Excessive White Smoke (was:Glow Plug Seat Depth)

[aloharovers]

Aloha.
I replaced the heads from my 1984 engine with a rebuilt pair from a mid 90's 6.5

I get gobs of white smoke from the left exhaust until I have been driving for a while. With the colder weather its getting to be close to 10 minutes. If I just start the engine and let it idle it will smoke for 30 minutes.

I have dual exhaust without a cross over so definately coming from the left side.

I checked compression using a gauge and an adapter that goes in through the glow plug hole, reading 400-425 in all 8 cylinders.

All 8 glow plus leads are getting power. The plugs are reading .9 to 1.1 ohms resistance.

I swapped sides when putting the glow plugs back in. Still smokes on the left.

It seems that the plugs screw all the way into the head until the hex head of the plug is against the head. So for the hell of it, I put them back into the old 6.2 head. There is a measurable gap beteem the head and the bottom of the hex. The glow plugs are screwing into the 6.5 head further then the 6.2.

If I clean off the glow plugs, install them, start the engine, drive around for a while. Let things cool, remove glowplugs, I have a definate soot build up on the plug threads. I think that the plugs are not fully seating on the left head and I am not getting full compression, thus white smoke until the engine getts really warm.

So is there a seat depth measurment? I think I can use the stem on a dial caliper to take actual measurements when I get home tonight.

I thought glow plugs between 6.5s and 6.2s were interchangable. Do I need to go get new plugs, or just chuck these up in a lathe and remove a little metal from below the hex head?

Thoughts?

Thanks\Pete
(edited 10-20 Subject Line changed, pete)

[ 10-20-2003, 05:46 AM: Message edited by: aloharovers ]

[britannic]

The glow plugs are interchangeable, so no worries on that score. Which type are you using and are they all the same?

If the glow plugs were leaking, I would expect to hear some high pitched squealing, or at least see some external sooting.

That's certainly a strange problem you have there. How about continuity testing the installed glow plug bodies with the head, to verify that the glow plugs on that side are properly grounded?

Try checking the resistance of the glow plug wires themselves to see if there's a difference between the two sides for whatever reason.

[aloharovers]

Originally posted by britannic:
Which type are you using and are they all the same?

If the glow plugs were leaking, I would expect to hear some high pitched squealing, or at least see some external sooting.

How about continuity testing the installed glow plug bodies with the head, to verify that the glow plugs on that side are properly grounded?

Try checking the resistance of the glow plug wires themselves to see if there's a difference between the two sides for whatever reason. I am user the "ner" glow plugs, I am thinking 60g but that could be wrong.

Cant hear anything, heads are black, but will try and wipe down, run, then do a white glove.

I have a very good tester that checks for power and ground. Head has good ground. Each glow plug installed, but electric wire disconected, check terminal end of GP and its grounds also. I will pull out the multi meter and check continuity also to verify.

I will check the resistance in the wires. The controller and plugs are all brand new, but the wires came from the donnor vehicle. Will also try swapping the wires side to side.

Thanks.
Pete

[britannic]

Does the white smoke smell like unburnt diesel or is it more like a wet steam/antifreeze smell - obvious question, but I feel all possibilities must be explored...

[gmctd]

I run 11g's in my '95 - starts easier and runs better cold. They all have a small gap (1/16th) between hex and head, on the driver's side where I can see them.
There are two sets of pre-cups for the 6.5 heads -normally aspirated and turbo'ed. Could be the difference in depth.
My truck is factory turbo'ed.
Symptoms sound like a coolant leak on that side, which is where Brittannic is heading. Hopefully the between-valve water passages have been 'tubed'?

jd

[whatnot]

Could a coolant leak cause this and not put any pressure into the coolant?
My 93 is doing something similar but I have a turbo on it so I don't know which side it is coming from.

[gmctd]

Pressurized coolant can leak into the exhaust port(s) without effecting visible signs in coolant or coolant pressure. Anti-freeze odor in exhaust is a dead give-away.
Can also leak into intake port(s) without effecting coolant, where turbo pressure stays below 16psi coolant pressure. This leak can effect cold-start combustion temps, resulting in unignited fuel vapor. Nasty burned odor is result.

