Ringing Noise
Q: My '94 Dodge Ram 1/2-ton regular cab pickup has developed an annoying ringing noise. My truck has the 5.9L V-8 with the automatic transmission. It's stock, except for the wheels, tires, and hard tonneau cover. I know that noises are hard to diagnose in person, much less by mail, but I thought you might have heard of a similar problem from other Dodge owners.
To my ears, the ringing noise is underneath the cab, not the bed. My passengers and I notice the noise most often when leaving a stoplight. The noise isn't as noticeable on the freeway, but I do have some pretty aggressive tread on my tires, and there's all the noise from other cars and big trucks.
I looked around for anything that was loose and even asked the quick-oil-change guys to look up the last time it was on the lift. There wasn't anything that seemed loose enough to cause that ringing noise. I even hear the noise on super-smooth roads, so I don't think it's a function of the road conditions. If you have any ideas, I'm listening. Thanks.
Alain Comeau, Windsor, Ontario, Canada
A: The most likely source of your ringing noise is the driveshaft. Dodge issued a service bulletin relative to this problem with '94 and '95 Dodge Ram pickups. If indeed the problem is in the driveshaft, Dodge recommends replacing the old one with a replacement design. Have your truck checked by your local Dodge dealer's service department before you run out and buy a new driveshaft.
Hi Ho Silver, Away!
Q: My wife and I recently got an '87 GMC 1/2-ton shortbed pickup from the estate of her late uncle. He was the original owner and the truck has only 84,000 miles on it. It has the V-8, automatic, air conditioning, and all the power options. It appears to have every possible option and everything is in excellent condition, except for the paint.
The paint looks like something you'd see on a 384,000-mile truck, not a cream puff like this one. Obviously, my concern is about the paint. I think these trucks are gaining popularity, and I'd like to mildly modify the truck while still keeping it as original as possible.
I plan to lower it and put widened and chromed rally wheels on it with modern tires. I plan to store the original rally wheels. I'll hide a better sound system and add a hard tonneau cover.
Since loaded trucks in unmolested condition are pretty rare, I'm wondering if there is any way I can fix the peeling parts of the paintjob without completely repainting the truck. Was there something inherently wrong with the silver paint on 1980's Chevy/GMC pickups and Suburbans? I've noticed many other silver trucks with bad paint, especially on the roofs and hoods.
The truck spent most of its life in Arizona, but it was usually parked in a carport. I don't know how often the uncle waxed the truck, but he took excellent care of it mechanically. The truck came with all the service records, including oil changes.
I don't want to totally repaint the truck, but I want it to look as pristine as possible. Can you help me? Thank you.
Mike and Shirley McCulloch, Alvarado, Colorado
A: Peeling paint was a common problem on GM products in the '80s. The problems seemed particularly severe on metallic colors such as silver. Vehicles in hot climates such as Arizona tend to have more fading, cracking, and chipping problems than vehicles from less sunny parts of the country. We've noticed more bad paint on trucks than cars, but maybe that's because more trucks are still in use.
The prevailing opinion of painters that we've talked to is that poor primer adhesion was the cause of the problem. Of course, if the primer doesn't stick, the paint won't either. We've never received a good answer as to why silver seems to be so problematic, but peeling paint on GM trucks seems to occur much more frequently on metallic colors rather than solid colors.
It doesn't much matter why silver flakes off, but it is a shame that you have the problem on such a desirable truck. We agree that these trucks, especially in the last couple years (before the new body style in '88), are getting more popular everyday. As with the '67-'72 trucks before them, it's the fully loaded shortbed Fleetside models that seem to bring the biggest bucks.
Your plan to mildly modify the truck without harming its originality is an excellent idea. The things you propose can even increase the truck's value.
There were so many complaints about poor paint adhesion that GM issued a service bulletin (#92-300-10) about the problem. At one time, there were some provisions for reduced cost repairs. It's probably far too late for you. It was something your wife's uncle should have addressed.
You should photograph the existing paint and document the whole repaint process. That way if you later sell the truck, you can prove that it was flaking silver paint that precipitated the repaint, not some horrific body damage.
A high-quality repaint in the stock (or very close to it) silver should add value. People who know anything at all about these trucks, or have looked at more than a dozen of them, recognize the peeling-paint problem. Knowing that the problem was fixed is a big plus.
All traces of the problem paint need to be removed; otherwise, the flaking will reappear. Consult a knowledgeable painter (second and third opinions/estimates are a great idea) about how to best fix the paint so that it looks as nice as the rest of the truck.
Flickering Lights
Q: The ABS light on the dashboard of my '96 Ford Explorer comes on sporadically. I'm concerned that this is the sign of trouble, although I haven't noticed anything different about how the truck brakes.
The ABS light comes on pretty randomly. It can stay on when the truck is first started in the morning. Or it can come on at a traffic signal, or when I'm cruising down the freeway.
