Cat 330 Engine Overheating

Lots of good ideas. I'll make sure my wife follows these directions exactly.

GM

You will find the worst of the CAC clogging will be in the corners outside of the radius of the fan. It is not unusual for that area to be 100% clogged with a mixture of dust and oil fumes from the slobber tube. With the CAC being in front of the radiator it blocks the fan blown cooling air from getting to the radiator. There is a very narrow gap between the CAC and the radiator so you have to be careful to get the crud from the CAC out from between them when cleaning or you will just blow it out of the CAC and into the radiator. It is not a easy job. I have made a small diameter tube wand that will fit in between them with a spray hole at right angles to the tube. I hook my pressure washer to the tube and blow forward into the CAC from the back and rotate it around and blow back into the radiator. Works for me.

Jim

Your "final approach" is the only one that will clean where the dirt is accumulating-- on the front of the CAC!

You have a SANDWICHED cooling system, with CAC in front of (front of coach) the radiator. It must be cleaned from the front.

Drove the last 200 miles home in 5th gear, maintained 2000, 2100 RPM, 62/63mph. No problem. My final approach is to take up the floor panel inside and spray the radiator from that point to make sure I get a thorough cleaning. After that, to Freightliner for proper tests and possible solutions.

I'll post the results.

GM

Yup, lots of things can cause overheating. But, I like to start with the simple/inexpensive things:

Water pump belt tension.

New thermostat(s).

Clean front of CAC.

At this point, you have maybe 2 hours of work and $25 invested and have covered the majority of the overheating causes.

Yes, after that, things get more complex/expensive.

School of HARD knocks - diesel cooling

Have the shop do a HOT leakdown pressure test of the radiator and engine

Followed by a COLD leakdown test, REGARDLESS of what you find.

This sounds suspiciously like the water pump is cavitating. A suction side air leak.

Please post what ends up working (the fix)

GM,

You said you cleaned the RADIATOR. Did you clean the CAC (Charge Air Cooler) from the FRONT?

What was ambient temperature when this occurred?

Was this on flat ground or a grade?

How is water pump belt tension-- it is on a separate V belt from the serpentine belt?

Have you changed the thermostats (Caterpillar calls them regulators)? That would be my next step.

Cleaned the radiator thoroughly, still having a bit of a problem. Seems to progressively heat up. I was in 6th gear, RPM around 1600, speed 62mph more or less. Finally downshifted to 5th, same speed, kept RPM at 2000/2100, engine cooled down to where it should be. Don't understand why this just started. I've put 25,000 miles on this coach in 6th gear, 1600 RPM, no problem. Should I accept 5th gear as a way of life,or look for another solution?

GM

Sprayed Simple Green on the radiator from both sides, let it sit for a couple of minutes, then powerwashed it off. Did this twice. Lotsa gunk came off. I've had no overheating problems since.

GM

Trackrig wrote:
Covering the expansion tank is a good idea. I'll do it when I get back to the MH.

Bill

Even easier, paint it with UV resistant paint in your choice of colors. Leave a corner that is not exposed to the sun unpainted if you want to be able to check the level without lifting the lid.