Greetings Gents (and Gals)I'm the proud owner of a nice litl black 73. Bought this one knowing she had a major issue (but hey, $800 bucks for a complete RUST FREE SL with hardtop and 67K orig was a no-brainer).
Here's the deal: Water in oil and an o-heat issue was the reason it got parked about 3 yrs ago (presumably) - The previous owner (i was told) did a "pick-n-pull" head replacement to remedy a problem - likely due to overheating - or the same problem still present of the "liquids" finding each other (oil and water/ethylene glycol) UGGGH....So, without belaboring things - what would you do? I am faced with a few options from excising this powerplant and dropping in a working used one from a kindly healthy donor. Next, I could do a compression check, at least to "look" for which area of the head, head gasket , or (god forbid) the block - is breached.

Pulling the heads and going thru the top end of the motor would most likely be easier than a full transplant - BUT - I hear so many mixed stories concerning the extent of damage that occurs when Worlds Collide (or - uhhhm fluids) - again, oil and antifreeze - SOME say it will etch the crank, bearings and so on which will cause early failure of the bottom end when put back together - others seem to ignore that theory and just proceed with the mantra "son - that bottom end is so stout it will run another 250,000" - WHO TO BELIEVE HERE???Any Opinions From the Cogniscente Here?????
Anyone have an "early" 8 (Bosch D-Jet) lying around for sale and with no known issues (and best yet - balanced and in spec compression on all 8?)???
Cheers (and thanks in advance for the input)

Jack King in Salt Lake City

 

Hi,
IMHO not possible to tell what's best without a look see.

The oil and water COULD have mixed for a relatively trivial reason i.e. head gasket / oil cooler (modine water type) or alternatively some catastrophic event MAY have happened!
The presence of water in the oil if left over a long period COULD have damaged surfaces thru "rust" / etching. On the other hand these bearing surfaces COULD be OK or at least serviceable. I don't suppose you intend using this motor on the track!

What would I do?
Guess I would remove plugs, pour/spray in a LITTLE light lubricant and crank (need good battery etc.) the engine over to get the "oil" moving around.
I would then do a compression check to see what it tells me.
IF compressions are OK (ish) I would change oil (optional?) etc and see if I could get the engine running and then proceed from there.
IF NO / inadequate compression on one or many I would take the head off the offending side(s) and have a look at what has been going on.
Best not to remove a cylinder head unless there is good cause.
With this info I would then ask. What next.

Stuart

 

Water in the oil long period WILL damage bottom end components. While you can get some idea of where the breach occurred by doing a compression test, and be able to gauge the severity by doing a leak-down test (you can also blow compressed air into each cylinder after putting it at TDC for that cylinder and that will tell you whether you have piston/intake/exhaust/gasket problems by where the air comes out) the only way to assess corrosion on bottom end components will be to pull the oil pan and look up or to pull and disassemble the engine.

However, if any of the components are rusted, turning over the engine will only cause further damage due to circulating rust particulates.

I think I would plan for a worst case scenario and price the difference between a good used engine and having yours competently rebuilt. Simply pulling the heads at this point is probably not a good idea since you really need to verify the extent of the damage. Who knows? You may get lucky and have a clean, intact bottom end and simply have to clean things up and re-assemble. At least you'll know.

I've brought many a vehicle back to serviceable driving condition after years of improper storage. I don't even bother to check the engines anymore. I simply pull them and rebuild them. My experience has been that you can get them running, but they will all have major problems that will precipitate out within 300-3000 miles - necessitating that engine rebuild you originally decided to skip.

If you plan on keeping the car and enjoying it in the years to come (and preserving value) - go ahead and pull the engine and have it rebuilt. While it greatly increases your initial acquisition cost of the car, it decreases long term maintenance costs and you'll be a lot happier with the end result.

 

Hi cycleboy,

Yep a complete rebuild is the only real answer BUT as you said yourself you just might be lucky.

Some corrosion WILL have taken place but if this ivehicle is to be used as a low cost transport rather than a show or race car (where everything just has to be perfect)_ you MAY just be lucky and get some life out of the old unit.

Oil and water mixing isn't really the issue. Its how long this acidic mixture is left in contact with parts and air. 3 years is a loooong time.
For rust you need oxygen so the bearings could escape and remain serviceable. I guess this is why there is a difference of opinon in the original post.

The cylinder bores are another matter and there will definitely be rust. Not good but COULD still be serviceable.

Since the guy was considering a replacement engine is there much to be lost in giving it a try?

Bottom line is ... How much rust has formed. How much time and money you want to spend and what the outcome objective is.

I was coming from a minimum budget and a wing and a prayer direction.

 

I completely understand. I've given up on wings and prayers. The rings will most likely have worn grooves in the cylinders and will immediately scour themselves and the cylinder walls when turned over. If he's super lucky then the coolant in the bottom of the oil pan will have raised the oil level sufficiently to cover some of the crank journals, but I wouldn't hold my breath.

I guess what I'm trying to say is that other than hoping to get lucky, rebuilding the engine so that he's dealing with a known quantity is the cheapest option in the long run. Even if he's not going to use it for a show car, if he's going to drive it anywhere it's going to fail if he doesn't rebuild/replace it.