Glow Plugs

[scrumpydude]

Last week, in the frost the old girl started second time. Not first. Subsequently, she has been a bit slow to fire first thing in the morning. More cranking than normal.

My finger of suspicion is pointing towards glow plugs but I've not looked at anything yet. The coil light operates as normal if that indictaes anything to anyone in the know. What checks should I do to narrow down the problem? Check for voltage when the coil light is on I presume. What kind of a job is replacing them?

Must admit, I had a quick look under the bonnet and couldn't even find them!

 

[Banshee]

To get to the glow plugs you need to remove the intercooler and move one of the coolant hoses out of the way.

Before you go to those lengths, it might be worth grabbing a length of thick wire and before attempting to start the truck from cold one morn.

Get your wire and touch one end on the positive terminal and the other end on the from of your bus bar which looks like this;

Hold it there for a good 30 seconds or so and then try starting the truck, you'll be manually energising your bus bar there and in turn heating your plugs. If it starts after trying that, you can guarantee that it's your glow plug relay gone duff due to corrosion either internally or more commonly at the plugs.

The relay is mounted on the inner drivers wing and always catches crap!!! I don't have any spare relays or plugs at the moment in stock either I'm afraid

 

[Banshee]

Oh.... and if it's still the same after that, it's time to whip the plugs out and check the tips

If the tips are still there and look visually OK, get your jump leads out and connect the negative to the plug body and touch the top threaded tip with the nut with the positive, you'll start to see the ends glow if they are good, if not, you've found your problem :clap

 

[Barrbeast]

There's a write up somewhere that I did when I changed glow plugs on my Y61 (which was also had the ZD30).

Assuming the set up is exactly the same for the Terrano, you'll need to remove the throttle body.

 

[Barrbeast]

There we go...

http://www.nissan4x4ownersclub.com/forum/showthread.php?t=23993

 

[Banshee]

There's a write up somewhere that I did when I changed glow plugs on my Y61 (which was also had the ZD30).

Assuming the set up is exactly the same for the Terrano, you'll need to remove the throttle body.

Didn't even spot he had a 3.0 :doh

Well done Rob, but same principles apply and pretty sure the relay is in the same spot :nenau

 

[scrumpydude]

Thanks both.

Something to have a look at on the weekend. Presumably I could check for 12v on the bus bar when the coil light is on and that would pass/fail the relay too.

 

[Banshee]

Thanks both.

Something to have a look at on the weekend. Presumably I could check for 12v on the bus bar when the coil light is on and that would pass/fail the relay too.

Yep!!! When the relay clicks you'll lose voltage, then if it's anything like a 2.7, the relay should cycle on and off every couple of seconds and you'll get voltage and lose it again if your meter is still connected.

 

[terranosaurusdoug]

I had a problem with mine a few weeks ago, it turned out to be the wire that connects at the end if the bus bar, it corroded and eventually snapped. It was getting harder to start as the connection was at the end of it's life then when it snapped was a rightvm twat to start. I put another terminal on the end and it's been fine since.

 

[TOSKA]

Hello !!

All above comments are valid.
obvious perhaps , but is your battery OK ??

COVID = not much travel = not enough time to recharge battery = ooops !!

The glow plug heaters knock sweet jesus out of the voltage and you can then be actually cranking at 11 or so volts or less. = engine not spinning fast enough to get the compression needed to fire

I'm on short usage at present and have to either " come back home the long way " or periodically give the battery a bit of a charge ( 3 weeks ?? )

I purchaed a £1.60p voltage meter that plugs into the cigarette lighter hole as an easy indicator of "starting volts "

TOSKA

 

[terranosaurusdoug]

Hello !!

All above comments are valid.
obvious perhaps , but is your battery OK ??

COVID = not much travel = not enough time to recharge battery = ooops !!

The glow plug heaters knock sweet jesus out of the voltage and you can then be actually cranking at 11 or so volts or less. = engine not spinning fast enough to get the compression needed to fire

I'm on short usage at present and have to either " come back home the long way " or periodically give the battery a bit of a charge ( 3 weeks ?? )

I purchaed a £1.60p voltage meter that plugs into the cigarette lighter hole as an easy indicator of "starting volts "

TOSKA

Good point! I like the cig lighter voltage meter idea :thumb2:thumb2:thumb2