VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Engine knocking 53 chevy

Hello everyone,

Just as I sorted out the electrical problems, I now seem to have a mechanical problem. Last Sunday I cruised to a yearly car show, about an hour and a half drive. Engine was running fine, then a couple of times at the lights when it was idling a loud knocking noise started from the motor. I don't know whether it was from the top or the bottom end, but it was reasonably loud but disappeared after I took off again. The knocking didn't occur on the drive back home after the show. Engine has never been rebuilt and done 89,000 miles.The oil pressure needle is about 3/4 to the right on the gauge, and cylinder compression varies between 115 and 125psi per cylinder when a compression test was done a few years ago ( 235 powerglide motor). I am assuming the oil level is fine as I changed the oil 2 months ago and there is no leaks anywhere. If this noise is caused by the main bearing how long can I keep driving until motor eventually comes out for a re-build.

That would be hard to guess "how long can you drive it, knocking?"
I never assume it is still full, also if it is a lifter maybe you have one not loading with oil. These old 53 Powerglide engines (IMHO) are finnikey to the right kind of oil, they run better on High Detergent 10w30 or 30 WT. moderate temporal area. I had a case years ago where the oil was changed by a service station and they used a non high detergent oil, it clattered and missed till I changed back to HD oil.

When it comes to the amount of oil in your crankcase, don't assume anything. Also, you may have a slightly bent pushrod that is banging against the side of the push rod cover on occasion.

:) :grin:

Mr Mack and Junkyard Dog,

I drove for about an hour no noise. Then stopped at the lights and it started knocking for a few minutes until I took off again, and the knocking stopped (I couldn't hear it unless it was below the engine noise). Had another red light and it did the same thing again. I then reached the destination about 15 minutes later, but stopped after acceleration. Car parked for about 8 hours that day. Drove back in heavy stop/start traffic for an hour and a half and no knocking at all during that drive. I used Castrol GTX 20W/50 oil which is meant to be for older engines. Do you think I should drain this all out and find a thicker 10W30 high detergent oil ? I think Penzoil may make one. I have to look into Castrol or other brands that are available here. I will also check the oil level when I get home today. Thanks for your info.

Is your car a Powerglide? Loose bolts on the converter could make the noise you mention.

The 20-50 oil is too heavy for your engine unless its just plain worn out. I would also suggest either 10-30 or 10-40 or 15-40.
If its a main bearing the oil prssure will be lower than normal when hot.It would make a thumping noise for about 2 seconds when starting engine after it sits over night. A few heavy thumps.
I would agree that it probably was a hydraulic lifter hanging up. This would cause a clicking noise, not a deep knock. Also could be a valve sticking but then the engine would miss at idle.
The flywheel to converter bolts often loosened up on the '53's.
There are only three and should be checked for tightness.

Thanks for this info Gene and everyone else. I will check the convertor bolts on the weekend. As for the oil, I'm getting a lot of different information from so called technical advisers of oil manufacters here in Sydney. The representative from a large oil/additive company called "Nulon" www.nulon.com.au said that I should use 20W-50 in my traditional old motor. When I questioned him about 10-30 he said that these high detergent oils are designed for modern engines and shouldn't be used in my motor as it will damage it. He was the "technical adviser" for the company, and told me that the US market is flooded with 10-30 oils because it is better for the environment, or less polution for the atmosphere. He also mentioned the oil I should use is based on climatic conditions and since the weather is hot here, the oil used should be different to say somewhere that snows. He then told me not to listen to advice you receive on forums because they can be misleading. I didn't really agree with him but didn't comment on what he said. I don't believe he would be very familiar with the chevrolet blue flame engine. Although when I did a search on the site for chevrolet 6 cylinder US models (it only had 57-62), see http://www.datateck.com.au/lube/NulonAus/default.asp it listed 10W-40 and 10W-30, not 20W-50, so this contradicted what he told me. The information on the oils on this link says multi-valve turbo, or modern-high tech engines. So now I am confused. Can someone have a look at this link and suggest which oil out of the two I should perhaps use. Many thanks.

The Nulon "tech advisor" needs a few lessons in Chevrolet 6 cylinder history .......the fellas here, especially Chev Nut, could bury him in an instant regarding tech matters of vintage Chevys.

