Diesel Tech Questions: You Have Questions-We Have Answers
EGR Cooler Failures
QUESTION: I’m frustrated to no end. I bought an ’06 Ford F-250 from an owner who was tired of dumping money into it. The price was right, and all it needed were injectors and an EGR cooler, which I replaced. Less than six months later, the EGR cooler has failed again (I can’t do a delete because of the stringent emissions inspections where I live). My question is: Did I make a bad decision buying this model Super Duty? Did I get a bum cooler? Or is there some other part of the [engine-cooling] puzzle I’m missing?
ANSWER: Ford’s 6.0L Power Stroke engine can be “rebuilt” into a great performer, as evidenced by the many owners out there who swear by their Six-Ohs. You didn’t mention replacing the oil cooler at the same time you did the EGR cooler. That could be the cause of your truck’s engine problems. In 90 percent of cases, the 6.0L EGR cooler fails because the coolant side of the oil cooler, which is located under the oil/fuel filter housing, is plugged. How does that affect the EGR cooler—and injectors? Excessive heat. The oil cooler is an integral part of the coolant flow within the system. Oil from the pan goes through the cooler on its way to being routed to rotating engine parts, the high-pressure injection pump, and injectors. The oil cooler is supposed to keep the hot oil cooled to within a few degrees of the engine coolant, which is what actually dissipates the heat. So the 180- to 210-degree oil is then diverted between the HPOP and the rest of the engine block. The hot oil has less than 500 to 3,000 psi of pressure when it is pumped to the injectors, and that ramps the heat up even more. And then that hot oil goes back into the sump, and the cycle starts all over again—at a rate of about 18 gpm. The cooling issue with the EGR comes into play if the oil cooler gets plugged or restricted from crud in the engine coolant, and little to no water/antifreeze flows through the EGR cooler. That, in turn, causes the exhaust gases to cook the EGR cooler from the inside, making it come apart. So, the tiny oil cooler plays a central role in both the flow of engine coolant and engine-oil cooling. In addition, if the oil cooler is bad, it may hurt the integrity of the new injectors, because they have been fed a diet of super-heated oil. One quick way to determine whether an oil cooler is doing its job is to compare the coolant temperature to the engine-oil temperature (Delta) using digital instrumentation. Ideally, the variance between the two should be less than 5 degrees under all driving conditions. If the temperatures vary more than 20 degrees, there’s cause for concern. As much of a hassle as it is, go back into the engine and rebuild, replace, or even remote-mount the oil cooler (with an aftermarket kit) in a place where it can do a better job. Also, make sure the inlet strainer (filter) for the oil reservoir’s pump is the new style, with the metal screen instead of the old plastic mesh. It’s also prudent to thoroughly flush the cooling system with Motorcraft VC-1 and refill with extended-life coolant that meets Cat EC-1 criteria. Some Power Stroke engineers we spoke with recommend changing the coolant every 30,000 miles instead of the 100,000 miles listed in the maintenance schedule to maximize the life of the oil cooler and EGR cooler.
No Idle Oil PressureQUESTION: We have an ’05 Ford E-350 cargo van with the 6.0L Power Stroke diesel engine, and it has 268,000 miles on it. The oil-pressure gauge started registering 0 psi at idle, and the engine is getting harder to start. If you give it some throttle, the oil pressure jumps up to normal, and everything is fine. I changed the oil-pressure sensor and put in new oil and a filter, but the problem still exists. Our other vans are gas, and I am more familiar with maintaining those vehicles. According to our service logbook, this van had the “HPOP” and oil cooler replaced at 203,000 miles. Do you have any ideas regarding how to narrow down the cause of the low oil pressure?
ANSWER: Whenever there’s an issue with an electric pressure gauge showing errant readings, it’s always a good idea to double-check its accuracy/function with a mechanical gauge. In your case, if the mechanical gauge indicates the same low oil-pressure readings at idle, turn your attention to the low-pressure oil pump located behind the harmonic balancer. Inspect it, as well as the inner cover, for any damage or scoring around the oval holes. The cover is actually the backside of the oil pump, so if you can see/feel any scoring, it needs to be replaced. Usually, the old LPOP (and regulator) is replaced once it’s out. If you don’t already have one handy, get Ford’s 6.0L service manual. Factory service manuals are a must for any DIYer.
