2004 XC70 - Lower Rod Bearing - Biuy a Re-man Engine or Have Mine Fixed?

[svenska572]

I got complacent. I got lazy. Despite having my car serviced only at dealers since I bought it new in 2004, I wasn't treating my XC70 with 165,000 miles on it like a "used" car. I didn't check the oil between 6,000 mile changes. It's all my fault and I know it. It makes me sick to my stomach to know that I could have prevented a major issue with just a few minutes a week of checking the oil level. Now it's done and I need to move on.

More than likely, the "knock" in my car is coming from a lower rod bearing, per my Volvo dealer (whom I trust very much). I am leaning toward a re-manufactured engine due to the warranty, but I'd like to keep the original engine and have it fixed. This would likely mean potentially more work, cost, and time than getting a re-man engine.

Any thoughts, advice, actual experience with making this decision?

[hoonk]

You might be able to get away with just replacing the rod bearings with the engine in the car as long as the crankshaft and rods are not damaged. Keep in mind if you run the engine low on oil, the turbo ($$$) is starved and can fail also.

The economics of replacing an engine in a 12 year old Volvo are not good - you could easily spend what the car is worth doing that and you would still have 12 year old everything else. Look at what EDmunds.com thinks your car is worth

[Astro14]

Bearings can be done with the engine in the car by dropping the pan. Pretty simple to inspect the crank (visually, or with a micrometer) with the pan off and rod bearing caps off.

Personally? This car isn't worth a lot. I would try the cheap fix. Pull the pan, see how the crank looks. If it looks OK, throw a set of bearings in there and see how it runs. You're out a few hundred...and it might work...

Clean the oil pick up while you're there. Make certain that the oil supply is good after this incident.

[svenska572]

Thank you for the great advice! The rest of the car is, as far as I know, in great working order. This is what makes it tough. I don't owe anything on the car and haven't in a while. A $3,500-$5,000 investment in an engine that gets me through another 3-5 years may be worth it.

[svenska572]

Another quick question: my dealer was still using conventional oil because that's what my car called for originally. I've often wondered if we should have been using synthetic due to the age of the engine. Any thoughts on switching to synthetic later in the life of an engine or are you (generally) better off sticking with conventional?

[Astro14]

I think synthetic is the best choice for this engine. You can change to synthetic at any time, despite the old wive's tales to the contrary. If you run conventional in this engine, you should change it very, very often. No more than 4,000 miles. Conventional oils don't meet the specifications for extended drain intervals. None of them do. IF your dealer is using conventional for a 7,500 mile oil change, or even a 5,000 miles change in this engine, then they're idiots. Note that there is more to oil than just the viscosity. Specification is critical.

But no matter what is in the sump, as the car ages, you may notice an increase in consumption. A failing/failed PCV system will certainly increase consumption. Sometimes, it just starts to use oil. Our XC uses a quart about every 1,500 - 2,000 miles now, despite its completely new PCV system. But at 204,000 miles, that's an acceptable level of oil usage. Our V70 uses about a quart every 6,000 miles and I don't have to add oil between changes unless I feel like keeping it at the top. That car has 179,000 on it. Engines simply age differently.

And yeah, checking the oil is important. I do it every fill up. That's how I was taught back in the days of carburetors and V-8s that could burn a quart quickly. I once found the dreaded "chocolate milkshake" on the dipstick of my '85 Trans-Am when a head gasket leak put coolant in the oil. The resulting emulsion of coolant and oil wasn't good for the bearings, but because I was checking every fill up, I caught it early and was able to repair the engine before any lasting damage was done...