Perkins Diesel Cold Start Problem

Bob Rooks · Jun 27, 2011

Bison said:
Best way to check the plugs is to take them out and test between the batt poles.

Disagree. It's one way, but not the best way.

tlbuser · Jun 28, 2011

Make sure there are enough amps available for the starter. Slow spinning starter will have similar effect.

wa5vpo · Jun 28, 2011

This machine was owned by a rental company and it appears they gave it regular maintenance. The oil and hydraulic filters had dates marked on them as Nov. 2010 and 1908 hours. When I got the machine it was showing 1916 hours. I assume it was probably setting on the dealers lot from Nov. until I purchased it. I pulled the air filter and it looked clean. I couldn't blow any dust out with compressed air. It cranks over quite fast at 50 degrees but it won't fire enough to keep running. It has a new battery and alternator in it. I was wondering if there was any particular part of the engine I could heat up with an electric heater that would indicate what the problem was if it started after I heated up that part. Just a thought on how to troubleshoot the problem.
Thanks again for all the help.

Transit · Jun 28, 2011

Wa5vpo, I would think the phrase Charging Voltage would say it all.
As for Bisons suggestion I can see his point, however I am not comfortable doing it that way.

Depending on how the plugs are installed in the engine, screw in or press fit with a yoke, there is a risk of breaking the plug in the engine.
Re-installing the plugs, everything must be clean, maybe new copper sealing washers, if not you could have a compression leak.

As for testing the plugs at the battery terminals, the plug tip will get RED HOT, you will need 14 Ga wire for the current and the body of the plug must contact the battery terminal NEVER the hot tip.

wa5vpo · Jun 28, 2011

Good points by all. I think I will ask the tech next time I talk to him how he tested the plugs. I can do the current measurement if the tech didn't do that. It just seems strange to me that there can be so much difference between 65 degrees and 50 degrees in temp. My old Yanmar 3 cyl diesel doesn't ever have any starting problems until it gets down around 10 degrees and then that is typically a turn over problem due to the thick oil and or low battery voltage. It just wont' crank as fast as it does when it is warmer. I can understand that one. This magic temp region of 60 to 50 degrees has me scratching my head. I would never had suspected a problem like that.
Thanks again for all the help. With all our combined knowledge I am sure we will finally solve the problem.

Bob Rooks · Jun 28, 2011

Hmm, you may want to consider looking into the starter motor. If it was assembled with thick grease that would definitely hold it back in colder weather. Also, the starter solenoid operator (piston / slug) should be lubricated with liquid graphite, not grease or oil.

wa5vpo · Jun 28, 2011

Bob,
It appears that it turns over just as fast at 50 degrees as it does at 90 degrees, it just won't fire enough to start running on its own. That is what has me puzzled. All engines I have ever owned would always start if you could get them to crank fast enough. This one doesn't seem to be dependent upon crank speed, just the outside air temp. That is why I am sure it won't start at all when the temp gets cold enough to slow down the cranking speed.
Thanks again.

Transit · Jun 28, 2011

Come to think of it, what engine oil are you using, 15W40 is typical, however it is much easer to start on 10W40 or a 5W40, all will give the same hot weather protection of 110-120 deg. Some owners use a electric mag base oil pan heater on the oil pan or the starter motor in the winter.

Not much to do but stay in bed, look at TV and see what is going on online, got to go and eat now, this chemo is kicking my butt.

wa5vpo · Jun 28, 2011

Transit,
Not sure what oil is in it now. I was planning on 10W40 when I change it. That oil pan heater sounds like something I need to look into before winter. I think if I can solve the 50 degree starting problem then all I have to worry about is proper cranking speed during the real cold weather, ie. below 20 degrees. An oil pan heater should solve that one. I keep a battery minder on the battery at all times so it is always fully charged.
Enjoy your lunch and good luck with the chemo.
Thanks again.