I'll put my money, and how to treat my Chevy, on advice from the Chat guys any day of the week. :grin:

For the last almost 40 years have have used 10W-30 in my "old" cars. A 1934, 1939,1950, 1957. Have driven for long distances at high speeds and all in hot summer weather. The detergent is just what these engines need to prevent lifter sticking. Also note thar 20-50 is a high detergent oil. The 20-50 is the viscosity of #50 oil when hot. This means that it is very heavy and takes a lot of force to push it through the bearings. Thus it will give a higher oil pressure. The oil passing through the bearings also cools them so it is desireable to have a lot of flow. The oil must pass through a space no more than .002" or .003" , and less on a fresh engine.
I know it is the practice to use heavy oils in Australia and Europe. Here we do just fine with the mid weight oils. Seeing your car is a 1953 most of its life it has had a detergent oil in the pan.
Back when the 1953's were new we had a lot of lifter problems. The first good oil that came along (in 1954) was Mobil Oil Special. It was the first 10W-30 high detergent oil on the market. It sold for 45 cents a Qt. back then. Most customers thought it was too expensive but it kept the lifters quiet.
By 1955 all brands followed with 10-30 detergent oils as most makes of cars had hydraulic lifters by then.
Todays oil is many times better, thats why most new car engine go for over 200,000 miles today - if the oil is changed on a regualr bases. Today most new cars call for 5W-20 or 5W-30 oils and do just fine. Actually too "thin" of an oil is better than too "thick".
Befor the 10W-30 we ran straight 10W in the winter and straight 20W in the summer. In the southern US they would run straight 30 in the summer.

Gene, this explains it very clearly. I will change over to 10W-30. Mr Mack also recommended this grade of oil and I noticed he is from Texas, and it would get pretty hot in Summer there. I generally avoid driving in the extreme heat anyway, so hopefully will see how the engine runs and if the noise re-occurs after looking at everything mentioned. Once again appreciate everyone's input.

I use either 30W or 10W-30 oils in my old Chevys. Have done so for nearly 40 years and never had an oil related problem. Here in Texas it is over 30C in the summer and 20-25C for the high temp in the winter. The "high" detergent oils have not been a problem even when put into used engines. The technical guys at the oil companies are familiar with the 4 cyl econoboxes and their high crankcase temps but not our old cooler running Chevys.

I prefer the 30W HD oil, as per the Chevrolet guide for our Texas Summer time temperature range but recently I have only been able to find 10W30 Pennzoil or Quaker State at my favorite oil supply store (Walmart)

Tony,

Hope you're doing OK, down under.

Like me, you may have had carbon break loose in a cylinder. This would explain the erratic nature of the "knock".

GM's "top engine cleaner" could be used to dissolve the carbon OR ...as I have done in the past ..... a small amount of water, in an 4 oz cup or so...... run into the throat of the carb, while the engine is running at a high, steady RPM. Do NOT stall out the engine, pour in a stingy fashion.

You'll hear the sound change, then gone. The carbon was dissolved. Worked for me many times in the Chevy dealerships ... back in the day.

Bob

30C???? Now did some foreign country go and buy Texas over night??? Now I know you’re an old codger just like me Chipper, what ever happened to 86°F?
When it comes to the oil issue I have some personal feeling I feel I should throw out on the table.
I certainly have to agree with all the guys that are advocating using modern technology when it comes to lubrication. It’s just plain illogical to think that because your engine is 50 to 70 years old that you should be using 50 to 70 year old lubricants or sticking with the factory recommendations from that period.
That’s like saying that mechanical brakes are better than disc brakes or that bias ply tires performing better than radials or that talking thru a tin can and string or crank telephone is superior to using a cell phone or that snail mail for communication has it all over email or that the Post Versalog slide rule is faster and more accurate than a TI-30. Oops, forgot one, can you even compare the your Webster Unabridged Dictionary with MS Spell Checker??
Taint ya ever heard of “better living through chemistry,” the oils of today are so much better than those of years ago that one would be foolish not to embrace them. And I would bet the farm on the fact that one of the main reasons that these vintage engines are going to be running far into the future is because of modern petrochemical advances.
Shell Rotella-T, 15W40 in my 216 solid lifter engine and haven’t seen a reason yet why I should even consider anything else.
Denny Graham
Sandwich, IL

I am also using 10-30 here in Montana where we can go from -40 degrees to +110, whre I live engines work harder as I live at about 4300 feet and to leave here there are 3 6,000 foot passes to get over. Now back in the day when the 52 was new detergent oils such as Union Oils purple were coming on market there was concern about putting those oils in engines that had been running on non detergent but other than that I recall nothing from Union or Shell regarding any harm The rule generally was to use a slightly heavier oil in summer and lighter in winter generally hovering around the 10 and 20 weights (not multi weights then).

