# Diesel Engine Gasket Replacement in Upland > Diesel gasket replacement in Upland for oil, coolant and exhaust leaks, from valve covers to head gaskets. Leak confirmed first, written estimate always. Source: https://route66autorepairshop.com/diesel-engine-services/diesel-engine-gasket-replacement Updated: 2026-09-17 Business: Route 66 Auto Repair, 1775 W Foothill Blvd, Upland, CA 91786, (909) 608-7699 Hours: Monday to Friday 8 AM–5 PM, Saturday 8 AM–2 PM, Sunday closed **TLDR:** We **pinpoint the leak** before quoting, and your estimate lists any parts that make sense to replace **while it is apart**. Diesel engine gasket replacement at Route 66 Auto Repair in Upland fixes oil, coolant and exhaust leaks, from a seeping valve cover to a failed head gasket. Diesels run high pressure and heat, so gaskets work hard. Our ASE-certified technicians clean and dye-test to confirm exactly which gasket is leaking, then quote the job in writing with the parts that should be replaced together. ## Which diesel gaskets leak most often? - **Valve cover gaskets:** oil seepage at the top of the engine, often with a burning smell - **Oil pan and front cover gaskets:** drips under the engine - **Intake and exhaust manifold gaskets:** boost loss or ticking exhaust leaks - **Oil cooler gaskets:** oil and coolant mixing on engines with a shared cooler - **Head gaskets:** coolant loss, white smoke or pressurized coolant hoses ## How do we confirm which gasket is leaking? Oil runs downhill and wind spreads it, so the wet spot is often not the source. We clean the area, add dye when useful, and drive the truck to find the true leak. For coolant problems, we pressure test the cooling system and check for combustion gases in the coolant to separate a head gasket from a cooler or hose. A head gasket job on a diesel may involve inspecting the head for flatness and cracks. Your written estimate shows every step, including any head inspection or reconditioning. ## Our gasket replacement process 1. **Confirm the source:** Cleaning, dye and pressure tests identify the leaking gasket. 2. **Estimate with add-ons:** Seals and bolts that should be replaced together are listed in writing. 3. **Disassemble and clean:** Sealing surfaces are cleaned and checked for damage. 4. **Install to spec:** New gaskets and hardware go on in the maker's torque sequence. 5. **Refill and verify:** Fluids are refilled, the engine is run and road tested, and the area is rechecked. ## What's included in diesel gasket replacement - Leak source confirmation - Cooling system pressure test when coolant is involved - Replacement gasket and required hardware - Surface cleaning and inspection - Fluid refill to spec - Road test and leak recheck ## Is a gasket leak need-now or need-later? **Need now:** - Coolant loss or coolant in the oil - Oil dripping onto the exhaust or turbo **Need later:** - Light seepage with a steady oil level - A dry, dusty stain from an old leak ## How pricing and timing work A valve cover gasket can be a same-day job when the board allows. Head gaskets and oil coolers are multi-day jobs with more parts. The written estimate lists each gasket, the hardware and the fluids, and we stop and ask if something else turns up. AAA members get 10% off parts and labor, up to $75. ## Aftercare Check fluid levels daily for the first week. Oil cooler leaks are covered on [diesel engine oil cooler repair](https://route66autorepairshop.com/diesel-engine-services/diesel-engine-oil-cooler-repair), and coolant problems on [diesel engine cooling system repair](https://route66autorepairshop.com/diesel-engine-services/diesel-engine-cooling-system-repair). A general [engine gasket set replacement](https://route66autorepairshop.com/engine-services/engine-gasket-set-replacement) page covers gas engines. ## Frequently asked questions ### Can I drive with a leaking diesel gasket? A slow seep with steady levels can usually wait for a scheduled repair. Coolant loss or oil on hot parts should be fixed right away. ### How do I know if my diesel head gasket is bad? Coolant loss with no visible leak, white sweet-smelling smoke, or coolant hoses that are hard when cold are warning signs. A pressure test and combustion gas test confirm it. ### Why replace bolts with a head gasket? Many diesel head bolts stretch when torqued and are designed to be used once. We follow the maker's instructions. --- Call (909) 608-7699 or visit https://route66autorepairshop.com/contact for a written estimate.