Caterpillar 3126B oil cooler problems

[hike]

Thank you @Keith Knight, and everyone else for thoughts and questions. While I would prefer not to do this you have pointed out that for some time and a couple hundred dollars this is a maintenance task level project.

Where did you find torque specifications and such? I recall having books on all our CAT equipment we used, though that was 30 years ago—

 

[hike]

Well the IFS filter is the real protection IMO, even thou I've not bought one yet. I'm Saving up lol..

The IFS is the high pressure filter on the HEUI output? Since I haven't kept up on this issue: filtering after the HEUI pump is better than before? or simply the best place to add a secondary filter?

Next question is for the time and money, isn't replacing the oil filter housing gasket best? Do we need secondary filter after replacing the gasket?

 

[Keith Knight]

On our 3126B we can’t put a filter before the HEUI pump so putting after protects the injectors and everything else after that. Basically preparing for the HEUI pump to fail. Replacing oil cooler and filter housing gaskets and if needed a flatter oil cooler or machining it flat what ever you decide. But the IFS kit is cheaper than replacing all the injectors. Replacing the HEUI pump is something that I could do on the side of the road if necessary. But replacing the HEUI pump and injectors on the side of the road not so doable. In my opinion.

 

[Keith Knight]

Thank you @Keith Knight, and everyone else for thoughts and questions. While I would prefer not to do this you have pointed out that for some time and a couple hundred dollars this is a maintenance task level project.

Where did you find torque specifications and such? I recall having books on all our CAT equipment we used, though that was 30 years ago—

I went with standard torque ratings for M8 bolts. For the filter housing and everything else is like alternator bolts and brackets I just tightened by feeling! LOL!!! Exhaust nuts tighten them really good too.
Also while I was working on it I discovered some soot near the exhaust manifold and block closest to the transmission. Turns out I had a loose exhaust manifold bolt.
Also found a missing bolt that holds the intake tube to the block. Just saying keeping a clean motor and looking for leaks or anything else on a regular basis prevents bigger problems in the future.

 

[GeneralDisorder]

The IFS is the high pressure filter on the HEUI output? Since I haven't kept up on this issue: filtering after the HEUI pump is better than before? or simply the best place to add a secondary filter?

Next question is for the time and money, isn't replacing the oil filter housing gasket best? Do we need secondary filter after replacing the gasket?

As with all engines - the main engine oil filter is not full flow. It is bypass filtration. So under MANY conditions the engine is already getting unfiltered oil. If the oil is cold, especially at high RPM (see ECO hub discussions), and if the filter element is partially plugged. If the differential pressure across the element exceeds the bypass spring rating in the filter head, it bypasses the filter on the principle that unfiltered oil is better than no oil at all.

The HEUI pre and post filters are FULL FLOW. In other words oil is not allowed to bypass them at all. Oil must flow through the filter or whatever is downstream from them receives insufficient oil.

 

[Ronmar]

Yea you could have a perfect oil filter and cooler assembly, but a HEUI pump failure is probably going to wipe the injectors also…

our main oil system actually has 2 bypasses in it. One pre-cooler, the other pre-filter..

 

[Keith Knight]

Thank you @Keith Knight, and everyone else for thoughts and questions. While I would prefer not to do this you have pointed out that for some time and a couple hundred dollars this is a maintenance task level project.

Where did you find torque specifications and such? I recall having books on all our CAT equipment we used, though that was 30 years ago—

I went with standard torque ratings for M8 bolts. For the filter housing and everything else is like alternator bolts and brackets I just tightened by feeling! LOL!!! Exhaust nuts tighten them really good too.
Also while I was working on it I discovered some soot near the exhaust manifold and block closest to the transmission. Turns out I had a loose exhaust manifold bolt.
Also found a missing bolt that holds the intake tube to the block. Just saying keeping a clean motor and looking for leaks or anything else on a regular basis prevents bigger problems in the future. The Gen 2 version has a filter indicator.

