Webasto Heater Troubles

[mike the van]

Got a diesel HL 18 works well when it does

Always been a bit finnickity on starting, takes a few tries to fire up and sometimes you get diesel dripping out of exhaust, tried running it for a good long time to burn off any crud yesterday, today no start , fuel is good battery is good,

fan comes on, ticking pump starts , continues to run no ignition sounds from the glow plug heating up or the jet roar ! then it cuts out , then does the auto restart, tried several times through the day

Is the flame sensor duff or the box of tricks ecu

Cheers

Mike

[Oldiebut goodie]

When was the burner mat last renewed? Have you checked that the glow plug is working?

[mike the van]

Hopefully not they were replaced about 4 years ago by a webasto repairer, they just overhauled the heater not the ecu etc

Glow plug seems Ok coz when it does work you can hear it 'creaking' as it heats up in the chamber

[Oldiebut goodie]

Depending upon how much use you have given it it may just need the mat replacing. You are not running it on red diesel are you? Some varieties of red can clog up the mat quite quickly. Also is it being run on half heat all the time as this can clog the mat also? 4 years is enough to clog it in some scenarios.

Have you checked that all connections are clean and tight including fuses/holders. Do you have the single resistance coil in the lead to the glow plugs - if so is that warming up? (or twin resistance coils if 24 volt) - you may not have this if you have the ecu with a pulsed glow circuit.

There is obviously nothing wrong with the pump as you can get excess fuel dripping (this can lead to difficult starting as you have a swimming pool of diesel inside!)
You can check the resistance of the glow plug and flame sensor - the glow plug should be around 0.6 ohm. You will have to wait for the flame sensor one until I go down to the workshop and check.

Check the voltage at the ecu as it is starting not at the battery as there can be high resistance points in the wiring that you don't notice with just a battery voltage check. If it has always been a problematic start it could be just down to inadequately rated cabling. I run a HL18 in my boat and have never had any trouble starting it, that said it is always run on full heat and road diesel.

[Oldiebut goodie]

Take out the flame sensor, attach your multimeter (resistance) to the terminals and hold the sensor in a flame - the resistance should drop from infinity to 10Mohm and continue dropping quickly to a very low value. If it doesn't drop it's duff. Use a blowlamp or gas ring to get enough heat although you can do it with a cigarette lighter!

[Plasticman]

being a pessimist, i wonder what they actually did and replaced
mm

[Oldiebut goodie]

The HL18/HL32 use a finer mat than the modern ones and therefore clog a lot more easily. They also disintegrate easily.

[mike the van]

Cheers that has given me plenty to go at will have a go over the weekend, it is really good when it does go just need it to be consistent

Mike

[sarran1955]

Hello,

will have a go over the weekend, it is really good when it does go just need it to be consistent

Mike

Beware of the 'out of context police'

Cordialement,