Piston Slap: Mad Vulcan Powah?
Dear Sajeev,
As a fellow Panther owner, I am seeking advice on the disposition of another Ford product. My 24 year old son just bought a new to him car and returned my 2000 Ford Taurus with the 3L Vulcan overhead valve engine to me. At 206K it runs great, but has one issue. Combustion gases are entering the cooling system and periodically venting through the coolant de-gassing tank.
Also, the OBDII system will ocasionally flag cylinder one for a misfire. This must be a very short lived event because the engine runs smoothly even when the CEL light is on. Two years ago, I had the car diagnosed by a AAA club recommend mechanic. He tested the coolant and found the combusion gases in the degass tank. He concluded that the engine had a head gasket leak in the vicinity of cylinder one. I should also mention that periodically, the spark plug on the cylinder number one gets coated with a white mineral. None of the other spark plugs have this type of deposit. So we know that coolant is getting into this cylinder. The car uses about one pint of coolant per thousand miles. Since there are no leaks, I assume it all ends up in cylinder one. At around 10K miles, the spark plug fouls with minerals, and I replace it. It’s a bear to get at since it is on the firewall side of the engine.
In March of 2010, I bit the bullet and replaced both head gaskets and resurfaced the valves. While the engine ran as smooth as silk, this job did not fix the coolant leak into number one cylinder. I believe that the cylinder head has a very small leak in this piston even though I could not find any evidence of it when I replaced the cylinder head gasket. It could also be a warped head. I am considering replacing the cylinder head with a rebuilt one from Advance Auto since I plan to give this car to #2 son who is a feshman in college.
Before I invest a $200 and a whole days work, I want to ask you and the B&B if you agree with my diagnosis. Has anyone heard of a cracked block doing this? When I replaced the head gasket, the block was shinny and smooth with no evidence of a coolant leak between it and the head gasket.
Sajeev answers:
Fellow Panther owner? I only got Foxes, Panthers are just the logical extension of my madness! My avatar don’t lie, son! But I digress…
Normally your OBD-II code and PCV (i.e. combustion gases) problem are the same concern. A bad PCV valve, worn out vacuum lines, etc can cause a code, but having these gases wind up in the coolant without it turning milky with oil contamination?
Maybe it isn’t the head, maybe the coolant expansion tank has an air leak…maybe at the cap? That makes more sense than needing to change the head, do machine work, etc on a Vulcan V6 that otherwise drives perfectly. Of course that doesn’t explain the spark plug issue…or was that resolved after the new gaskets and machine work? Now I’m seriously confused.
Confused by one of the most basic engines in modern history! Oh boy.
The other concern: how the hell did your son overheat/abuse a Vulcan V6 to the point it warped the head/block? This all-iron motor is about as bulletproof as it gets. Maybe the Taurus forums can help, because I’m drawing at straws.
Get your Vulcan On, Best and Brightest.
Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry.
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In my opinion, the car is at the end of its useful life. 200K from a Taurus is well above average for that line. I'd send it to the scrapyard.
i would put a can of these block sealant into the coolant system, u may wanna pinch off the heater core, these can cause blockage in heater core. the one i bought called ceramic a long plastic tube, next day or so when i go to local parts place i can look u the name for u.