Hey everyone I am wondering what is going on with my radiator and the cap. I got this vehicle awhile back and it was not taken care of at all by the previous owners. I ended up replacing: cylinder head, heater core, ac evaporator, radiator, radiator cap, and all the coolant lines. But the coolant keeps on spraying from the radiator cap. I think the pressure keeps getting too high. It's not over heating at all. The coolant gauge only reaches 1/4. I'm also having problems with the oil. Whenever I come to a stop the pressure goes to zero. It only happens when it's been running awhile. I guess I should have replaced the entire engine. 🤷

 

Welcome to the forum, Pedro.

You may have a blown head gasket, or a cracked head. This can allow combustion gasses into the cooling system, creating pressure. The 2000 and 2001 models had a defective head which is prone to cracking in one particular spot. If it's a cracked head, you might see the coolant by looking down the oil filler cap.

You can rent a pressure tester at many auto stores to see if your cooling system is holding pressure. A better test (but bit more expensive) is to get a test kit for exhaust gasses in your coolant.

Drain a little engine oil into a clean container and see if you have coolant in it.

 

I already replaced everything. It's a completely brand new cooling system. Should I just replace the cap with a new one? If so do y'all recommend a certain radiator cap?
​​​​​​

 

you need to establish whether the head is cracked and causing the issue..in the meantime, you could try a new cap, in addition, failed OP sender is a known fault.

see if there is any creaminess in the oil cap...or bubbles in the radiator neck

 

Do not buy any parts until you know if the head is cracked.

 

I have a brand new cylinder head in it. It's not a cracked head. Could the coolant recovery tank get clogged and cause this to happen?

 

Nope. Something is causing excessive pressure in the cooling system. The things that can cuase that are:

1. Overheating.
2. Blown head gasket
3. Cracked head
4. Cracked block

The exhaust gas in coolant test will tell you about #2-4. It won't tell you which one it is, but it will tell you that one of them is the problem.

You can't assume that a new head is not cracked unless you test. If the car was overheating and cracked the head, and you replaced it with the same type of head (0331 casting), you could easily have cracked the new one.

 

Turns out the back part of the cap wasn't locking onto the connection with the radiator. I fixed that part but I'm still getting a small leak from the cap. Is there a way to get the cap to lock on better so no fluid escapes? Just so that the connection for the cap to the radiator is more secure, because it feels like I can still wiggle the cap around when it's on the radiator.

 

I have bent the tabs on a radiator cap slightly. This will produce a tighter seal. You can give that a shot.

 

OR just buy a new cap.

 

True, but I just answered the question asked. Of course, buying a new cap is an option. I'm making the assumption that he is still troubleshooting his issue and looking to avoid just throwing money at parts.

 

If you never changed the cap, start there. Get the best one you can buy. If that doesnt work then you could have problems.You could run the truck with the cap off and look for bubbles as a cheap test.