idle surge/foam in coolant

[ProjectGTP]

a few weeks ago i broke a valvespring. so i replaced them all and also installed a waterpump underdrive pulley(not that it has anything to do with this). once i start the car it will run fine for awhile and then after it warms up my cheap a/f gauge goes all the way to lean and it starts idling like crap and surging and eventually dies. and when i checked the coolant in the radiator its foaming. i heard these are symptoms of a head gasket going but i find it hard to believe. the car seems to run perfectly fine other than the idle. any help?

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[10sec]

My car had 2/3 of the coolant in the oil from a faulty head gasket and it ran like a top. Couldn't even tell anything happened, aside from it overheating.

 

[ProjectGTP]

The only thing guy confuses me is the a/f going lean. Why would it do that?

 

[ProjectGTP]

Also its intermittent. It just idled fine for about 10 min and then started running bad out of nowhere. I'm confused

 

[RICH17]

Coolant temps might make the pcm think it needs to lean out if its too hot?

What coolant are you running?

IMHO dexcool seems to get faomy on mutiple cars when it has faster than stock water going thru it. I have had a couple customers come in with foamy problems ( one a GAGT and one LS1) and both said they had a pulley on the pump. Might be too much turbulence in the system

 

[ProjectGTP]

Coolant temps might make the pcm think it needs to lean out if its too hot?

What coolant are you running?

IMHO dexcool seems to get faomy on mutiple cars when it has faster than stock water going thru it. I have had a couple customers come in with foamy problems ( one a GAGT and one LS1) and both said they had a pulley on the pump. Might be too much turbulence in the system

I'm just running green antifreeze. And its and underdrive pulley so its less water moving. I'm leaning towards it being a head gasket or a cracked head. Maybe the broken valvespring caused something? I drove for about 1 min with it broken.

 

[CrunkMaro]

check the plugs, see if theres any deposit in em.

what color is the foam? any coolant in the oil? any oil in the coolant?

borrow a compression tester...

if one cylinder is low, prolly something effed up in the head

if two adjacent ones are low then its prolly a gasket.

 

[RICH17]

I'm just running green antifreeze. And its and underdrive pulley so its less water moving. I'm leaning towards it being a head gasket or a cracked head. Maybe the broken valvespring caused something? I drove for about 1 min with it broken.

dur..... Lol


Im leaning towards the same as far as head gasket or LIM leak. Motor swap time

 

[ProjectGTP]

Lol. Motor swap was last winter. 15k mile L26. And the heads are zzp refurbished ones. I used ARP head studs too that's why I don't understand why the gasket blew out. It's a felpro.

 

[RICH17]

Its an odd problem to have tho. I would pull the LIM at least then go from there

 

[10sec]

It's probably not blown if the car doesn't over heat, and there isn't any coolant in the oil. Your maf could be bad. Many things, start diagnosing shit and figure out it out.