• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

Another one of those white/blue smoke issues

smillysmil

New member
10
7
3
Location
Olympia, WA
Hey all I just picked up my HMMWV and it acts kinda strange. On cold starts, (65-70f degree weather) I get a lot of white smoke and runs a little rough. After a couple minutes, the white smoke dies down but a misfire sound can be heard here and there but once it hits the operating temp the white smoke is gone and runs decent.

After it reaches full temp, The white smoke is gone but when I accelerate quickly, I get blue smoke. Especially when it goes into 2nd gear. Fuel starvation? Bad piston rings? I'm not sure. When picked up, oil was low but on the stick. Added about 2 quarts to full mark and hasn't moved since, but only driven a few miles. The oil looks brand new. Cleanest diesel oil I have ever seen. Anyway, that's beside the point. Oil pressure cold is approx 45-50psi, 25-30 hot.

At first, I thought it was glow plugs. So I bought some Chinese plugs as a test and I get the same exact results. While warm I can still hear a random clank noise like the noise you hear when the Detroit is cold. But maybe I am overreacting. Here are some videos.
HMMWV Cold Start (youtube.com)
HMMWV Blue Smoke (youtube.com)
Hmmwv idle (youtube.com)
Ideas? Thanks

Also like to add exhaust smell does not smell like a blown head gasket. To me, it smells like normal diesel. Blue smoke smells maybe a little like oil. Again, Im not sure.
 
Last edited:

Coug

Well-known member
Steel Soldiers Supporter
2,874
4,123
113
Location
Olympia/WA
You won't get smoke from fuel starvation.

Some smoke is common during heavy acceleration, but if it's excessive could be either an air intake restriction (plugged filter or maybe the mushroom cap on the intake is shoved down too far)

Check with a multimeter to make sure you are getting voltage to all of the glow plugs. Also verify approximately 1.5 ohms resistance for each plug.

bluish/grey smoke is a sign of burning oil. Could be a sign of stuck rings or similar, or could be something more serious.

Where did you pick it up from? If this truck just came from auction, then who knows how long it's been since it last ran, or if the engine is even broken in yet.

Misfire and smoke could also be a bad injector or two, causing rough running and incompletely burned fuel into the exhaust system.

Bad internet here so I couldn't watch the video.
Just curious, what part of WA are you in? I'm near Olympia.
 

Mogman

Moderator
Staff member
Moderator
Steel Soldiers Supporter
6,007
8,383
113
Location
Papalote, TX
No matter how clean the oil looks change it and the filter right away.
 

smillysmil

New member
10
7
3
Location
Olympia, WA
You won't get smoke from fuel starvation.

Some smoke is common during heavy acceleration, but if it's excessive could be either an air intake restriction (plugged filter or maybe the mushroom cap on the intake is shoved down too far)

Check with a multimeter to make sure you are getting voltage to all of the glow plugs. Also verify approximately 1.5 ohms resistance for each plug.

bluish/grey smoke is a sign of burning oil. Could be a sign of stuck rings or similar, or could be something more serious.

Where did you pick it up from? If this truck just came from auction, then who knows how long it's been since it last ran, or if the engine is even broken in yet.

Misfire and smoke could also be a bad injector or two, causing rough running and incompletely burned fuel into the exhaust system.

Bad internet here so I couldn't watch the video.
Just curious, what part of WA are you in? I'm near Olympia.
Hey again Coug! We had this conversation about a month ago. I'm actually in Olympia. On the North East side.

I will definitely check glow plug ohm test. It has been on my to do list.

Picked up from Auction. So yes definitely no way to tell. I am leaning towards this being a brand new engine and might not be broken in. That would be crazy if that was the case. Glow plugs were original that came with the engine, oil looks amazing, and no leaks. I'll have to check again but it looks like absolutely no blow by.

