Buying a used car engine isn’t something most people do every day, so it’s easy to feel a bit out of your depth. Whether you’re replacing a dead engine in your daily driver or fixing up a project car, the engine is the heart of the vehicle—and getting it wrong can cost you big.
The good news? With the right knowledge and a bit of patience, you can find a solid used engine that’ll give you thousands more kilometres on the road. In this guide, we’ll walk you through exactly what to look for before you hand over any cash or swipe your card.
1. Check the Engine’s Mileage
Mileage is a big deal. A used engine with 80,000 km will almost always have more life left in it than one with 250,000 km. But keep in mind: it’s not just about the number—it’s also how the engine was used and maintained.
An engine pulled from a highway-driven car might be in better shape than one from a vehicle used mostly for stop-start city driving. Ask for documentation if available, and don’t be afraid to ask where the engine came from.
Quick tip:
Most reliable wreckers or engine sellers will list the mileage and offer a warranty period. If they can’t tell you how many km it’s done? Walk away.
2. Inspect for Leaks and Cracks
Engines should be dry—if there’s oil leaking from the seals, or coolant residue around the head gasket area, that’s a red flag. Check around the valve cover, oil pan, and head gasket. Cracks in the engine block or signs of repairs like messy sealant could mean the engine’s been overheated or patched up.
If you’re not sure what to look for, bring a friend or a mechanic who knows engines. A few minutes of inspection can save you thousands in repairs later.
3. Look at the Oil Condition
Remove the oil cap and check the oil’s colour and consistency. If the oil looks milky, that could be a sign of coolant mixing with the oil—possibly from a blown head gasket. If it’s pitch black and thick, the engine might not have been well-maintained.
Same goes for the dipstick—if it’s dry, rusty, or smells burnt, that’s another warning sign.
4. Check the Compression (If You Can)
Compression testing is one of the best ways to know the health of an engine. It tells you if the cylinders are holding pressure properly. If one or more cylinders are low, the engine could have worn piston rings or valve issues.
Now, you might not be able to run a compression test yourself, especially if the engine isn’t installed. But if the engine is still in a car or can be turned over, ask the seller if they’ve already done a test—or see if they’ll allow one. A healthy engine should have consistent readings across all cylinders.
5. Check the Engine History
If the engine is from a reputable wrecker, ask for the VIN of the donor car or any service records. Has it had major repairs before? Was it pulled from a crash-damaged vehicle, or did the previous owner simply upgrade to something newer?
Getting this context gives you a clearer picture of how the engine was treated—and helps you decide if it’s worth the asking price.
6. Inspect the Timing Belt or Chain (if visible)
Engines typically use either a timing belt or chain to keep internal parts moving in sync. A broken timing belt can ruin an engine. If you can see the belt and it looks cracked or frayed, budget for a replacement.
Some sellers might even throw in a new timing belt or water pump with the engine if you ask—never hurts to negotiate!
7. Check for Excessive Rust or Corrosion
Surface rust on metal components is normal, especially in older engines, but heavy corrosion—especially around critical areas like mounts, water jackets, or intake ports—can indicate long-term water damage or poor storage.
Engines stored outside without protection are more likely to develop corrosion that compromises performance and longevity.
8. Listen to It Run (If Possible)
In the best-case scenario, the engine is still in the vehicle or can be hooked up and started. Listen for strange noises like knocking, ticking, or irregular idling. A smooth-sounding engine without hesitation is a good sign.
If the seller refuses to start it or says “it just needs a jump,” be cautious. There’s a difference between a flat battery and an engine that won’t crank for deeper reasons.
9. Buy from a Reputable Source
This one’s big. Always buy used engines from licensed wreckers, engine importers, or reliable sellers who offer warranties—ideally something like a 30-day or 90-day start-up guarantee. If you’re shopping on Gumtree or Facebook Marketplace, you might save a few bucks upfront, but the risk of ending up with a lemon is much higher.
At Richmond Cash 4 Cars, we deal with used engines every week. If we wouldn’t install it in our own car, we won’t sell it. Simple as that.
Before You Hand Over the Cash…
Take your time. Don’t let a cheap price tempt you into rushing the decision. A great deal on a bad engine can turn into a very expensive mistake. But if you do your homework and ask the right questions, you can find a reliable used engine that gives you years of trouble-free driving.
And if you’re replacing a dead or damaged engine and want to get rid of the old one—we buy non-running cars, damaged vehicles, and even cars with seized engines for cash. No stress, no roadworthy needed, and we’ll pick it up free of charge.
Something to Think About…
A used engine might not be brand new, but that doesn’t mean it can’t serve you well. With a little knowledge and a good eye, you can avoid the dodgy ones and score a solid engine that’ll get you back on the road without breaking the bank.
If you are in Niddrie, Victoria 3042, and looking for a cash for cars service, this is the best way to visit us.
Richmond Cash 4 Cars
(03) 7047 6388