I have a 2000 4 door 4x4 and have been noticing that i have been loosing antifreeze. The weird thing is that i have replaced the radiator, thermostat, heater core, and water pump. All those were bad and leaking and needed to be replaced. But its been about 3 months and every two weeks i notice its gone out of my Over Flow. I have checked for water in my oil and think goodness there was none but were could it be going? Thanks for any ideas

Matt

 

Could be a bad intake manifold gasket leaking into the intake port. Could be a failed head gasket...

 

ok So How do i check the Intake Gasket? I could possibly see that. Would that cause your exhaust tobe white?

Matt

 

intake gasket- pressure test the cooling system and see if it holds pressure. listen and look for leaks. im pretty sure its supposed to be 16psi. head gasket you need to remove the spark plugs and pressure test each cylinder. inspect spark plugs. a piston taking in coolant will have spark plugs that look brand new, shiny, steamed cleaned. the cylinder with low pressure also indicates bad head gasket.

 

Sweet, will get the tools tomorrow, Will post updates on what i find out. Thanks for the help. Hope its the easier of the two which my guess would be the manifold. Its getting cold out and i leave for college here in like two weeks so i have to get crackin on this.

Matt

 

Well all is well so far, i did the pressure test on the Radiator with about 16lbs of pressure and it held for over two mins with no change. The Compression test i am working on right now but all have good compression and the spark plugs are clean but dirty, so not a steam clean lol. Any ideas what i should look for its kinda puzzling.

Matt

 

When you did the radiator pressure test, did you also test the radiator cap?

When the springs get old and weak, they'll allow coolant to flow out below the rated pressure level.

 

That's a good idea to check it, but it didn't because the weird thing is that i see no signs of water anywhere. if it were leaking out there i would notice it on the radatior its self and other areas close by. Thanks for the idea though.

Matt

 

Ordinarily, you'd notice a leak when your engine overheats. But if a bad cap isn't allowing enough pressure to build, you won't get a regular steam-gushing type overheat. Check the less obvious places for evidence of leaking.

The weephole at the bottom of the water pump.

The carpet and underpad in front of the passenger seat - Heater core. (When my old '93 leaked, I first noticed it when the defroster steamed my windshield. I didn't see a leak until I pulled the carpet back from the firewall. The underpad was soaked. When I opened the ductwork, I had a big rush of coolant pour out)

The back of the engine especially on the right side - intake gasket leak.

The backside of the right wheel well - Heater hoses connect to core right above.

The front side of the wheelwell - Coolant overflow tank may have a crack on the bottom.

Don't automatically rule out a bad head gasket if all the plugs appear dirty. Such leaks can be tricky to find, especially if its caught early... some small leaks only show when the engine gets hot. Heat expansion opens the leak, cooling off closes it. A good cylinder compression test would normally rule out head gasket, but only if the leak was at the combustion chamber seal.

Another possibility is a cracked head, although this is fairly rare. If the crack occurs between the water jacket and the exhaust port, you wouldn't find evidence like a steam cleaned spark plug, since it's leaking downstream from the combustion chamber. However, you would get white 'smoke' from the tail pipe. Actually, steam. Look at it closely. When the weather is cold, it can be hard to tell the difference between a regular exhaust plume and a small amount of steam added in. The steam will make it smell funny, too. Kind of a nasty-sweet smell.

I've reached pretty far on more than one of these... beyond this, I'm out of ideas.

 

Ok, hmm Well i will replace the Cap and see what happens. I am getting frustrated with all this. i have a feeling its leaking from a head but what one and were do i start. I also have been getting worse fuel mileage the few weeks. I was getting about 250 per tank and now i am getting like 200. Also i will get ses light come on for a bit then go off. I have been able to scan it whille its on and its a O2 Sensor bank one i believe. Then after a bit it will just go away. I smelt my exhaust and it seems to be a bit steamy but not getting the smell. I also kinda noticed more then usual water dripping out on the ground. I am not getting a white smoke though. It does have 203xxx miles on it. Just need to get the problem diagnosed so i can get it fixed before i leave for college and have to drive it 1500 miles. Thanks for everyones help i really apprecate it greatly.

Matt

Edit: I have put an inline filter (the ones you can put on air compressors) on the pcv valve line. it catches a lot of the oil and cleans the air going back into the engine and i have noticed a white milky substance in the past i wonder if its catching some of the water in there?