When is it time to rebuild your engine?

[Graham Man]

Ok I have had lots of cars and fixed lots of problems, but I have never had an engine I could not get to run well.  Some engine smoke is just part of old cars for me, usually stuck rings from sitting.  I watch the oil pressure, and listen for ugly noise.  Normally driving them helps the most.  Have I just been lucky?

[paulrhd29nz]

I have friends that tear the engine to bits for one small oil leak or a tick. Thousands of dollars spent and time not driving. 
my 46 Hudson 8 truck has 12 thou taper in the bores , it’s smoked a bit, it’s a little noisy. I have new .30 over pistons to go in it. Have had for a while. I keep an eye on the bottom end. I‘ll drive it till either power loss is an problem or it’s to embarrassing. 
It’s also fun to just keep them going. 

[edinmass]

Depends on the vintage and quality of the engine company. The big question is how easy it is to get another block and if it will effect value............take a chance on a Model J Duesenberg block? Not at 200k for a replacement. On a Chrysler six? Why not.

[Bloo]

Any sign of lower end or bearing trouble means the car shouldn't move another inch. Bad valves require at least a valve job if not a complete overhaul, because you will never get it to run acceptably. Worn rings? No big deal within reason. Just keep it FULL of CLEAN oil.

[trini]

The rule of thumb "run your finger nail up the ridge. If the nail catches the ridge it needs an engine job. " Otherwise leave the engine alone. Valve jobs can be done with the block in the bay but you may have to stand on your head at times.

Blloo is correct to say keep engine oil clean. Cheapest insurance. Run the engine as much as you can even a few hours a month until the engine gets hot.

[Rusty_OToole]

Before the rod is sticking through the block is as good a time as any.

[Graham Man]

My son just bought a 2008 Lincoln with a huge hole through the oil pan, rod dangling out for $400, they forgot to check the oil.  He plans on putting in a new engine and flipping the car.  As basic as the last 100 years of automobile ownership has been, you still have to check the oil.  How long before the computer just shuts it down when the oil is low?

 

Edited December 27, 2019 by Graham Man (see edit history)

[Rusty_OToole]

Chevy Vegas had the ignition wired to the oil light, if one ran dry of oil the engine shut off before it hurt itself.  Lots of owners did not know this, when the engine quit they sold the car for junk, but all you had to do was put in a quart of oil and it was good as new.

[TerryB]

Lack of blue smoke out the tailpipe was another good way to tell if your Vega was out of oil.

[Graham Man]

I started the question because so many people talk about rebuilding their engines.  I watch the oil level/pressure, change regularly and listen for bad sounds.  I agree with a more valuable engine you would want to be more cautious, with a 1977 Ford, not so much.

 

Thanks for all the help

[FLYER15015]

Last line = "Thanks for all the help".

Now there is a forum member with MANNERS.

Don't know his name, but he's got manners, and this is currently being discussed in the "General thread".

 

And X 2 to what Rusty said.

 

Mike in Colorado

[C Carl]

The absolute necessity of properly checking the bearings when dropping and cleaning the pan can give you a go/no go answer as Bloo warns above. You may also find a "take it very easy" result, to last you for a limited amount of miles. You know : heavy-up the oil. keep your foot out of it, and spend some of your discretionary slow driving time doing other things. Like working some overtime to pay for that which you can not do yourself for the impending overhaul. Another component seldom mentioned, is timing chain and gears condition. The the results of checking these can also mean no go in some cases.   -   Carl 

[Bloo]

21 minutes ago, C Carl said:

Another component seldom mentioned, is timing chain and gears condition. The the results of checking these can also mean no go in some cases.

 

This^^  Although you may be able to take care of it without an overhaul. Some cars in the late 60s and 70s had PLASTIC timing chain sprockets. When it fails it is like having a timing belt break on a modern car. There is no possible way you are moving another inch without a tow. Like modern cars with timing belts, some (but not all) of these are "interference" engines. "Interference" means that when the sprocket breaks, it bends valves, and the car won't run again until it has had a valve job (with a bunch of new valves). On some cars, residual plastic can get sucked into the oil pump, twisting the oil pump drive off and causing catastrophic engine failure. If you have one of these plastic timing sets in your car, get rid of it now, before it leaves you stranded.

 

Some Prewar and early postwar cars have gear driven cams, and gears made of fiber. When these strip, it is the same deal. You aren't moving another inch. It probably pays to preemptively replace these if their condition is questionable. For some engines, aluminum replacements are available. Aluminum was often used in trucks for better reliability, but it is much noisier.

Edited December 28, 2019 by Bloo (see edit history)

[plymouthcranbrook]

On 12/27/2019 at 11:31 AM, Rusty_OToole said:

Before the rod is sticking through the block is as good a time as any.

Where were you when my Father was driving back in the 50's and 60's?  Three out the blocks that I know of. Two Mopar flatheads and one slant 6.  Changing oil was a waste of money.

Edited December 29, 2019 by plymouthcranbrook (see edit history)

[JACK M]

One will have plenty of time to rebuild the engine while that lamo painter is wasting your time.

[Pfeil]

When is it time to rebuild your engine?

 

When the engine doesn't pass the normal sounds of a engine, doesn't pass the leak down and compression test, doesn't pass the smoothness test and runs rough dropping cylinders, doesn't pass the exhaust pipe test and smokes, oil leak test. 

 

  You may get by with a smoking engine going down the street, but it gives us old car enthusiast a cringe because you know someone in the neighborhood is going to be the loud mouth advocate for getting old cars off the street! Especially in this sensitive snowflake era.   

[John_Mereness]

On 12/26/2019 at 5:16 PM, paulrhd29nz said:

I have friends that tear the engine to bits for one small oil leak 

They all leak - at least pre-1950's 

[John_Mereness]

So, why do you think you may need an engine rebuild ?