Losing coolant even after new headgasket

[superorange]

So my car was loosing coolant. I built a head on the side then swapped it onto my car as well as a new mls 4 layer head gasket and new arp's for safe measure. Well cars been back on the road for 2 weeks and its loosing coolant faster than ever now. The head was toured down in the right order and to the right specs and was also machined and resurfaced before the install. The car has still yet to see over 190 degrees. So it doesn't make any sense to me. What could it be? I don't see coolant or anything in my driveway ever either. any advice will be greatly appreciated.

 

[BogusSVO]

Depends if the block is distorted or not.

It needs to be checked for warp, just like the head.

 

[superorange]

So this is the tester I should get?


Radiator & Cooling System Pressure Tester Kit

 

[bryanwheat]

No, do a cylinder leakdown test.

 

[BogusSVO]

So this is the tester I should get?


Radiator & Cooling System Pressure Tester Kit

Thats a good kit to have also. It will show when a HG has failed into coolant...Along with finding other cooling issues, on a cold car.

 

[superorange]

Gonna do a leak down and compression test tomorrow. Would it be a bad idea to loosen the head studs a little then tq them down to like 105-110?

 

[superorange]

No advice on that huh?

 

[MHuddy1213]

doing so may only work temporarily you need to do it the right way even if it were to work your only putting a bandaide over something that need stitches as a saying goes do it the right way and you never have to worry about it

 

[WES_393]

Only torque the ARP studs to spec. Over tightening them will not help, it will just stress the studs.

My honest advice is to toss that MLS gasket out the window. Without getting the head and deck professionally resurfaced with a near mirror finish, it is going to leak. There is no way around it.

 

[BogusSVO]

Gonna do a leak down and compression test tomorrow. Would it be a bad idea to loosen the head studs a little then tq them down to like 105-110?

Yes it would be a bad idea... oil and coolant could then weep between the head, HG, and block...

 

[AlaskanDsm]

It was pretty much losing it right away. Just wasn't going into the overflow tank. Now it is. And the head was 100% torqed down properly. And I'm assuming the machine shop surfaced the head properly.


And it has a new 24 psi cap.

Just a quick question, is having a cap at 24PSI good/bad? I know that the stock cap is somewhere around 13-15PSI. I just wanted to clarify for myself on why or why not that this would be okay. I understand that at the stock pressure rating, the system is designed to hold a certain amount of pressure with the 15PSI cap and with an increased PSI rated cap, the coolant system also is increased in pressure as well as increases the boiling point of the coolant. What would be the benefit of doing such a thing to that degree of difference?

 

[bryanwheat]

Just a quick question, is having a cap at 24PSI good/bad? I know that the stock cap is somewhere around 13-15PSI. I just wanted to clarify for myself on why or why not that this would be okay.

It is not a real good idea to have a cap with that high of pressure. You want to keep it around 1 bar.

 

[AlaskanDsm]

What would be the drawback to having a cap with a PSI rating that high?

 

[bryanwheat]

What would be the drawback to having a cap with a PSI rating that high?

More stress on the cooling system components. The hoses are radiator are designed to be run at a certain pressure, when you increase that you run a way higher risk or rupturing something.

 

[BogusSVO]

ok ....

For every pound of pressure a rad cap holds it allows you 3* over boil point of water of 212*

13lbs x 3* = 39* common cap for imports

16lbs x 3* = 48* common cap for domestics

24lbs X 3* = 72* commonly found on race cars with upgraded cooling systems


Running a 24 psi cap on a stock cooling system is not a good idea for it puts more pressure on the system, Hoses can pop off, plastic tank rads can split ect....

 

[AlaskanDsm]

Thank you both.

I pretty much had that idea but just wanted to have the additional information to confirm what I thought I knew. I understand that especially with stock plastic end tanks and without upgrading the cooling system that there would possibly be severe consequences. I was also googling the information while you guys were responding so I understand about the increase in temperature and pressure. So where I understand that this would be bad in the purpose of a stock engine or stock with some minor upgrades, how does this benefit a race car?

Is it just because of the sustained high performance use, abuse and heat created that they need a higher point for boiling so that they don't have an abundance of coolant going to the overflow?

I know I probably sound quite dumb asking but its something I have always wondered and wasn't really sure how to go about asking for the information.