Head gasket job, worth it?

professorsunshine · Post by **professorsunshine** » 12 Nov 2022, 09:52

I own a 1996 850 Platinum. To make a long story short, I blew a coolant line on the highway, and I must have overheated the engine before I had a chance to pull over, because the head gasket is right fucked, unburned gasoline coming out of the coolant overflow tank. It has me worried that it might be a cracked block, or that I might have spun a bearing.
My main question is, is there any way to check for a cracked block or spun bearings without tearing down the engine? If the engine is in one piece, I think I'd like to try my hand at replacing the head gasket, but I don't want to waste my time tearing it apart just to find out that the block is toast, not to mention that I live in an apartment complex and I'm not technically supposed to be working on my car here, let alone doing a head gasket job.
I understand that some auto parts stores can have loaner tools, will a borescope be useful in checking for a bad block? I have 3 videos of the car running, the first is right after I found out that the gasket was bad, numbers 2 and 3 are a day later when the engine was dryer, because I thought that the squeaking sound was the belt slipping. If any one can diagnose from the videos, please be my guest.
Video 1:
Video 2:
Video 3:

Post by **Sveedy** » 12 Nov 2022, 10:17

Bad news is that I think that engine is toast. Sounds like its deeper than the head.
Good news is that the car is worth something, regardless. I don't know the condition of the rest of it, nor how attached you are to it, but I think it's worth fixing.
Maybe find someplace where you could store and work on it, if your mechanically inclined. Otherwise $$$$

Post by **abscate** » 12 Nov 2022, 10:51

You will not crack the block on an overheat. The head will let go and destress the engine before that happens.

I would dive in and expect 99% success

professorsunshine · Post by **professorsunshine** » 12 Nov 2022, 11:06

abscate wrote: ↑12 Nov 2022, 10:51 You will not crack the block on an overheat. The head will let go and destress the engine before that happens.

What about the possibility of a spun bearing? any way to tell without tearing down the block? I plan on draining the oil to check for sparkly bits when I get a chance to.
Take a listen to video 3. Any idea what the squealing noise is? it kind of sounds like it's coming from the AC compressor, but I don't know why it would be locked up or whatever. Maybe I'll try running it without the serpentine belt.

Post by **scot850** » 12 Nov 2022, 13:07

Only way to really check on a spun bearing is to drop the oil pan and remove the caps to check.

Neil.

Post by **abscate** » 12 Nov 2022, 13:47

The bottom end of these engines is really tough. An overheat stresses the top where the head and block alloys are different

I would plan on a head job only

Post by **BlackBart** » 12 Nov 2022, 15:33

But what is all the knocking and clashing going on if it's just the head?

Actually, now that I write that and watch the last one again, those could be an external assembly disintegrating, not rod bearings. Either way, it doesn't sound good.

Post by **MoVolvos** » 12 Nov 2022, 18:47

.
The second video sounds like a bearing is out on the alternator or AC compressor (EDIT: Include Waterpump)? What is the source of the smoke (EDIT: Hydrocarbon or as you say raw fuel so headgasket)?

The knocking sounds like the O-Ring in the pan problem so the rod is knocking.

The 3rd video has the ticking which is air being drawn due to the dried out oil pan gasket not sealing the oil circulation. It's creating that intermittent knocking noise also when oil is scarce. Surprise you don't have a P1672 Code.

"Your car uses a system called Continuously Variable Valve Timing which uses oil pressure to change cam timing based on engine load. Because it runs on oil pressure, clean and full oil is critical to the operation of the system. Does the engine tick excessively when running? If so, the seals in the oil pan can be bad, causing air to enter the oil system."

https://www.justanswer.com/volvo/4txcc- ... s-its.html

Spray (stream) water from a spray bottle at every pulley and bearing (EDIT: Including waterpump) to see if the noise subsides. If so you know which one it is. Don't run the car too long. Do an oil change with a 20W50 oil and if the knocking and ticking subsides you just need to remove the pan and replace all the O-Rings.

I am currently nursing the ticking on our 2000 S70 by adding STP & ATP AP205. The ticking has reduced but am hoping the old gasket will swell / rejuvenate enough so I don't have to take the pan off. Already have the O-Ring Kit from FCP just in case.

https://www.walmart.com/ip/STP-High-Mil ... z/19897926

(www.amazon.com/ATP-AT-205-Re-Seal-Stops ... B000NVW1LM)

.

Post by **Sveedy** » 13 Nov 2022, 06:53

Take a long steel rod / bar or big screwdriver, and use it as a stethoscope to try and isolate where the sound is coming from.

454cid · Post by **454cid** » 13 Nov 2022, 11:17

MoVolvos wrote: ↑12 Nov 2022, 18:47 "Your car uses a system called Continuously Variable Valve Timing

On a 96? My engine doesn't.... no phaser on either cam, just standard pulleys.

The sound reminds me of what the Buick 430 sounds like in my 60 Electra, after I took it for a test drive and discovered glitter in the oil.

I can't speak to the pan gasket/o-ring problem, but it sounds like more than a headgasket to me. Poking around with a stethoscope might not be a bad idea. Harbor Freight is where mine came from.