Engine Oil Cooler Upgrade
Adding an aftermarket oil-coolant filter can prevent headgasket failure in the Ford 6.0L
By Steve Temple
The symptoms were obvious, but not the cause. Mechanics at BD Diesel were seeing a string of head-gasket failures on Ford’s 6.0L engines.
Some technicians blamed them on an insufficient number of head bolts, others the design of the EGR cooler.
Only after tearing down a number of faulty heat exchangers (for both the EGR and oil system), and comparing the variance between oil and coolant temperatures, did the source of the affliction become obvious: sludge.
When murky coolant was drained and allowed to stand for a time, fine silt settled out.
The source: Sand from the casting of the 6.0L engine blocks can leach out of the metal and into the water jacket.
(Which, oddly enough, doesn’t seem to be a problem with other Ford diesels, nor other brands.)
As the sediment plugs up the oil cooler, the problem gets compounded. Less coolant flows to the EGR cooler, and the engine runs hot.
Then the fluid begins to break due to the high temps, and isn’t able to do its job. And the thin vanes of the EGR cooler suffer damage as well, until you end up with a molten mass of metal.
Of course, that means plenty of work for diesel repair shops.
“Fixing oil and EGR coolers is a common problem, and keeps us busy,” admits Tim Anderson of T&A Performance in Sparks, Nevada.
A rebuild kit runs about $400, and nine to 12 hours of labor.
Even worse, he points out that a 260-degree oil temp will peg the coolant temp gauge (if the truck has the latest calibration), and 300 degrees melts just about every plastic part under the hood.
At that point, the engine is not repairable, a total loss.
You can avoid this expensive scenario with a simple fix: install a coolant filter. That, and follow a few other maintenance tips (noted below).
Installing a coolant filter usch as BD Diesel’s takes bout an hour, or slightly more if you’re doing it the first time.
BD Diesel’s Cheyne Beukes notes that the filter is a “passive system,” meaning that it’s not mounted in front of the water pump (not feasible), and doesn’t filter on every pass of fluid, since the feed line is from a T-fitting off the heater system.
But that’s good because in the unlikely event there’s a restriction in the hose, it can’t cause any damage to the engine.
The kit is mounted in-line with the engine coolant hoses and includes a filter head, spin-on filter, mounting bracket, hoses, clamps, fittings and mounting hardware, along with a bypass valve to make changing the filter easier.
What else can you do to keep your coolant flowing steadily? Anderson says to use the right type, for one thing, as diesel coolant has a conditioner that regular automotive green coolant doesn’t.
This additive is an anti-corrosive and prevents corrosive cavitation (bubbles that implode, pitting the outside of the cylinder walls and eventually eroding into the combustion chamber).
In addition, replace the filter, along with draining and flushing the coolant system, at the manufacturer’s recommended intervals, if not sooner when operating in extreme temperatures.
Beukes says radiator caps on the 6.0L are “notoriously bad,” and a defective cap that’s venting a white, milky fluid can be mistaken for a blown head gasket.
He also recommends installing gauges to monitor the variance between the oil and coolant temps; if it’s more than 13 degrees, the heat exchanger might not be functioning properly.
Lastly, if you spot sediment in your coolant, shorten the service intervals and flush the system more often. It’s no guarantee that sludge won’t form, but it’s certainly better than ignoring those troubling symptoms.
BD Diesel: 888/841-8884; dieselperformance.com
T&A Performance LLC: 525 Spice Island Drive, Unit A, Sparks, NV 89431; 775/358-5549; tandaperformance.com