68 Roadster over heating

[Chevyguy68]

Have a 68 Roadster with a 427, bought the car in Spetember. In late October, went on a road trip. About 300miles one way. No problems with it what so ever. On the return trip made it about 60 miles and it over heated and lost oil pressure. Had no tools on me so had it towed and the shop could find nothing wrong. Trailered it home just to be safe. haven't done anything to it since other than a few short trips around town. Any ideas as to why this may have happened? Would like to go on another road trip in the spring.. Thanks

Mike

[Bob Weiss]

What a loaded question.

1) Could be blown up (spun bearing(s)).
2) Could have blown head gasket.


Did you shut it off right away?
Does the engine turn over?
Does the engine oil look like choclate milk?


As far as overheating-Could be many problems.

Fan Shroud? Water in system? Clutch fan? Do Car have A/C? When was cooling system serviced? How about Radiator (original/Replacement/aftermarket)?

So many questions.

Bob Weiss

[carboman]

Bob had it right, far to many potential issues to diagnose from your description. Sad fact is that 68 big blocks overheated when brand new. Run your finger over the front of the fan hub. If it's really greasy and dirty could be the clutch fan is shot and not providing any cooling. Could be a clogged, under filled, or incorrect radiator. Dewitts makes and excellent replacement that looks stock when painted but offers a ton more cooling.

As Bob suggested if could be a head gasket. Is the exhaust always steamy? Does it smell like burnt anti-freeze? Does coolant disappear after topping off the radiator and overflow?

As for the drop in oil pressure that could be related to the overheating but I doubt it. How clean is the engine inside? It's worth pulling a valve cover to see how much crud is in there. If there's a lot of build up of crud the oil passages could be partially blocked. There are ways to clean that out without hurting anything.

[Joel Fellman]

Sounds like a job for Super Steve at Bryner Chevrolet!! Want it fixed - right - first time, give them a call!! 215-886-3140. That's all I have to say about that.

[JSPERFORMANCE]

As stated above there are too many different problems that could cause your end result of break down. The engine will have to be pressure checked first to see if there is a leak in the cooling system (ie. head gasket, radiator, etc.) If there are no leaks present in the cooling system the condition of the engine has to be assesed. If the engine checks out ok the root cause for the overheating must be found, be it a bad fan clutch, clogged radiator or other. Either way you cut it this is no problem to try to diagnose via the internet get the car to the shop of your choice asap in case there is water in the cylinders which could cause rust.

[red68vet]

Hi Mike, I also have a 68' roadster. Mine has the L36, 427/390. If you are able to drive it on short trips, does it heat up? If not, check the thermostat, maybe it stuck on the long trip? Replace it with one that fails open. As far as the loss of oil pressure, you probably cooked the oil when you overheated. This would lead to thermal breakdown and little viscosity. Just my thoughts. Good luck.

Ken