Common areas for water leaks into the vehicle

# Common areas for water leaks into the E30.

#### Left front:

Left front sunroof drain. This drain runs from the sunroof to the left sill panel. |
If the sill panel drains become clogged, water can build up in the sill and overflow into the vehicle. Front drain show, rear drain is beside fuel tank. |

#### Left or Right front:

Overflow from air intake plenum at the base of the windshield. |
This can occur when the plenum drain(s) become blocked and water comes in via the exterior air intakes beside the blower motor. |
Clean drain tube(s) on firewall. |
WARNING: Do not remove tubes. Replace them if they are damaged or hardened. Removal to tubes will allow fumes to enter vehicle.

#### Right Front:

Right front sunroof drain. This drain runs from the sunroof to the right sill panel. |
If the sill panel drains become clogged, water can build up in the sill and overflow into the vehicle. |
Rusted battery box. All E30's have a battery tray at the right rear of the engine bay, regardless of actual battery location. Rust where the tray meets the firewall can penetrate to the interior of the vehicle, allowing water to enter.
To confirm rust penetration, remove glove compartment, pull down firewall insulation behind glove compartment. Photo shows example of rusted battery tray from inside the car. |

#### Left or right rear:

Other than water flowing under the seats from front leaks, the only rear water collection is caused by blocked rear sunroof drains. These drains run from the rear corners of the roof to the air vents in the side of the trunk, behind the bumper. They are not visible in the sunroof opening. If blockage is suspected, disconnect the hose at the vent and clear it using something that won't pierce the hose, such as plastic weed cutting cord from a power weed trimmer. |

#### Trunk:

Trunk seal damaged or misshapen. Place a fine coat of grease or petroleum jelly on the seal and close the trunk. Open trunk and check trunk lid for grease. Anywhere that does not have grease, the seal is not making contact. Replace seal or repair seal lip as required. |
Tail light gaskets. There is a foam gasket between the tail light and the rear body panel. Leaks from this area will usually leave stains below the lights on the inside of rear body panel. |
Tail light housing. The colored lens of the tail light is bonded to the gray plastic housing. Water can leak through the seam between the two. Clear RTV sealer along the seam can stop this leak. |
Body welds at tail panel. The seams where the rear body panel is welded to the rear quarter panels is susceptible to leaks if the seam sealer is damaged. |

E30 M3 Repair Manual V2.7. Copyright ©1999-2001 Koala Motorsport & Brett Anderson