Cost for a 500 rebuild

[benji808]

What are ballpark reasonable cost and timeframe? I realize they may vary between different geographies but curious what some folks have paid. Not sure when but it is likely in the cards for me at some point.

["Cadillac Kid" Greg Surfas 15364]

Benjamin
Depending on how much of the work you do yourself a "legitimate"'rebuild will run upwards of $5k. " bargain " rebuilt have historically proved to be no bargain.
Greg Surfas

[TJ Hopland]

I did my last one close to 10 years ago now and I recall having about $3500 into parts and machine shop work.   I did all the disassembling and assembling with some help from friends.   If you were also playing for that I could see that $5000 number being pretty easy to hit.

Do you know something is wrong with yours?    Its not that common to have major wear issues with these engines.  Many times you can yank them out and pull all the 'tins' to do a good inspection and cleaning.   Most times they will just a timing set and some new seals and gaskets.   

[benji808]

Thank you for the info! Makes sense, and yes, I may be premature in checking, but I seem to have some significant variance in compression, so that is one of the possibilities. More diagnostic testing underway so hopefully something simpler.

[Big Fins]

You're looking at higher that $5G's if you can't pull and replace it yourself. If this is in an Eldorado, the engine and transmission is easiest when pulled as a unit. The weight is not for the faint at heart and a top quality engine hoist will be needed.

Then the old adage comes in, while it's out...
Clean and repaint the engine bay, refresh the transmission, maybe the CV axles and on and on and on. $$$$$$$$$$$$$$$$$$

Buy hey, on the plus side, your wife will always know where you are. In the garage! 

[chrisntam]

I spent about $10k, having it done by a Cadillac performance specialist (MTS/Cadillac High Performance).  I took the motor to them, they rebuilt it using upgraded parts I selected from them, they sent it back to me, I installed it.  That was in 2014, engine is still doing fine.

[Scot Minesinger]

It also depends upon where you are in the Country.  In NY or LA it will be more than in the central USA.  My 472 was rebuilt in 2005 by a high quality machine shop in the area, which including removing and replacing the engine.  The cost was 7k (the charge to remove and re-install engine was 1.7k, so 5.3k for the re-build).  This did not include a valve job, which if anything should be done first along with timing chain.  Since then it has accumulated 48k miles, and she runs very well.  I did have to get a valve job done though.  Usually this does not include a carb re-build which is also usually required.

As others posted - why a re-build?  I would perform a valve job and timing chain replacement first. 

Highly recommend doing as much of it yourself as possible, especially pulling the engine.  If you hire the entire thing out, remove engine (hood has to be removed), valve job, rebuild and re-install engine, it is likely well into 10k.  Also consider where will the car be while the engine is rebuilt - outside in the rain or in your garage?

[benji808]

Good thoughts- thank you! It's the "slippery slope" conversation. Compression test indicates I have significant (30lb in one case) variance between cylinders. Doing further diagnostics (leak down etc) to figure out exactly what it is. I'm also wanting to replace oil pan gasket and RMS to stop oil leaks, which require engine to be lifted (I can lose a quart in 2-3 hours of driving). At this time, I don't have space to safely pull the engine myself, so was planning to bite the bullet on cost with a shop.

So if I'm pulling the engine to do pan and rms, I'll go ahead and do timing chain, then if I have, say, a valve job as well, I might already be in ~$3k...so if it's another $3k for an engine I don't have to worry about (now finding someone I trust to do it may be another matter), that may be worth it.

It will all work out- thank you all for your input and for humoring my musings 😁

[TJ Hopland]

Wow a quart in 2-3 hours is a lot so you do have a serious issue going on there.  Can a rear main even leak that much?  Or do you have some other major issues like some really bad main bearings letting it flop around?   I'm thinking there may be an oil galley plug on the back of the engine, I wonder if you could have one of those rusted and leaking back there?   

It will be interesting to see what the leakdown test shows.   Maybe find someone with a bore scope to peek in that one to see if anything looks unusual?

[Cape Cod Fleetwood]

Had my 472 completely rebuilt last year, the only things stock are the block and headers.
Pro shop removed the engine and sent it to another pro shop who did the rebuild including dyno, 1st pro shop detailed
the engine bay, re-installed the engine, shook it out and handed me back my keys. 10K
This is MA.

[TJ Hopland]

I also just went and looked at your other posts and assume this is with your 75 Eldo?   With an Eldo you can't just prop the engine up to get the oil pan off.  Engine and trans have to be spit apart to remove the pan which means one or the other has to come out of the car. 

I think a bore scope would be a good thing here.  Figure out where that oil is coming from and after the leak down why that one hole is lower than the rest.   Like we have been saying serious issues are fairly rare with these engines but they are pushing 50 years old now so they have been through a lot.   

A good thing is they are not especially rare or expensive so if a proper rebuild isn't really an option for you you can still often find a decent running car to pull and engine from for a couple thousand dollars.  If you have the time and space parting out the car can get you a lot of that money back if its got some decent parts.

