Engine blowing up, sort of.

Post by **FLXC90** » 16 Jan 2016, 11:23

The next step in this repair should be: do a seafoam treatment to the intake, and then add some seal plasticizer to your oil. This will clean deposits from your exhaust valves, and reduce oil leakage through your valve seals. I did this on my 200k + S70 and improved my compression numbers across the board.

TripleEight · Post by **TripleEight** » 16 Jan 2016, 12:57

The car starts up in a jiffy!

Has a weird blip between stop and the first gear change, but everything else seems the same, maybe better with the cleared out pcv and EGR.

@erikv11
It's the DIY mod where you make the pcv return hose alot larger with a heater hose. This is a must do mod.

https://www.matthewsvolvosite.com/forums ... =1&t=53448

I initially replaced all the PCV components with a brand new one and cleaned out the holes but it didn't help, gas out of the dipstick and fill hole like a train. Only after I changed out the new OEM return hose with a larger diameter heater hose, the gases were properly plumbed.

Yes the lawnmowering explains the no start! but the sudden pressure build up in the crankcase or the loss of compression and explosion, I got no clue, but it's fixed lol

I'll look for the plasticizer, already got seafoam, I still need to check the compression.

I also have plans to do the thermostat as the car runs cold.

Thanks for the input guys,

Post by **erikv11** » 16 Jan 2016, 17:58

Thanks for the tip. It has been discussed at length that the larger diameter heater hose is irrelevant, there are other orifices in the path that are smaller. Except that perhaps it will clog more slowly. But the generic hose is a lot cheaper. Glad you got it running!

TripleEight · Post by **TripleEight** » 16 Jan 2016, 21:01

^Thats what I first thought, but the more I thought about it, the tiny plastic tube couldnt have been sufficient with the amount of blow by gas that was blowing out from the bottom of the block(dipstick) and the top of the cam cover(fill hole).
I guess it takes less effort for the intake vacuum to suck the blow by gas with a bigger 5/8 tube than a tiny 3/8' tube. Like drinking water with a slurpee straw vs a coffee stirrer.