When the light comes on first thing in the morning, I've tried turning off the engine and restarting it right away. That usually cures the ABS light problem. Does that suggest anything? When the ABS warning light is on, does that mean that the ABS system isn't functioning?
Is this a serious problem or just an annoying feature of a well-used truck?
Jimmy Parise, Columbia, Missouri
A: It appears that your Explorer's ABS system has an intermittent fault. This type of problem can be tough to track down, but there should be a diagnostic trouble code stored in the truck's computer. When a fault is detected, the ABS stops working. Possible problem sources include the actual ABS part, the connection to the part, or even something in a related system. You should take your Explorer to the dealership or a trusted independent repair shop.
You briefly see the ABS warning light at start-up while the vehicle's computer runs a check of the systems. As soon as the computer determines that everything is OK, the warning light turns off. If you're in the habit of putting your foot on the brake pedal as you start the truck, the ABS test will be delayed until you start moving and hit 4 mph. Aside from the start-up tests, additional ones are run while you drive.
A major problem with intermittent faults is reproducing the problem at the shop. A technician who is an expert at diagnostics can speed up the process and save you money.
Same Gears, More Cubes
Q: The original 4.3L V-6 engine in my '90 Chevy 1/2-ton work truck died for good just short of 250,000 miles. I have no complaint about how much use I got out of the old engine, but I wanted more power for the replacement. I found a wrecked same-year GMC pickup (a couple of big trees fell on it) with the 305 V-8. The donor truck has an automatic and my truck has the manual five-speed transmission. I want to keep the manual transmission.
Do I need to do anything special to keep the five-speed transmission with the new V-8? What about motor mounts? Can I use the ones from the wrecked truck, or do I need new ones? I need a new clutch. Do I need to do anything different now?
Scott Mayhew, via e-mail
A: You can use the original five-speed manual transmission with the bigger-displacement V-8. Transmissions usually stay about the same place in the frame, regardless of which engine is used. Different engine mounts are used. You need the V-8 engine mounts. You could use the ones from the donor truck, but we'd suggest buying new ones.
The V-6 uses offset motor mounts and different brackets to accommodate the 90-degree V-6. The V-8 motor mounts are non-offset. The correct parts are readily available from your local Chevy parts department.
For the clutch, be sure to get a truck one. Pickups use a 168-tooth 14-inch flywheel with either an 11- or 11.85-inch-diameter clutch. Passenger cars use a smaller 153-tooth flywheel with a 12.75-inch flywheel. You must use the large-diameter truck components because your transmission uses the integral bellhousing. Your current parts will work fine with the 305 V-8, but the same-year V-8 manual transmission parts are stronger.
The Little 6 That Could
Q: I'd like to make the 2.8L V-6 in my '90 GMC S-15 perform better. I know it's never going to be the fastest truck on the block, so I don't want to drop a ton of dough. The engine is in good mechanical condition. I ran a compression test and all cylinders were within a couple pounds of each other and within the factory specs. What can I do to make this six behave more like the bigger 4.3L V-6? Any help would be appreciated.
Gary Nielsen, Springfield, Missouri
A: This is a popular question. Many readers would like to get more power out of this little V-6. As popular as this engine seems to be with readers, it isn't the most popular GM engine for aftermarket performance companies. It's easier to find parts for the 4.3L V-6, which comes with an extra 35-75 hp to start with. Speaking of the 4.3L V-6, swapping your little six for the bigger one is very doable. Besides the many S-series variants that were available with the 4.3L engines, it was also a staple of the Astro/Safari GM minivans. Additionally, it was the base engine in fullsize GM 1/2-ton pickups, so finding one at a reasonable price shouldn't be difficult.
Unless you never plan to sell the truck, we'd go easy on the investment in your 2.8L V-6; the little engine will hamper the resale value. Your best bet for increased performance at a reasonable price is to stick with the basics: Increase the amount of air, fuel, and spark coming into the engine, and increase the efficiency of the spent gases leaving it.
One of the easiest things you can do is install a high-performance air filter, such as those offered by K&N Filters. A performance computer chip will adjust relevant functions toward performance, away from the factory economy settings. A set of exhaust headers and a free-flowing exhaust system should complete your basic hop-up. Companies such as Edelbrock offer bolt-on exhaust systems for your truck. You won't be a contender at the dragstrip, but you will notice better 0-to-60 acceleration and easier freeway merging.
305 Overbored
Q: Can I bore the stock 305 V-8 in my '90 Silverado to make it a 350? I figure I could save a lot of time and money by using all my existing accessories and still get the extra power via the added displacement. Aren't these two engines the same size externally?
Matt Hobson, Eugene, Oregon
A: Both small-blocks have the same external dimensions. Even their crank journals are the same, so boring out a 305 would seem like an easy thing. Unfortunately, the 305 casting uses thinner cylinder walls. The maximum sensible overbore for a street-driven truck is 0.060 inch. Doing this would produce a 315ci engine, 35 short of your goal. If you want a 350, you're going to have to get the real thing.