How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dr. Hamman Your Own Question
Dr. Hamman
Dr. Hamman, Automotive Engineer
Category: Car
Satisfied Customers: 6286
Experience:  30 years experience, Repairing, building, & designing, automobiles.
9795573
Type Your Car Question Here...
Dr. Hamman is online now
A new question is answered every 9 seconds

Thomas Saf-T-Liner: Looking at a 1999 Thomas Bus, Rear Engine.

This answer was rated:

Looking at a 1999 Thomas Bus, Rear Engine. Has a CAT 3126 diesel engine. Owner says the bus had a fuel pump replaced. Said after it was replaced, the engine starting blowing white smoke from the blow by tube. According to his garage, the new pump was so powerful that it must have blow a ring? Said the repair would be between $200-$400. Does this sound right, or is that an engine problem?

Hi, I am a professional certified mechanic, with an engineering background, and 35+ years experience. I will do my best to assist you. Also keep in mind I don't know if you are a pro or a novice, so feel free to add any additional info at any time.



White smoke from that tube is a BIG BIG red flag. The smoke is a sign the the engine has serious internal problems. Also the story about a fuel pump that is too powerful is just bull. There is no way a pump can cause these symptoms. CAT engines are great quality, but the down side is they are expensive to repair. With white smoke out the blow by tube, it will take some serious repairs, where the engine has to come almost completely apart. You might find once you open it up that it is far more than a ring as suggested. If it needs a complete rebuild, and you have it done, expect $12,000 to $14,000. I have dealt with Buses a lot, you try to find a southern bus, from areas where road salt isn't hardly ever used. Most buses from northern states have serious rust issues, it's often hidden. States like Texas, Arizona, New Mexico, Southern CA, and so on normally don’t have the serious rust the northern state buses have. Rust is probably the #1 issue when buying a used school bus. Go over all of this and if you have any more questions at all, I am here to help. Good luck with it, have a great day, and Thanks for using Just Answer.


I do not get paid for my work unless you rate at 3 to 5 Smiley Faces or Stars, a bonus is always greatly appreciated. If the answer is not clear, let me know what additional help you need, and I will be happy to assist you further.


Dr. Hamman and 6 other Car Specialists are ready to help you