1970s 1973 coupe deville

[34837]

Hi, another crazy question. I knew there were minor oil leaks on this motor which has 82000 mi. and runs great except needing a carb rebuild happening soon. After putting the vehicle on a lift at a shop it was determined that there are numerous leaks from gasket failure, all the usual, pan gasket,manifold gasket , probably both front and rear main seals etc., you get the idea. So- if I pay a shop to yank the motor clean it, replace the failing gaskets and whatever but not an internal rebuild am I saving much money or being foolish? Last I checked a rebuild to stock can be $5000 to 10 grand, labor rate at my shop $95 per., not in the budget. Or I can just ignore it and hope for the best. Any thoughts appreciated! A.H

[35-709]

All those things can be changed with the engine in the car.  As to the rear main, be certain first that the oil pressure sending unit at the back of the block isn't leaking, allowing oil to run down the backside of the block, making it look like a rear main leak.  The oil pressure sending unit is a WHOLE lot easier to replace and it is not uncommon for them to leak, requiring replacement. 

[TJ Hopland]

How bad are the leaks?  Once you dig in on any level there will be A LOT of might as wells and as long as you are theres which means time and or money. 

What's the cars recentish history?  How much has it been driven?  Are the valve cover and oil pan bolts all snug?  They are likely cork gaskets so they should never be 'tight',  that will just damage the 'tin' pan or covers. 

Overall these engines are not known to have issues that require them to come apart like many others often do.  Head gaskets are rare, bearing issues are rare so just removing and resealing the 'tins' is often a viable hope.  One 'time  bomb' these engines do have not all others did is they had a plastic covered cam timing sprocket.  Age and mileage were not kind to them back in their day and now in the half century range its all age.  I don't think I would trust a plastic one I had stored on a bookshelf with no heat cycles or exposure to oil so one that has been in an engine?  Heck no. 

Good news is these are not interference engines like most are today.  Interference means if for some reason there is a failure in the timing system, belt, chain, or sprocket the valves will come in contact with the pistons and at a minimum destroy the valves but could also take out the pistons and bearings and who knows what else.  These engines if that happens it just quits running.  Other good news is there is a by the book process that you can replace the chain and sprocket in the car. 

Just because you can should you?  Dunno that's a tough call. These engines are not that hard to get out of the car if you are set up to do such work so given that you also want to deal with the leaks and if there are leaks there is likely cleaning to do that would be easier with the engine out?  Has the transmission been rebuilt in the last 20 years?  If not its due and even if it appears to be working fine its likely got some petrified soft parts that are not doing what they are supposed to do anymore so its not working right and will at some point start damaging hard parts which is where it gets really expensive.  You got the transmission out how is the drive shaft?  Ya learn about double cardin joints or find someone to work on them?  Oh the rear end has a wet spot?

How bad was that oil leak again?  Ya you have some spots to clean in your parking area and have to think about where you park and for how long but at least not a lot invested.  Ya your timing sprocket  could fail and leave you stranded,  trans could fail and leave you stranded but you haven't invested $1000's you apparently don't have yet. 

Especially if the car or classic cars in general are/is fairly new to you I would suggest making sure you are up on safety stuff like brakes, tires, steering and see how much you drive and enjoy the car.  You may find that you don't enjoy it enough or just don't have the resources to play the classic car game and need to move on and will be glad you didn't invest more that you won't be able to get back selling.  You may also find that you really enjoy the car and you can trade some other expensive thing you do for this expensive thing that gives you more enjoyment at which point you will have and want to spend the money for all the you might as wells and while you are theres.       

["Cadillac Kid" Greg Surfas 15364]

Bad news TJ, a 73 is definitely an interference motor. Large chambers started in 74. Timing gear/chain slip, valves go boom
Greg Surfas

[TJ Hopland]

Bad news TJ, a 73 is definitely an interference motor. Large chambers started in 74. Timing gear/chain slip, valves go boom

Good to know. Guess I got lucky on the ones I tangled with that turned out to be missing all their plastic and had slipped.  They came to me not running and you could tell by the cranking that compression wasn't right. Peeked down the dizzy hole to confirm that was where the issue was. Slapped a timing set in em and they lived again.  I was never had the heads off those motors so no idea the exact combo of bits I was dealing with.  They were not my rigs, just people that came to me for help so I don't know how long they lived either. 

[34837]

Thanks all, the first thing I need to do is find a garage willing to throw it up on a rack  so the afflicted areas can be cleaned and the leaks fixed if plausible. Not having much luck with that in my neighborhood, doesn't fit the business model of get-it-in-and-out as quickly as possible. A.

[TJ Hopland]

Yep you are learning about one of the many challenges of classic car ownership especially these days.  Finding a shop willing to try is just the first hurdle.  Next one is will they have the required skills to actually help?  Or will they make it worse while costing you time and money in the process?  Those are among the reasons many of us do as much as we can ourselves. 

An important question is are you willing and able to do some work yourself?  Don't worry about limited tools and knowledge, those are fairly easy to deal with.  Able is the big question in both physical ability and a place to work.  If you can't bend over and get on and off the ground easily and can't lift more than a couple pounds there isn't a lot you will be able to do.  Having a space to work is also important.  Owning your own house with a garage or being in a more rural setting should not be a problem but if you are in a more dense area with no space and things like a Home Owners Association or landlord to please things can be a lot more difficult.