 

[Lostchain]

The HEUI pre and post filters are FULL FLOW. In other words oil is not allowed to bypass them at all. Oil must flow through the filter or whatever is downstream from them receives insufficient oil.

This post filtering (and the restriction that creates) is known to have absolutely no effect on the HEUI system? Is there any CAT documentation about this modification?

 

[GeneralDisorder]

This post filtering (and the restriction that creates) is known to have absolutely no effect on the HEUI system? Is there any CAT documentation about this modification?

The HEUI actuation pressure sensor is located in the cylinder head HEUI oil passage and if the filter system was some kind of restriction to flow it would cause a fault on the ECM as it tries to control pressure through the HEUI injection actuation pressure control solenoid on the HEUI pump. There is no documentation I'm aware of from CAT but the system is very popular on HEUI engines in lots of application - trucks, busses, RV's, and equipment. You can always call and talk to George the guy that makes them. Since the 3126 injectors are $1,000 each and this filter can prevent them from being contaminated by a pump failure.... you are looking at saving roughly $5k in the event of a HEUI pump failure.

That said - both of the 3216's I've worked with that had HEUI failures did not have the injectors replaced and they run just fine. Oil looked very clean in both situations and I have my theories as to what actually is going on (IE: HEUI pump isn't actually making a bunch of metal contamination and the failure is related to pressure regulation issues) but as yet have not confirmed the exact cause of these problems.

 

[MatthewWBailey]

The IFS is the high pressure filter on the HEUI output? Since I haven't kept up on this issue: filtering after the HEUI pump is better than before? or simply the best place to add a secondary filter?

Next question is for the time and money, isn't replacing the oil filter housing gasket best? Do we need secondary filter after replacing the gasket?

I'm just bringing up the rear since this has been answered above. The IFS is a post HEUI filter. The pre filter from CAT doesn't fit a 3126B and only fits a C7.

I'm curious if and why people are not adding the typical 2um bypass filter on these? I put the large Amsoil unit on there using the oil sampling port at the cooler, returning to the block port on the rear starboard side. I noticed most commercial trucks run some sort of bypass filter, luberfiner etc. seems more bang for the buck over the long run.

custom bracket required, which I'm getting good at. Rick knows the saga of how I removed the lifting cykinder

 

[Keith Knight]

I'm just bringing up the rear since this has been answered above. The IFS is a post HEUI filter. The pre filter from CAT doesn't fit a 3126B and only fits a C7.

I'm curious if and why people are not adding the typical 2um bypass filter on these? I put the large Amsoil unit on there using the oil sampling port at the cooler, returning to the block port on the rear starboard side. I noticed most commercial trucks run some sort of bypass filter, luberfiner etc.

Post pictures of your amsoil filter and part numbers. I’ve considered it but running out of room in there.

 

[MatthewWBailey]

Post pictures of your amsoil filter and part numbers. I’ve considered it but running out of room in there.

The kit comes with hydraulic lines that you must assemble, but I used high temperature lines made at the hydraulic shop instead

https://amsoilcontent.com/ams/lit/databulletins/g2552.pdf

 

[MatthewWBailey]

Post pictures of your amsoil filter and part numbers. I’ve considered it but running out of room in there.

It has to go here or up behind the engine or it hits the tire.

 

[MatthewWBailey]

I'm just bringing up the rear since this has been answered above. The IFS is a post HEUI filter. The pre filter from CAT doesn't fit a 3126B and only fits a C7.

I'm curious if and why people are not adding the typical 2um bypass filter on these? I put the large Amsoil unit on there using the oil sampling port at the cooler, returning to the block port on the rear starboard side. I noticed most commercial trucks run some sort of bypass filter, luberfiner etc. seems more bang for the buck over the long run.

custom bracket required, which I'm getting good at. Rick knows the saga of how I removed the lifting cykinder
View attachment 932429View attachment 932430
View attachment 932431

of course the chosen location is benefitted from me rerouting my exhaust straight back and up, so you can see there's lots of room next to the engine there.

better picture with all the heat shields etc...

