Mishimoto MMHOSE-CIV-88BK Silicone Coolant Hose Kit for 1988–1991 Honda Civic and CRX

Compatible Factory Engines

Depending on year, market and trim, compatible applications can include factory D-series engines such as:

• D15B1
• D15B2
• D15B6
• D16A6

The original engine, thermostat housing, intake manifold and radiator arrangement must still match the hose shapes supplied in the kit.

Not for B-Series or K-Series Swaps

MMHOSE-CIV-88BK is intended for the factory-style D-series cooling system. It should not be used automatically with:

• B16A or B16B swaps
• B18A, B18B, B18C or B20 swaps
• K20 or K24 conversions
• H-series swaps
• Custom radiator installations
• Modified coolant outlets

Mishimoto uses the separate MMHOSE-CIV-88B16BK designation for applicable B16-swapped 1988–1991 Civic and CRX builds.

A hose kit cannot determine which engine was swapped into a 35-year-old Honda. At some point, the hood must be opened and the evidence examined.

More Than Two Radiator Hoses

The published measurements identify ten individual hose positions, indicating that this is a broader coolant-hose package rather than only an upper and lower radiator-hose pair.

The supplied hoses may cover:

• Upper radiator connection
• Lower radiator connection
• Heater-system connections
• Thermostat and water-pipe connections
• Intake-manifold coolant passages
• Smaller bypass-coolant circuits

Exact hose use varies by engine, trim and market. Match every hose against the removed component before installation rather than choosing by diameter alone.

Hose Dimensions

The product description contains a small overlap between the inside- and outside-diameter groupings. Use the supplied hose diagram or compare each molded hose directly with the original before installation.

Reinforced Silicone Construction

The hoses combine high-grade silicone with heat-resistant embedded fibers. Mishimoto rates the material for temperatures up to 330°F and improved pressure tolerance compared with old factory rubber.

Key features include:

• Reinforced silicone construction
• Embedded heat-resistant fibers
• Maximum temperature rating of 330°F
• Molded factory-style routing
• Multiple coolant hoses
• Black finish
• Mishimoto Lifetime Warranty

Silicone improves resistance to heat and aging, but it is not naturally as resistant to fuel and engine oil as a purpose-made petroleum hose. Repair oil or fuel leaks that contaminate the cooling-system hoses.

What’s Included?

The available dimensions indicate a 10-hose coolant set. Confirm the current package contents and supplied clamps with the seller before ordering, as listings may use older images or condensed descriptions.

Do not assume the kit includes:

• Radiator
• Thermostat
• Water pump
• Coolant
• Fan switch
• Every vacuum or emissions hose

When Should EF Civic Coolant Hoses Be Replaced?

Replace the hoses when you find:

• Cracks near a hose end
• Soft, swollen or oily sections
• Hardened material that no longer flexes
• Coolant residue around a connection
• Abrasion from brackets or wiring
• A hose collapsing during cooldown
• Repeated coolant loss
• A sweet smell after driving
• Temperature fluctuations
• Visible steam or leakage

Use our guide on how to find a coolant leak when the source is unclear. Small bypass and intake-manifold hoses can leak onto the engine and evaporate before coolant reaches the ground.

Installation Overview

Only service the cooling system when the engine is completely cold.

Because this is a multi-hose kit, replace the hoses methodically:

1. Confirm the installed engine code.
2. Photograph the complete factory hose routing.
3. Label both ends of each original hose.
4. Drain the coolant into a suitable container.
5. Replace one hose at a time where practical.
6. Compare every new hose with the removed part.
7. Clean each metal connection before installation.
8. Inspect pipes and housings for corrosion.
9. Route each hose without kinks or contact with moving parts.
10. Position clamps behind the fitting beads.
11. Refill with Honda-compatible coolant.
12. Bleed trapped air from the system.
13. Confirm radiator-fan operation.
14. Inspect every connection at operating temperature.
15. Recheck the coolant level after the engine cools.

Our cooling-system flush guide explains how to remove contaminated or deteriorated coolant before installing the new hoses.

Inspect the Complete EF Cooling System

New hoses will not repair a clogged radiator, failing water pump or damaged head gasket. While the coolant is drained, inspect:

• Radiator core and tanks
• Thermostat and housing
• Water pump
• Cooling fan and fan switch
• Radiator cap
• Metal coolant pipes
• Heater core connections
• Overflow reservoir
• Drive belts
• Coolant condition

Our complete car cooling-system guide covers the entire coolant circuit.

Additional diagnostic resources include:

• Why a car overheats while driving
• Seven signs of a failing radiator
• Bad thermostat versus bad water pump
• Car overheats while the heater blows cold
• Can radiator stop-leak cause damage?
• How to avoid overheating-related head-gasket damage
• When should you stop driving?

Frequently Asked Questions

What vehicles does MMHOSE-CIV-88BK fit?

It fits compatible 1988–1991 Honda Civic and CRX models retaining the factory-style D-series cooling system.

Does it fit a Civic Si?

Yes, on applicable 1989–1991 U.S.-market Civic Si models using the original D16A6 cooling configuration.

Does it fit a CRX Si?

Application catalogs list compatible 1988–1991 CRX Si models with the factory D16A6 layout.

Does it fit the CRX HF?

Yes, compatible CRX HF applications are listed. Confirm every hose against the vehicle because the smaller coolant connections can vary.

Does it fit a Civic Wagon or RT4WD?

Compatible Wagovan and RT4WD applications appear in established fitment data. Verify the engine and hose arrangement before ordering.

Does it fit a B16-swapped EF Civic?

No. Use the B16-specific Mishimoto hose kit or select hoses according to the exact engine, radiator and thermostat-housing configuration.

Is this only an upper and lower radiator-hose kit?

No. The published specifications identify ten hose positions, making it a broader coolant-hose set.

Are clamps included?

The supplied description does not clearly establish the clamp count. Confirm the current package contents before purchasing.

Will these hoses work with an aluminum radiator?

They can work with a direct-fit radiator that retains factory neck locations and diameters. Measure custom or half-size radiators before ordering.

Will silicone hoses reduce engine temperature?

Not directly. They provide durable coolant routing and increased pressure tolerance. Actual engine temperature depends on coolant circulation, radiator efficiency, thermostat operation and airflow.

Product Specifications