4 replies to this topic

[DoriDori]

So no compression in cylinder 4 of my 1995 Volvo 850 left us tearing the head down. We suspected a burnt valve and after pressure testing #4 with the exhaust manifold removed it was clearly a valve. Compressed air was pouring out. So here's the state of the car. Waiting on some new valves, gasket set, and misc things.

1) with the head removed and stuff, what else should replace for preventive maintenance?

2) what are you tips for installing new valves and lapping them by hand? How should I clean the bowls without scratching them? (brass brush on a dremel?)

3) Would you recommend using valves from a junkyard engine?

3) what is your take on running synthetic oil in 850 natural aspiration engines?

4) Should I clean out the oil/air separator?




Car has 115k miles, 10k on rebuild.



While the Volvo is down I've been replacing random things to my liking from junkyard donor cars lol. Replaced the old wrinkle leather panel inserts with perforated ones in the next picture.




The Patient

(new radiator from 2010 rebuild along with new timing belt, tensioner, pump, thermo stat)

The operating room

The wound

So my Father bought this car in 2010 with a blown gasket to repair for my sister to drive. After repairing it, she drove it for a year. Eventually the coil is distributor went out and began to misfire. She knows nothing about cars and continued to drive it because she assumed everything was okay since the "check engine light" was not illuminated (it was burnt out thou!). So a burnt out little bulb is what led to having to so this! Haha! Here's a pic of the burnt valve and unburnt fuel accumulated on the bowls.


The correct way to store hydraulic lifters


Submerged in oil to prevent them from drying and easy to remember which valve they sat atop.


Homemade tools my Father made to ensure top head layer is torqued down by pushing cams down equally,


Thanks to members for helping with headlight reflector painting! Turned out fine but now the pitted glass lens are the weak link.



Thanks for any help, guys!

[DoriDori]

ALSO!!! When car was being rebuilt in 2010, my Father received a gasket kit for a turbo 850. He reordered a correct gasket kit but used the valve stem seals from the turbo kit. Could this explain why it still burnt some oil? The other cylinders compression tested perfect. So I was thinking we should replace stem seals with correct 850 NA seals while the valves are being lapped.

[Jardim]

I know the exh. valves on turbo models are sodium filled to handle extra heat. I dont know if that would make a difference on a N/A or not.

[erikv11]

1) Do all 4 cam seals if they weren't done last time, good time to fix the + lead to the starter if it needs it, sounds ike you've already got timing and igntion parts covered. Only use Victor Reinz valve stem seals or you may be going back in there sooner than you like.

2) On the valves I don't do machine work, no comment I would take it to the shop.

3) Used valves from a junkyard engine should work just fine.

3) Running synthetic oil in 850 natural aspiration engine is fine, but quality dino is fine too. What was it running before?

4) Definitely clean out the PCV

[DoriDori]

Great help, Eric. Thank you. It was running quality regular oil. 5w20 I think. Checking into Victor Reinz.