2006 CAT 242B Skid Steer – Serial Number BXM03117 – 1930 hours We have had our 242B for 3 years now and over this time I have found that it has progressively been harder to start. When I first got the skid steer, it started relatively easily, and I did not need to use the glow plugs at 0 C / 32 F. During this time, it was mainly parked in a 5 C / 40 F garage. Over time, it got a bit harder to start … and I found in the past year that I had to use the glow plugs (15 to 20 seconds) to start it more easily even in the warmer months (15 to 25 C / 60 to 77 F). This winter, it has been kept in an unheated building. Last week we had -32 C / -26 F and after having the block heater plugged in for 4 hours (500 watt insert CAT block heater) and applying the glow plugs for 30 seconds, it took 3 or 4 glow plug cycles to get it started. Once warmed up, I used it for 4 hours without any issue. We are using full winter diesel rated to -33 C / -27 F plus treating with Stanadyne Performance Formula Diesel Additive which can reduce the cold filter plug point by up to 13 C / 23 F depending on the base fuel composition. I am confident that we do not have a fuel waxing / gelling issue. This week I have been having difficulty starting again now at -10 C / -3 F. Yesterday I started it, warmed it up a bit, moved it and it stalled out. I restarted it, it was idling rough so I gave the fuel primer pump a few stokes and the idle smoothed out and it ran well. I was only moving it a short distance and not using it that day. Today I was trouble shooting the fuel delivery system. My fuel tank level was at 3/8. I visually inspected the in-line screen fuel filter that has been in place for 123 hours – no debris is present. I removed the rubber fuel line to the injection pump. There was a slight vacuum on the fuel line indicating some flow back to the fuel tank. I stroked the manual primer pump on top of the fuel filter / water separator assembly. Fuel pumped easily, with good flow … no air bubbles, no restrictions, no water present in the water separator. I pumped 10 strokes in 10 seconds and recovered 100 ml of diesel … a rate of 36 litres / hour (9.5 USG / hr) indicating no restriction in the fuel system when priming. I then cranked the engine to measure the mechanical fuel pump output. I recovered 25 ml fuel in 10 seconds of cranking … which is a cranking fuel output rate of 9 litres / hour (2.4 USG / hr). At engine operating speed, the fuel pump output should be considerably higher. I connected the fuel line back up to the injection pump, bled the air off at the banjo bolt and the engine started easily at 0 C / 32 F with 20 seconds of glow plug used. I am thinking of proactively (reactively?) replacing my mechanical fuel pump for the following reasons: 1) When I removed the fuel line from the injection pump, the fuel line went on a slight vacuum. I “assume” the fuel pump should not be leaking back (not sure of this assumption). 2) I’m thinking that the mechanical fuel pump rate when cranking of 25 ml in 10 seconds (to put it in perspective, that is ½ teaspoon per second) might be on the low side. 3) After restarting and with a rough idle, pumping the fuel primer pump a few strokes smoothed out the idle … perhaps the strongest evidence of a weak fuel pump? I was thinking of possibly measuring the pressure after the fuel pump with the engine running to see if it is in spec. Does anyone know what this spec should be? From some of my reading, it might be in the 3 to 5 psi range but that is just a guess. If anyone has access, a procedure for measuring the fuel transfer pump pressure would be appreciated. Is there anything that I might be missing for this Hard to Start situation? There are no problems when running … just when starting. Thank you for any insight you can offer.
Go ahead and replace your fuel supply pump. There are check valves inside of it that only allow fuel to be pulled and pushed in one direction. When they get worn and leak, the efficiency of the pump starts to severely lack. It's a common problem.
Does your machine always start good if u restart it within few minutes of shutting down Symptoms that u describe sound like the fuel is running off while engine is not running In the last picture it appears as though the mechanical fuel pump is serviceable You have only ur time to loose in taking that pump apart and check for dirt in the check valves and make sure its sealed off good Many fuel systems can have the fuel run off over night (can cause hard starting) if there is a small leak as in hose clamps not tight and/or cracked fuel lines and/or dirt in the check valves of hand primer or mechanical fuel pump
Has this engine ever had the valves adjusted. If they haven't been they are way overdue. As vetech63 said " transfer pump check valves get worn out." Have you hooked up a clamp on to see how many amps the glow plugs draw, in case some are burn't out. Is your engine cranking with good speed or a weak battery. In case you are loosing fuel from leaks, puttting 1PSI. of air to the fuel tank with a blow gun and rag over opening can cause loose hose clamps to leak. Not there, just asking? Simon C
Seeing that you already have an inline screen (3972), have you fully disassembled the filter head, including removing the priming pump (just screws off) and fully cleaned the inlet path? Is the O-ring present between the separator bowl and the filter?
