Resolved Coolant blowing out of valve cover??

[sav22rem22]

Hello wonderful people of stangnet, I’m back again with another strange issue. The other day I was free revving the car while testing my dashpot decay and noticed after revving that I smelled coolant but I didn’t think much of it as there’s no smoke out of the tail pipes and I also just flushed the coolant to get some new antifreeze in for the winter.

Today I bought a mechanical oil pressure gauge to verify what my warm idle psi was so I could decide if it’s time for a bottom end rebuild in the future when I do some other upgrades. Everything was going great until I revved the car and coolant blew out of the passenger side valve cover and caused a bunch of smoke. I shut the car down immediately and started it back up to get a video of it and to move it so I could pull that valve cover.


View: https://youtube.com/shorts/IxKNJENj7wA?si=R2Q5vKcGH_xg7l9f

That’s what I managed to catch on video. I’m at a loss. I pulled the valve cover and didn’t see anything obvious at all. When pulling the dipstick the oil doesn’t appear to have any coolant contamination and there’s no coolant burning in the cylinders or coming out of the tail pipes. Car isn’t overheating and hasn’t overheated at all since my top end rebuild. The only thing I saw when I pulled the upper intake and valve cover was that there was old coolant pooled up on the lower intake. It also appears that coolant has been all over my valve covers as they look awful which I should’ve noticed a long time ago but didn’t.

Does anyone have any ideas as to what could be going on? I don’t even want to start the car anymore until I figure this out.

 

[AeroCoupe]

Might be a cracked head? Pull the valve cover and fire it up.

 

[sav22rem22]

Might be a cracked head? Pull the valve cover and fire it up.

That’s my thought as well. Ive got the valve cover loosely pulled. Over the weekend I’ll throw another intake gasket on and fire it up without the cover and see what I see.

If it’s cracked I guess that’s an excuse to snatch me up some nice AFR heads that finally came back in stock

 

[General karthief]

Look very carefully around the intake on that side along the top, the heater tube/hoses and the egr coolant lines/bottom of the egr spacer. Coolant may be traveling around the back of the valve cover and not actually inside the cover.

 

[Noobz347]

It might be worth rinsing down the whole engine and starting new to find the source.

You don't even have to wait until the t-stat opens to check the areas that karthief mentioned.

 

[AeroCoupe]

The other part of a cracked head would be water in the pan or at least I’m 99% sure it would get in the pan. I would check out what the guys are saying as water will travel some weird paths on motors.

 

[sav22rem22]

Look very carefully around the intake on that side along the top, the heater tube/hoses and the egr coolant lines/bottom of the egr spacer. Coolant may be traveling around the back of the valve cover and not actually inside the cover.

I think you’re right. Looking closer it does look like it’s hugging the bottom of the valve cover and traveling around. That would also make sense as to why coolant was puddled up on the top of the intake. I know it’s not the egr spacer as I’ve got the spacer water lines capped off since I’ve got an egr block off plate. I’ll see what I can find once I get it thrown back together

 

[limp]

I think you’re right. Looking closer it does look like it’s hugging the bottom of the valve cover and traveling around. That would also make sense as to why coolant was puddled up on the top of the intake. I know it’s not the egr spacer as I’ve got the spacer water lines capped off since I’ve got an egr block off plate. I’ll see what I can find once I get it thrown back together

And there goes that excuse for buying those new AFR heads.... LOL

 

[sav22rem22]

And there goes that excuse for buying those new AFR heads.... LOL

Knowing me I’ll have another excuse by the end of the day lol

 

[Kid wita 5oh]

Why not just pressure test it..... Instead of making a mess

 

[GUNNER81]

From watching the video my guess is is that it's not coming out of the valve cover itself it's coming from somewhere around the valve cover someone else mentioned heater hoses and EGR I would check around the valve covers because if it was coming out of the valve cover you would have it in your oil pan and in your oil and it would be smoking so I would check all the hoses and anything else that has coolant in it good luck

 

[sav22rem22]

I left work early yesterday and threw the car back together and fired it up and found the leak. Right where I have the flow restrictor in the heater core hose is somehow leaking only when the car is hot and has some pressure in the system. The hoses are ancient anyway so it’s about time to replace them anyway.

 

[Noobz347]

I left work early yesterday and threw the car back together and fired it up and found the leak. Right where I have the flow restrictor in the heater core hose is somehow leaking only when the car is hot and has some pressure in the system. The hoses are ancient anyway so it’s about time to replace them anyway.

Along with any others that find during your travels!

 

[sav22rem22]

Along with any others that find during your travels!

Sounds about right. At least if I keep up at this rate the whole car will be brand new by the time I’m done I wish haha

 

[GUNNER81]

I left work early yesterday and threw the car back together and fired it up and found the leak. Right where I have the flow restrictor in the heater core hose is somehow leaking only when the car is hot and has some pressure in the system. The hoses are ancient anyway so it’s about time to replace them anyway.

I'm glad you figured it out shouldn't be to difficult to fix take care

 

[sav22rem22]

I'm glad you figured it out shouldn't be to difficult to fix take care

Yeah thankfully it was something simple. Got new hoses on the way and should be back up and running in no time. You take care as well!

 

[Mindseye007]

Yeah thankfully it was something simple. Got new hoses on the way and should be back up and running in no time. You take care as well!

Where did you buy the hoses from?

 

[sav22rem22]

Where did you buy the hoses from?

From LMR. The hoses that were on there I’m not sure where they came from. When I bought the car it needed a heater core and the previous owner already had the hoses and heater core just hadn’t put it in.

 

[Mindseye007]

From LMR. The hoses that were on there I’m not sure where they came from. When I bought the car it needed a heater core and the previous owner already had the hoses and heater core just hadn’t put it in.

How long are all the heater hoses supposed to last? because mine are all original from 1991.

 

[sav22rem22]

How long are all the heater hoses supposed to last? because mine are all original from 1991.

Probably a lot longer than they did. I’m gonna assume any new hoses are probably not the best quality. Could also be the way I had the flow restrictor clamped that caused it to pop