cat 3126 overheat & excessive blowby

[microsprint9l]

didn't use coach last year but now looking to get back on road. now have problem with coolant system. low water light comes on & overheats after driving for approx. 1hr.  check coolant in radiator now low. also now have excessive blowby from crankcase breather. smoke is whitesh in color. checked oil no signs of water in oil[at least on dip stick]. no smoke in exhaust. because of motorhome age don't want to spend alot of money to repair.

[sstgermain]

Sounds like a bad head or head gasket causing blow by and water getting into cylinder.

[rayin]

Some engines use a liquid-cooled air compressor, other brands use oil-cooled. I would first run a pressure check on your cooling system.

[jleamont]

Do you have Aquahot? 

[microsprint9l]

On 8/1/2021 at 11:53 AM, jleamont said:

Do you have Aquahot? 

don't known what aquahot is. please explain.

[microsprint9l]

On 7/31/2021 at 6:17 AM, sstgermain said:

Sounds like a bad head or head gasket causing blow by and water getting into cylinder.

would't a bad head or head gasket with water getting into cylinder show up in exhaust as vapor. no smoke or vapor in exhaust. also would't the engine have a misfire?

[jleamont]

43 minutes ago, microsprint9l said:

don't known what aquahot is. please explain.

Hydronic Heating system in lieu of a propane furnace? 

I would cap off the heater hoses up to the front (back at the engine), see if it still leaks down. There is a lot of places where that coolant could go while running down the highway with little to know trace between the engine and the dash on a pusher. 

[manholt]

Linda had that engine in her 06 Phaeton....No Aqua Hot, no Oasis...think it was a 10 gal Atwood.

[microsprint9l]

On 8/6/2021 at 11:29 AM, jleamont said:

Hydronic Heating system in lieu of a propane furnace? 

I would cap off the heater hoses up to the front (back at the engine), see if it still leaks down. There is a lot of places where that coolant could go while running down the highway with little to know trace between the engine and the dash on a pusher. 

got propane furnace. checked heater hoses to dash. found 1 leak repaired it. ran yesterday for at least an hour @idletime with no overheat. saw coolant gush back into overflow tank and popped the cap open. may have leak between cylinder and coolant channel pressureizing coolant system.

[manholt]

Your thermostat may be bad. 

[wildebill308]

8 hours ago, microsprint9l said:

saw coolant gush back into overflow tank and popped the cap open.

If it was low on coolant it may still be purging air from the system. I agree with Carl. New thermostat and cap would be good.

Bill

[microsprint9l]

14 hours ago, wildebill308 said:

If it was low on coolant it may still be purging air from the system. I agree with Carl. New thermostat and cap would be good.

Bill

thenks for the info. Bill & Carl. i will try the simple things first.

[Orrin]

You may have a cylinder head gasket leak.  When the turbo spools up under heavy load  hot gas can leak into  the cooling system and cause coolant loss and over heating.  When the engine shuts down and there is no pressure in the cylinder, coolant can leak into the engine.  This can cause erosion  of the top of the liner or block deck.  If coolant gets into the oil it will cause cylinder scuffing and or main and rod bearing galling.  Then you are looking at a major engine rebuild.

I recommend taking it to a CAT dealer and have the problem diagnosed.

[manholt]

Orrin, you could be right...we just want to eliminate the cheap stuff before we move on to the big $$$$

[sstgermain]

5 hours ago, Orrin said:

You may have a cylinder head gasket leak.  When the turbo spools up under heavy load  hot gas can leak into  the cooling system and cause coolant loss and over heating.  When the engine shuts down and there is no pressure in the cylinder, coolant can leak into the engine.  This can cause erosion  of the top of the liner or block deck.  If coolant gets into the oil it will cause cylinder scuffing and or main and rod bearing galling.  Then you are looking at a major engine rebuild.

I recommend taking it to a CAT dealer and have the problem diagnosed.

That is exactly what my son said. He is a mechanic at Cat for 25 years. He said even though it is rare it does happen.

[microsprint9l]

22 hours ago, sstgermain said:

That is exactly what my son said. He is a mechanic at Cat for 25 years. He said even though it is rare it does happen.

hay all you guys  thanks for the info. i guess my next move is take it to a cat dealer. if you can find one. i have learned from past experience even a heavy equipment dealer will service that engine. 

[Orrin]

This will be the most economical in the long run.  Glad your doing it.

[manholt]

Mustang is CAT dealer and Service Center!  They are all over most cities

[hermanmullins]

"Holt" is a big Cat dealer & service center in North Texas.

Herman