401 sticky valves

[Guest Robert Ricci]

Any suggestions on a sticky valve issue? I have a ticking in exahust in my 401 motor. Thanks Bob

[RivNut]

Exhaust leaks sound just like sticky valves. Did someone put exhaust manifold gaskets on your car? The factory doesn't use them; they machine the sufaces of the head and the exhaust manifold for a leak free fit. There's also a plug in the bottom of the intake manifold that goes into the exhaust gas crossover; it too will corrode and leak.

There are lots of "old skool" fixes for sticky valves. One thing I've done is to run a quart of automatic tranmission fluid in place of a quart of oil for a couple of hundred miles before changing the oil. Marvle mystery oil added to the crankcase will do something similar. I've done this in the past - some guys may cringe but here's what I did. Drain the oil from the pan, but don't remove the filter. Put the drain plug back in. Pour two quarts of new oil and two quarts of kerosene back into the engine. Start the engine and let it IDLE for about 10-15 minutes. DO NOT, repeat DO NOT run the engine any faster than an idle. Drain everything, change the filter, and add new oil.

Good luck.

Ed

[petelempert]

I agree on the exhaust point made by Ed. When I first got my 63 I thought my lifters were the problem...lots of ticking. Turns out I had a hairline crack in the drivers side exhaust manifold, on the underside so it was virtually undetectable until it came off the motor. I should have figured it out earlier...the ticking sound changed and improved as the car got warmer...because as the manifold heated up, the crack closed somewhat i assume. PRL

[gungeey]

Who would of thought you could get a mechanical diagnosis based on a one sentence description, all by way of the internet??

Could be lots of things...if an exhaust valve is sticking you'll likely get a backfire thu the exhaust,...the rocker arma have pressed in steel inserts that could be worn, a lifter might of sh!t the bed, or maybe even the car hasn't run in a few years and just needs to get some use..I would start by disconnecting the ignition wiire to one cylinder at a time til the sound dissipates..Also, these cars have a butterfly valve that's spring loaded in the passenger side exhaust..though they typically rust in place, it just could be that yours if flopping around making that tapping sound...

[CTX-SLPR]

Also, these cars have a butterfly valve that's spring loaded in the passenger side exhaust..though they typically rust in place, it just could be that yours if flopping around making that tapping sound...

Been there and done that!

Take a long screwdriver and press it to your ear or spend the money on an automotive stethescope and poke around for the noise. If it's the valve you should hear it over the top of it on the valve cover vs the exhaust should be notice able on the manifold itself. The butterfly valve you can grab with your hand when it's cold and see if that's the source of the noise or you can use something to wedge it in place if it's still loose enough to move.

[Guest REX STALLION]

Okay, is it constant or does it go away after a while?

[Guest Robert Ricci]

it comes and goes and car car has a slight skip. I have tuned up new everything and rebuilt carb. Baffle plate in place been running it to see if it will cure

[Guest REX STALLION]

Lazy/sticky lifter, doesn`t want to pump up?

[Guest 1963 Riviera]

Hi Guys, I have a similar problem

I have a honest (I think) mechanic who is just about to give me a final diagnosis of why my motor is idling rough

Not being a mechanic I would like to be able to 'talk the talk' when He give me his opinion. He believes the valves are worn/sticking that will need reseating. He has given me a rough estimate of BIG $$$ to do this. I will know tomorrow what he suspects.

Until then......

When I purchased the car (63, 401 that had done 256000 miles) I sent it to him for a tune up. He did a thorough job, including carby, plugs, leads etc but found Cyl 5 and 6 were missing with 175 compression (manual states 180 being the acceptable) on all cylinders and suspected mechanical issues.

I have driven about 5OO miles since, including a 150 mile round trip in a day

I felt it was time to to do something about the idle which was starting to get me a little nauseas and includes the following symptoms

Idles rough but does not stall

Ticking noise on start up (sometimes)

Ticking noise on cruise ( I hear it rebounding off parked cars, walls etc.)

Vapour (?) not smoke from left exhaust

Uses very little oil

Does not backfire

So my question to the brains trust is...

Is he on the right track ?

What else do I need to ask him ?

