[dv657172]

A couple of weeks ago I started up my 71 GTO with a basically stock 400 I got white smoke out of DS exhaust for about 10 minutes then it stopped.

Started it again today and same thing. Checked and drained the coolant and it appeared fine, tranny fluid on the dipstick appeared fine. Checked oil dipstick and looked like a milkshake. Drained the oil and definitely contaminated.

Car never ran hot, idled and appeared fine under acceleration although I didnt drive it out of garage.

I am assuming I need to replace head gasket but curious why or how it was in oil but not coolant, at least not noticeably?

Recommended head gasket?
Any advice on removing head, car has power steering.
Should I do both sides?
What other cleanup do I need to do to not have residue issue once fixed?
I havent done one of these before but I guess its time to learn.
Thanks for any advice and/or education

DV

[25stevem]

You now need to replace more then a head gasket, it’s rebuild time after have milkshake oil and running the motor.

At least the bearings will need to be replaced and the crank polished, and assumes a head did not crack.

[sdbob]

I had leaking timing cover,coolant into oil when in college.traveled 200 miles on way home changed oil on trip. Pulled engine bearings were flaked missing pieces. I did drive engine gingerly afterwards with bearings that way, yes ugh,but out of necessity,$$$$.

[tom s]

I would throw a hail mary,change the head gaskets,pickle the engine with some dsl fuel,drain everything,new filter and new oil and drive it some and pull the filter and check it out.JMHO,Tom

[Steve C.]

There are many who have good things to say about these gaskets, a fwiw......

https://butlerperformance.com/i-2445...tegory:1459615

( their website has others to evaluate )



.

[tom s]

Steve,those are my choice of head gaskets.Tom

[mkpontiac]

Tom
What does it mean to pickle the engine with diesel fuel?
Mark

[tom s]

Yes,they do it all the time to boat engine that sink.Tom

[F ROCK]

It seems you've had this same problem with the same car back in 2018?
https://forums.maxperformanceinc.com...d.php?t=818487

I've got a '71 GTO with power steering; It's not a real big deal changing the head gaskets. Hardest part for me was pulling the manifolds off and lifting the heavy head out from the engine bay.
Brad, (Sirrotica) made some good suggestions in the old thread.

FWIW: I once overheated the bejesus out of my #96 headed 400. Really, really bad, at 3 AM in the middle of nowhere. Thermostat stuck and i had no tools, and it was 0* degrees outside. Engine seized. One hour later, it fired up. I made it home. Heads didnt crack. That was about 1995. Engine lives today, untouched, in another car.

[Half-Inch Stud]

Like Post 4 says, buy my 1st thought was 5 quarts of Mineral Spirits. Diesel fuel may be better!

Water crossover lesking down thru valley cover would be a better problem to fix. Blaming a Headgasket might be random.

[straycat]

Like those Butler gaskets also. Liked the water hole openings compared to the Fel Pros.

[Formulas]

diagnose a head gasket / coolant leak

fill radiator to top leave cap off
remove sparkplugs
use compression tester that has 1/4" QD apply compressed shop air to each cylinder
may require rotating engine to get valves right to hold air CAUTION engine will rotate with shop air applied in certain conditions
watch for air bubbles escaping top of filled radiator to narrow down search for affected cylinder or not

[Half-Inch Stud]

Probably wise to keep air pressure near 20 psi.

[dv657172]

F Rock

I drive the car so little I had to go back to my own notes to remember that it smoked in 2018. It did smoke, same side, nothing in the oil or coolant back then. Kind of wrote it off as being due to sitting as it doesnt get driven much at all..my fault. No smoke since.

Then on Sept 18th of this year car had white smoke when I started it, for 3-4 minutes then the smoke stopped (car stayed in garage). Oil looked fine, coolant fine. Thought maybe valve seal leaking or something but wasnt sure.

Started it on the 23rd no smoke, ran fine at idle (stayed in garage)
Sept 25th started it - white smoke again for 10 min at idle, then it stopped, idled fine (kept it in garage). Coolant fine, checked oil and it was a milkshake.

Car has only went about 50 miles in the last 4 yrs...no lectures please, time and life goes by fast.

[nUcLeArEnVoY]

Motor rebuilt at any point? If it's an original motor, it's not unreasonable to figure maybe the original head gaskets finally just gave way or the water openings corroded out into a compression or oiling opening. You run antifreeze or straight water? Corrosion protection in a cooling system is almost as important as the cooling capacity of the fluid itself.

It is a rather odd thing to happen out of nowhere. I'd do further testing to diagnose a head gasket such as compression test, the suggestions above, or maybe the CO2 fluid testing kit, though that would involve running the engine while it's potentially vulnerable. Don't forget that with these engines, there is an entire other part of the motor where coolant has an opportunity to mix with oil, and that's the timing cover - those openings are only separated by a crapola paper gasket.

[F ROCK]

no lectures here.
If it were me; I'd just flush it the best i could with fresh oil or kero or whatever, change the gasket if needed, (fix the problem) put fresh oil & filter and roll.
some folks will hate on that...

[dv657172]

Thanks for your opinion. I am leaning that way too.

Is it possible to have a head gasket leak and only the oil be contaminated, never the coolant?

I also through a vacuum guage on it before I realized the oil was bad and had steady albeit low vacuum...used vacuum fitting that goes to distributor which is also shared with PB and one other thing

[25stevem]

The oil rings don’t like to flush out easy and you’ve got 8 of them!
Found this out many decades ago on a buddy’s Olds 350.
I would drain out the Milkshake leave the drain plug out and fill & pressure test the cooling system.

See then if system can’t hold pressure, and water after a while comes down out of the pan or if when baring the motor over you have a hydro locked cylinder.

Once again, if either of these two take place I would be pulling the motor out to look at some of the bearings.

[dv657172]

Nuclear Envoy

engine was rebuilt prior to my purchase

car has always run 50/50 coolant/distilled water

When I originally bought it it always ran hot but car didnt have the piece between front grill and core support to force air through radiator and a weak cap. That has all been fixed and radiator recored in late 2018. Now it runs cool. Car also kept in heated shop so freezing of anything not a consideration.

[Formulas]

possible rebuild kit head gaskets were used, that require a re'torque, and that re'torque did not happen
regardless simple diagnosis will pin point the leak fix that change oil be gentile with it for a few hundred miles change oil again have fun