I drive alot of HMMWV’s for work and this one runs strong! Its just the weirdest thing

I did think it might be injector but who knows.
 

smillysmil

New member
10
7
3
Location
Olympia, WA
Tested ohm at each plug. Chinese glow plugs are 3.6ohm originals are 2.2. New Wellman plugs come Tuesday. Have not been able to test if 24v is going to all plugs. Changed oil, Ran Diesel Kleen, and a whole tank of diesel. Starts right up in the morning. Still, get a cloud of white smoke and rough running on cold starts but dissipates after 30 seconds and gets intermittent blue smoke until warm. The coolant has not moved, and the oil level does not appear to have moved. (still testing)

I get blue smoke when driving cold but once warmed up 100% very little blue smoke comes out. I've noticed when I'm driving and floor it, the engine rpm comes up and sounds like it hits redline and then finally shifts (otherwise, it shifts normally under lighter throttle). When floored and high rpm, I get what looks like mainly blueish smoke followed by black and a little white. All that while hearing what appears to me as some sort of rev limiter until the transmission finally shifts.

I feel like my symptoms have gone down by a little, but could be due to the fact it has been warmer out. The motor has what appears to be 0 blowby, clean coolant that has stayed full, no obvious flakes in oil, and nothing picked up by the magnetic drain plug. Of course, I'll have to continue my troubleshooting. But appears to me as an engine that may have been overheated. I found the "Cadillac valve" had been unplugged. When plugged in, runs hot and came up to 220. So overheating damage? Now to find out where.
 
Last edited:

smillysmil

New member
10
7
3
Location
Olympia, WA
220 is normal for the HMMWV, 235 or so is where you should start to worry.
Took a drive and watched the thermostat gauge. It got to 220, stayed there for a bit then rose up to around 235 and the fan finally kicked on for about 20-30 seconds bringing temps back down to 220ish and then kicked back down. Happened again for about a minute this time. So I assume I'm good? I guess I might have been freaking out about nothing.

Other than that, I changed out the glow plugs to new Wellman's and I still get the rough running while cold or after it sits for a few minutes. Starts right away but runs rough with smoke for a minute and then everything (almost) is good. Maybe I have air in the line. Not looking forward to pulling that fuel filter. Also checked Cold Advance for ohm resistance and it looked solid.

I have noticed a knock in 1 cylinder when hot, kinda like the combustion knock when cold. Maybe the timing is off or 1 cylinder is bad. Not sure

I'll have to play around with the TPS for that shifting issue. Any Idea on Voltage for that?

What surprises me the most is that I cannot find any blowby in this engine. The listing indicated Blowby was visible but I cannot find a dang thing.
 

Mogman

Moderator
Staff member
Moderator
Steel Soldiers Supporter
6,007
8,383
113
Location
Papalote, TX
Took a drive and watched the thermostat gauge. It got to 220, stayed there for a bit then rose up to around 235 and the fan finally kicked on for about 20-30 seconds bringing temps back down to 220ish and then kicked back down. Happened again for about a minute this time. So I assume I'm good? I guess I might have been freaking out about nothing.

Other than that, I changed out the glow plugs to new Wellman's and I still get the rough running while cold or after it sits for a few minutes. Starts right away but runs rough with smoke for a minute and then everything (almost) is good. Maybe I have air in the line. Not looking forward to pulling that fuel filter. Also checked Cold Advance for ohm resistance and it looked solid.

I have noticed a knock in 1 cylinder when hot, kinda like the combustion knock when cold. Maybe the timing is off or 1 cylinder is bad. Not sure

I'll have to play around with the TPS for that shifting issue. Any Idea on Voltage for that?

What surprises me the most is that I cannot find any blowby in this engine. The listing indicated Blowby was visible but I cannot find a dang thing.
The knock could be a bad injector, that is a common symptom of a bad injector, break each line loose one at a time until it stops, changing the fuel filter is a MUST do.

Your temp gauge is likely off, they are not known for being very accurate, get a laser thermometer and shoot the thermostat housing, I suspect you will find a difference to the gauge.

On the TPS, if you want it to shift (edit EARLIER) look at the direction the shaft going into the TPS turns when coming off of idle and rotate the TPS in the same direction a little bit at a time until you get it where you are comfortable or you pull a trans light in which case you went too far.
If the TPS is already against the stops in that direction then there may be an issue with the TPS and some voltage measurements will need to be taken.
 

Mogman

Moderator
Staff member
Moderator
Steel Soldiers Supporter
6,007
8,383
113
Location
Papalote, TX
I forgot to ask, you do have a working trans light yes? it should come on when the IGN switch is turned to run and go out when the engine is started.
 
Top