White smoke on startup but clears

[dawg runner]

Hi,

 

Over the weekend I flushed my cooling system on ZD30 patrol GU3. I did a lot of reading about air bubbles in the system and was very careful when refilling to get all of the air out. or at least I hope I was.

 

Took the car for a drive to Wollongong ( I live in Sydney ) and back on Saturday night. Knowing I had just done a coolant change my eyes were on the temp gauge more than the road and it did not seem to move at all on the journey. My eyes were particularly glued to it when I was coming up Bulli pass. Drove all then way up in 4th at 80 and it chugged all the way up with no apparent issues.

 

Got in the car to go somewhere at 8 the next morning and started it up and there was some white smoke coming out the exhaust. I thought fogg at first but then I checked it and it appeared to be more than that. Gave it a rev or 2 and it cleared and stopped smoking. Car was running fine so I thought nothing of it. Got to where I was going that morning which was a couple of KMS down the road and stayed for approx. 30 mins. When I was leaving it smoked a little more but again dis appeared with a rev or 2. Left home about an hour later and it did it again but again dis appeared after a rev or 2. This time I went about 15kms in traffic and stopped for 3 hours. By now I had a lot of time to think over the course of my lunch and am beginning to think the worst and I was expecting when I started it again that there would be white smoke but nothing this time.

 

I have noticed over the winter in the morning on first start up it will be a little rough for a second but then settle to idle. I put it down to being cold but this is my first diesel so I am all ears.  I have never noticed any white smoke before Saturday morning but I guess I have not really been looking for it and also I usually start my car up on cold mornings and go back inside for a cuppa and maybe I have missed the white smoke if it was there before Sunday.

 

Research is pointing me in 2 directions. 1 glow plugs or 2 head issues. The car runs fine. There is no power loss apparent and there is no coolant spewing out overflow when hot so I am hoping it is glow plugs.

 

Can glow plugs have intermittent faults which would cause it to smoke and I guess the same for head issues?

 

Any help or experience appreciated.

 

Cheers

 

Dave

Edited July 29, 2013 by dawg runner

[Rumcajs]

Firstly coolant change is always a source of airlock in the system which causes temporary overheating. Watching coolant gauge is pointless as the gauge is set not to react until temp is too high and is too late.

Really bad idea from Nissan but Toyo is the same.

If you didn't have a coolant level drop after the change and didn't need to top up than you got away with.

ZD30s are known for glow plugs failures so it is entirely possible that white to light grey smoke is just unburned fuel when engine is cold especially if it is harder to start or it runs a bit rough first thing.

You can also smell unburned Diesel in the exhaust sometimes.

I'd suggest to monitor the coolant level and perhaps check the resistance of each glow plug to pintpoint the faulty ones. Usually no 3 and 4.

Edited July 30, 2013 by Rumcajs

[dawg runner]

RUMCAJS

 

Thanks for your reply.

 

I will check glow plugs and monitor coolant level.

 

If i do need to replace glow plugs what is the best brand/type of glow plug to get for replacement and also i am assuming if i do 1 i should just replace them all.

 

Thanks again for your help.

 

Cheers

 

Dave

 

 

[Rumcajs]

Well with glow plugs, it is funny business because there are both metal and ceramic tips available and yes you probably need to replace all 4 of them. I replaced mine recently and two were dead and two still fine.

*The metal glow plugs will not last for long (expect max 50K km at most)but can be had very cheaply as low as $20 for a set (nasty) or $30 a piece (better)

*The ceramic plugs are very expensive only NGK brand is available (or Nissan OEM which are NGK again but even more expensive) around $65-75 a piece but they will last 100,000 km or more.

The ceramic units are more fragile and are known to drop a tip in to the combustion chamber if certain conditions exist.

The biggest problem with glow plugs however is their control system for which Mr Nissan should be "hanged, drawn and quartered"

It is in fact the control system which contributes to the glow plugs early or catastrophic failure. Nissan uses the glow plugs excessively (up to 5 minutes) after the engine has been started to keep smoke under control when engine is cold. This combined with poorly designed engine (pistons, intake, EGR) and poor fuel spray pattern from worn injectors can also cause engine head cracks around the glow plug holes which ain't the best for overall system health.

So, do not fit new glow plugs until you have fitted "glow plug timer" mod which stops the plugs wearing out prematurely especially when fitting cheaper metal tipped ones. (See Dronus' NADS pages about the timer mod)

I have decided to fit ceramic tipped ones back again recently, with the timer mod carried out at the same time they should last another 200,000 km minimum. With the timer I have a full control over glow time (more sensible 30 seconds), I can override it as well when needed with an addition of kill switch, example even at the ambient temperature way over 20 degrees C Nissan will still glow the plugs even though it is not needed at all. It is relatively simple and cheap mod it is just a bit fiddly to do.

