I've recently noticed thick white smoke from the exhaust when I start up in the morning. I bought the truck last summer and never had this problem,
It's cooler now, about 50 or 60 degrees in the mornings.
It runs good and smells normal while its smoking, it smokes for about 2 or 3 minutes then clears up.
Can someone please tell me what causes this, what the smoke consists of and if its harmful to the engine?
Thanks

 

You may have 1 or more glow plugs that are not up to snuff, or the glow plug relay isn't good. The white smoke is unburned fuel. At the cooler temps, it takes a little longer to get heat in the cylinders to get a clean burn on the cylinder that the GP isn't working on.

 

Great info, I sure do appreciate the help, I'll test the relay and GPs,
Thanks again

 

I am having the same issue, I just changed the glow plugs, but still have to plug it in on a 40* morning to start. I have a new valve cover gasket set to put it, though all of the plug/connections look good still. A bad relay still wont allow start after plug in, will it?

 

With the block heater plugged in, the cylinders are warm allowing the heat, along the compression to ignite the fuel being injected. So yes, the engine can start without the GP relay working, if not in sub zero temps.

 

Thanks, I'll run the relay test and see if that's the issue.

 

Mt truck started this routine again. I am considering putting two gpr's in. One for each bank....

 

Not a bad idea... Built in spare

 

^^^^^ Way overkill, and more wiring to have to troubleshoot, compared to ONE good quality relay. Stancor 586-902 or Western Plow 56131-K will handle the load of our GPs without breaking a sweat. Plug-and-play replacement for the OEM, or whatever FLAPS cr@p some PO might have thrown in.

 

I agree. More connections, more problems.

 

I have put a few relays in. New glow plugs and the harness checks out. Just getting tired of dealing with it....

 

Have you done a compression test lately? Remember that low comp on cold weather also makes you smoke more on start up.

 

A compressoin test will be on order. A little worried that a rebuild will be at hand.

 

Yeah, but in the end if it does need a rebuild you know your engine will probably out live you once its done

 

How much smoke are we talking? I've never owned a 7.3 that didn't let out a little smoke on start up. Now that I have the big injectors in mine it's even more smoke