Denny,
Texas WAS an independent nation [some still think it is] and agreed to join the Great Old US of A with some stipulations. No one could afford to buy Texas like they did with Alaska, Lousiana and many other states.

Now I understand both the Celsius and Fahrenheit temperature scales and also the "Better living through Chemistry" since I worked in chemical research for 30+ years. I was just trying to show that we understand and appreciate our overseas brethren. Right Mate?

Ya sound P$%%@& Chipper, hope ya know I was just pullin' your jebber mate. Now all along I thought you were just an old grease monkey!
27 years spent at what was once the worlds largest particle accelerator as a sr. research tech and I had to work with C a bunch over the years, but, I still gotta convert it, never could “think” Metric. Used a lot of K also but can't “think” Kelvin either, I always had to look at a chart; fact is, I hope I never have to look at another cornversion chart!
Denny G
Sandwich, IL

Bob, things are going ok down here, almost the end of Spring, Summer starting in another month. The top end cleaner sounds like a good idea. I'll look for the equivalent product here. Our equivalent of Walmart is K-mart, and they have a good range of auto products.

Also thanks Denny & Chipper.
Having worked as a gasfitter for several years after high school in the early 90s, we mainly used imperial measurements with materials, pipes etc, so am pretty familiar with measurements. For some reason we converted to the metric system including currency around 1966 (not that I was born then). Now what's that got to do with the old chevy ? I just use conversion tables for mass, capacity, temperature, etc when converting to the US system when reading the manual etc, and there is a table in the front of every diary and dictionary usually. Not a big deal, and most of it I've memorised by now anyway, except for temperature so thanks for that Chipper.
One minor issue down here is that speed limits/signs are in Kms so when driving my '53 I need to do the maths in my head to convert speeds to avoid a fine, as there are speed cameras everywhere, and police with handheld cameras in hidden locations trying to fine you; more for revenue raising as opposed to safety factors. For example, doing 65km/h in a 60km/h zone (that is doing 40mph in a 37mph zone). Big issue at the moment.
Incidentally my oven has both Celsius and Fahrenheit on it, so that way I don't burn a good Aussie roast lamb dinner or nice roast Kangaroo. Thanks to all my mates on this forum:grin:.

Tony,
If you use a product that is poured through the carburetor air horn with the engine running let it stand and soak over night if possible. It will makes a lot of exhaust smoke. I usually run the engine at a fast idle and pour it in slowly, keep doing it until alsmost all is used then pour the reat if fast as to kill the engine. THEN DON'T FORGET TO TURN OFF THE IGNITION.
If you find Marvel Mystery oil that is good for the useage.
We have K Mart and Walmart here.

Tony
The "Nulon Carb and Injector Cleaner" is about the best available here in Aus. Best method is to put the bottle full into the near empty fuel tank then fill the tank.
Subaru sell a upper cylinder cleaner in a pressure pack that is sprayed in while the engine is running at a fast idle (1000 to 1200 rpm) that seems to work reasonably well. I have used it several times.
Tony

Denny,
Not a bit P$%%@& just standing up for our beloved TEXAS. You know that we have a reputation to uphold.

Tony53,
It seems that when operating in metric world those units seemed natural. The exception was temperature. Had to always think about conversion 9/5 + 32 never took hold. Thought it was interesting that -40 was the same for both C & F.

I also used the GM carbon cleaner using the directions by Chevygene. It was many years ago. Was most impressed with the amount of smoke it produced. So make sure to do it outside! Don't know how well it worked as I never took that engine apart. Was running when I gave it to my brother. There are actually some automotive chemicals that work but you have to search to find them. Too many are sold with exaggerated claims backed by testimonials or special testing only no real scientific data or testing. It is a shame that the "snake oil" salesmen are still with us today.

