Replaced thermostat.planed heads. Pressure checked heads.bypassed turbo. Checked oil line going into radiator.put dye in oil still showing up in radiator. No leaks from block.what is wrong? Changed head gasket and head bolts.What is a porous block?help! Mechanics don't know what is wrong after $1800 HEAD GASKET REPAIR.

 

First, would you kindly post the model and engine and mileage .
The 2008 SS 2.0 litre for instance had issues with porosity in the cylinder block casting.
The cylinder sleeves in the 2.2 and 2.4 can crack after exposure to high coolant temperatures due to a bad thermostat.

 

The OP has another thread regarding this same issue.
The 2 threads should be combined to avoid any confusion.

 

Threads merged, thanks George, you said it right before I logged on.

To the OP Jefferey, at this point, it's sounding like you might have a cracked block rather than a porous one.

Porosity problems usually showed up fairly quickly on the affected units, we're talking in the first few thousand miles and months of ownership, which is why I'm discounting the "Porous Block" theory.

To answer your question from err..post #13, a porous block is one that has a flaw in the casting. Either through being cast at a temperature too high or too low, or from impurities in the aluminum, small pores are left in the block.

These pores can allow coolant or oil under pressure to seep into areas where it isn't desired, like coolant into the oil galleries or the pan.

Being that you're now in possession of a "known good" head, assuming the work was done correctly, then your best option might be finding a good used block.

You're basically halfway to a full engine rebuild now.

 

My porous block 2008 had orange oil.
The coolant was disappearing for over 10K but didn't present where until 100,800 miles.
99K - no coolant in oil
100,800 - bright orange oil, 800 miles past extended warranty
GM did a courtesy swap. They cast a new block for me and swapped it free with no warranty.
Good enough.

Mine cracked between cyls 2-3

 

Just spent 1800 on head gasket. Still leaking oil into coolant.mechanics are stumped.checked turbo, oil cooler.put dye in oil.1half quart went unto radiator at idle in an hour.no leaks from block.

 

Thanks Mowgli, as soon as I'd said that the porosity issues usually presented themselves early on, a little bell went in my head saying..."somebody had one replaced at around 100,000 miles".

But I forgot it was your HHR, oops!

 

You say no leaks in block, how was this determined???
Are you indicating you think it could be the oil cooler?

I asked earlier to post model engine and year
As this discussion is pointing toward an '08 2.0 Turbo SS, but I'm not sure.

 

The oil cooler is bolted to the engine block just above the transmission housing to the right of the oil filter housing.
It's not in the radiator, like the automatic transmission fluid cooler is


One of our members addressed his oil cooler issues on this thread

https://www.chevyhhr.net/forums/prob...located-52605/

 

Mechanics replaced head gasket .had heads planed.showed signs ofsteamcleaned streak on head gasket.put back together.still has oil going into coolant and now a small am out of condensation going into oil.mechs say they flushed radiator 26 or 32 times. Put dye in oil showed up in radiator but no sign of cracked or leaking block.now trying water pump gasket.