Blown head gasket? (and overheating)

[roads]

Recently I had issues with coolant boiling and overheating so I decided to replace the water pump (thermostat, and timing belt). After I replaced it all I keep overheating (but no leaks!) with lots of steam coming out of the radiator bleed plug.

Heres a video of what the steam is like. It does it every time after revving when warmed up.
https://drive.google.com/file/d/1mNL...ew?usp=sharing

The air from the heater when its blasting is barely warm so maybe there's still air pockets?

I fear I might've warped the head or blown the head gasket by overheating it (I got into the red the first time it started leaking coolant).

The oil looks like this (kinda milky)..


Here's a video of revving (lots of white smoke)..
https://drive.google.com/file/d/15gz...ew?usp=sharing

Thanks!

[e30davie]

Compression test and a coolant system pressure test will tell all.

[jeffnhiscars]

That oil just looks used. "Milky" would look like a milk shake and would mean either a blown head gasket or cracked head

[Andre3127]

Is your coolant system staying pressurized?

That oil doesn't look milky. This is what milky oil (milkshake) looks like from my car:

https://www.instagram.com/p/BfJwXyPhJKU/?taken-by=325e_e30

Good news for you, head gasket replacements are easy on m20's. It's a pain, but nothing is difficult. I did mine and rebuilt the head without much other entry-level car maintenance experience. I used a Goetze gasket and Permatex copper spray.

[e30davie]

Remember the headgasket can fail in many different ways....

- Between two cylinders (low compression on those two cylinders, no effect on oil or cooolant)
- between a cylinder and a water gallery (possibly low compression on cylinder, possible pressurizing or coolant system and possible coolant being burnt out the exhaust)
-Between a cylinder and an oil gallery (low compression, low oil pressure? burning oil? pretty rare if even possible)
-Between a coolant or oil passage and the side of the block - (loss of coolant or oil out the side of the block - oil is common on m20 at front of engine)

and you can either have the gasket itself fail, or you can bend the head from overheating which helps the gasket fail easier.

Now you can also have a crack in the head between a cylinder and the water gallery.

The video if the steam coming out the exhaust does not inspire confidence. I reckon you've either done a headgasket or a crack in the head. You will only know if you take the head off and drop it off to a machinist to get it checked.

But if you think you have air pockets you really need to make sure that the coolant system is blead properly. i assume you know about the bleed screw near the thermostat?

whatever you do DO NOT put that head back on without having it checked. Be prepared for it to cost a fair bit.

[DÌEGØ]

Doesnt seem to be an abnormal amount of white smoke.
Usually low heater output is from air pocket or bad water pump.
I would try purging your coolant system again....or you can also check for combustion gases in cooling system if youre paranoid lol

[roads]

Thank you all for the help!

I did a compression test and all seems fine with that.
Here's the numbers going from the spark plug closest to the radiator (car was cold).
140,148,155,148,140,140

I am going to take it to a shop to attempt to troubleshoot the overheating issue.

Edit: I think I bled the system improperly, so I got the rest of the air out.

The car is still overheating though and the coolant levels in the overflow on the radiator drops to basically nothing when sitting for 30 minutes (with no leaks!), then boils right back up to the top when heated.
The compression test shows that the head gasket isn't blown right?

Maybe the head is messed up? (I hope not)

[roads]

Good news! I got a new radiator and re-bled the system and now temps are sticking right at half! Thank you all for helping.