Auto problem '90 3.1 ltr chev

[captmello]

Sons got heat issues with his Lumina. Took off radiator cap and it's bubbling and spitting antifreeze out. Is this a blown head gasket?

 

[Gary H NC]

Re: Auto problem '90 3.1 ltr chev

Could be the head gasket or Thermostat stuck,cooling system in need of flushing.
Does it have a miss in the engine or does it sound normal?

 

[captmello]

Re: Auto problem '90 3.1 ltr chev

The car has had a slow leak for years. He just recently has had interior heat issues also. If the heater core is plugged or starting to plug, maybe it needs flushing, or needed it before the core plugged.

It seems to be running good still. Started this morning 15 below.

Maybe I'll change out the themostat and put some flushing additive in and see if it helps bring back the heat.

The only time i've seen the radiator bubble like that it was a Head gasket.
deep single belches of antifreeze, not small bubbles or boiling.

 

[Gary H NC]

Re: Auto problem '90 3.1 ltr chev

The slow leak for years sounds like the intake manifold gasket leaking.pretty common on the Chevy engines during the 90's.
If its had stop leak put in it several times it could have plugged the heater core.
The heater core being plugged should not cause an engine over heat though.
Usually no heat is a sign of low coolant.
Flushing it good should show up where the leak is because that usually makes the leak worse.
It may be worth having a shop put a pressure test on the cooling system...

How hot did he let it get while driving? It may have head gasket problems now...I hope not.

 

[dolluper]

Re: Auto problem '90 3.1 ltr chev

3.1 slow leak ......err intake gaskets ......or tubing for that age .....you don't want it to be the tubing very pricey ...have done both many many many times.....fix it right the old bird will double it's life again Ifin it was the heater core you will hear some sloseing on pass side or wet puddles on pass{enger}floor

 

[captmello]

Re: Auto problem '90 3.1 ltr chev

Thanks for the feedback, guys.

although its leaked for a long time i've never added any stop leak products. the slow leak is, descrbed by my mechanic a couple years ago, a small nipple that is screwed into, i believe, the intake on the back of the motor. This has one of those V6 motors that you are only allowed to work on the front half. Apparently it is fairly common but not an easy repair as once you try to remove the nipple, it breaks off and you must cut it out with a hacksaw. My mechanic said he'd done a few.

I haven't touched it yet. It's so far down on my list right now.

dolluper - looks like you've crossed pathes with a few of these.

Can't someone tell me the motors shot so I can put it out of its misery!!

 

[dolluper]

Re: Auto problem '90 3.1 ltr chev

Naaaaa fix her ......there's a little tool that replaces the DOGBONE>> upper engine strut.... that pulls the motor forward with a threaded rod you tighten up 10-12 bone tool worth it for small cars not to get BIG SCARS ...very handy could be CHEAPER in the states I would think

 

[Gary H NC]

Re: Auto problem '90 3.1 ltr chev

That leak at the back is one of the great designs of GM.The quick connect coolant hose...I know exactly what your talking about.
They are about 12 bucks to replace but getting to them can be a pain.
I never had one break off.The factory uses a thread sealant on them.
A big socket usually breaks them free with no problem but in my area we don't get all of the road salt and corrosion.
I still would take a hard look at the manifold gaskets...

 

[Xcusme]

Re: Auto problem '90 3.1 ltr chev

There's also a flow restrictor in that fitting too. Remove it to allow more coolant through the heater core.

 

[captmello]

Re: Auto problem '90 3.1 ltr chev

Gary H NC, you hit it right off.

The temps spiked to double digits today and I got home early so I picked up a thermostat. When I went to put it in, the block below was empty.

That explains why there was no heat even though the radiator was full. I poured about 3/4 of a gallon of antifreeze in the thermo hole and put in the new thermostat.

Goes to show, if you have a leak on the block side of the cooling system and the thermo stops working...

I don't have a set of keys or I'd road test it. Hopefully this will cure the belching rediator, and he'll back on the road.

I'm not sure if I'll tackle that nipple on the back of the motor just yet.

Thanks to all for the ideas and encouragement.

Joe

 

[Gary H NC]

Re: Auto problem '90 3.1 ltr chev

Good to hear Joe,
Hopefully it will last for some time before you have to get to that fitting on the back of the motor.
Just keep a close eye on the coolant level...