautifully"

So don't go looking for problems or ways to burn money. The snake oils won't, don't, can't do what you "hope" they will.

Use quality fuel, use quality oil and keep it changed on time. Drive it on the freeway and get it warm, no short trips.

 

[Big_John]

I'm reading this and the location "Rochester" jumps out at me. Assuming Rochester, NY, it's cold. In Syracuse, it's low 40's and a "warm" day by comparison.

So, starting involves the choke. An incorrectly adjusted choke, or a couple extra pumps of the gas pedal will cause this.

So.... That brings us to the question of why exactly are you starting it? It's cold, there's snow on the ground, and salt on the roads. No reason to start these cars during winter storage. If you have to start it, like to move it, then the car really isn't getting driven and not coming up to temperature. After a few times of this, it might sneeze a little the next time you start it as the plugs might be a little dirty. It also might have "summer" gas formulation that doesn't start as well in the winter.

So, my advice is leaving the car alone until spring. Then take it out and drive it.

I know, that doesn't fit the mold of "let's find something wrong that isn't", but there it is.

 

[spstan]

I'm reading this and the location "Rochester" jumps out at me. Assuming Rochester, NY, it's cold. In Syracuse, it's low 40's and a "warm" day by comparison.

So, starting involves the choke. An incorrectly adjusted choke, or a couple extra pumps of the gas pedal will cause this.

So.... That brings us to the question of why exactly are you starting it? It's cold, there's snow on the ground, and salt on the roads. No reason to start these cars during winter storage. If you have to start it, like to move it, then the car really isn't getting driven and not coming up to temperature. After a few times of this, it might sneeze a little the next time you start it as the plugs might be a little dirty. It also might have "summer" gas formulation that doesn't start as well in the winter.

So, my advice is leaving the car alone until spring. Then take it out and drive it.

I know, that doesn't fit the mold of "let's find something wrong that isn't", but there it is.

John; I'm trying to do what Mike of Mike's carburetor recommended. He said leaving a car not started for over 6 months would lead to clogging of the small passages in the carburetor. So I try to start the car every once in a while over the winter to get the gas and other fluids moving. Paul

 

[Big_John]

John; I'm trying to do what Mike of Mike's carburetor recommended. He said leaving a car not started for over 6 months would lead to clogging of the small passages in the carburetor. So I try to start the car every once in a while over the winter to get the gas and other fluids moving. Paul

That sounds good on the surface and for someone that lives in Washington State (Mike's Carbs) where the temperature doesn't get below freezing very much, it's OK advice. (I checked the weather there before posting LOL). Living in NYS, you know we get a bit colder.

Here's the issue. Cold starts are the worst thing for engine wear. So, for the sake of the carb, you sacrifice the engine.

Myself, I never start the engines in my cars during the winter and I never have a problem.

If you want to start the engine once in a while, that's your decision and there are people that do just that. Just remember that the car is running on slightly old gas, probably formulated for warmer weather and it's running on the choke. Point being that you don't want to do any diagnosing, particularly anything that might cost you a lot of time and $$ until the weather is warmer, and you can figure out if it's just a choke/cold weather start problem or something else.

Also FWIW, winter gas is formulated for better starts and summer gas is formulated for less evaporation. Myself, I run non-ethanol gas 99% of the time, only deviating when I leave the Finger Lakes area and there aren't as many gas stations that sell it.

And please don't think I'm trying to disagree with you or anything like that. My advice is always aimed at guys so they can have some fun with their cars and not spending $$$ and/or time that they don't need to.

 

[CBODY67]

In the later 1980s, when some cars started to have oil temp gauges in their driver info centers, on a spring day, starting from an overnight rest, I started the pickup, enabled the oil temp reading, and started to drive normally at highway speeds. Predicably, the coolant temps came up by the end of 2 minutes of driving, but the oil temp took a good 10 miles to approach coolant temp. Why? the cast iron in the block, heads, and such had to be heated, too. Remember the "Severe Usage" recommendation for oil changes? Until the oil gets hot enough to cook out the moisture/condensate out of the oil, it just collects in the oil until it does. THEN guess what happens as the engine cools down? More condensate possibilities.

Crankcase ventilation is a BIG help to these things, but even 10+mile (one way) trips can clog a pcv hose (in a low spot behind the carb on LA motors), from my experiences with my '80 Newport 360 2bbl.

LOTS of side issues to consider!

Enjoy!
CBODY67

 

[spstan]

That sounds good on the surface and for someone that lives in Washington State (Mike's Carbs) where the temperature doesn't get below freezing very much, it's OK advice. (I checked the weather there before posting LOL). Living in NYS, you know we get a bit colder.

Here's the issue. Cold starts are the worst thing for engine wear. So, for the sake of the carb, you sacrifice the engine.

Myself, I never start the engines in my cars during the winter and I never have a problem.

If you want to start the engine once in a while, that's your decision and there are people that do just that. Just remember that the car is running on slightly old gas, probably formulated for warmer weather and it's running on the choke. Point being that you don't want to do any diagnosing, particularly anything that might cost you a lot of time and $$ until the weather is warmer, and you can figure out if it's just a choke/cold weather start problem or something else.

Also FWIW, winter gas is formulated for better starts and summer gas is formulated for less evaporation. Myself, I run non-ethanol gas 99% of the time, only deviating when I leave the Finger Lakes area and there aren't as many gas stations that sell it.

And please don't think I'm trying to disagree with you or anything like that. My advice is always aimed at guys so they can have some fun with their cars and not spending $$$ and/or time that they don't need to.

John; when I do cold start the engine in the winter I usually use a bottle of gas mixed with 2 cycle oil. I pour that mixture down the bowl vent and the throat of the carb. Paul

 

[Big_John]

John; when I do cold start the engine in the winter I usually use a bottle of gas mixed with 2 cycle oil. I pour that mixture down the bowl vent and the throat of the carb. Paul

That could be the reason it doesn't start and run quite like it should on a cold start. There are guys that like to run a little bit of stuff like that in their gas, but it's at a much higher dilution.

Not saying that's a bad idea, just saying that's not going to give you the best starting or running. In other words, like I said, don't make any judgements or decisions based on how it runs now, wait until its warm out and you drive it a bit.