How To Tell If You Have a 53 Block Cummins (Number Location)

Identifying the block is not going to be a hard task as there were only about 100,000 of them made at the time. Unfortunately, these problem blocks went beyond the Dodge Ram trucks and just about anyone can have one. But if your block is an ‘02, it shouldn’t be a 53.

There is a stamped digit on the driver’s side of the block just over the oil pan. This two-digit number should read 53 on it. If you cannot find this number, then you do not have a 53 Cummins block. This is the only way to identify these blocks.

To learn more about this identification tag, just continue to read our article. It has the information you want to know about so you can find out if your engine block was from this weakened batch. It is as simple as looking on your block to find the answer.

How To Identify a 53-Block Cummins


As you have just read, you can find the number 53 stamped on the block. These numbers should be in a fairly accessible location so spotting them should not be that difficult. But you may have to crawl under the truck to see it.

What you may not know is that the 2-digit number identifies the block as made in the Brazil plant called TUPY. They should have the company name marked somewhere on the block as well.

The blocks with the number 54 stamped on them are supposed to be the blocks that rectified the problem with 53 block. Why do we mention this fact to help you distinguish engine blocks made in Brazil and those made in Mexico?

The Mexican company is called Teksid and they did not make any blocks that had the same problem as the 53 did. However, their identifying mark is a series of numbers, longer than 2 digits, which may not mean anything except to the Mexican plant.

It seems that the Mexican plant made better-quality blocks than the Brazilian plant did. Why are people worried about this issue? It is because the 53 blocks can crack on you and you will lose your coolant.

You know what losing your coolant means. You will see your temperature gauge rise quickly when it happens.

Where is 53 Stamped on a Cummins block?


This number and all successive 2-digit numbers are usually found on the driver’s side of the block, just above the oil pan. It should be easy to see and if you have more than 2 digits on the block, then it was not a 53 model.

Also, the 53 block were installed in the Cummins 24v ISB engine in a 1998-2001 model year vehicle. But those engines did not just go into the Dodge Ram trucks of those years.

This engine was also placed in a variety of medium-duty trucks from different manufacturers as well as the following vehicles- mobile homes, public school buses, and mass transportation buses.

One minor correction needs to be made, the number 53 may also appear on the passenger side of this block. It is located close to the oil filter, also just above the oil pan.

If you do not see it on the driver’s side of the block, check the passenger side to make sure. What we should point out is that not all 53 block are bad. There are some owners who have owned their vehicles since 1997 and have not reported any problems with their block.

It is just that the potential for the block to crack is there. This crack usually takes place right below the freeze plugs and right behind the transmission heat exchanger.

Generally, the crack seems to only happen when you are towing, going up moderate hills, and having lots of weight behind the vehicle.

Cummins Block Number Location


Before we provide any more information on this topic, there is one thing you need to know about the 53 block. There seem to be 2 types of 53s and only one type has a cracking problem. Determining which type you have is not going to be easy.

There are no distinguishing features to tell them apart. If yours doesn’t crack you may have the other type or you got lucky. To find the numbers for the 53, just look on your block as the numbers are about 1 inch tall.

There is no other location for them other than what we described. There are numerous tags placed on the engine in different locations, However, those tags usually hold the engine serial number, not the block number.

There is a difference between those two numbers. We have looked at those tags and there is no box for the block number.

Fixing The 53 Cracked Block


Unfortunately, there is only one option to repair this problem. It is called block stitch and welding. The job looks like a medical stitch when it is done right.

There is more bad news. This is a temporary solution only. It should give you time to find a new engine. The reason it is a temporary solution is that the wall thickness in that area of the block is thin.

The block could crack again in another part somewhere other than the stitch. If you want to see pictures of the location of the stamped 53 or photos of the stitch repair, just click here.

You will get some good information on the 53 block on that website.

Some Final Words

You may be the lucky one and got a good 53 block from Cummins. That would mean that you have not had any cracks in the block at any time. If you do get a crack, have the repair work done, and then start looking for a new engine.

There is no telling when the crack will take place a second. Then check your engine for the block number even if you do not have a Dodge Ram truck. This engine went everywhere.

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