: 1998 DeVille Overheating

07-29-10, 08:51 AM

My 1998 DeVille is over heating and bad head gaskets.

Tried Barrs Leak & Barrs Leak Aluminum.

After flushing all Barrs out, tried K & W Nanotechnology Permanent Head Gasket & Block Repair.

Pressure tested holds 25 lbs. pressure.

Replaced Radiator & Thermostat.

Help is appreciated! Thanks.

07-29-10, 11:43 AM
If the sealers haven't screwed up the block and heads it's time for a top overhaul. Include a good head check, too: the cam followers are prone to wear through the case hardening and develop dishing which ruins the cams. The lower end is bulletproof so don't open that up unless you have some pretty severe oil pan or halfcase leaks.

The engine and drivetrain comes out the bottom - you lift the car off the entire assembly.

Do some reading in www.northstarperformance.com (Jake's head stud site)

The cause of your problem cannot be fixed with any sort of sealer or magic: One or more head bolt hole threads are failing causing head bolts to lose clamping pressure and allowing exhaust gas to blow into the cooling system, overpressurizing it and blowing off coolant which causes overheating. NOTHING will regain the bolt tension except top overhaul and either inserting or studding the block.

07-29-10, 05:40 PM
After I posted I checked out Jake's stud kit. Luckily enough, Nemesis Mustang installs in my state.

Have you used the stud kit yourself?


07-29-10, 09:31 PM
No, I have not. Most of my stud experience comes from building racing and marine Olds 455 engines as well as a fair number of GM 454 marine conversions. .................and, way back in the Dark Ages, Volkswagen and Porsche air-cooled flat fours - the jugs were studded.

08-02-10, 09:31 PM
Got any built 455 Olds motors laying around?

08-03-10, 10:31 AM
Not at the moment: The boating business is down the tubes on the Chesapeake Bay and the commercial watermen are also in the midst of a huge downturn in the crab and clam population, so replacement engines aren't high on anyone's list right now :crybaby:. I do have a '72 Olds 455 short block and a set of Ga heads here - you need a 475 hp stump puller ??? Piece of cake - takes about 2 weeks and $5,000. (Every part except for the block, crank, rods, and heads would be new - the pics are of one I built a while back......)

For an automotive engine for your '67, talk to either Dick Miller Racing, or Lynn at Joe Mondello's old shop in CA. You might also find something in the Performance Automotive Warehouse catalog - Chatsworth, CA - lots of Olds parts in there, as well as engines.