An engine will usually blow white vapors (unignited fuel) for a while in colder weather.
Only takes one or two flaky plugs, connectors and\or wiring to cause it more on one bank than the other and is easier to tell with dual exhaust.
Can occur with hot-start in cold weather, but should not continue as long as cold-start.
It's colder most places now, so we'll be reading about white vapors more often.

Equal compression figures are the best reassurance, along with clean exhaust odor.

jd

[aloharovers]

OK, been a busy after noon.
The white smoke doesnt smell like anti-freeze, it has a stinging smell, take a big sniff and burns the sinuses and the eyes.
I also am not loosing any coolant after a 100 mile drive.
I tested the resistance in all of the glow plug leads, its .2 to .4 ohms.
I also tested each glow plug and harness. Run a ground wire to the threads, apply power to the lug at the controller end of the harness. Each glow plug was red tipped in 4-5 seconds.
Double checked compression again in all 8 cylinders, 400-425 psi.
So put it all back together and started her up.
She starts instantly and runs pretty smooth.
Its 50 degrees outside.
The right side produces white smoke for about a minutes, but at a much less volume then the left. The left side produces huge clouds of smoke.
It took about 5 minutes for the cold idle and HPCA to kick down.
It then takes about another 15 minutes before the radiator really starts flowing and the white smoke from the left side to subside.
The truck has always run cold. I have electric fans and have them off unless I start going up steep hills at speed or offroading.
My oil and water temps are both around 160 cruising down the road, or just sitting at idle. But again it took 20 minutes idling in the driveway to get there.
I have my coolant temp reading from the rear of the left head. The oil temp sender is just below this in the block.
After the engine is warmed up, engine idling, floor the pedal and release real fast and get a big cloud of white from the left, smaller from the right.
Before the engine fully warmed, while the left was still smoking, I also loosened each injector line one at a time. Each one had a dramatic effect on the smoothness of the engine, but had no effect on the white cloud.
Last thing I can think of is the return lines.
Just how much fuel should I get out of each injector? I just quickly unpluged the hose from the number one injector to the crossover pipe and nothing came out.
Thanks again.
Pete

[aloharovers]

OK, souple more things.
I let the engine cool down and then restarted.
Big cloud of smoke. I have a momentary switch on the glow plugs, so I held it in with the engine running. After about 8-10 seconds all of the white smoke on the left side disappeared. Held it down for an additional 10 seconds, no smoke. Let go of the switch and after about 5 more seconds the white smoke returns.

Second thing, after the engine warms up and all the smoke disapears, I had the radiator cap off and I started getting a bunch of small bubbles in the coolant. Looked like soda bubble fizzes. The level went up, overflowed, then dropped down about 1/2 inch below the level of the neck. I can see fluid flowing, filled it back up, no more fizzing.

I am getting worried that this is a coolant issue. Heads only have about 500 miles on em and it has been happening ever since the swap.

Oh, since changing the heads I havent been able to get the egts above 600, and most of the time they are around 200-250 degrees. The egt sensor is on the left hand down pipe.
So I have all of my temp senders on the left side of the engine. Is it possible for one side to run colder then the other?
Would explain why the left side smokes longer.

Any ideas?
Thanks
Pete

[aloharovers]

update:
got a second temp gauge and put it in the right head. Before I did I pulled both of them and put them into a pot of boiling water and they read the same.
Both heads are running the same temp.
So tons of white smoke out the left head. If i hit the glow plugs smoke stops and engine smooths.
Takes only a minute for the smoke to clear from the right side and its no where as heavy as the left.
The left takes about 15 minutes at idle or maybe 5 miles of driving to warm up enought to go away.
Pete

[britannic]

Well it definitely seems linked to ignition heat, as you proved with the glow plug control.

What type of glow plug controller setup do you have? My understanding is that the glow plug controller will provide afterglow when the engine is running, until the GP temperature switch is activated when the engine is hot enough to run without GPs.