Drop the Anchor
QUESTION: I drive a lifted ’16 Ford F-350 with 45,000 miles on the odometer. I purchased the truck with 15,000 miles on it from the original owner who I know took good care of it. I love the truck but feel the brakes are weak compared to my previous rig, an ’02 F-250 with a 7.3L. I've had a few emergency-braking situations—towing and empty—and I feel the truck just did not slow down as quickly as it should have. I've bled the brakes and inspected the pads. Everything appears to be in order, but the brakes are not as firm or good as they should be. In the emergency braking situations, the brake pedal is too soft and the truck takes longer to slow down than it should. Of course, this is all based on personal experience, so it's hard to say if the issues really lie in the truck’s makeup or my expectations. With that being said, are there any worthwhile upgrades to increase the stopping power of this truck? I know I can install different pads and rotors, but will they really make a difference?
ANSWER: Making braking comparisons is similar to doing fuel-economy runs: There are so many variables in both that saying one vehicle is better than another (even of like make/model) is difficult to do unless they are tested side by side under the same conditions and with the same driver(s). In controlled comparison tests for braking from 60 to 0 mph, unloaded and towing identical trailers, the newest heavy-duty pickups usually stop within a hoodlength of each other. Out in the real world, road conditions have a tremendous effect on braking. The smallest amount of sand, gravel, road compound, moisture, etc. can change braking perspective and performance as the ABS system works to keep the tires from locking up and the driver losing steering control. The “soft” pedal feel doesn’t really reflect how much pressure is actually being applied to the calipers, and consequently, the pads clamping down on the rotors. Stopping power is also a reflection of how much a trailer (if one is being towed) adds to the equation. That’s why it’s important for the brake controller to be adjusted properly; nothing increases stopping distance like thousands of pounds pushing from behind! Braking performance is also a reflection of tire/wheel weight and tire-tread design. Taller, heavier tire/wheel combinations put more load on the braking system and can cause the brakes to be a little less responsive than when using stock tires and wheels. Tire-tread patterns also affect braking ability; the more aggressive the tread, the less effective the braking performance. As for upgrades, there are several good choices for diesel pickups. Brembo, Stage 3 Motorsports, Wilwood Engineering, Power Stop, and others have performance brake kits with drilled/slotted rotors, more or bigger pistons, and ceramic brake pads, all designed to increase clamping power and reduce heat that leads to “brake fade.” Where aftermarket brakes shine is in helping keep the front brakes from overheating on roads with lots of curves and long, steep downhill grades, especially when the truck is heavily loaded. They will also apply more initial braking power when applied compared to the stock setup. You can replace the original brake pads with ceramics. Beware: Because the ceramics are harder and more aggressive, they will shorten the life of the stock rotors. Again, the factor that controls the distance it takes your pickup to come to a complete stop is always going to be at the behest of the ABS system, which is doing everything it can to keep any of the wheels from locking up in emergency braking situations.
QUESTION: Will I have any issues selling a “deleted” truck? I'm seriously considering having my ’17 Ram 2500’s 6.7L Cummins engine deleted, because I am sold on the benefits of more power and better fuel economy. I plan to keep the truck for at least five years. I would just like to hear if anyone has experience with trading in a deleted truck at a dealership. I live in Michigan and don't have to deal with yearly inspections (yet), knock on wood.
via the Internet
via the Internet
ANSWER: There are two major concerns here: 1) Federal law forbids anyone from removing smog-related equipment from a vehicle licensed for street use, and 2) It’s illegal for a dealer to sell a vehicle that has had its emissions equipment tampered with or removed. And, yes, the government does prosecute and convict individuals and companies that are in violation of such laws. Removing emissions-related components also voids the engine warranty and can be used to void a drivetrain warranty. Most reputable dealers will turn away a “deleted” diesel for trade-in. Those that do accept such trades usually subtract the cost of bringing the truck back into federal compliance from the normal trade-in value, which can easily be a $3,500 to $4,000 hit. Ridding a diesel of its emissions equipment has obvious benefits. However, it also has serious downsides that must be weighed during the decision-making process.
Fuel to Spare
QUESTION: My family and our friends head to the desert or dunes several times a month, and we all tow big toy haulers. My 36-foot fifth-wheel weighs close to 17,000 pounds loaded. It’s a five-hour run each way with mountains to cross and very few places to get diesel—especially late at night. The 36-gallon fuel tank on my ’16 Chevrolet Silverado 3500HD has created some close calls, and I’m tired of sweating from the idea of running low on fuel and dealing with the high prices at the “last-chance-gas-n-go.” I’m seriously thinking of installing a replacement underbody tank. I need the full capacity of my bed, so an in-bed auxiliary tank is not an option. Do you have any recommendations for a bigger tank? Is steel better than plastic? Can I install one myself?
