307 Glow Plug Relay

Degrees

Member
Fellow Frogger
Joined
May 20, 2015
Messages
45
Location
Brisbane
During routine OBD scans, I have noticed P1351 recurring after being cleared.

Naturally, I have tried testing the relay with reference to SEDRE diagrams but unsure what voltage needs to be supplied to the BSI output pins.

Is this relay known to fail relatively early or could it actually be the glow plugs? I'm at 110K/Kms.

I'm in Brisbane and would be hugely appreciative to get hold of another relay for troubleshooting, part number 51252002.

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For anyone who encounters this in future, I have checked resistance on all glow plugs on the relay connector per SEDRE for my 307 HDI 136hp with FAP.

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I found continuity between ground and pins 1, 7 and 2. Open circuit on pin 6, indicating glow plug #4.

Pretty annoyed as I hear a plug change is an arduous and expensive exercise.
 
For anyone who encounters this in future, I have checked resistance on all glow plugs on the relay connector per SEDRE for my 307 HDI 136hp with FAP.

UiTylbL.png


I found continuity between ground and pins 1, 7 and 2. Open circuit on pin 6, indicating glow plug #4.

Pretty annoyed as I hear a plug change is an arduous and expensive exercise.
Digging up a very old thread …

Yesterday, I priced the glow plugs from a Peugeot dealer for the 2.0 litre HDi engine in my 307. $50.00 each. Ouch.

Then I thought that I'd ask the service department how much to replace the four of them, because I, too, had heard that it is an arduous exercise. In excess of $470.00 Labour. Double ouch!

Degrees, did you replace the glow plugs yourself? Or did you get them done?

Has any 'home mechanic' successfully performed this operation? I'm interested in anyone's experiences performing this surgery on this particular model. The glow plugs seem to be located under the air vent intake on the firewall, right at the back of the engine bay. That's not what I would call the most convenient location.

Anyway, if you have experience of doing this job yourself, I'm interested in hearing from you!

Thanks,
Andrew
 
You should be able to get the plugs for the 307 hdi at around 20~ ish a piece. Might as well do all 4 when you're there too.

It is a bit of a nuisance doing the job but it isn't too crazy to do. Will take you a few hours if you have not done it before. Might as well clean the egr out (heater and piping too). I used this vid as a reference, was quite helpful https://youtu.be/yikcb9UTi8M. Take the scuttle panel off can give you some more space too.
 
Hi melon,

Thanks for your reply. The music in that video is nearly enough to make me not want to do the job! He tested each plug before replacing them. I don't see a need to do that, but maybe there is. What's your advice, please?

I got the plugs posted from European Auto Imports in Sydney for a bit under $140.00. I wasn't going to even consider doing just one, but thanks for suggesting it.

What's the advantage of cleaning the EGR? And what's involved?

Thanks for your help so far.

Andrew
 
If you have a multimeter, I'd test each one via the glow plug connector. Just to be sure your glow plugs are faulty.

You have to take it all off anyway, and you'll see the piping full of soot and crud. You'll want to clean it a bit anyway.

There's vids on egr cleaning and removing the scuttle panel (don't have too but it gives you more space to get your hands behind the engine)

https://youtu.be/G0cXkfnVKlY (egr vid)

https://youtu.be/koGS3B2TXeo (I'd remove the one bolted in on each side too makes it easier) will need to unclip the brake res and stuff too
 
Morning fellow RHR engine owners, at the moment I have 4 of those engines and 3 cars that used them on the road for many K's over the last 11+ yrs. My view is why do you even contemplate going to all the trouble for 1 glow plug that in this country makes little or no difference to starting. I have been on the dark side of that engine in a 407 to remove the #1 glow plug as part of chasing a compression issue in that particular cylinder. Though somewhat arduous it did allow me to prove the comp problem, but in hindsight the same could have been done by turning up a bit of metal that would fit where the injector lives and make access to the compressed cylinder air much easier. Was going to fit 4 new injectors till talking with a local mech who is a Fiat accredited workshop where he gets to see a few RHRs in Ducato campers and etc. The new plugs are still in the cupboard enjoying an easy life.
 
At what temperatures do you think that glow plugs do make a difference to starting one of these engines? I'm really curious.
 
Yes it's all very well for you fringe dwellers to dismiss glow plugs as unnecessary, but those of us who dwell in the real Australia have a different view!

I had to educate my daughter-in-law that lives in Canberra (307 HDi) - turn the key on, wait for the little ram's horn symbol to disappear, then hit the starter. She had been starting the car in winter without waiting, and (surprise, surprise) finding it hard to start :rolleyes:.

Cheers

Alec
 
If you can manage it, better to replace it. I'm sure it's mentioned on here somewhere they also help with depollution on start-up. Also it will clear the code on the Peugeot if it's the plugs that are faulty.

The car will run fine without 1 of the plugs, I guess. Once you've taken it all out might as well do all 4 haha.
 
Once you've taken it all out might as well do all 4 haha.
As I said earlier in this thread, I had every intention of replacing all four plugs, not just one.

If I’m going to go to that effort, I’m going to get my effort‘s worth!
 
