Weak batteries causing me to burn more oil at startup?!?!

[mgray]

My batteries have been on the fritz for the last month or so(actually have my red tops, just need to get around to installing them), and my morning starts are borderline, sometimes requiring my 800amp booster pack. But usually it's just a few more seconds of slow crank needed to start. When my batteries are able to start me, it's after some slow cranking, and my usual small puff of blue smoke is now turned into a big puff of blue smoke and a few seconds of "soft" idle.

Anyways, I've noticed my oil level has been dropping a lot faster then normal, so I assume that bigger cloud of blue smoke I'm getting at start up is me burning more oil.

But the weird thing is, if I have a normal start(with strong batteries), that big puff of blue smoke is now reduced to the usual small puff of blue smoke, and my oil consumption isn't as bad.

So what I don't understand is how slow cranking can increase oil burn at start up? Is it just valve seals or is there something else I should be thinking about or inspecting?

Thanks for any ideas

 

[sparky18]

I'm just kind of amazed your starter is still alive.The worst thing for a starter is running low batteries through it for any length of time.IMO.

 

[mgray]

Hmmm, good to know...I didn't know that...I guess I'll speed up the install...But my cranking time is still only a few seconds, just doesn't crank as fast. Still bad?

 

[sparky18]

Maybe it isn't even the batteries.It could be the starter is dying slowly,or your grounds are getting bad.There are quite a few threads on that part in this very section actually.As for the smoking issue,I'm kinda waiting for someone to chime in on that one too,lol.

 

[mgray]

Maybe it isn't even the batteries.It could be the starter is dying slowly,or your grounds are getting bad.

Well the batteries definitely can't hold a charge, that I'm sure of(tested with a multimeter). And all the grounds were done somewhat recently so I think I can safely rule those out.

But yeah, the smoke and oil consumption is what really worries me.

 

[ak diesel driver]

have you checked your cables? And what exactly do you mean by "soft" idle?

 

[mgray]

Cables were ok last time I checked, but I will check again when I replace the batteries. Cable resistance should be 0 ohms right?

As for the "soft" idle, here is a link to a thread with a video showing it. The truck doesn't give the usual clanking when it's "soft" and it spews blue smoke, then a couple seconds later the usual clanking begins and smoke goes away. Here are the the threads on that.

http://www.dieselplace.com/forum/showthread.php?t=360666 -WITH VIDEO-
http://www.thetruckstop.us/forum/showthread.php?20989-Shaky-Start-with-Lots-of-Blue-Smoke

 

[ak diesel driver]

I remember that thread now that I reread it. I still stand by my original guess of IP dying a slow death. Are you running any oil in the fuel?

 

[bison]

I remember that thread now that I reread it. I still stand by my original guess of IP dying a slow death. Are you running any oil in the fuel?

X2,i just know it is IP related,cause when i rebuild the engine of a 95 (truck with that same cold start issue)and put it in my 98,The only thing electrical a took along from the old truck was the IP.Guess what,the problem followed the engine.

IMO the blue smoke is nothing more than to much unburned fuel for the idle at the time,advance way out of wack.

If you consume more oil than normal ,you may have a leaking turbo exhaust seal.

 

[schiker]

I suspect something else causing extra oil burning. Yeah slow and extended cranking could pull more oil but its still too short of time to matter I would think. Slow cranking speed means more fuel injected not combusting crisp enough thus smoke on start up. Tired IP would make it worse.

Add some Cetane improver and SAE 30 ND oil to fuel and see what it does to starting smoke.

 

[WarWagon]

A quart in 1000 miles is normal. 1 quart in 500 miles is normal for balls to the wall trailer pulling. Check the CDR system as that can cause oil consumption. How is the blow by? Low compression can also cause starting issues.

Get your starting system up to par. Also make a habit of testing parts before you just replace them. Finding a bad cable by corrosion is expensive after changing a good set of bats and then a starter... The only way to test a cable of that size is by voltage drop across it under cranking load. If you have 100 RPM cold, and 180 RPM hot cranking then you meet the min specs...

 

[mgray]

The only way to test a cable of that size is by voltage drop across it under cranking load.

So I can't just test a cable by checking the ohms? I just used my multimeter to test my cables and they all have no resistance, but could a cable still be bad even if it shows no resistance?

 

[schiker]

worst case (not realistic)
Yeah, it only takes 1 strand of a wire to read ohms but with only 1 strand couldn't carry any appreciable current. The meter only puts a small voltage and amperage through the wire to test. The starter draw will be way bigger and thus a lot more current (heat).

V=IR so with appreciable current during starting might make a few strands heat up and increase resistance significantly. Then there would be a voltage drop and less current delivered to the starter too even with good batteries.

Hence, why warwagon suggested checking voltage at starter during cranking. Can't test resistance with power on a circuit so you have to either measure current and/or voltage and or know power usage then calculate resistance (while current flowing).

edit to make it clearer and more descriptive.