Common Cat 3406B Problems – Should You Be Concerned?

Are you wondering what the most typical CAT 3406B problems are?

You may have been thinking about buying this engine, yet still on the fence as to whether you should pull the trigger or not.

After all, there are so many things to consider before making a purchase. You want to make sure that it is indeed worth the money and will not end up causing so much problems for you.

This is why we are here to have a closer look at these CAT 3406B problems – what the symptoms are and what you can do about these. Let’s get right into it.

cat 3406b problems

CAT 3406B Problems

Some people who have the engine have been quite pleased with its performance. In fact, there are those who have had this engine for decades without any issue at all.

However, after some time, problems began to present themselves. With only about 20,000 miles, the engine appears to be non-responsive. It would require some coaxing to get it started, which includes pumping its throttle. Sometimes, all of these would be necessary even when the external temperature is not cold. 

But one quite concerning issue that some owners have experienced with this engine is when it began to blow out some white smoke from its stacks. Then, it started to have difficulty with  starting the engine. In fact, it can even fail to idle, just like when you are dealing with an old car that has a bad carburetor.

As soon as it has begun to warm up, it would be easier to start. However, this does not eliminate the problem with white smoke exhaust. There is also fuel in both the filter and the tank,  and yet, the starting issue persists.

You may assume that it could be solved with a compression test. But it is always best to have an expert diagnose the problem to make sure that it does not have further issues that you may not be aware of.

For the most part, however, white smoke always means that there is raw fuel. This can be due to a number of factors such as bad injectors or low compression. When there is white vapor, it could mean that your coolant is entering your exhaust or cylinders. Thankfully, vapor tends to dissipate fast. But then, smoke remains in your air.

You may have the automatic timing checked, as well as the injectors. You need to get these components checked by your mechanic or take your vehicle to your dealership. 

But primarily, the 3406B is a reliable engine. Yet, it can have issues throughout its lifespan. This is why it is very important to take it to a CAT dealer to make sure you get original parts for components that need to be replaced. Aftermarket parts are not ideal, and you are better off with original components that should last a long time.

It is also worth mentioning that pumping your throttle to try to start the engine does not always work. In fact, it only causes your foot to get exhausted. So, when it does not start, you may check the servo located in the governor. In this portion, there is a walking beam part held by a pivot pin. The pins tend to go out of position, which causes the beam to detach. 

As a result, the engine shuts down and fails to restart. But we highly recommend that you check the fuel pressure and other relevant components inspected by a specialist.

We have also heard of some people complaining about having coolant problems in the rocker area. There is no oil mixed in the water, yet there appears to be some fluid in their rocker area. If so, it is best to get the compression checked since it could be a problem with this part. 

But one important thing to note is that you should never go for cheap parts when you need to get any problem components replaced. Original CAT parts can be costly, and there is a need to use special tools. Yet, this is the best way to do it when you want to get the finest results and make sure issues won’t keep recurring.

Read More: Common CAT C13 Twin Turbo Problems And Is It A Good Value?


cat 3406b problems

Although the CAT 3406B is a dependable engine, there are issues that can occur at certain points throughout its lifespan. We have mentioned the most common ones that people complain about, yet there are other concerns that may also happen. So, we highly recommend that you get your engine checked by a specialist and to only opt for original CAT parts to get the best results and solve the problems you are having once and for all.

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