Coolant reservoir filling up

[91Bird305]

I use the smaller overflow unit from alkycontrol.

Recently I've noticed that the more back to back runs I make, the more the little reservoir fills up. Even popped its top once.

It's never done this before. Any ideas on what would cause this? Temps when driving around are 178-182 and when racing cane range from 190-200.

 

[Pablo]

Water expands when heated. Back to back runs will heat up the coolant a lot. Thats why coolant reservoirs have a "hot" line and a "cold" line.

The more water (as a percentage of coolant) you use the more expansion happens. Coolant does not expand like water. Your radiator cap could also be weak and venting pressure early.
The small reservoir also has less room for this expansion, so you could be well within the normal amount of expansion. You just don't have a large enough reservoir to compensate for it. You might want to try starting with an empty reservoir and a full radiator when cold.

Of course if it's way excessive it could be a blown HG but that's not what it sounds like.

 

[91Bird305]

Thanks Pablo.

 

[Nick Micale]

Sounds like a head lifting, or soon to be blown head gasket.

 

[91Bird305]

Sounds like a head lifting, or soon to be blown head gasket.

Ack! Don't say that!

Copper gaskets, ARP studs, I hope it's still holding. Haven't noticed anything like chalky oil or leaks

 

[Nick Micale]

Have you re-torqued the heads lately? This is necessary on a continuing basis with copper gaskets.

Also, add a GM coolant tablet.

 

[Lee Thompson]

I agree with Nick

Have you re-torqued the heads lately? This is necessary on a continuing basis with copper gaskets.

Also, add a GM coolant tablet.

Add 2 tablets--it don't have to be blown--just lifting.

 

[91Bird305]

Don't think I ever heard of these. Can you get them anywhere or only at the dealership? They have an actual name other then GM coolant tablet?

 

[bison]

Head lifting from detonation

 

[DailyDrifter]

Water expands when heated. Back to back runs will heat up the coolant a lot. Thats why coolant reservoirs have a "hot" line and a "cold" line.

The more water (as a percentage of coolant) you use the more expansion happens. Coolant does not expand like water. Your radiator cap could also be weak and venting pressure early.
The small reservoir also has less room for this expansion, so you could be well within the normal amount of expansion. You just don't have a large enough reservoir to compensate for it. You might want to try starting with an empty reservoir and a full radiator when cold.

Of course if it's way excessive it could be a blown HG but that's not what it sounds like.

+1 Its probably just the coolant expanding. No need to jump to conclusions on a headgasket (depending on sevarity of course).

 

[bison]

+1 Its probably just the coolant expanding. No need to jump to conclusions on a headgasket (depending on sevarity of course).

Unless he had the reservoir at 70% or more cold im still sticking with lifting heads

 

[91Bird305]

It's a very small reservoir that comes with the alkycontrol kit. Not sure if that matters.

 

[DailyDrifter]

Unless he had the reservoir at 70% or more cold im still sticking with lifting heads

It could very well be HG's or lifting a head. I'm still sticking with the coolant expanding . But with these cars a HG is a very possible problem .

OP is there any residue of oil in the overflow?

 

[S10xGN]

Head lifting from detonation

Not to hijack, but when this happens, is it a "temporary" thing? I'm running dual steel shims and this has been happening recently...

 

[Nick Micale]

Not to hijack, but when this happens, is it a "temporary" thing? I'm running dual steel shims and this has been happening recently...

Same comment, the steel shims need constant re-torque or they WILL blow by with 20+ or so of boost.

Once they "track", the gaskets are done, as you can get a leak even low boost pushing water through them.

Even though Cometic states no re-torque needed, I do not put too much faith in that either.

The Felpro head gasket is the only one we have found not needing re-torque if installed properly.

 

[yullose]

Sounds like a head lifting, or soon to be blown head gasket.

BINGO.

This is exactly what my car was doing before I pulled the heads off it. Compression was seeping into the cooling system and pushing coolant into the overflow bottle and popping the cap off.

 

[yullose]

Nick, I'm curious what head gaskets you trust @ 30psi on an 8-bolt setup ?

I'm told by my machinist to use Cometics, but every damn post I read on the board here has something to say about them leaking.

I just pulled a set of leaking RJC's off my motor, but I believe they were the older/discontinued thicker ones.

I don't know which ones to go with anymore...

 

[spoolie]

i also want to know where to purchase tablets...

 

[RmvBfrFlght]

i also want to know where to purchase tablets...

Bar's Leak makes them. Big horse pill like tablets, 6 to a pack. Can get them at a local auto store.

RemoveBeforeFlight

 

[Nick Micale]

Nick, I'm curious what head gaskets you trust @ 30psi on an 8-bolt setup ?........

Does not make much difference which head gasket you use a 30 psi on an 8 bolt set up. it will NOT last long.

Even with head clamps and extra bolts, the 109 block will deform, head lift or whatever happens, it will blow by.

If you want to go there, the best way, even though not cheap, is to go to an alum or stage block that is much stronger and has 14 head bolts. After an "issue" with a 109 block, the difference is cost may not be any different factoring in the repair [is possible] cost.

Have seen 45 psi on these blocks, and they keep on going! Have NOT seen 109 blocks last long at ~30 psi, if lucky, only the head gasket is damaged.

Last time at the track, I raced a 109 block GN that beat me by a fender. He paid the price, torched the head, took out pistons and damaged the block!

For what he paid for the original build and now the cost to fix it, he could have had a stage or alum block build?

He needed almost 30 psi to beat me, I was at 18 psi and had a bad reaction time. My alum block is ready for the next event, the 109 will try again after an expensive visit to the engine builder!