Awaiting in anticipation ....and also awaiting my ROA #

[Yellowriv]

Hi Nick. Since this is the internet and I'm not a mechanic, I thought I should offer some misleading and uninformed comments;)

Eliminating really dumb things first, are the plug leads in correct sequence. Firing order is 1-2-7-8-4-5-6-3, with 1 being on the right as you look at the engine and the engine rotating clockwise. This is not the same as for a small block Chev. So right bank is 1-3-5-7 and left is 2-4-6-8, basic stuff I know.

If this is not the issue, the comp test sounds ok and I wouldn't think of itself indicates major issues, however lower compression and water vapour could be a head gasket issue. Since these cars have a transverse muffler that mixes both sides, water vapour out of of one side doesn't indicate anything. Is there emulsion under either the radiator cap or oil cap? Does the water look like latte or the oil greenish?

I could go further but then you'd really be in trouble....

Regards

[60FlatTop]

Didn't the cars exported to the southern hemisphere have a barometric pressure inverter to help the air/fuel mixture draw upward into the engine? If you have one it might be creating eddy currents if it needs service. That can cause those symptoms.

This is the internet and everything is fact.

Kings Cross R&R Vet 1969

Bernie

[lrlforfun]

OK Riviera People: I really swear by Marvel's Mystery Oil. You can debate all the magic addiditives added or taken away from motor oil and I still say the magic combination is........

4 quarts of 30 weight motor oil

+ 1 quart of marvels mystery Oil

------------------------------------

= Happy crankcase

One can of Berryman's B-12 in the tank every fill-up

-------------------------------------------------

= A clean and happy fuel system

You will notice the difference in performance almost immediately. It won't make the metal grow back or heal broken parts but it sure cleans and lubricates to the point of where the engine will run much better. Mitch

[CheezeMan]

guess I can add more miss-information 'cause this is the NET!...

Last week, I finally figured out the reason my '63 was running rough at idle (while in gear), but not so much when in park. The motor mounts were loose. I had already ordered a new set of mounts thinking they were shot and needed to be replaced. I discovered that the previous owner replaced them, so the problem was loose bolts. While taking them out (replacing anyway), I found that the hard to reach bolts were not tight. So, after much wiggling and going to the store to buy more tools, I finally got the new mounts in. Although I couldn't torque the hard to reach bolts; just got 'em tight. Hope that lasts. Next time I might have to pull the engine out.

[RivNut]

+ 1 quart of marvels mystery Oil

Great product. Take a look at some of the previous threads. Look for an oil that still has a minimun of 1,000 PPM (Parts Per Million) of Zinc (ZDDP)

Today's oils are not made for flat tappet engines. Without the ZDDP, cams will go flat.

I like the Mobil 1 Synthetic 0w-40.

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

Wally World sells it in 5 qt. bottles for less than $30.

Ed

[Guest 1963 Riviera]

Hi Guys, I have a similar problem

I have a honest (I think) mechanic who is just about to give me a final diagnosis of why my motor is idling rough

Not being a mechanic I would like to be able to 'talk the talk' when He give me his opinion. He believes the valves are worn/sticking that will need reseating. He has given me a rough estimate of BIG $$$ to do this. I will know tomorrow what he suspects.

Until then......

When I purchased the car (63, 401 that had done 256000 miles) I sent it to him for a tune up. He did a thorough job, including carby, plugs, leads etc but found Cyl 5 and 6 were missing with 175 compression (manual states 180 being the acceptable) on all cylinders and suspected mechanical issues.

I have driven about 5OO miles since, including a 150 mile round trip in a day

I felt it was time to to do something about the idle which was starting to get me a little nauseas and includes the following symptoms

Idles rough but does not stall

Ticking noise on start up (sometimes)

Ticking noise on cruise ( I hear it rebounding off parked cars, walls etc.)

Vapour (?) not smoke from left exhaust

Uses very little oil

Does not backfire

So my question to the brains trust is...

Is he on the right track ?

What else do I need to ask him ?

Awaiting in anticipation ....and also awaiting my ROA #

Hi Guys,

Firstly thank you for informative feedback. So many things to ponder.

I got her back from the mechanic today and he is almost sure its going to be a valve job and Cam replacement.

Quoted me about $4k. I have decided to hold off for now until I get the bucks together and go through all the options you guys have kindly suggested.

