Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
BMW Operating Fluids - Body Cavity Sealing And Undercoating (97 07.10)
Reference number: 97 07.10
BMW OPERATING FLUIDS - BODY CAVITY SEALING AND UNDERCOATING
TECHNICAL SERVICE
| GROUP: | 97 Body Cavity Sealing and Undercoating |
Fluids and sealers that are described in this Operating Fluids manual are BMW approved. Using non approved fluids or sealers can lead to premature failure and will not be covered under Warranty.
1.0 GENERAL INFORMATION ON PRESERVATION MEASURES
The classic quality of BMW automobiles is based on the long-term comprehensive research and testing, the design, the applied materials and the manufacturing procedures in modern production plants.
BMW recommends cleaning the engine, engine compartment, vehicle underside, axles and engine/transmission at least twice annually, and then waxing the car or repairing the wax coating. This should be performed before or after the period of salt usage on streets.
New cars parked outdoors should be waxed at BMW centers before delivery to customers. This is to avoid deposits damaging to the paint finish, such as air-born rust particles, chemical dust, oil saturated soot, sulfur dioxide (acid) rain, etc. settling on the horizontal surfaces. Bird and insect droppings as well as tree resin could mar the paint finish, forming spots, swelling and pitting in the paint coat.
Wax films on the engine, engine compartment and A pillars (hinge areas) are intentional and prevent corrosion. Such wax film should not be removed.
Unwaxed cars should be washed at least once each week. Parked cars must never be protected with plastic or other nonporous material covers. This will damage the paint finish due to condensed water in conjunction with plastic softener diffusion and scratching.
2.0 BODY CAVITY SEALING
It is only necessary to rewax or seal the affected area after repairing the body.
Only BMW approved products may be used to comply with the six year warranty against rust perforation. These products protect cavities effectively and permanently against corrosion. Their excellent coating and waterproofing properties let them flow into all inaccessible corners and folds for unsurpassed overall protection.
Underbody and Body Cavity Sealing Compound
For sealing of body cavities, such as doors, A-pillars, front, side and cross members, etc. (Former BMW Part No. 81 22 9 407 479)
- 3M Part No. 8891
- Wurth Part No. 892080
Also: Wurth "Brushable Seam Sealer", Part No. 8901021.
3.0 BODY CORROSION PROTECTION
To comply with the six year warranty against rust, specially selected waxes and additives produce an elastic, temperature-proof, corrosion inhibiting protectant. The corrosion protection thickness should measure a maximum of 30 microns, but can be varied as desired by repeating the spraying procedures accordingly.
Procedure:
Clean underside of car to remove grease, oil and dirt. Cover rotating parts and parts not undercoated, such as driveshaft, brake discs, brake hoses, springs, exhaust pipes, etc.
After completion of body repairs, the affected areas must have corrosion protection reapplied. This applies, also, if the BMW Annual Check shows that the corrosion protection has to be repaired.
Underbody Sealing
Quick-drying, rubber-based, paintable. Compatible with PVC-based undercoat, front apron and door sill coatings. (Former BMW Part Nos. 81 22 9 407 001, 81 22 9 407 521/522)
- 3M Part No. 8883
- Wurth Part No. 892072
- Loctite Part No. 81833 (or PX135EA)
- CRC Part No. Siloo 28A
Also: Wurth "Body Seal, beige", Part No. 0892091 U.
Body Sealant, Light
Sealing compound for all joints and seams, can be painted over. Good adhesion, free of shrinkage, resistant to heat and cold temperatures, permanently elastic. (Former BMW Part Nos. 81 22 9 400 013 and 81 22 9 407 313)
- 3M Part No. 8361
- Wurth Part No. 893430
Seam Sealer, White
Elasto-plastic sealing compound based on polyacrylate.
Applications: Protection of door and hood panel seams. (Former BMW Part No. 81 22 9 407 675)
- 3M Part No. 8361
- Wurth Part No. 890100025
Also: Wurth "Gray Seam Sealer", Part No. 089228 U.
Transparent Wax
Prevents corrosion on painted and non-painted metal surfaces. Serves mainly for treating edges and folded-over seams. (Former BMW Part No. 81 22 9 400 711)
- 3M Part No. 8892
- Wurth Part No. 893082
Anti-Chip Compound
Sprayable coating compound for outside and inside. For sealing, noise-insulation and as protection against flying stones. Quick-drying can be painted over, permanently elastic, heat and cold-resistant. (Former BMW Part Nos. 81 22 9 407 001 and 81 22 9 407 416)
- 3M Part No. 8964
- Wurth Part No. 893075
- Loctite Part No. 81833/PX135EA
4.0 OTHER FLUIDS
Adhesive Remover
(Former BMW Part No. 81 22 9 407 388)
- 3M Part No. 8984
Rust Remover
(Former BMW Part No. 81 22 9 407 121)
- Wurth Part No. 89091801
- Loctite Part No. 82075
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.