Was driving down the highway when a series of loud
‘Clunks’ came from the engine followed by it turning off at 70mph. I pulled her over and tried to start her back up. But white smoke came from the oil cap.
I checked the dipstick and there was much more oil than should have been there. And it was yellow. Like coffee.
A couple more tries and she stopped turnin over altogether
My friends say it’s head gasket. Maybe? Bent piston too?
I’m told it’s easier and cheaper to replace the engine. Plus it’ll come with a warranty.
Any advice?
She wasn’t running hot. All was fine up until it wasn’t.
At the least a blown head gasket maybe more. If it’s the “born with” engine I would be inclined to have it rebuilt; if not you’ll have a big decision as to how many “ponies” you want to put under the hood.
Doesn’t sound promising. Best bet is to drain the oil and see what comes out. Sounds like it might have coolant contamination which could indicate a head gasket issue or worse. Also I would pull the plugs and turn the engine over by hand to see if it’s hydrolocked from coolant entering the cylinders or if it’s locked up from a mechanical failure.
Which way your repair it will depend on the extend of the damage and how set you are on the original(assuming it may be) engine going back in.
Ssava, put a socket and wrench on the crank pulley bolt with the plugs out and see if you can turn the engine over by hand. 1/2" or 3/4" drive on the ratchet works best.
The lower pulley on your engine is the crank pulley. The bolt that holds it in place is in the very center of it. It will need a larger size socket, I forget exactly what size. Something like 15/16. Depending upon the length of your socket you may need to also use a short extension. Then put a breaker bar on the extension, place the socket on the bolt head and try to move the breaker bar. You should be able to move the it in both directions if nothing is wrong inside your engine. Before you try to turn the breaker bar you will need to put the transmission in neutral so be sure to block your tires to prevent even bigger problems.
Most likely what has happened is a head gasket failure between the water jacket and an oil passage. That let coolant mix with the oil. Since water is heavier than oil it went to the bottom of the oil pan where the oil pump pick up is located. Water makes a lousy coolant. It probably caused a bearing failure at the crankshaft. Many times the bearing, sort of a bronze looking sleeve, will stick to the metal of the crank shaft and spin with the shaft causing untold havoc. It really sucks. If this is the case, then you would want to rebuild the engine replacing all of the internal bearings. This is a big job and one you would probably want to farm out.
Very sorry for your misfortune, but on the bright side, now you have so many options.
If you have the original block, I’m sure it can be machined. You can choose to overbore it and add a mild cam, and add something like GT40 or Edelbrock Performer heads.
If you don’t have the original block, but you want to take the car back to original, WCCC sells rebuildable cores that they’ll date match to your car.
If you don’t care about originality and want to go the cheap route, there’s engine exchange places that sell remanufactured motors fairly cheap, usually with a one year warranty.
You can also order a new crate motor through Jegs, Summit or CJ Pony Parts. They have stroker options where they can get 500hp out of a 302 block.
If you love to deal with wiring, you can score a late model fuel injected 5.0 and drop that in.
Two things to remember:
If you go with a 70 or newer 302, they have 4-bolt crank pulleys, so you’ll either need to change the harmonic balancer to make your 3-bolt crank pulley work or buy a 4-bolt crank pulley with 3-bolt spacing of the Vs.
If you go with roller heads, the cool Cougar valve covers won’t fit.
Oh man, that really stinks. Reminds me of when I lost a valve on the highway in my 66 289. When I pulled the engine apart the valve was actually imbedded into the piston. I still have that piston around somewhere.
The failure was in the worn valve guide and valve stem. However, it was a big backfire under hard acceleration that led to the failure, and I finally traced that down to bad wiring on the back of the ignition switch which would heat up and basically shut off the engine momentarily.
It was the original engine in that car, so I had it rebuilt bored .030. I think it was about $3k all said and done, but that was back around 2001.
