Potentially blown head gasket? (Page 2/4)
jelly2m8 MAY 20, 01:14 AM
3 places in a 2.8 that oil and coolant could possible come in contact. 1: Head gaskets 2: Intake gaskets 3: Timing cover gasket. Good news is you caught it early, It is most likely just a gasket.

[This message has been edited by jelly2m8 (edited 05-20-2024).]

Patrick MAY 20, 01:43 AM

quote
Originally posted by jelly2m8:

Generally the coolant pressure will be like ~ 16 PSI, that should be less than a high mile 2.8's oil pressure, so here is where you have to think, what and where is over powering the other.



For sure, oil pressure in an oil gallery would be higher than the coolant pressure. My comment was directed more towards where oil is relying on gravity to make its way through the heads, the lifter valley, and the inside of the timing chain cover back into the crankcase. Perhaps "pressure" was the wrong term for me to use, as there's actually a vacuum in these areas, due to the PCV system.


quote
Originally posted by Patrick:

I would hazard to guess that wherever this cross-contamination took place, that the coolant pressure (when hot) was greater than the oil pressure at that location.


[This message has been edited by Patrick (edited 05-20-2024).]

jelly2m8 MAY 20, 01:56 AM

quote
Originally posted by Patrick:





We seem to butt heads, but we aren't that far apart
1985 Fiero GT MAY 20, 02:02 AM
Saying the same general thing in 2 different ways haha, oil feed is high pressure, oil return/ambient crankcase is low/no pressure, coolant is medium pressure. In my case coolant is flowing into the oil, so into a return channel or more directly into an open cavity in the engine, such as the timing chain area or beneath the intake.

Does this felpro gasket set include all the gaskets needed to fix the leak if it is indeed in the intake, if so, I have that set already, and can get started sooner then later, knock the intake off the list.
https://www.rockauto.com/en...6&cc=1249040&pt=5424
Patrick MAY 20, 02:37 AM

quote
Originally posted by jelly2m8:

...we aren't that far apart



Just 4,444 kilometres... as the Canada Goose flies.

[This message has been edited by Patrick (edited 05-20-2024).]

Patrick MAY 20, 02:58 AM

quote
Originally posted by 1985 Fiero GT:

Does this felpro gasket set include all the gaskets needed to fix the leak if it is indeed in the intake, if so, I have that set already, and can get started sooner then later, knock the intake off the list.



Yes.

Hopefully you can actually see the break in the old intake gasket when you remove the lower intake (as I did all those years ago with my Z28). If you can't see an obvious break in the old gasket, I'd hold off putting the intake back on until you've eliminated other potential coolant leakage points. (Actually, I'd hold off even removing the intake until you've exhausted any/all testing procedures looking for the coolant leak.)

One thing I'd do before ever starting this engine again... is after the crankcase has been drained and oil filter replaced (with a cheap one), I'd add a couple of quarts of cheap oil to the crankcase, turn the oil pump with an electric drill to flush out all the oil galleries (while rotating the engine by hand, easier with the spark plugs removed), drain the oil, change the oil filter (to a good one), and add the proper amount of good oil.

[This message has been edited by Patrick (edited 05-20-2024).]

82-T/A [At Work] MAY 20, 07:40 AM
Hey 1985 Fiero GT... do you want / need those heads sooner than later?

My daughter just got the engine off the stand and onto the cradle with the transmission. So, I have room and can put the motor on the stand and take the heads off. Let me know, and I can ship them out. I just need about a week.
theogre MAY 20, 08:24 AM
Oil Pressure means Nothing because Where the Coolant leaks in most places the Oil is @ 0psi.
Like Coolant Leak into Head oil drain(s), engine valley, & V6 timing cover.

The coolant get to the pan & sinks & Oil Pump is now mix master sucking coolant & oil....

"high" oil pressure on the dash may mean very little to nothing as the sender or wiring are known to lie from electric problems like...
https://www.fiero.nl/forum/Forum2/HTML/146784.html Fuel, Engine Temp or Oil Pressure gauges have problems?
1985 Fiero GT MAY 20, 08:30 AM

quote
Originally posted by 82-T/A [At Work]:

Hey 1985 Fiero GT... do you want / need those heads sooner than later?

My daughter just got the engine off the stand and onto the cradle with the transmission. So, I have room and can put the motor on the stand and take the heads off. Let me know, and I can ship them out. I just need about a week.



Well, I will be digging deep into my engine, so this would be the time to install them, along with all that porting in the intake, so if you could get them out, that would be wonderful, don't rush so much you don't video it though, you have to get your YouTube content!
82-T/A [At Work] MAY 20, 09:08 AM

quote
Originally posted by 1985 Fiero GT:

Well, I will be digging deep into my engine, so this would be the time to install them, along with all that porting in the intake, so if you could get them out, that would be wonderful, don't rush so much you don't video it though, you have to get your YouTube content!




Ok, this weekend I'll pull the motor out of the crate and remove the heads. We can start the video and do comparisons of the stock and worked heads, and then I'll box them up.

PM me your mailing address. I'll try to ship them as cheaply as possible... you don't have to reimburse me for the shipping immediately... just whenever you get around to it.


Thanks