recman67

Guys, I've about reached the end of my fuse with this car and I need some advice.Last month the head gasket blew, overheating the engine and warping the heads. I had the heads surfaced and a valve job completed. An hour after getting this thing running, a hose blew and she overheated, blowing the head gasket. I had the heads inspected and replaced the gaskets and head bolts. Since then, She's been running good, although a little warm in my opinion, for a few weeks. We've bled the system, installed new tstat and rad ca, etc. Yesterday, my son (it's his car) was driving home when she severely overheated again.
Now there's pressure pushing the coolant right out of the radiator when I start her up. the only thing I can think is that we've blown another head gasket or worse, warped the head. This time, there is no steam coming from the tailpipe, just huge amounts of bubbling from the radiator.
Is there even the slightest possibility that the new head bolts stretched allowing exhaust to enter the cooling system? Is there something I have missed? Thanks in advance for any advice.

Kevin Blown 95 TA

A lot of people don't bleed the air out correctly and have overheating problems like that after they work on these cars.

chevyz4life

I'm pretty sure some if not all need it.

recman67

Thanks, but the air has been bled on several occasions to make sure it's all gone.
As far as thread sealer, that's affirmative. directions were followed to a T.

Wild1

This is very odd. Are you cleaning the threads with a tap? Make sure your steam pipe in the back of the engine is not crusty or obstructed with chunks... mine had a few large chunks I cleaned out.

Bolts do stretch, you can re-use bolts as long as they are not torque-to-yield.

Maybe your thermostat is sticking closed. Drop it in a pan of water and boil it with a thermometer. It should begin to open at 195F.

ACE1252

If your blowing coolant out of the radiator, then you have problems. I personally think that bolt stretch causing this issue is a "stretch". I'm not saying it isn't possible, but I doubt it.

I think your going to have to pull it apart. I'm hoping that it's only a head gasket issue.....but you need to re-examine the heads and block to see how true they are.....

A crack in a cylinder wall will also cause this problem.

You can use a coolant pressure tester to verify if the coolant system has a leak or if it is being pressurized by a cylinder. It should hold pressure for at least 2 minutes when not running(mine does not leak down at all). Don't exceed the cap pressure.

It should normally perform like this idling(steady needle unless revving...with pressure building as it warms up).....

http://www.ace1252.com/images/CC503_...ant_tester.WMV

If the needle vibrates while idling or if it leaks down upon pressurizing the system, then....

Wild1

These engines are a pain to run a leak-down test. If you can get a leak-down gauge, it will help you isolate if it is a gasket, a cylinder wall, or a cracked cylinder head. Typically, a leak-down test is at Top Dead Center, but if you let the piston go to the Bottom Dead Center then you can check the cylinder walls.

Check the dipstick to see if the coolant has mixed with the oil.

Have a shop run a straight-edge and check the trueness of the block. Magnaflux or Xray the heads.

This sucks... sorry to hear the bad news.