Reply
Cat Dealer
Employee
Dealer

Re: CAT 3126B engines with diesel in coolant

Diesel in your coolant is coming from bad seals from your injector sleeves!

Ask your local dealer the replace the seals.

Contributor

Re: CAT 3126B engines with diesel in coolant

Fuel in coolant is almost 100% bad sleeves or seals.

 

Pull the injectors and replace the injector sleeves, it's a quick and easy job with the CAT tooling avaliable, should be able to do it in 3-4 hours easily.

Contributor

Re: CAT 3126B engines with diesel in coolant

Tony:

 

If the cobwebs aren't too thick on your post and you see this, then you will want to visit www.boatdiesel.com where your issue has most likely been discussed.

 

Paul

New member

Re: CAT 3126B engines with diesel in coolant

Tony,

     I'm in the process of deciding to put in an offer on a Cabo with the 3126B engines(2001).  I'm very interested in what you find out as well as any additional information that will help me decide if I should avoid these engines.  Please share whatever information you can.  I'd really appreciate it.

 

                                                                                      Thanks

Contributor

Re: CAT 3126B engines with diesel in coolant

Hi Tony,
What do you mean by magnetic precipitate, steel particles in water?
Does your injectors are cooled?
If you found DO in your coolant liquid it might not be a cylinder head or cylinder liner crack or gasket wear , only combustion gases pass through. To be sure you can make a simple test with PH indicator band. Combustion gases creates sulfuric acid with water, so compare PH of new and in use cooling liquid. A more acid, in use, cooling liquid might indicate that combustion gases come into water.
New member

CAT 3126B engines with diesel in coolant

I've just purchased a 46' motor cruiser with 2 CAT 3126B 450HP engines, and (long) after survey, got a coolant report back showing extreme levels of magnetic precipitate and diesel fuel present in the coolant. The coolant looks very cloudy/opaque compared to the other engine. On sea trial, both engines seemed to run fine, and evenly. Since then, I've used them for a few hours mainly at idle speeds without any problems. I've had suggestions that the problem might be injector sleeves/o-rings leaking fuel under pressure into the coolant, or it might be a cylinder head gasket or (worse) a crack in the cylinder head. Has anyone had any experience with this problem? Or does anyone know how I might be able to differentiate between the causes? Thanks.