Cheers

Edited July 30, 2013 by Rumcajs

[Glort]

Glow plugs are a possibility but I have also heard from an NRMA road service guy in the country that the diesel blends are particularly off this winter. 

Apparently there was a lot of the normal " Summer" diesel still going out recently instead of the winter or alpine blends and that was causing a LOT of diesel issues. When I visited my uncle recently in Northern inland NSW, he mentioned the same thing. In some of the cooler inland areas, loads of people were having trouble getting their vehicles started because of thick or solidified fuel. What was really pissing the cockys off was when they had to wait till lunch time to get their tractors and machinery started or put blow lamps on the engines like in the old days.

Personally, if if your truck is only smoking for a few seconds, I wouldn't be worried. My old girl  smokes real well when I start it up any time of the day in winter given I run the thing on veg oil. Last one was fine 3 years later and this one certainly isn't slowing down any or getting harder to start so I'm far from concerned.  

As for glow relays, Mercs do much the same thing. Keep the plugs on for 3 min regardless if the engine is hot, cold or already running. 
I bypassed mine completely and just put a momentary switch in it's place. Glow the thing for 10 Sec, hit the key, hold the plugs on for a few sec if needed till it smoothed out and all was good. Lots of people had problems with their plugs burning out but I was lucky to escape that. 

I haven't looked for Trolls but I found plugs HEAPS cheaper for the wifes car on flea bay from the UK. They were cheap but seemed to last just as short as anyone elses plugs even the oem ones that cost more each than I paid for 5. 

One thing I have found with GP's is if you have the fuel turned up, they tend to burn out much quicker.  When I had the mrs car turned up they were going real fast. My mate had the same problem but when he changed injector pumps to one that was much leaner, the problem went away. He was doing his every 6 months and now has had the same set he put in just before he changed the pump for a tad over 2 years now. 

[dawg runner]

Sorry it has been a while. I reckon that it was the fuel. I filled up from same Caltex I always had the other day and it is fine. I will still put the glow plugs on the list of things to do. Will probably do it when I get my bigger cooler and do EGR block.

 

Thanks for your input.

 

Cheers

 

dave

Edited August 18, 2013 by dawg runner

[dawg runner]

Took cooler off this weekend to clean after doing EGR block and fitting catch can. Tested glow plugs and sure enough the 4th rear plug is faulty. I tested 2 ways to be sure. Checked voltage at battery 12.36. Removed bus bar and first 3 plugs had same voltage as the battery. Last plug 11.5. Also no resistance on first 3 and got a reading on the rear plug. Pretty sure it is faulty.

 

I am just going to change the 1 for now with a ceramic and I will replace all with metal once I do the glow plug timer mod. My question is

 

How do you get the glow plug holders out ( the black plastic cups ) so I can remove the glow plug?

 

Any help appreciated.

 

Cheers

 

Dave

[Ropes]

Happy to be corrected but I'm thinking your number 4 might be the only one working?

My reasoning is this,

resistance = heat, therefore "glow" and voltage drop

no resistance = open circuit

low resistance = short circuit

[Rumcajs]

......................

How do you get the glow plug holders out ( the black plastic cups ) so I can remove the glow plug?

 

Any help appreciated.

 

Cheers

 

Dave

 

Use "pointy nose" pliers and just unscrew them out, they're threaded and easily undone you'll see 4 slots to engage pliers. You are meant to replace them too.

Also each plug should have a resistance 0.5 Ohm between the post terminal and ground at 20°C. So if there is no resistance at all aka open circuit than there is a fault in the plug. If I read your post correctly than number 4 is the possibly one working. Measuring a Voltage drop is different to measuring a resistance.

.

Cheers

Edited August 24, 2013 by Rumcajs

[dawg runner]

Turns out the gasket was faulty but head is ok. Should be able to get out of it for $500 or so doing work myself.

 

I also replaced all the glow plugs to be sure but they were metal ones so i will get the timer mode done soon.

 

Rumcajs - Is it absolutely necessary to replace the glow plug holders? There did not seem to be anything wrong with the ones in there.

 

Cheers for all of your input.

 

Dave

Edited September 25, 2013 by dawg runner

[Rumcajs]

...................................................

 

Rumcajs - Is it absolutely necessary to replace the glow plug holders? There did not seem to be anything wrong with the ones in there.

 

Cheers for all of your input.

 

Dave

 

I didn't do them either. They're dust seals so if not damaged, hardened or anything else wrong than just put them back in.

 

Cheers