Troubleshooting Hard To Start CAT 242B

[ahart]

Ok I didn’t see a breakdown of each glow plug’s current draw and resistance measurement. Have you cracked open the injector lines at the injectors before an initial attempt to start so you can verify there is good fuel there from the start? Do you get smoke while you’re cranking right away? How long does it have to sit before it experiences hard starting again?

 

[John C.]

How often do you change your engine oil?

 

[ThreeCW]

1) Have you cracked open the injector lines at the injectors before an initial attempt to start so you can verify there is good fuel there from the start?
2) Do you get smoke while you’re cranking right away?
3) How long does it have to sit before it experiences hard starting again?

ahart .... Thank you for your feedback
1) I have not cracked open the injector lines to check for fuel ... but I can certainly do that as part of my troubleshooting.
2) Without using the glow plugs on a cold start, I get some white(ish) smoke but the engine will not start. When I use the glow plugs on a cold start, I will get a quick puff of black smoke when the engine starts.
3) I have not noted how long it takes to experience hard starting again. If I shut down for an hour, it typically would restart without glow plugs. If I shut down overnight, I would have to use glow plugs to start. I can certainly try shutting down for a set time period and attempt to restart without the glow plugs as part of my trouble shooting.

I did up a YouTube video on some cold start that I videoed. Hopefully I can get some feedback on how to troubleshoot based on diagnosis of the exhaust smoke when cold starting.

Here is a link to the video:

 

[ThreeCW]

How often do you change your engine oil?

I change the engine oil and oil filter every 100 hours ... am using 5W-40 Shell T6 full synthetic and an OEM CAT oil filter.

I put on an average of about 50 hours per year ... depending on how much it snows.

 

[ThreeCW]

If anyone with access to SIS can provide an engine valve adjustment procedure and specs, I would appreciate it so I can expedite my troubleshooting.

2006 CAT 242B Skid Steer – Serial Number BXM03117

I have ordered a CAT Service Manual for my 242B from eBay but am getting impatient on waiting on delivery from eBay

 

[ahart]

Valve adjustment procedure

 

[ThreeCW]

ahart - Thank you for the procedure. I hope to get on this in the next few days.

 

[ThreeCW]

Will I need to replace the valve cover gasket or is it resilient enough to re-use?

Is there a torque spec / pattern for the valve cover replacement?

I don’t see it mentioned in the adjustment procedure, if the adjustment should be done on a warm or cold engine? I’ll likely do the adjustment in our partially heated garage at 10 deg C (50 deg F) as we have a cold snap coming in.

 

[ThreeCW]

I am still working through the starting problem of my CAT 242B.

On the glow plug test, everything checked out well. With all 4 glow plugs activated, I measures 70 amps of current draw at 5 deg C (41 deg F). Each individual glow plug drew between 18.0 to 18.5 amps. Resistances of the glow plugs were 0.4 ohms each.

We have a warm spell coming up and I am ready to do the valve adjustment, but was thinking to really trouble shoot this problem, I would do a engine compression check before and after the valve adjustment procedure.

Can anyone provide a Compression Test Procedure for my 2006 CAT 242B - Serial Number BXM03117? I'm not sure if it is best to remove the injectors for the test or test by removing the glow plugs. I have a compression test kit that has adapters for both glow plug and injector ports.

The CAT Service Manual that I ordered off eBay has not been delivered yet and I am keen to get trouble shooting. Thanks.

 

[Nige]

A compression test is not part of Cat’s testing procedure so the service manual will contain no information in that regard.

 

[John C.]

I don't know about now, but Cat used to specify a leak down test. Air pressure was plumbed into the cylinder and then checked for the amount of time it took for the air pressure to leak off. I never bothered with it after reading about it in an old service manual for some machine. I went to the infra red thermometer to check heat on the exhaust manifolds for a quick test.

 

[ThreeCW]

I have been doing some research on this forum and there is some mention of compression testing of diesel engines ... but no procedures that I could find.

YouTube research has resulted in a bit more information ... but as YouTube does, the procedures vary by the presenter.

I plan to use the following procedure:
1) Warm engine up
2) Disconnect electrical connection to fuel shutoff solenoid on the fuel injection pump
3) Loosen off the high-pressure fuel line connection to each fuel injector
4) Remove glow plug from cylinder to be tested
5) Insert adapter into glow plug port and connect pressure gauge
6) Engage starter for 5 seconds or longer to get a stable pressure reading
7) Reinstalled glow plug
8) Repeat steps 4 thru 7 for the other cylinders

The one thing that I have not confirmed is what compression test pressure will be acceptable … from what I have read, acceptable is somewhere in the 400 psi range and each cylinder should be within 10% of each other. But this is just word of mouth … with no confirmed source at this time.

Does anyone have any suggestions on the above procedure? Anything missed or wrong?

I am a bit concerned that “a compression test is not part of Cat’s testing procedure” (thank you Nige) … I wonder why that is … and I hope I don’t find out why either by doing a compression test

 

[Nige]

I am a bit concerned that “a compression test is not part of Cat’s testing procedure” (thank you Nige) … I wonder why that is …

Because generally there are other methods of checking whether or not a diesel engine is suffering cylinder/piston/ring problems than a compression test that don't require removing anything. To the best of my recollection in all the years I've been around diesel engines I have never seen anyone perform a compression test on one. I certainly have never done one.

The most common test for cylinder issues is by measuring blowby, the air flow from the crankcase breather in other words, using a special tool. A large percentage of today's mid-size and larger electronically-controlled engines monitor crankcase pressure using a sensor and sound an alarm if it gets above certain specified limits.

 

[ThreeCW]

I don't know about now, but Cat used to specify a leak down test. Air pressure was plumbed into the cylinder and then checked for the amount of time it took for the air pressure to leak off.

Here is an interesting video about the cylinder leak testing that you referred to. Jump ahead to the 10 minute mark to get to meat of the matter. Or watch the whole video as it covers some pretty interesting information. There are several other interesting diesel engine videos in this series from Fanshawe College.

 

[ThreeCW]

And since we are discussing Diesel Engine Compression Testing, here is a direct link to a pretty good video, again from Fanshawe College, School of Transportation Technology.

 

[John C.]

The guy is a Christmas turkey full of spouting points to sell a potential student on a school or class.

I don't know of anyone who would allow that kind of time be spent on troubleshooting a compression problem.

 

[Nige]

It's one thing for an educational institution to do stuff in the way of experimentation and/or illustration of principles.
IMHO try that sh1t out in the field and you would be laughed off the job site a millisecond after being canned.........

When time is money the KISS principle is aways a good one to live by.

 

[ThreeCW]

You guys are a tough crowd ... but you tell it like it is.
I appreciate your experience, guidance and your sharing of knowledge on the HEF forum (with over 35K posts between the 2 of you).
As you both suggest, following the KISS principle makes sense.
Thanks for the feedback.