P1351

Hi guys


Just went out to my van today plugged in obd to see any codes back up with pending p1351..cleared code took van for a run checked no codes.
So p1351 comes and goes. This is confusing me! Please can you shed some light on this matter..???

any advice please


Thank you


Moh

 

If a glow plug is on the way out this will eventually become a permanent fault. However if you are doing long motorway miles the dpf will still regen passively so the ecu won't need to intervene and turn on the glow plugs. I would still look at getting the plugs tested/sorted though.

 

Hi thank very much.

Is there any way of testing glow plugs before changing them?
Also any diagram or information on how to change them please ??

Thank you


Moh

 

Firstly, have they been changed before? If not then how many miles are on the engine? If there's a fair few (80k miles for example) then I'd say it's worth changing all the plugs anyway.
If you want to test them then you will need and multimeter to measure the resistance between each plug terminal and earth. I believe they are wired is series so if one is dead none will energise.
General advice with the 1.6hdi is to change all the plugs if 1 is defective. This is because the plugs are located at the back of the engine and are annoying and time cosuming to get out.
Basic method is to ensure you have a deep socket (13mm I think, don't use a Halfords Pro one, they will not fit due to internal bevel) and get the engine as warm as you can (you will be working from the top so don't want it red hot!).
Disconnect the battery following the usual procedure.
Remove the top engine cover.
Undo and remove to one side the wiring across the top of the engine.
Unclip and remove the egr to manifold pipe (bottom clip is a pain to get back on).
Check you have the right replacement glow plugs, there are ones with push and screw fit terminals, some hdi's use one type and some the other).
Hopefully the engine is still warm, this will help get the plugs out as they can be stubborn (google for reports of snapped plugs).
Slowly loosen of each plug in turn with the socket starting with the right one as it's the easiest.
If you are lucky the plug will just unscrew and lift out with little resistance.
If resistance is felt screw backwards and forwards to loosen but make sure an pressure applied is straight down, a couple of plugs on mine took 20 minutes each of careful persuasion).
4th plug is the hardest as the is a lot in the way so a good torch is handy.
Fit the new plugs, don't overtightened, just a little more than finger tight, check Haynes for torque.
Reconnect wiring harness and the rest is in reverse.
If all went OK and you have a p1351 permanent fault it should now clear on starting.

 

Hi, just to be a bit cheeky - have you checked the relay itself?

Its easier to swap over and may fix the fault.

By all means use Eccles excellent guide for the glowplugs if you want, but it may just be the relay.

 

True. Rarely at fault but easily accessible. It sits on the outside front of the engine fuse box/ecu housing. Was just thinking that the intermittent nature probably wasn't the relay.
Just checked the glow plug torque and it's 10Nm/7lbf ft.

 

Thanks eccles for your advice really means alot as you have given detailed information.

I have been given a company car recently so my van only gets used on weekends on short journeys but I like to take it for a blast time to time so the dpf does not get blocked. As I have read on here you need glow plugs to run the regeneration cycle.

See how I get on....cheers

 

Try some electrical contact cleaner in the relay connector.

 

Not trying to be a smart arse but glow plugs are not wired in series there is no way you could wire in series they are wired in parallel but in some engines it is 2 parallel pairs.

Basically if you could wire in series 1 failing would indeed kill the others but in parallel they can fail individually but others will still work.

Glow plug faults are nearly always present on HDIs it only becomes a problem if the regens don't happen.

 

Fair enough, makes sense. Always does with comments from you :thumb: I did say " I believe...".
I still think that glow plugs are only needed when an active regen is required ("if the regens don't happen", I think you agree?). See it mentioned all the time that fully working plugs are always required.
On long motorway journeys under normal conditions this wouldn't be the case. On my 1.6HDi a glow plug went but as I was doing longer journey's at the time the DPF was still regenerating (checked with Diagbox), physically checked the DPF after 600 miles of having a duff plug. Fitted new plugs, told the ECU there was a new DPF (Risk of filter blocking then popped up and wouldn't clear) and it's been ok. Think that was 15000 miles ago.
When it works , when it goes wrong it can be a right p.i.t.a!