[aloharovers]

Originally posted by britannic:
What type of glow plug controller setup do you have? I have the 85-93 HDC904 controller and 60g plugs.
I did some more diagnosing between rain showers this weekend.
I again flipped Glow Plugs side to side. No Change.
Then flipped GP wires side to side. NC.
Then changed Injectors side to side. NC.
I then one at a time loosened each fuel line at the injector. Each one made a noticable differance in the smoothness of the engine running. But on #5 the fuel squirting out was very foamy. So for the heck of it I left it loose. After about 10 seconds the smoke totally went away. Retighten, 5-10 seconds and smoke comes back.
I went ahead and again changed the #5 injector with the #1. Startup, loosen #5 fuel line and smoke goes away.

So I am going to go ahead and replace the steel fuel lines.
I am hoping that its line and not injector pump.

Funny thing is the #5 is the same one that lost the exhaust valve and caused me to replace the heads to begin with.

Only other thing I still want to do is do to a cold/hot compression comparison. #5 was at 405 cold. #1 400, #3 420, #7 425 just for comparison.
Thanks
Pete

[britannic]

It's pretty rare for a line to be the cause, but you never know...

Make sure the #5 outlet on the pump isn't blocked/restricted etc. If there was something up with the pump, all of the injectors would be affected (unless the cam ring has a broken lobe - has anyone ever heard ot that?).

[TimK]

I have read all the entire message string and I do not think this a problem with the glow plugs at all. With the compression values you are providing, your combustion temperature should be very good at start up with any white smoke going away very quickly. The fizzing in the radiator is a concern and the foaming injector is very weird. I you swapped injectors from one side to the other and had the same results, It doesn't sound like the injector and yet it is strange for the IP to be bad on only one cylinder but I guess it is possible.

TimK

[aloharovers]

Originally posted by TimK:
The fizzing in the radiator is a concern and the foaming injector is very weird. I you swapped injectors from one side to the other and had the same results, It doesn't sound like the injector and yet it is strange for the IP to be bad on only one cylinder but I guess it is possible.
TimK I was reading that air getting into the fuel draw tube causes white smoke, so it "seems" possible that either a partial blockage of #5 line or a problem with the IP is where I am headed.

I still need to do a cold-vs-hot compression check.

Have also been thinking about trying to attach some clear tube to the steel lines and run into a clear jar. Run engine for 30 seconds. Then do the exact same thing for a good cylinder. A flow comparison.

What I really wonder is if this problem could have been the cause for the #5 exhaust valve disintigrating.
Pete

[aloharovers]

I just wanted to close the loop on this one.
Took a while to get the #5 steel line from the dealer but it finally showed up yesterday.\Installed it last night, what a world of differance. I still get a bit more smoke from the left (#%) then the right, but I dont need to roll the truck down the driveway before starting to prevent me smoking out my house.
Not very scientific but the old line was much harder to blow through then the new one. With the new one I could actually breathe through it. Old was very forced. Wish I had like a 2 foot long pipe cleaner and I could try reaming it out.
I did then try using compressed air, but nothing came out.
My DB2 only has 15k on it, but still wondering if something isnt in it that caused the problem with #5
Thanks for the assist
Pete

[britannic]

The older DB2 pumps weren't hardened against low sulphur diesel and the governor ring assembly could fail, break into little pieces and then travel through the pump, blocking passages lines and injectors etc.

Pumps rebuilt or manufactured after the low sulphur fuel was introduced, should have the hardened components.

If your pump was one of the later ones, some debris may have been present or introduced after the fuel filter. You may have more debris in the system, because of the way a rotary IP works, it won't always localize the damage to one port or injector line.

[aloharovers]

Originally posted by britannic:

If your pump was one of the later ones, some debris may have been present or introduced after the fuel filter. You may have more debris in the system, because of the way a rotary IP works, it won't always localize the damage to one port or injector line. Brand new filter(Racor) and line from filter to injector pump, rebuilt pump, but ya never know.
So how hard/easy is it to open up the pump and find out?

[britannic]

A cursory inspection could be made by removing the 3 housing screws on top of the IP and lifting the cover. If you have no idle or WOT governor symptoms, you're probably OK, however, the real question is how the #5 line became blocked. Besides, if it ain't broke, don't fix it right :D ?

How about an autopsy on the removed line by sectioning it or using piano wire to rod it out to see what the blockage is?