1) Machine fires right up again after restarting it ... never a problem. 2) Fuel running off is likely part of the problem ... no external leaks evident ... likely through the fuel pump. 3) I serviced the fuel pump 123 hours ago when I had a major plugging problem in the screen of the fuel pump. I installed the in-line filter upstream of the fuel pump at that time and there has been no new debris captured in the basket of the in-line filter, so I assume the basket filter of the fuel pump is still clean. Some photos are posted below. Here is a link to that repair: HeavyEquipmentForums Thank you for your feedback
1) I have not done the valves in the 150 hours that I have had the machine. I will add that on to my "maintenance to do list". 2) Another vote for transfer pump leaking back ... seems like a trend here. 3) I did check the glow plugs about 30 hours ago with a clamp on amp meter. Total draw was 42 amps for the 4 glow plugs ... measured about 10 amps per glow plug if I recall my individual checks. Total battery cable amps was 68 amps. I believe that I was getting good glow plug response when using them. 4) No physical fuel leaks were noted but slight pressure on the fuel tank might be a good check if I didn't suspect a fuel pump problem. Thank you for your feedback
GOOD CALL to whom ever suggested taking it apart.!! The valves still may be weak/leaking but at least I know something..
Hey "heymccall", With your assistance in my plugged pump repair (linked above), I performed your inlet path cleaning and O-ring check. It was clean as a whistle and the O-ring was in place. I also added the in-line screen based on your recommendation. Thank you for your continued support
Vetech63, I thank you for your recommendation to replace the pump ... it is sounds like the most logical solution but I wanted to bounce it around a bit to see if there was anything else I was missing. I will be heading to CAT today for a replacement fuel pump and will post my results when I have it installed. I appreciate the support you provide on this forum
I missed responding to one of your questions. The engine cranks very well ... even at -32 C / -26 F. I have an onboard NOCO Genius 2 amp battery maintainer ... whenever the skid steer is parked, the NOCO keeps the battery fully charged and ready for its next start.
It has been a few weeks since I replaced my mechanical fuel transfer pump, so I thought I should update this thread. The result of the fuel transfer pump replacement is that I have seen no improvement in cold starting of my CAT 242B. It has been pretty warm lately, with starting temperatures from -10 C to 0 C (14 F to 32 F). With the new fuel transfer pump, I have tried starting at the above temperatures without using the glow plugs but have not been able to get it started. But after 10 seconds of glow plugs, the 242B fires up immediately. When the 242B has warmed up, it will restart immediately without using the glow plugs … as was the case with the old fuel pump. As I indicated in my original post, when I first got the skid steer, it started relatively easily, and I did not need to use the glow plugs at 0 C / 32 F. Over time, the 242B has become harder to start … and I found in the past year that I had to use the glow plugs (15 to 20 seconds) to start even in the warmer months (15 to 25 C / 60 to 77 F). I think my next step, as SimonC suggested earlier, will be to check the clearances of the engine valves. I have ordered a CAT Service Manual for my 242B from eBay and should have it in the next week, so I can follow the correct engine valve adjustment procedure.
