i have 2002 4.7 the first problem i had (the 1st since i got it 3 years ago) it overheated then later i drove it and it didn't. it run fine so thermostat? i put 2 different ones in still had the problem. then pulled the water pump looked almost new checked upper and lower hose look fine no leaks. got it to stop overheating but every time i drove it the antifreeze level would drop in the upper and fill the overflow up but not suck out i got a new cap and tried to burp and fill the system for over a week. i talked to my dodge guy and said it could be a plugged radiator so 3 days ago i put a new radiator in and i still can't get it.

when you drive it and get it up to temp and stop and let it cool down the fluid level will drop but the fluid level in the overflow will go up tell i siphon it out i keep filing the system but it keeps ending up in the overflow. every time it takes about a half of quart and that's what i siphon out of the over flow. and i will have to do this 2 3 times a day. if i dont siphon the overflow out it will just keep filling up tell it overflows

i don't no anymore please help.

 

4.7 have a common problem with head gaskets and the timing cover leaking coolant in the motor. I would start with a compression test and a pressure test on the cooling system.

 

i pressure tested it and it held around 15 lbs would drop slowly for 20

 

Hi guys,
Master tech, is this something that us owners of 4.7's should take extra care watching for? Is it that common that it's a syndrome? I just downloaded the TSB list,I'm looking through to see if there's a bulletin for this but it's a longggggg list,(always better to ask someone in the business anyway)
I myself have really clean looking coolant and haven't noticed a rise in my oil level so I don't see any of the symptoms but it's new to me and if this is that common I want to address it right away.....TY

 

what should it test at like what lbs would be good and bad and thanks for the help

 

I wouldn't apply too much pressure at all,20 lbs may have been risky if you suspect an issue already, plus the risk or damage to your radiator,heater core, etc. Look at your cap, it should have it's rating stamped on it,I wouldn't exceed that.....
You wrote that yours held at 15 lbs, correct? Did you notice anything? Smoking exhaust,leaks, anything?

 

the cap said 20 so thats what i tested it to. no smoke not really any water vapor only at start up then stops (normal) no sweet smell plugs look good they have 8500 on they and thats what they look like. both front and rear heater cores work great it get hot as ****. no leaks that i can see. and like i said the same amount of antifreeze i top off end back in the overflow.

 

There are no TSB for the cooling to start with. This is what I have seen. The timing cover will get a small pin hole from the electrolysis in the cooling system. Thats why you need to change the coolant maybe every three years. The head gasket are made of steel gaskets and over time they will start to leak combustion temp into the cooling system and cause an overheat when driving. I'm posting some information on checking the combustion cambers.

Operate the engine without the pressure cap on the radiator until the thermostat opens. Attach a Pressure Tester to filler neck. If pressure builds up quickly it indicates a combustion leak exists. This is usually the result of a cylinder head gasket leak or crack in engine. Repair as necessary.

If there is not an immediate pressure increase, pump the Pressure Tester. Do this until indicated pressure is within system range of 110 kPa (16 psi). Fluctuation of gauge pointer indicates compression or combustion leakage into cooling system.

Because the vehicle is equipped with a catalytic converter, do not remove spark plug cables or short out cylinders to isolate compression leak.

If the needle on the dial of pressure tester does not fluctuate, race engine a few times to check for an abnormal amount of coolant or steam. This would be emitting from exhaust pipe. Coolant or steam from exhaust pipe may indicate a faulty cylinder head gasket, cracked engine cylinder block or cylinder head.

A convenient check for exhaust gas leakage into cooling system is provided by a commercially available Block Leak Check tool. Follow manufacturers instructions when using this product.

COMBUSTION LEAKAGE TEST—WITHOUT PRESSURE TESTER
DO NOT WASTE reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

WARNING: DO NOT REMOVE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN RADIATOR DRAINCOCK WITH SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN OCCUR.

Drain sufficient coolant to allow thermostat removal. Remove accessory drive belt.

Add coolant to radiator to bring level to within 6.3 mm (1/4 in) of the top of the thermostat housing.

CAUTION: Avoid overheating. Do not operate engine for an excessive period of time. Open draincock immediately after test to eliminate boil over.

Start engine and accelerate rapidly three times, to approximately 3000 rpm while observing coolant. If internal engine combustion gases are leaking into cooling system, bubbles will appear in coolant. If bubbles do not appear, internal combustion gas leakage is not present.

 

Thanks for the info master tech. Never heard about the 4.7 issue. I see a lot of it with raw water cooled marine engines though. After I read your previous reply I worried that I missed something. Seems like cruiser234's going to find
exactly that area adding pressure with his overheat/overflows.Would've been nice to catch it before investing in a new radiator.Better late than never. I luckily seem to have no issue at this point,whew....I'm replacing my intake gaskets this weekend. Any advise there? IE; OEM gaskets or aftermarket,special sealants etc etc? Any heads-up advice from a tech is huge...Thanks again...
Oh, Cruiser,best of luck,hope it all comes out well for you....

 

ok i have the truck on a tester 2 different time and i get no Fluctuation of the needle. when i bump the throttle the gauge with go up to about 20 then down to 10 then right back to 16lbs. i had it running for over 30 min and the gauge said 16 ibs without any movement tell i gave it throttle.

and im still having the same problem. still no smell of burning antifreeze no loss of antifreeze it just end up in the overflow and no more overheating i have put over 100 miles on it since the new parts and im still having problems so anymore ideas.