Disappointed. New heads and gaskets. Expansion tank is 1\3 full, and coolant trickles from overflow tube. Is it something as simple as expansion tank cap, or thermostat? Engine has new radiator, no check engine light appears, and heater works fantastically. I don't get it. I really don't. What is going on here?

 

How old is the coolant reservoir cap? I had a similar problem. The cap wasn't holding pressure. A new $15 cap solved the problem for me.

Remember that fresh headgaskets restore pressure to a cooling system that wasn't holding pressure before. That means the next weakest points in the system are then revealed. That happened to me after I finished headgaskets five years ago. I suddenly had a throttle body heater leak that wasn't there before. And a week later, after the TBH leak was addressed, the bleed fitting in the old-style top radiator hose blew. Once those items got buttoned up the coolant level held steady until a couple of years later when the cap failed. And then the TBH again.

Don't panic. If you're confident the headgaskets were installed correctly you should be fine once the other weak points are addressed.

Good luck, and please update the group with your results.

 

I would agree; replace the cap its cheap then pressure test the truck

 

I"ll get the cap tomorrow. It will cost me $50 at the dealership. Thank you, Gentlemen

 

Auto Zone has em for 16.00

 

No need to buy a coolant res cap from a dealer. Any auto parts store ought to have one.

 

I wanted to be sure and get OEM, for warranty purposes. So....with the expansion cap replaced, dripping and leaking has stopped. What a difference. A simple thing can have such a devastating affect on an engine. I feel so relieved. Thank you every one and have a Happy Thanksgiving.
Tom

 

FYI Auto Zone cap is a 100% identical replacement for $16.00 vs the stealership's 50.00. I just bought one so I fully looked it over and it matched up 100% with the same exact markings on it. Now Motorad's cap is complete junk and I would run away from it ASAP.

 

You're welcome. There's a little THANKS button in the lower right corner of my earlier post that you can click. I'm glad it wasn't anything more serious or more expensive.

Warranty? On a DII?

At any rate the $15-$16 cap would have not voided any warranty.

 

I picked up a coolant system pressure tester from Amazon and it said it also fits my Disco I. I could check the system and also an adapter to check the cap. I mainly bought it to check my son's Chevy Cavalier. Glad it also works on my Disco!! It fould the cap was marginal so I replaced it.