I wonder how they even got a Apollo space ship close enough to the moon , with slide rule accuracy. Ha!

Well Denny Graham,
I didn't realize that you were an old codger with new ways.....I haven't figured out how to change the batteries in my Post Versalog (1955 model) I do have a hard copy of the Versalog manual, and it sure don't help in regards to changing the batteries, by the way the batteries in mi TI-30 are needing changing too, as are the batteries in my TI5008. know where I can get a new little do-hicky that does the printing (burns the numbers in the thermopaper?)
:vcca: I drive an Old Timey Car but my computer is up to snuff, It says it is now 57 degrees outside... and so is my oils and greases, now if I could just find some of that good old Texaco Firechief Regular!... :vcca: yet I is stuck with a boss that is almost as old as I am, Hallelujah! I don't think I could even start to stay up with a younger one!

Was we talking about a knocking 1953 Chevrolet engine? I bet it can be fixed without replacing the whole thing.....

Think your right, maybe we should get back on track.
Clunk, thud, rap, slap, those sounds are pretty difficult to put down on paper, bout the same as trying to describe a smell! Over the summer my 1950, 3600 with its original 59k 216 has started to give me a rather solid “clunk” when I start it. It's only there for a few revs until the oil pressure starts to register. I’m carrying around 14lbs at cruise and around 6-7lbs at idle but I suspect that I'm bout due for mains.
When I did the valve job a short while back there was about .008" or .010" ridge at the top of the cylinders so I think I'm also in for a little re-bore. With winter fast approaching it might be a good time to get the short block rebuilt. I'm also hearing a sharper metallic rattle (not a ping) when I apply throttle at cruising speed it increases the more throttle I give it and I'm not really sure what that is. It maybe a combination of all the wear combined in the bottom end.
What does have me most worried is that I’m getting a little bit of yellow/tan frothy discharge from the breather over the last few months. Not much, but when I go out in the morning there is a blob about the size of an olive dropped down on the concrete from the breather. There is nothing showing up on the dipstick and didn’t see anything under the rocker cover when I last went over the valves a month or so ago. I always drive her long enough to get the engine up to operating temp at which point I also see the oil pressure gradually drop from 25-30lbs down to 14 or 15lbs. This frothy bit of puke may very well may be at the heart of my coolant level not staying up where it belongs which we discussed in another thread. I can’t see where else it could be going.
So I guess some serious engine work is in order this winter.
Gonna try an do a leak down test this weekend and see if I can nail it down.
Denny Graham
Sandwich, IL

I hate to say this but the yellow/tan frothy stuff is most likely from water or coolant or both mixing with oil vapor. Now the water can easily come from exhaust gas bypassing the rings. That is very likely the source if you don't find any indication of brown or tan gunk in the oil. I would not be too concerned with a little of the stuff as long as the oil stays clear and not milky. Yes it will darken with use particularily if you get appreciable blowby.

The clunk or thud is most likely from main bearing gaps that are a little too wide to retain a full oil film. Some of the oil drains away when the engine is not run and it takes a few seconds until oil flow again fills the space. It is a sign of needed attention, maybe not immediately but soon. Sure wish we could do a little tightening on our ourselves as easily as the old Chevy engines.

Yeah, that’s the conclusion I’ve come to also Chipper. I’ve thought about trying some patches like just breaking the glaze in the cylinders, cleaning up the old pistons and re-ringing it, but it really should be re-bored. I could drop the crank a bit and slip in a new set up mains and might get by with that but I would really rather have the crank re-ground. I might be able to pull a few shims and prolong reworking the rods but in the end I want to have them machined for inserts and using the old pistons and rods I still haven’t addressed the wrist pins which are probably sloppy by now. Then ya got the cam; I really wouldn’t put a new cam and timing gears in without new bearings. So in the end I think my best bet is just to nurse her along for a couple more months and plan on pulling it this winter and have it all done the right way. That should keep me rolling with out worrying for another 34 years till I hit the big 100! That’s the day I’m gonna turn in my drivers license and hang up my driving goggles.
I know the rings are bad, especially the scraper since I’m using a quart every 100 miles or so. No visible smoke yet if there were I’d shut her down immediately and do the engine work, that would be way to embarrassing.
Denny Graham
Sandwich, IL