Bad head gasket?

[LEAKYSEALS951]

Scratching my head a bit here.

Symptoms-
Dropping coolant.
No drips (well, there was a loose hose, but I tightened that- and still losing coolant)
No intermixing- oil clean- coolant clean.
No smell of antifreeze in engine bay, heater when on, or exhaust.

(side note)- It appears the sweet smell of antifreeze has been removed as of late in at least two concentrates I bought, so perhaps the sweet smell of antifreeze isn't the best test anymore.

Dropping coolant from "high" to "low" in one drive (triggering "coolant low" warning, but I refill it before any overheating occurs. No overheating has occurred. This is the volvo, not a 944.
Pressurized system causes coolant DROP in coolant expansion tank, not coolant rise.
No bubbling in coolant tank when running.
I cleaned the underside of the engine as clean as a baby's bottom today.
No coolant drops/leaks noted on subsequent driving.
Water pump area seems dry.
High pressure in coolant lines, even after a day of not running. Now I'm thinking the high pressure originally knocked the hose loose, making me think I had an easy fix.

Oh yeah, an intermittent miss on occasion when starting.
My thoughts- gasket bad, flooding one cylinder, until coolant burns off.

Before I pull the head- Thoughts?

[Scott Douglas]

Could the overflow tank have a hole/crack in it?

[LEAKYSEALS951]

Originally Posted by Scott Douglas

Could the overflow tank have a hole/crack in it?

Thanks for playing
I'll take anything to keep it easy.
I'd like to think so. I pulled it up today and cleaned it 360 degree around. The overflow tank to engine hose is old, and slightly bulged, but no leaking. It doesn't seem to have enough mass to account for the level the coolant tank drops. It needs replacement, but I don't see leaks. The tank seal also seems good, as it is holding pressure after the fact.

I'm going to go play tomorrow, and ensure the tank stays clean and dry.

Half of me wants to pull the head cover and torque the living ****e out of the head studs to see if any are loose. I did replace the head 60k ago.

[Scott Douglas]

I'd expect to see plums of vapor out the exhaust on those cold start ups with the miss.

Have you tried starting it cold with the rad cap off and watch for bubbles as it warms up?

[masraum]

Sounds like a head gasket to me, but I think I've had a car in the past that was losing coolant that was a tiny leak that was very hard to find. It's possible that it's something simpler, but it sounds like you've thoroughly ruled any of that out.

[Arizona_928]

Evaporation/vaporization.

Sealed system... so it has to go somewhere. Get some coolant dye before tearing off the head

[porsche tech]

No external leakage…pull the plugs, do a leak down check and look for bubbles or movement in the expansion tank while doing it. White smoke out of the tail pipe is also a telltale.

[Bob Kontak]

Originally Posted by Arizona_928

Evaporation/vaporization.

Sealed system... so it has to go somewhere. Get some coolant dye before tearing off the head

Harbor Freight has a cheap kit to see if there are combustion fumes in your coolant. You have to buy a separate bottle of dye which is $10.

https://www.harborfreight.com/search?q=head%20gasket%20test

It works

[LEAKYSEALS951]

Dang! You guys are great. This gives me some extra test to confirm the gasket before I start ripping the head off.

The car did have some condensation coming out at startup yesterday(had my wife start it while I was at the back), but it was also very cold, humid, and raining out. I stuck my nose in it and it smelled like exhaust, but no antifreeze. It was hard to conclude anything. I will try it again today (its dry out today) after my obligatory HF trip.

On other news, there is a used 2020 volvo V90 for sale locally and the salesman wants the "end of the month" sale. There's a part of me that wants to let my current car die, but the new one is just one big silly computer screen of gimicks to break with a poor little super/turbocharged 2 liter engine.

Will "it" make it to 300k? I don't know. My current car is one head gasket from making it!

Thanks again. R

[hcoles]

Originally Posted by porsche tech

No external leakage…pull the plugs, do a leak down check and look for bubbles or movement in the expansion tank while doing it. White smoke out of the tail pipe is also a telltale.

Excellent idea. That big of a leak might also show with a compression test.

[LEAKYSEALS951]

Thanks everyone.
I went to HF this AM and Bob's Turkey Baster confirms combustion gasses in the coolant .

That's a slick little test.

I also tried to pick up some UV dye but LAPS didn't have it, and I don't have a leakdown kit (both excellent ideas).

Thanks again.

I'm going to go mow the lawn and not think about this for a bit.

[LEAKYSEALS951]

Oh, btw, no one told me about all the LAPS head gasket repair elixirs out there:

Why replace the head gasket when I could just pour that in....



I think I'll pass though. Skinned knuckles and cursing awaits!

[Scott Douglas]

Good luck with the lawn!
Pics or it didn't happen....

[RANDY P]

Originally Posted by Bob Kontak

Harbor Freight has a cheap kit to see if there are combustion fumes in your coolant. You have to buy a separate bottle of dye which is $10.

https://www.harborfreight.com/search?q=head%20gasket%20test

It works

This, and your coolant hoses having morning wood are a dead giveaway.

rjp

[LEAKYSEALS951]

Originally Posted by Scott Douglas

Good luck with the lawn!
Pics or it didn't happen....

I'll make sure so get some. (hopefully not of a cracked block)

"This, and your coolant hoses having morning wood are a dead giveaway"
Yeah, looking back on it, there were some dead giveaways.

[LEAKYSEALS951]

This setback might be the perfect time for a vista cruiser conversion on the volvo wagon.

Just found this on FB marketplace:

https://www.facebook.com/marketplace/item/795984935772915/?ref=browse_tab&referral_code=marketplace_top_picks&referral_story_type=top_picks

[porsche tech]

I don’t have a leak down kit either but I made this out of an old brake hose, a spark plug and an air fitting. I used to use it to pressurize the cylinders to do valve guide seals, etc. I’m a cheapskate.

[LEAKYSEALS951]

^Thanks. I was thinking of making something like that, but Bob's thingee (the test kit) turned green so quick I didn't bother. It might be good to isolate the cylinder to know where to look extra hard for a potential block issue, although this engine has a good reputation for a stout lower end.

I might make one just for fun with spare parts from my HF compression tester kit.

I might try to go low budget on this one for my dad's sake. He once bought a 924 with a scored piston, pulled the head and oil pan, dropped the pistons, reamed the cylinders in car, and put in some new pistons even using the old head gasket and bolts.
The car never lost a drop of oil and we got 100k out of it

(I might not go that cheap- but I will use him for inspiration)

[LEAKYSEALS951]

Just a friendly update on my life:
(say in a jean luc picard voice----)

WE HAVE ENGAGED THE HEADGASKET

I stripped it down today. Got the head off and located the offending cylinder/head gasket breech. No block damage. Honing marks from engine construction still present in cylinders at 275k miles.

The head gasket has some corrosion/leakage at the one cylinder that the leaking coolant steam cleaned up as shiny as a baby's bottom. The other cylinders are age appropriately dirty.

Funny thing about car work at age 53- I am sore as hell. Like somebody slammed me with a baseball bat sore.

Pics to follow tomorrow when advil kicks in.

I am getting too old for this sh#$! (I wouldn't have it any other way).

[1990C4S]

Make sure the head is dead flat...a small cut to flatten it never hurts.