What makes it an Eldo specific engine is just the oil pan and pickup tube being different and the dipstick is in a different hole in the block to match.   You can get an engine out of a RWD car and swap/move that stuff and it will bolt in.   Even a 425 out of a 77-79 will bolt in so if you happen to find a great one of those it may be worth considering even though it won't be correct and it will have slightly less power.   Just depends on your situation.   

[Cadillac Jack 82]

10k seems a bit high.  I had a 68 430 (yes, not Cadillac but an odd size motor) rebuilt earlier this year for around 5k.  Granted it still had some clearance issues on the valves but that was due to poorly constructed parts.  I'd say 6-8k should be the target.  10k seems like someone is taking you to the cleaners just because its Cadillac.

["Cadillac Kid" Greg Surfas 15364]

Depending on EXACTLY what parts and using a QUALITY, KNOWLEDGEABLE machine shop you use, and with you doing the R and R of the motor and accessories, a good place to begin is about 5K. You can go up from there. I have over $10,500 in my (511 inch) motor and I did all the wrench work myself.
Greg Surfas

[Big Fins]

Look at the rear center top of the block, right behind the intake. Specifically the oil pressure switch. These are notorious for leaking and can dump a 1/2 gallon of oil in no time. It gets pumped out and runs all over everything leading you to believe you have major gasket failure. It's a $10 part that can cost you thousands.

[benji808]

Well, shop is confirming bad news (wanted a professional to test out what my inexperience suspected). Compression test shows a high of 170, a low of 140, and several in between (one ~144, a couple 160s etc). Leakdown was 25% - 30%. They also said there is about 1/4" of play in the crankshaft. This shop seems trustworthy, and doesn't do rebuilds, so doesn't have a vested interest.

So looks like a rebuild is in order. I suppose that's what I get for buying a "diamond in the rough". I'm getting some quotes and will go from there...so far looks like $7k-$9k with R&R is likely, or $4k-$6k without.

I appreciate everyone's thoughts!

[bcroe]

Just my opinions, I would NOT rebuild an engine with that level
of compression variation.  As long as oil use is reasonable and
it makes no bad sounds, likely it will go a lot more miles.  I
have had way too many rebuilds turn out badly. 

A quart in 3 hours is bad, but first determine where the oil is
going.  A bad gasket or rear seal does not require a rebuild. 
Pulling an engine to fix these is not an expensive deal if you
can do it.  Many pull the engine and trans together just to
avoid some work under the car.  I always pull the engine first,
to avoid having so much weight on the hook, and to lessen
the chance of it swinging around doing collateral damage. 
Yes an Eldo requires a support for the final drive, I use a
chain. 

This month someone wrote about a beautiful 79 they bought,
but the mechanics could not run it.  I told him to replace the
timing chain, that cured it.  good luck, Bruce Roe

[Cape Cod Fleetwood]

10k seems a bit high.  I had a 68 430 (yes, not Cadillac but an odd size motor) rebuilt earlier this year for around 5k.  Granted it still had some clearance issues on the valves but that was due to poorly constructed parts.  I'd say 6-8k should be the target.  10k seems like someone is taking you to the cleaners just because its Cadillac.

LMAO!
6K for the total rebuild from a real engine shop, with dyno.
4K to the resto shop to remove engine, take engine to engine shop, bring engine back. detail engine bay, re-install
engine, shake down the car.

[wheikkila]

You stated the shop said you have 1/4 inch of play in the crankshaft. That is a lot of play. I would think you would have knocking noises with that much play. If the engine is quite and runs good I would rethink a rebuild. I would also find a different shop for a second opinion.
If you don't turn wrenches then $7 to $12 would be a turn key estimate for a rebuild. But the hardest thing to find is a good shop that will do the job correctly. Good Luck to you!
            Thanks Wayne   

[TJ Hopland]

That 1/4" play is also a very unusual issue to have with a Cad.   Most common time you see that is with manual transmissions from pressure from the clutch but we know that wasn't it.   It can sometimes happen in autos if the converter swells up but that tends to be more of a truck hauling a lot of loads issue,  not a car, even a heavy car like ours.

Thinking further I don't think the thrust part of the bearing with the thrust flange on it is that thick so if it is that much the bearing has to be gone and its ground into the crank and main cap.   If this engine is really that bad maybe looking for another one would be better than fixing this one?   

[Jeff Rosansky CLC #28373]

1st thing is to be sure you have multiple opinions. That 1/4" play is enough to make you question if the mechanic really knows what they are doing or if they are just trying to buy Christmas presents for their extended family with your money.
If you go the rebuild route, be sure to be in control over what is done.
Mine was done and the owner of the machine shop/builder was very sick and I had poor communication with him. When it was done he died and I had to get it out of there fast. I ended up paying more than I expected and it's always been off just a bit.... But I got the engine back.
Good luck.
Jeff R