Look, I get it. You're here because your car is doing something weird, or a customer just hit you with a part number that doesn't match anything you've seen. I've been ordering and selling automotive parts for 12 years, and I've personally screwed up enough orders to build a checklist around. This is the FAQ I wish someone had handed me before I started.
- Is Dorman a legit aftermarket brand?
- Is the Dorman engine crankshaft position sensor worth buying?
- Why would you replace a Dorman oil filter cap?
- What's the right vacuum pump oil type?
- What's the deal with the Hyundai oil pump recall?
- How much is it to repair a head gasket?
Is Dorman a legit aftermarket brand?
Let's start with the boring but important background. Dorman is a major aftermarket supplier, not a no-name reseller. They run stamping plants, forging ops, aluminum extrusion lines, CNC machining, and a full mold/die shop. That's genuinely unusual. A lot of aftermarket brands are just marketing companies with a catalog. Dorman actually makes stuff.
Most of their components I've touched have been solid. There was one camshaft position sensor connector that wouldn't click onto a Ford harness unless you wiggled it at the right angle. We returned that batch and got a newer revision. It happens. But the failure rate on Dorman parts I've sold is lower than a lot of price-focused brands.
I'd say they're the middle ground: not the cheapest, not the most expensive, and usually better documented than the no-name stuff. If you're a shop, they're easy to get, and their customer service actually picks up the phone.
Is the Dorman engine crankshaft position sensor worth buying?
A crankshaft position sensor tells the ECU where the crank is, so it can fire ignition and injectors. When it fails, the car might crank but not start, or stall randomly, or set a code like P0335. It's a cheap part compared to a full ignition system, but only if you buy the right one.
Dorman's sensor is a direct replacement for a ton of common applications. I've installed them on Ford 5.4L 3-valve engines, GM 3800s, and a bunch of 1.8T Volkswagens. Fitment has been good. They usually come with an O-ring or a spacer, and the connector matches the OE. The price is typically a good bit less than going with the dealer.
Here's the mistake I made: I ordered a case of sensors based on what the counter guy said was the 'universal' part. Universal doesn't exist in sensors. The harness connector was the same, but the trigger ring was different. 12 out of 40 didn't work. Since then, I verify the part number against the VIN every time. So glad I did on the next order, because the same engine family had three different sensor lengths.
That's my advice: buy the part number, not the engine size. And if you're replacing two sensors at once, get the diagnostic done first. I've watched a few customers throw a crankshaft sensor at a no-start, and it turns out the timing chain skipped. The sensor was fine, the engine was not.
Why would you replace a Dorman oil filter cap?
Oil filter caps are one of those parts that seem too trivial to think about until you're on your back in the driveway. The factory cap often is plastic, and if it strips, you're stuck. You can't even get the filter off without a specialty tool. Dorman's metal cap replaces that weak link.
Some of these caps have a built-in insert or a barbell for a socket, others are just a hex head. The important thing is the thread pitch and the sealing surface. Honda, Toyota, Ford—they all use slightly different caps. The listing will tell you, but you have to actually read it.
I didn't. On a 40-unit order, I matched the outside diameter and the filter number, but not the thread. Ended up with 40 caps that fit only if you forced them, which nobody should do. $300 plus a month of being the punchline in the parts room.
If you're stocking for your shop, grab a few of the common ones. They're cheap enough to keep in the drawer. And always check the torque spec. Metal caps strip less than plastic, but over-tightening can crack the housing.
What's the right vacuum pump oil type?
Let me break this into two worlds.
On a vehicle, the vacuum pump can be a mechanical pump bolted to the engine (often behind the camshaft or on the valve cover) or an electric pump for brake assist. Mechanical ones usually share the engine oil. So 'vacuum pump oil type' is just the same oil you'd put in the engine. But some cars, like certain Ford Powerstroke diesels and Mercedes OM642 engines, have a separate oil reservoir or use engine oil that's circulated to the pump. The owner's manual is your friend.
If you're talking about a shop vacuum pump—the kind you use for brake bleeding or vacuum testing—that's a different animal. Those pumps need oil with low vapor pressure, like a dedicated vacuum pump oil. Using 5W-30 engine oil will cause it to smoke, create bad vacuum, and wear out the vanes. I learned this when a customer called back after two days. The pump sounded like a coffee grinder.
Another thing: don't use the same oil you'd use in your lawnmower. Viscosity matters. Most rotary vane pumps specify a certain ISO viscosity grade. If it says ISO 68 or ISO 100, get that. Mixing synthetic and mineral is usually fine, but for a tiny pump, just buy the right thing and save yourself the drama.
What's the deal with the Hyundai oil pump recall?
If your Hyundai or Kia has oil pressure issues, first check the NHTSA recall database. As of January 2025, there are Hyundai oil pump recall campaigns that cover certain models. The dealer will handle it free if your VIN is included.
Independent shops have to be careful here. A customer might come in with a Hyundai or Kia that's showing low oil pressure. If there's a recall on the oil pump, sometimes the dealer will fix it free. I almost ordered an aftermarket pump for one customer, but we checked the NHTSA VIN lookup first. It turned out the dealer already performed the recall. If I'd ordered the part, we'd have been stuck with a return and an unhappy customer.
The takeaway: always check recall status before you sell someone a repair. It's a five-second lookup, and it turns a $600 repair into a free one for the customer.
Also note: some manufacturers have warranty extensions that cover related engine damage. So it's worth having the customer call the dealer with their VIN even if the recall status shows closed.
How much is it to repair a head gasket?
A blown head gasket can show up as white smoke, milky oil, coolant loss, or overheat. If you catch it early, you might just replace the gasket. If you let it go, the head can warp or crack. Then you're not talking about a gasket repair, you're talking about a cylinder head replacement or a new engine.
Labor is the big variable. There are engines where the head comes off in two hours, and engines where you pretty much have to pull the whole engine bay apart. The 'book time' can be anywhere from 6 to 15 hours. Shop rates vary from $80 to $150 per hour. That's why you'll see quotes anywhere from $1,200 to $3,500 for the same job.
As of December 2024, RepairPal's national average for a four-cylinder is about $1,500 to $2,000, and V6/V8 jobs often run $2,200 to $2,800. I've seen some German cars hit $3,500 because of labor and parts. And that's with a good scenario.
When you get a quote, I'd ask whether it includes head resurfacing, pressure testing, new head bolts, and coolant/oil. If they look at you weird when you say 'pressure test,' walk away. The cheapest quote isn't always the best. A friend got a low bid for a head gasket, and the shop reused the old head bolts. The gasket failed 8,000 miles later. So pay for the person who does the job right.