As a fringe dweller I find it best to undertake considerable research and talk with those who know, and will tell you that the modern High Pressure common rail diesel engines are not like those of yore. The Fiat Service mechanic, and probably the best in Coffs, who identified the slight issue with an 05 407 with RHR (2.0 HDi engine) put it quite bluntly; "Forget all you know about old diesels and start again, cause they are very different." All diesels love air and lots of it because it is only the heat generated by the air when it is compressed that makes it fire. Most of the pre High pressure engines had pre-combustion chambers in order to reduce the diesel knock and by design they were not Direct injection like they are now in the modern diesel. Because the pre-com chamber and indirect injection were reliant upon heat transferring from the top of the piston where it was hottest glow plugs were used to heat the surrounding metal and/or incoming air. Older pre computer diesels are very sensitive to timing because if it is a tad early the air ain't hot enough and the injection of fuel just robs the combustion area of heat and you'll never start it - hooray for glow plugs. By comparison and still talking pre computer and High Pressure I own Komatsu earthmoving gear from circa 1990 in which their standard engine is what they call Direct Injection Micro Turbulence (DIMT) which means they have done away with pre-combustion chambers and though fitted with glow plugs you'll never wear them out because they are not necessary whilst ever the engine has enough compression and so far 15,000 hrs of wear has not brought on the need for glow plug usage. When it comes to the 'new' era of diesel engines not only is there direct injection but there is an electronic control unit (ECU) which gets input from many sensors and etc in order to help it make the right decision re quantity and timing of fuel. Without going into how the different injector types work they are generally capable of firing multiple (about 6) times per cylinder per compression stroke and because the ECU is smart enough to know that too much fuel will defeat the goal of hot enough to cause combustion the engine is certain to fire and run from the very beginning until the ECU gets a bit weary or ornery. This multiple firing avoids the old loud knock from the single heavy dose of finely atomised diesel and thereby has made the engines much quieter without the need for pre-com chambers. Pursuant to reading Armidillo's comment about a 307 HDi in Canberra I looked at my HDi engined vehicles fitted with RHRs and found that the 2010 308, the 2007 407 and the ex-Armidale stat write off restyle 307 do show the 'rams horn' glow plug indicator for all of 1 second and the 2001 406 with RHZ engine also does but stays lit for 1.5 seconds and consequently would have damn all input into aiding starting. In fact like on the Komatsus I just get in and turn the key to start and they do. By comparison the trusty old '96 405 SRDT displays the ram horns for 5-6 seconds. It could be that in the new ECU controlled cars the duration of ram horns is varied according to ambient temperature, but that will require research by someone other than a 'fringe dweller'. It would be a quick and interesting exercise to undo the glow plug connector one evening and then see how well it starts on a frosty morning. Or alternatively give the glow plugs 20 -30 seconds after their short glow to cool down and then see if there be any noticeable problem starting it. From what I've been told by mechanics far more experienced with RHR engines than me the glow plugs are far more used during the DPF regen activity when the ECU creates high exhaust temps by over-fueling and adding the special, and expensive, additive in order to burn the collected fine soot and etc off the filter plates.

Not being burdened by having eons of time and needing to find ways to spend excess funds I have an aversion to fixing things that ain't really broke. If it goes well and the economy is good leave it alone is my way of thinking, and on top of that what will be the downside if a glow plug refuses to leave its hole - it won't be the first time it happens. Putting a plate in the EGR that all but blocks it is worthwhile and common practice if one reads up on the benefits that result. My poor ole 406 HDi had to have major surgery that involved removing the head so that the virtually completely blocked inlet ports could be opened up to regain air flow and like I said at the beginning diesels love air, lots of it and the cooler the better!! Will be interested to hear the results if any of you go to the trouble of checking the duration of lit up ram horns at different times of the day, or early morning. Perhaps Armidillo you could get your daughter to do a count down on her 307 HDi. It is also pertinent that because the RHR has a turbo the engine has a lesser amount of air to compress at start up than when running and extra air is being force fed into it. Obviously, the more air that is fed into it will result in increased cylinder compression temperature and the ability to vary the timing of injection to gain power and economy.
 
Thanks - it is as you say a brave new world. My diesels are both around 20 yrs old (Japanese) with manual pumps, and the son's 307 is a T5 (RHY) so all a bit primitive.

I can confirm that, in the vehicles I have experience with, the glow plug light displays for a longer time when the ambient temperature is low. Obviously most Australians live on the coast - I can see why the experience of those of us further inland is of little relevance to the majority.

The daughter-in-law now drives a C4 Grand Picasso with an RHH lump, which they've only had since last summer. I will be interested to do a back-to-back cold start comparison between it and the old 307 (RHY) if we get a chance to go for a visit to Canberra this winter.

Cheers

Alec

Ps - have already had 3 serious frosts in Armidale this month, all around -4C.
 
I have a 20 year old land cruiser direct injection diesel with the glow system disconnected and removed to fit an intercooler and it starts first turn over in most areas including the snow.

Interesting read, my 307 also needs new plugs but as discussed not necessary in the sub tropics.

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