I have a 1998 Ford with the 4.6 I have replaced the radiator 3 times already, it seems to crack right on the side, I have also replaced the water pump and a back hose that runs antifreeze through it. Everything That I have replaced on the truck has somehting to do with the coolant system. Why does it keep springing leaks in different places? Is it building to much pressure? Any suggestions on what could keep causing this? Also My truck misfires to, I have tried different types of plugs and wires, it will go about 2-5 thousand miles then start misfireing again. Pleas help!
Thanks!

 

whats the condition of the cap in the overflow tank??? possible its not releasing pressure when it needs to.

 

I am not sure of that never checked. The cap of the overflow is suppose to release pressure? How can I tell if it is doing its job or not? Thanks

 

Absolutely- I agree with Keith, you need to check that cap, but it would be a good idea to get a radiator shop to pressure test your whole system - also, have you checked the thermostat? If that sticks, it can put a lot of pressure on your system. It's essential that the "radiator" cap, as they used to be, is tested/replaced periodically, as it's your safety valve, essentially. It could also be that it's the wrong cap for the job.....they're not expensive, you should probably just change it.

Radiator caps can be tested, but you need special tools - cheaper to change it, but, like I said, it might be worth seeing a radiator shop - what you're getting is not normal. It may also be possible you have some sort of corrosion issue, if you do a search on "electrolysis" you'll see some people were experiencing premature radiator failure, it's very unusual what you're getting. In the electrolysis issue, the engine's electrics attempt to ground themselves through the coolant, setting up an electro-chemical reaction.

With your misfiring, you probably have a weak/failing coil/COP. Do a search on the forum here, it's best to replace all of them at once - you can get them quite cheaply on ebay. Before that, though, you should read the engine computer codes, it will probably tell you what's up. I believe Autozone will read them for free, if you don't have a reader....which is a pretty good investment, you can get one for around $100 or less.

 

i agree. have the whole system pressure tested. the thermostat theory is also a possibilty if that gets stuck nowhere for the cooland to go.

 

Ever consider that a possible blown head gasket is pressurizing the cooling system?
Have the coolant tested for exhaust gas content.