Thanks again.

Nick....ROA # in the mail

[RivNut]

$4K for a valve job and replacing the cam:eek:. I haven't priced a valve job for a while, but that seem a little high. If it is valves, have you considered trying to find a set of heads that are in good shape already? Go over to V8Buick.com and find the 'Da Nailhead forum. Register and ask some of the engine gurus over there what they think. They're into engines only. Nailheads in everything from '22 Buick Roadsters to late model Chevy S-10 pickups to rail dragsters. See what Doc, Tom, or any of the other gurus have to say about your problem and what a reasonable price for a valve job should be.

Ed

[lrlforfun]

OK Riviera People: I always respond with a given. So far my "given" is the 30 weight and Marvels because I have seen it work in almost every car it was put in. The other given is diagnosing mechanical problems on collector car forums. Nick, if you were a mechanic who was going to tear into your engine it's always good to get advice from people that have had some degree of experience with a similar issue. If I'm correct in understanding, your issue is with the valve job and cam job costing $4000. I believe that finding a shop that you can really trust might be your ultimate solution. Why? First of all because if a shop is good they will know how to diagnose a problem and give you an idea of what it's going to take to solve the problem. 175 pounds of compression vs. 180 is almost completely insignificant.

Let's say your Riv needs a cam and a valve job. Well, if it's that bad chances are that the lower end is in need of attention. This is rebuild time. Now what if your car really doesn't need a cam and valve job? It may not. That's why an accurate diagnosis with "real world" suggestions is so important. I know that you don't want to hear this but finding a shop that can diagnose correctly and interpret the results so you can make a responsible decision as what to do is numero uno!! Mitch

[60FlatTop]

I hate to second guess a shop diagnosis through online forum threads. I would be curious to see the notes, though. In my garage there would be a paper with the compression readings. In this case a second set with oil in the cylinders to gauge the ring wear. Then there would be the dial indicator measurements on the cam lobes from the suspicious cylinders. I couldn't imagine 16 flat lobes.

Then you have the average of 1,000 miles per year. I expect it didn't occur that evenly and there must have been some years of idle time. Long periods of sitting makes for stuck rings and rusty cylinder walls. At $50 and hour a guy can get a lot of diagnostics done in a day for $400.

Now, let's say you were in Buffalo, New York and brought the car to me. Knowing the story so far, with the engine cold, I would put my radiator tester on and pump the system up to 18#. Just watching the gauge and listening for water (where we don't want it). Once satisfied with that test, I would start the car and bring the engine up to temperature. Then real quick, I'd pop that carb off, careful not to tilt and spill. I'd peek down into the manifold and look for wetness or vapors floating around. On the old Q-jet Caddies I'd see them soaked from leaky plugs in the base of the carb. I know you don't have the Q-jet, but a wet manifold is an easy check..... before I got the compression tester out.

Three things; your mechanic might have done those things, he might not have done those things, you might wish you lived in Buffalo.

Bernie

[Guest 1963 Riviera]

Ed and Mitch, I hear you, and thanks for the sound advice.

My mechanic is an "old school" guy ( cigarette permanently stuck to his lip) with a good reputation around here (Eastern suburbs. Sydney) and works on some beautiful cars.. but a second or third opinion is now my plan.

A rebuild around here would be about 6K PLUS.

Coz money don't grow on trees, I'm going to hold off the heavy stuff for now and tick all the boxes of advice, and also get me some of that "mystery" oil before I commit.

If only it didn't have that roughish Idle, and the occasional start up tick. Otherwise she runs great , but if I ignore it , will it lead to something more sinister down the line ?

In the meantime, I took her out today on a beautiful winters day, and man does she get some looks.:cool:

[lrlforfun]

OK Nick: You can do this yourself. Warm up the car. Change oil and filter with 4 quarts of 30 weight, add 1 quart of Marvels Mystery Oil. Drive it for day or two. Warm it up again and pull the plugs and take a compression test. Simple. let us know the results. An oil filter wrench, funnel, compression gauge and a drain bucket for the waste oil and filter is all you'll need.

Let us know as soon as you get this handled. If you are a little jittery about doing it yourself ask a friend for help. it's pretty basic stuff. I'd help you myself but I'm too far to go there! Mitch