Official Caterpillar3116/3126 Thread

Back your trim tabs down a little bit, and with all the work I bet your right at or slightly below 800.

 

hope so, that will make the cleaning turbos with q-tips worth it

 

Do you 2 guys realize that you have different engines?

They are both 3126's but if memory serves me correctly, David's are 420hp 3126TA's and Ryan's are 350hp 3126e's . You will not and should not try to have the same EGT and boost readings because the engines are designed to meet different specs. The 350hp 3126 is the engine Cat designed to meet the emission standards they were not able to meet with the 3116 or 3126TA. The common sense mechanic in me says you will see higher EGT's in the engine that does meet soot and particulate standard because to get a cleaner exhaust, you need to have hotter combustion temperatures.

Also note that these engines are rated at 2800 room, not at cruise speeds of 2400 rpm or below.

 

I’m 3126-TA 350 hp.

 

Mine are also 350HP. Frank, after we spoke a few weeks ago in the other thread I reached out to the local dealer to confirm. His email is below and based on this info makes me believe we are also 350HP 3126TA’s. My engines do not have a HEUI pump, and going by what he says it sounds like the E model was a heui engine


Hi Ryan,

Your engines are mechanical-the 3116/3126 were similar to each other and the 3126E was the predecessor for the C7 (electronic). The fuel injectors for the 3116/3126 are actuated by the engine’s camshaft and fuel rate is controlled by the mechanical governor. On 3126E/C7 engines the fuel injectors are hydraulically actuated via a high pressure oil pump and the fuel rate is controlled electronically via their engine ECM.

 

The same information is available for the 385 hp and 420 hp version in the same document thats is published for the Marine 3126. I wish we had a document library to post up to.

The biggest difference is the 385 and 420 burn more fuel at a given hp, and have a higher EGT reading. The 350 have the lowest EGT of the 3. If heat is the enemy, that should help with longevity.

 

There was a thread a while back about maintenance videos for the 3116, but the thread died out. Does anyone have these that they would be willing to sell or share?

 

Closing the loop on my compressor O-Ring hunt - CAT had the correct part available. They advised they are usually reusable but for $17 I replaced them.

part number 133-8525. Clamp bolts are 1255466. As always, double check with the dealer on your SN’s. I believe the higher HP versions have different turbo geometry than my 350HP

 

Jim, I have copies of the videos.

 

Thanks, @Steve S I'll connect with you offline.

 

I should have done this when I bought new panels from Flounder. (upgraded tachs to Aetna's, removed and replaced non working raymarine gear etc.)

Anyway, would you be able to share pics of where the pyro probes are attached/inserted as well as the boost gauge fittings? Apologize if posted already, unable to locate.

 

sure thing. I’ll grab them tomorrow, I’m going to clean the other compressor for a couple hours

no drilling or tapping necessary, both existing holes with threads

 

here you go. My aftercoolers are off but they’re easy to install even with them on. The plug on the manifold can be a pain, a good impact freed it without stripping. They’re straight threads so it takes so torque to get them out.

 

Thanks!

 

fresh paint! Time to start getting these things back together and start thinking about spring

 

I'm currently looking at upgrading to a 410DA with diesels, local one has 3116 CATs in it. So from what I'm reading for the most part the 3116 wasn't (shouldn't) be affected by the French made soft blocks that I keep reading about. These motors have ~930 hours on them so I know the 1000 hour maint. is coming up for these and have heard that it can be costly.

I currently have a 01 340DA with 7.4 horizons and do most of the maintenance myself. Do most people do the maint themselves to save the money or pay to have it done. It looks like somethings (valve lash adj) need to be done by CAT.

Anyone have a CAT dealer/servicer in the DC area that they use/trust?

 

the overhead needed to be done at 250 hours and then is due again at 2000 hours. Chances are the PO didn't have it done at 250 hours (ask for records) so yes, it should be done now if it hasn't already.

There are not 1,000 hour specific tasks but other things that should be checked would be old hoses and clamps, coolant (flush and replace if not done in the last 4-5 years or so), aftercooler clean and pressure test (replace the turbo to AC hose!), turbo inspection, etc.

Asking for a CAT dealer is a step in the right direction - you want them do perform the engine survey and take samples. They will verify much of what was listed above, run the oil analysis, take blow-by readings, and give you a full engine health report.

 

From what I understand, the 3116s were not affected by the soft block issue, that was the 3126s. However there were some soft valves made by TRW that would cause the engine to drop the valve and trash the engine that affected the 3116s. Both the soft block and valve issues typically showed up around 150 hours. Cat replaced all the affected engines that were reported and ended the program back in 2005. With almost 1,000 hours on them, you should be good to go as far as those issues are concerned.

Adjusting the overhead adjusts the valves/fuel injectors and should have been done at 250 hours as mentioned above. The valve lash adjustment should be done by a Cat tech. But changing oil, filters, etc is easily accomplished on the 3116s. (I have them in my 400 Sedan Bridge.)