ANSWER: We feel your pain. Big trailers and little stock fuel tanks don’t make a happy marriage for a lot of diesel owners who would rather spend their time on the road than burning precious moments waiting in line at a fuel stop—or paying a premium for diesel at places that know they are the only station for miles around. The good news is there are several well-known companies that produce “mid-ship” replacement fuel tanks that can significantly increase your driving range while maintaining all the features of a stock fuel tank. Two players we often turn to are Titan Fuel Tanks (titanfueltanks.com) and Transfer Flow (transferflow.com). Both offer exceptional products. Titan’s tanks are made from a special ¼-inch-thick super-strength polyethylene said to be far stronger than the original tanks they replace, while Transfer Flow’s mid-ship tanks are built from 12- and 14-gauge aluminized steel, which are also more stout than plastic. We have installed both and are quite happy with their ability to extend driving range. Installing a replacement fuel tank is a relatively easy job that’s best done with the truck on a hoist, using a transmission jack so the old tank can be easily dropped and the new one raised into position. Also, be sure to empty the old tank before removing it. Fuel is heavy. The installation part is straightforward; it just takes a little time to remove the stock fuel pump and sending unit and get them adjusted to read correctly on the truck’s fuel guage with the larger-capacity tank installed. Transfer Flow offers a 61-gallon replacement tank for dualies like yours, while Titan’s is 60 gallons. All aftermarket replacement tanks are not only longer and wider than what they replace, they are 1 to 3 inches deeper, increasing the chances of high-centering in extreme conditions. The only concern with the mid-ship replacements is ensuring the “miles-to-empty” estimate on the driver’s information center is accurate. Doing this will probably require a trip to the dealer to get the ECM reflashed with the new tank’s size. All fuel tanks, stock or aftermarket, have a certain amount of fuel that’s not usable because of the draw straw’s location. Hence, a 60-gallon tank will not provide a full 60 gallons of diesel that can be burned. Typically, 5 to 10 percent of the tank’s listed fuel capacity sloshes around at “empty” unless the draw straw in the tank is upgraded with an aftermarket sump and suction tube. Still, having nearly double the fuel and significantly increasing the mileage range with a mid-ship replacement tank is a big plus.
Black OilQUESTION: I just stepped up to a ’17 Ford F-350 with a 6.7L Power Stroke diesel engine. The new truck is so impressive it’s hard to describe. But I’m worried it already has an oil issue. I changed the oil for the third time at 11,000 miles, ran the engine for one minute, and then pulled the dipstick to make sure the oil level was where it was supposed to be. The oil, synthetic per Ford specifications, was already black. Oil in my ’99 Super Duty’s 7.3L engine would still be its normal honey color, not black with soot at the same service interval. I’m quite concerned there’s a blow-by issue or some other problem causing the new oil to get loaded with soot right away. It just doesn’t seem normal. I paid a lot of money for the new truck, and I hope to get my money’s worth over the next 10 to 15 years.
via the Internet
via the Internet
ANSWER: What you are seeing is normal for diesels equipped with EGR and other emissions control systems. The ’99’s 7.3L engine doesn’t recycle exhaust gases loaded with soot back through the intake system, so oil looks cleaner on the first startup. Today’s synthetic oils are designed to handle the soot with all the special additives essential to keeping the engine components properly lubricated. The new oil just mixed with some of that old oil. If you are worried, the best way to ensure all is well in the oil pan is to set up a regular oil-analysis program with a lab that specializes in analyzing engine oils. There are dozens across the country offering these services, which typically cost around $25. (Wix Filters even has an oil analysis program through the O’Reilly Auto Parts chain). Send the lab a sample from your next oil change to set the baseline. Then send a sample at every other oil change to compare with your base sample. The report will show any anomalies that are cause for concern. The reports also give a great insight on extending oil-change intervals, quite possibly saving you a ton of money over the years compared to changing the oil per the odometer. The old practice of changing the oil every 3,000 to 3,500 miles is severely outdated. It doesn’t apply to the newer generation of diesels, which tend to be serviced every 7,500 miles or more. However, don’t throw away $75 to $100 worth of oil just because the odometer hit a certain mileage; follow the owner’s manual recommendations for the first year of oil drains, and while doing that have a sample of the oil analyzed to see how those intervals compare to the reports. Black oil doesn’t mean bad oil—it’s the molecular makeup that determines oil’s health. Analysis can show you need more or fewer oil changes. (The onboard computer trips the oil-change warning based on mileage, not the condition of the oil. Also, the engine’s sensors don’t analyze oil.) Having oil samples analyzed by a lab on a regular schedule is just another part of preventive maintenance for diesel engines, a lot like when we have annual physical examinations.