This month’s Ask a Tech question comes from the owner of an older Bonanza who’s dealing with an unexpected engine overhaul and is starting to feel the pain of the extras that add to the invoice. “My shop is insisting on sending the oil cooler off for overhaul, but I never had cooling issues and the engine and cooler never leak a drop of oil. Why should I spend nearly $1000 on this service?” he asked.
The short answer is the same reason you wouldn’t reinstall an old oil filter on the new engine. Moreover, oil coolers—as simple as they may be—are accessories that most owners don’t really think about and don’t always get the attention they deserve on the shop floor. Most specialty shops will advise the average lifespan of an engine-mounted cooler can be around 10 to 12 years, but failure can occur much sooner. Common failure modes include stress cracks and corrosion-induced leakage. Remote coolers can live a long time, but only if serviced regularly and properly.