Here are a few details on my mechanical fuel pump replacement. I bought the updated CAT fuel transfer pump 295-4070 today. The pump looks exactly like my original pump (176-7712). An O-ring Seal was included with the new pump. I removed the air filter housing to allow access to the pump area. There is not a lot of working room and short wrenches are required. The two bolts holding the pump down have 8 mm hex heads which is pretty close to 5/16”. I found myself using both 8 mm and 5/16” box end wrenches as well as an 8 mm flex head ratcheting wrench. I would suggest loosening the back side bolt first and completely removing it, since you are pretty much working blind on the back side. The front side bolt will hold the pump securely (with the pump plunger compressed) making it easier to remove the back side bolt. I actually used a mirror to help me guide my wrench onto the back side bolt (see photo below). I’m ashamed to say that it took me the better part of an hour to remove the fuel pump as I removed the bolts in the wrong order (I did the front bolt first … which I believe is not the way to go). I adjusted the orientation of the pivoting pump inlet to match the pump that I removed and installed the new pump in about 15 minutes using mainly the 8 mm flex head ratcheting wrench. I then used the manual primer pump to displace the air out of the system. I noticed after priming, the fluid did not drop in the fuel hose like the old pump did, so the check valve in the old pump was certainly leaking back. I then cranked the engine to measure the fuel pump output. I recovered 30 ml fuel in 10 seconds of cranking … which is a slight increase from the 25 ml / 10 seconds test rate of the old pump. I connected the fuel line back to the injection pump, primed and bled the air off at the banjo bolt and then reinstalled the air filter housing. I am glad that I replaced the fuel transfer pump … even though it did not appear to improve my cold starting performance.
I’d be interested to hear what the valve clearances are when you get round to adjusting them. I’ve got money that says they are closed up and you are losing compression. TBH I’d always recommend doing first whatever doesn’t involve laying out money on parts but maybe that’s just me.
I saw lots of issues with glow plug timers and automatic control of them. Most of those small engines won't start without them and the timers don't run them long enough when it gets really cold out.
Thanks John C. Those glow plug timers can certainly be troublesome. My CAT 242B is equipped with a manual glow plug rocker switch (spring loaded to the OFF position), so as long as I hold the switch down, the glow plugs are activated. Based on your response, I had a look in my Operations and Maintenance Manual and it suggests below 0 C (32 F) to hold down the glow plug switch for 10 seconds before starting. It also notes to not operate the glow plugs for more than 30 seconds at one time or damage to the glow plugs can occur. I'm confident that my glow plugs are working since when I use the glow plugs on a cold start, the engine will start. If I don't use the glow plugs on a cold start, the engine will not start, no matter if the ambient temperature is 27 C (80 F) or -30 C (-22 F). Warm starts after the engine has been running are no problem ... if fires right up without using the glow plugs. But 150 hours ago, I was able to start the engine without using the glow plugs on a cold start at almost any temperature, but of course I would use the glow plugs if it was very cold. So something has changed and an engine valve clearance check / adjustment is next on the books.
That's what I'm getting at. An engine that will start after the application of the glow plugs does not usually indicate a fuel system issue.
John C. I was updating my previous post when you posted your reply. Good to hear that you think it is not a fuel system issue ... as I would not look forward having to rebuild / renew the injection pump or injectors. Here is the update to my previous post again: But 150 hours ago, I was able to start the engine without using the glow plugs on a cold start at almost any temperature, but of course I would use the glow plugs if it was very cold. So something has changed and an engine valve clearance check / adjustment is next on the books.
Can you go through this procedure and record your results? An overall current draw measurement of the system is only a good number if all 4 glow plugs are contributing equally, you could be surprised to find that this isn’t the case.
Thanks for your feedback regarding glow plugs. I did check the glow plugs about 30 hours ago with a clamp on amp meter. Total draw was 42 amps for the 4 glow plugs ... measured about 10 amps per glow plug if I recall my individual checks. Total battery cable amps was 68 amps. I believe that I was getting good glow plug response when using them. I certainly can check the operation of the glow plugs with the CAT procedure you provided but I'm pretty sure my glow plugs are functioning, because I am able to cold start the engine when I use the glow plugs. My problem is when I do NOT use the glow plugs, I am not able to cold start the engine, even at summer temperatures.
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?
How often do you change your engine oil?
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:
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.
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
Valve adjustment procedure
ahart - Thank you for the procedure. I hope to get on this in the next few days.
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.
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.
A compression test is not part of Cat’s testing procedure so the service manual will contain no information in that regard.
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.
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
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.
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.
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.
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.
It's one thing for an educational institution to do stuff in the way of experimentation and/or illustration of principles. IMHO try that **** 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.
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.