Glow Plugs

Bosch Glow Plugs

Engineered for superior cold-start performance

Overview
Features/Benefits
Technical Info
Documents
Promotions
FAQs

Key Features

Make Bosch Glow Plugs a part of every diesel tune-up.
A regular preventive maintenance program keeps your diesel vehicle running right and can save you the cost and inconvenience of unexpected repairs down the road. When it's time for a tune-up, be sure to include a new set of Bosch Glow Plugs with Duraterm® technology, to deliver superior cold-start performance.

Features/Benefits

Bosch patented Duraterm® technology*

Glow plug reaches higher temperatures more quickly for fast engine start-up

*Available for most diesel powered cars and light trucks. Some applications employ standard glow plug technology per original equipment manufacturer's specs.

Regulating coil

Controls current draw for rapid heat-up of heating coil

Heating coil

Provides rapid heat-up of the glow tube and quick start-up

Glow tube material (Iconel® 601)

Resists corrosion and vibration for long service life

Fine-grained ceramic insulating powder

Provides superior electrical insulation and high thermal conductivity

Twin Viton® seals

Protect coils from exhaust gas damage for long life

Connectors designed to OE specifications

Precise fit and easy installation

Technical Details

201232_GlowPlugTechGd08.pdf (784K)

Glow Plug Technical Guide

Documents

Download the consumer brochure for more information on Bosch Glow Plugs.

Glow Plug Consumer Brochure

Promotions

No Promotions for this product at this time.

FAQs

Why do diesel engines require glow plugs and what function do they perform?

Unlike gasoline engines which use a spark plug to ignite an air/fuel mixture, diesel engines rely on the heat of highly-compressed air to ignite a precise amount of fuel to initiate combustion. Heating the air to a minimum starting temperature of 850°C is critical for diesel engine start-up.

In low temperatures, factors such as cold intake air and cold cylinder walls hinder the attainment of the necessary starting temperature. In these situations, glow plugs function as an additional heat source to bring the intake air up to the temperature necessary to initiate the combustion cycle.

There are two basic types of diesel combustion cycles:

Direct-injection engine
1. Nozzle holder with injection nozzle
2. Sheathed-element glow plug
3. Combustion chamber

Pre-chamber engine
1. Nozzle holder with injection nozzle
2. Sheathed-element glow plug
3. Pre-chamber
4. Combustion chamber

No matter which type of diesel engine a vehicle has, Bosch supplies just the right glow plug to give you dependable cold-start performance.

What is Bosch Duraterm® technology and how is it different from other glow plug technologies?

Bosch’s revolutionary Duraterm® glow plug technology utilizes a self-regulating control system that reduces glow wait time by more than 50%. The patented dual-control regulating and heating coil effectively directs current draw, enabling the glow plug to reach higher temperatures more quickly for faster engine start-up. The regulating coil keeps the heating element within the 1000° – 1100°C optimal temperature range, preventing engine damage due to over voltage/overheating.

For vehicles with a post-glow† control system, this advanced technology offers a post-glow heating phase. During the post-glow phase, glow plugs continue to operate for up to three minutes after the engine has started, improving overall engine performance and reducing smoke emissions and combustion noise.

Bosch Duraterm® technology is available for the majority of diesel car and light truck applications. Other applications employ standard glow plug technology per OE specifications.

What causes glow plug failure and what are the results?

Excessive voltage is the leading cause of glow plug failure.
Glow plugs are designed to operate within a temperature range of 850° – 1100°C. During operation, the glow plug controller switches current to the glow plug for a specific period of time to allow for proper heating. However, when the controller fails, current could be applied for a longer than specified time causing the temperature of the glow plug to exceed the 1100°C upper limit. Under these conditions, the glow plug overheats causing the casing to swell, split or burst which allows air to enter the coil area causing immediate failure.

Other causes of glow plug failure include:

Improper testing procedure (applying 12 volts directly to a glow plug designed to operate on 6 volts)
Incorrect engine timing
Improper fuel injector spray pattern
Continual cycling of the glow plugs

Damage like this will most likely result in engine failure. Removing a glow plug with a distended or broken tip may require engine head removal — a time-consuming and costly repair.

Heed the warning signs of worn glow plugs (see Question 5) and replace them with a brand new set of Bosch Glow Plugs!

What conditions indicate that it's time to replace the glow plugs?

The following signs most likely indicate that it’s time to change a vehicle’s glow plugs. If any of these conditions exist, be sure to check the vehicle’s glow plugs and if necessary, replace them with a new set of Bosch Glow Plugs.

Vehicle won’t start
Vehicle starts only after excessive cranking
Vehicle idles roughly after initial start-up
Excessive exhaust emissions after initial start-up

Can only the worn or failed glow plug(s) be replaced, or should all glow plugs be replaced at the same time?

If one glow plug fails, chances are the others won’t be far behind. To minimize vehicle down-time and save on labor costs, Bosch recommends changing all glow plugs at the same time.

Bosch is not the OE glow plug on this vehicle. Is Bosch comparable to the OE brand?

You can replace OE glow plugs with Bosch with complete confidence. Bosch is currently the OE glow plug on most European diesel vehicle applications. And for Domestic and Japanese vehicle applications, Bosch Glow Plugs are designed to meet and/or exceed the OE glow plug specifications.