glow plugs stuck on

[hvguy]

Not sure why, but if you watch my recent video, I mention my glow plugs are still on.... any idea why this is? I tapped the relay thinking it was stuck, but its not.

Im glowplug-less now.

Any ideas?

[Jason]

If they are on, the relay is bad. It must be stuck there is nothing else that runs them. Just get yourself a high amperage starter relay and wire it to a push buttom switch. Cheap and easy fix. The volvo relays are expensive no matter where you buy them.

Jason

[hvguy]

lol, my buddy with an old 6.2L chevy diesel did that... said the old one went out at like 120k lol.

Will do, ill just put that on the long list of things to do =/

[240diesel]

I also had that problem, i replaced the Volvo-relai for another Volvo-one because a had a spare.
To notice if it happens again, i placed a second seatbelt-reminder-light in the middleconsole paralel to the glowplugs to "see" them glow.
So i can even notice if they're glowing a while after the engine just starts running, especialy in wintertime.

[Jason]

Ya know it could be the temp sensor, you should check that for resistance against the other one, they are both the same sensor. Don't really hear of them going bad all that ofter but should be checked anyway.

Jason

[ngoma]

Ya but could the temp sensor cause the GPs to stay energized? Thought the temp sensor only provides signal to cycle the GP relay for a period of time-- not able to force the relay to stay energized over its "max" time?

[hvguy]

Ya know it could be the temp sensor, you should check that for resistance against the other one, they are both the same sensor. Don't really hear of them going bad all that ofter but should be checked anyway.

Jason

a temp sensor eh, I hear there are 2? which one would be the one to be checked, and what resistance should it read?

[Jason]

Ya thats a good point, it shoul go out anyway I suppose. Just replace the relay.

FYI, the sensors are at the back of the head below the cam sprocket, and at the front of the head just below the forward most glow plug. The rear one runs the glow plugs, the front one is for the temp gauge. Don't know what the readings should be, but if your gauge works correctly you could just measure both and compair. I don't think thats the problem though.

Jason

[hvguy]

Ya thats a good point, it shoul go out anyway I suppose. Just replace the relay.

FYI, the sensors are at the back of the head below the cam sprocket, and at the front of the head just below the forward most glow plug. The rear one runs the glow plugs, the front one is for the temp gauge. Don't know what the readings should be, but if your gauge works correctly you could just measure both and compair. I don't think thats the problem though.

Jason

Ahh, fine point when the comparison. Ugh, was it necessary to place it in the back of the engine... omg.

Ill just make it push-button for now... =) tha way it will always work the way I want it to.

[v8volvo]

Even if the GP temp sender is unplugged the plugs should still go out shortly after the engine starts.

If a relay sticks on and the plugs never get turned off, they can melt themselves and the tips can get swollen... and then you may have trouble getting them out. Or even worse, a tip could come free and drop into the combustion chamber and do major damage. If the relay sticks, unhook the power to it right away, otherwise you may end up causing lots of other trouble for the motor.

A light on the dash to monitor if the plugs are glowing or not is a great idea to avoid this problem.

[hvguy]

Even if the GP temp sender is unplugged the plugs should still go out shortly after the engine starts.

If a relay sticks on and the plugs never get turned off, they can melt themselves and the tips can get swollen... and then you may have trouble getting them out. Or even worse, a tip could come free and drop into the combustion chamber and do major damage. If the relay sticks, unhook the power to it right away, otherwise you may end up causing lots of other trouble for the motor.

A light on the dash to monitor if the plugs are glowing or not is a great idea to avoid this problem.

well, even if the relay is unplugged 'entirely' the light stays on... it actually comes on immediately after I put my key into the ignition... O_o? forget the OEM crap... im making a control panel for everything at the moment, as well as doing a stage 1 weight reduction... no ac or sound deadening.

thanks again for everyone's help

[240diesel]

If the extra control-light on the dash stays "on" i can imediatly switch off the power after i put the car near the road because i fitted a betteryswitch to prevent joyriding, fire while i'm away etc.
So for me it's allright to have the light.

remember also that what kind of contact you apply to power the GP's they all can meltdown some time (yeah, even my bat.switch :-) :-) )

[hvguy]

got around to installing the GP switch this evening... I tapped into the defroster power supply in the dash, switched that to the relay and spliced a wire from the glow plug side of the relay to an indicator light... to indicate that there is power flowing through the relay.

here is how the switch came out: I used an old control panel switch I pulled from a factory scrap job a long time ago, the faceplate was a plus =)

off
http://i35.tinypic.com/2uohtz9.jpg
on
http://i37.tinypic.com/2cwn4i1.jpg