1988 4Runner · 98 5VZ-FE swap
Paint: block and oil pan
Engine primer, then gloss black enamel, on clean bare metal. The valve covers were powder-coated, so only the block and pan get painted.
Tick boxes on this page are saved in this browser only. HAVE parts start ticked.
The rule that matters most: no paint, primer, overspray, dust or chips get inside the engine or onto any sealing, mating or grounding surface.
- Paint under a gasket or FIPG bead leaks. The FSM wants every FIPG surface bare and cleaned with non-residue solvent.
- Paint in a bolt hole throws off torque.
- Grit in an oil passage takes out bearings.
This guide is general shop practice, not from the FSM. Follow the can for coat timing, temperatures and cure.
Products (decision 2026-10-14: engine primer, then gloss black enamel; no rust converter, clean the rust off instead)
| Item | Why | Status |
|---|
| Rust-Oleum Automotive Engine Enamel Flat Gray Primer ×2 (bought on Amazon 2026-10-14) | Same engine-enamel line as the topcoat, so they're compatible. Goes on clean bare metal | HAVE |
| Rust-Oleum Automotive Gloss Black Engine Enamel 248932 ×3 (block + pan; covers are powdercoated) | 500 °F, gas- and oil-resistant, ~12 sq ft per can. Goes over the primer | HAVE |
| Cleaning, scuffing and masking supplies (tape, plugs, rags, solvent, respirator) | Already on hand | have |
No rust converter: it's heat rated to only about 200 °F, and the outside of a running block gets close to that. Clean every rust spot to bare metal instead (Step 2).
Enamel rules (Rust-Oleum data sheet): 50–90 °F, humidity under 85%. 2 or more light coats a few minutes apart; all coats within 1 hour, or wait 48 hours. Full hardness takes about 7 days.
| Step | Notes |
|---|
| Find every leftover-paint spot, rust spot and casting flash | Mark them with a paint pen or tape flag |
| Find every surface that must stay bare (list in Step 3) | Mark those too, in a different color |
| Decide: paint the bare block before assembly (this guide), or the assembled short block | Bare is easier to mask completely. The cylinders, mains and deck must be fully sealed |
Step 2. Strip and scuff
| Step | Notes |
|---|
| Plug and cover openings first (Step 3 list) before any scuffing | Sanding dust in the oil gallery is the worst outcome here |
| Leftover paint: feather edges with maroon Scotch-Brite or 180 grit until there's no ridge | Use stripper gel only on heavy build-up, outside surfaces only. Neutralize and rinse per the can |
| Rust: wire-brush, then Scotch-Brite or 180 grit, down to bare metal on every rust spot. No rust left under the enamel | Enamel over rust lifts and flakes. Do this before the final clean so no rust dust is left |
| Scuff everything that will be painted, including sound old paint | Paint grips a dull surface. Gloss over gloss peels |
| No sandblasting or media blasting on the machined block, pan or covers | Media hides in passages and threads and gets into the bearings later |
Step 3. Mask: what must stay bare
| Surface | How to mask |
|---|
| Block decks (head gasket faces) | Tape plus masking paper cut to the deck outline; trim with a razor |
| Cylinder bores | Plastic bag or paper stuffed in, taped at the deck |
| Main bearing saddles + caps, the whole crankcase inside | Tape the pan rail opening shut with paper/plastic |
| Oil pan rail (block) and pan flange (pan) | Tape exactly to the edge. FIPG goes here |
| Rear oil seal retainer face and oil pump / front cover face | FIPG surfaces |
| Water pump face, water bypass pipe groove/face, oil cooler face | Sealing surfaces |
| Freeze plugs (already in, red Loctite) | Paint over them or tape them; either is fine. Keep solvent away from the plug edges |
| Oil filter union boss, oil pressure sender hole, dipstick bore, drain cock hole | Bolt, plug or foam |
| Every threaded hole | Thread in old bolts or foam plugs. Paint in threads ruins torque readings |
| Dowel pins and dowel holes | Tape over |
| Knock sensor bosses (valley) | Bare metal: the sensors need clean metal contact |
| Ground strap and ground eyelet mounting points | Bare metal for good grounds |
| Bell-housing face (rear of block) and engine mount pads | Mating surfaces |
| Crank sensor mounting area, idler bracket and accessory bracket pads | Mating surfaces |
| Oil pan: inside, drain plug seat, dipstick tube bore | Paint the outside only |
Step 4. Clean
| Step | Notes |
|---|
| Blow off all dust with clean, dry air, working away from the openings | Check the masking is still sealed |
| Heavy grease: wash with Purple Power (or any degreaser/detergent) before masking, rinse with plenty of fresh water, and blow dry right away | Rust-Oleum's own prep step is a detergent wash + rinse. Water on bare iron flash-rusts, and residue left behind stops the paint sticking, so never use it as the last wipe |
| Final wipe: non-chlorinated brake cleaner, one clean rag to wet and one to dry | Leaves no residue (it's also fine on the FIPG faces). Don't touch the surfaces with bare hands after this |
| Conditions for every coat: 50–90 °F, humidity under 85% | Cold or damp makes gloss go dull or run |
Step 5. Gloss black
| Step | Notes |
|---|
| Primer first: 2 light coats of the gray engine primer on the clean bare metal (spray soon after the solvent wipe; bare iron flash-rusts). Then the black over it within the same 1-hour window, or after 48 hours (check the primer can). All coats within 1 hour, or wait 48 hours before another coat | Spraying between 1 and 48 hours can wrinkle or lift the paint |
| 1 light tack coat, then 2–3 medium wet coats, keeping the can 8–12 in. away and moving | Overlap each pass ~50%; start and stop off the part |
| Get the hard spots first: valley, under bosses, behind ribs, then the big faces last | Big flat faces last give the best gloss |
| Wait the flash time between coats per the can | |
| Optional: engine clear coat from the same line for extra gloss | Same window rules |
Step 6. Cure
| Step | Notes |
|---|
| Air-dry per the can before handling (usually overnight or longer) | Gloss enamel stays soft longer than it looks |
| Heat cure if the brand calls for it (some want a bake or engine run-in) | Small parts (covers, pan): bake per the can if you can. The block can cure on first run-in |
| Don't stack, hang by painted surfaces, or set tools on it while curing | |
Step 7. Unmask and clean up before assembly
| Step | Notes |
|---|
| Pull tape slowly while the paint is firm but not fully hard; cut along tape edges with a razor | Stops the paint film from tearing off with the tape |
| Razor any overspray off sealing faces; final wipe with non-residue solvent | FSM requirement for FIPG surfaces |
| Remove every plug and blow out every oil gallery, coolant passage and threaded hole | Look into each one with a light |
| Wash out the cylinders and crankcase if anything got in (hot soapy water, rinse, dry), then oil the bores and bare iron right away | Bare iron flash-rusts within hours |
| Chase threads if any paint got in | |
| Fresh tape over openings until assembly | Keeps dust out |
Touch-ups later
- Keep half a can.
- After assembly, mask nearby parts and touch up bolt heads and chips with the same gloss.