 

[Keith Knight]

I thought something was missing. So with that and I’m assuming you use full synthetic oil? What kind do you use? What are your oil and both filters change intervals?

 

[GeneralDisorder]

I thought something was missing. So with that and I’m assuming you use full synthetic oil? What kind do you use? What are your oil and both filters change intervals?

I have the same filter but yet to install. Might do it on the passenger side.

Personally I run Amsoil 15w40 Signature Series diesel oil. And oil changes are guided by analysis.

 

[MatthewWBailey]

I thought something was missing. So with that and I’m assuming you use full synthetic oil? What kind do you use? What are your oil and both filters change intervals?

Same as Rick said. Amsoil 15w40 Signature Series, and the Amsoil full flow filter. I doubt I'll be pushing beyond 5k miles in a year so IDK on intervals. I gotta see how much oil consumption there is.

 

[Keith Knight]

With this latest oil and filter change I still use the cat filter but I switched from rotella t4 and 1qt of Archoil additive to only full synthetic rotella t6. My oil changes have been around 10,000. That’s about every 6 months.

 

[Keith Knight]

I have the same filter but yet to install. Might do it on the passenger side.

Personally I run Amsoil 15w40 Signature Series diesel oil. And oil changes are guided by analysis.

That’s very interesting, so being guided by analysis you should know exactly how many miles you can go on the oil. I’m guessing you haven’t driven enough miles yet? Please share how many mile you do have on the oil and what the analysis says.

 

[GeneralDisorder]

That’s very interesting, so being guided by analysis you should know exactly how many miles you can go on the oil. I’m guessing you haven’t driven enough miles yet? Please share how many mile you do have on the oil and what the analysis says.

Ah! Funny you should ask. I'm about to do an analysis and actually take the results seriously. So this is how it's been on my truck:

Got the truck with 2,750 miles. Seller had just changed the oil with Rotella T4 and I drove it home 2,700 miles where it promptly had an air compressor failure and had pushed a bunch of oil out of the breather tube onto the ground. I did send in an analysis of that oil - which came back in good condition but did show the viscocity was "slightly low", and "minor levels" of both copper and lead - which were possibly from the oil cooler. But they said no problem to keep running it.

Being it had slightly low viscosity and I wanted to run Amsoil 15w40 full synthetic going forward I changed it shortly after that report. Probably around 7,500 miles.

Then I went down the rabbit hole about low oil pressure being a problem on this range of engines..... Changed the oil pump on @Lostchain 's truck (at 6,500 miles) due to oil pressure idiot light when hot and that corrected his low pressure problem. Decided I would have to do the same for peace of mind - and wondering if the elevated copper was the idler gear bushing on the pump - and then didn't worry about doing an analysis because I was dropping the pan and changing the oil anyway. Time got a little away from me and I did end up changing the oil once before I got to the oil pump so in that time I put about another 10,000 miles on the truck with no issues. So about 5k miles on the first and second Amsoil 15w40 fills. Then I pulled the pan and changed the pump - didn't have any effect on hot idle oil pressure thankfully. It's a little over 20 psi when hot before and after.

So I'm now at about 5,000 miles on the latest oil fill with Amsoil and the new oil pump and I'm about to send in a second analysis to see where I'm at with it. And I'm likely about to install my bypass filter as well so we shall see what that does for the oil that's already in it - assuming they don't tell me to change the oil (doubtful).

And to the supposition that I will know exactly what mileage to change it at - that's actually the opposite of what I'm looking for with analysis. I'm not looking necessarily for a trend to follow so I can stop doing analysis (although some people choose to use it that way) - I'm looking to head off problems before they become nuclear meltdowns, and ALSO to get the longest life out of the oil investment. Basically to maximize the $$ I'm spending on the engine AND the oil. Changing expensive synthetic when it has more than half it's life left is just throwing away money...... The analysis through Amsoil is available online through an app or you can download the PDF and print it if you prefer so it can be done on the go.