head gasket or cracked block ? 2002 v70xc

crazycat · Post by **crazycat** » 03 Jun 2022, 19:09

I have a misfire on startup cylinder #5. Extremely SLOW coolant loss. Exhaust gasses in the coolant verified by test. Clean oil and clean coolant. High gas pressure in coolant tank. How can I determine if it's the head gasket or cracked block? I'd hate to attempt a head gasket replacement and then still have trouble. I can do a compression test next week but I would think a bad gasket or cracked block will both show low compression. Any other way to determine what's going on? Ty

Post by **RickHaleParker** » 04 Jun 2022, 00:57

The odds of a cracked block on a B5244T3 are pretty slim.

You description points toward a head gasket maybe some head warpage but not a cracked block or cracked head.

Mixing of oil and antifreeze in the crank case or cooling system would be a give away for a cracked block.

How does the engine run as it is now?

Post by **abscate** » 04 Jun 2022, 03:17

You can also carefully inspect #5 for cracks but RHP is on point here, cracked blocks are very rare in street driven Volvos

One of the R motors had an issue where the sleeves were thin but it also only cracked when teens “ I only boosted to 28 psi for a few minutes”

crazycat · Post by **crazycat** » 04 Jun 2022, 10:04

RHP, after an initial 1-2 minute warm up, the rough idle misfire goes away and it runs quite well. I am chasing a ecm6805 currently, but that is only causing a drop off in power at about 3000rpm when I really get on the throttle. Thanks for all the insight about the possibility of a cracked block vs headgasket. I've been driving it for short trips <4 miles for more than a year with the slow coolant loss and gas pressure in coolant tank. I did have some kind of backfire? that blew the intercooler hose off the intercooler a few months ago, maybe that is related to the CBV not working properly and causing the overboost? I was thinking my wastegate was stuck or actuator was frozen as I can't budge the actuator arm at all by hand. Thanks again

Edit: Finally got turbo heat shield off and Wastegate was frozen shut. Actuator arm movable! Soaking the WG shaft with PB blaster now. Hopefully I’ll have proper boost back.