Why would a 2005 SSR overheat, normal maintenance is done?

It can be faulty thermostat or worn out waterpump.Or it can be issue with no coolant or blowd head gasket or head itself needs replacement.
To confirm the issue.Click the link below and follow step by step test procedure:----
http://www.gresk.com/2013/09/2005-chrysler-300-overheats.html
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Thanks.

engine? the maintenance schedule says every 30K miles. I would follow that, and use top quality coolant.

Other have purchased an after market fan.

NORMAL MAINTENANCE @ 150,000 MILES (240,000 Kilometers) - COOLANT - REPLACE - [Drain, flush, and refill every 150000 miles (240000 Km) or every 60 months, whichever occurs first.]

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - EXHAUST SYSTEM - INSPECT

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - FUEL SYSTEM - INSPECT

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - AIR CLEANER/ELEMENT - REPLACE

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - FUEL FILTER - REPLACE

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - SPARK PLUGS - REPLACE

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - TIRES - ROTATE - [Tires should be rotated every 5000 to 8000 miles, and/or at maintenance I or II service intervals.Check tire pressure, thread depth and wear.]

1. The leaky coolant hoses will only deteriorate further and need to be replaced before a serious leak occurs and you overheat and damage your engine.

2. It's very important to carry out all scheduled maintenance on your vehicle as recommended by the manufacturer as well as attending to additional maintenance issues that will arise.

Cooling systems need to be flushed out and refilled with the correct specification new coolant every 2 years. It is very important that all air is bled from the cooling system when coolant is changed as failure to do this properly can cause air locks in the cooling system and result in overheating and engine damage.

Water pumps wear and fail and if not replaced will result in your engine overheating and very expensive engine damage will be the result. The cooling system thermostat should also be changed when the water pump is changed.

Maintenance of the engine's cooling system is extremely important and, if neglected, will certainly result in engine damage.

3. It is important to change the engine's air filter element as these clog up with fine dust impairing air flow to the engine for combustion. Once the filters begin to clog the engine will run very inefficiently and poorly and your fuel consumption will increase. You will end up burning your dollars on extra fuel when all you needed to do was replace a cheap part. These filters should be changed every 12 -18 months (more often than the car manufacturer usually states). On most cars the air filters are a very inexpensive item and very easy to change over.

Most of the car dealers recommend to perform Maintenance services scheduled at 30K, 50K, 90K and so on.
At 30K they mostly inspect all the systems, and replace fuel filter.
At 60K they inspect systems and flush must of the fluids, transmission oil and filter, coolant, brake fluid, differential and transfer case fluid, and replace the air filter. Some replace the spark plus at 60K some at 100K.
At 90K all timing belts are replaced, and the status of the timing chain checked. A deviation of more than 5 degree means, there it is the time ayes on the timing chain.
At the Owners manual for 2005 Chevrolet Trailblazer recommend:
Inspect all the systems at 25K, and replace fuel filter.
Replace engine air cleaner filter, automatic transmission fluid, automatic transfer case fluid every 50K.
Replace spark plugs every 100K.
Maintenance Services for your car are scheduled at 25K, 50K, 75K,100K and so on. All are tune ups but they are not the same.
The only concern for GM is the GM Dex-Cool antifreeze. There are some complaints regarding this product. I recommend to flush the cooling system every 50K to 60K.

Most of the dealers recommend Scheduled Maintenance Services at 30K, 60K, and 90K.
At 60K the coolant has to be replaced with a new one, to avoid a corroded radiator or partially clodged heater core. Radiator Flush. The air filter.The spark plugs has to be replaced with the original OEM. The transmission oil starts breaking at 30000 miles and has to be changed at 60K. This is the best insurance for the transmission of your car. It is optional but, it is recommended to flush the breaking system too. This protect the ABS system from corrosion. Do not forget to replace brake bleeding nipples with new one. They are cheap, and avoid costly problems in the future.
The EGR valve has to be inspected.
The last and most expensive service is the timing belt change between 60000miles to 100000miles.

What you have is a Navistar 6.9L Diesel engine in your van-RV.
They are know to blow head gaskets----nomally its a matter of taking the heads off --clean everthing --check for unusual large crack in the glow plugs pre-cups, check heads for flatness and than slap the heads back with new head gaskets.
This engines if the normal maintenance was done regularily they will do a easy 300,000 miles--with the head gaskets replaced when needed.
the easiest way to check for this is look for bubbles in the coolant resorvoir bottle with the engine running.
Also the other most important thing is make sure that the cooling system is clean--means new coolant on schedule and radiator removed and have it rodded --cleaned out.
You can tell if it needs rodding by draining a little coolant -enough that you can see the tube ends thru the radiator cap neck --to see if they are plugged or open.

hello, other things if not recently done should be done oil change,new plugs and a new air filter its a basic tune-up along with the things youve done this will keep your car running strong.