volvo 850 -94 is knocking

HyperOskar · Post by **HyperOskar** » 19 Jul 2005, 19:56

Hello

My 850 is knocking when i accelerate , i have been told that it could be the hydralic arms to the valves that have to be changed.

Today i changed my oil from 10w-40 semisyntethic to a pure oil, the knocking didn

Post by **kelvin6** » 19 Jul 2005, 21:41

What octane gas are you using? Too low can cause knocking. Try using an higher octane...

Well actually a lot of things can cause knock, but try raising the octane level and see what happens first.

Hutchie · Post by **Hutchie** » 20 Jul 2005, 01:44

Hi guys
The 850, like several other models run a fairly advanced timing and require the 'knock'senser to pickup pre-ignition and retard the timing to suit the conditions. If the senser fails the timing continues to run at full advance and you hear the knock. It is not good to run like this as the pre-ignition causes high load on the piston which it transferrs to the big end bearing.

HyperOskar · Post by **HyperOskar** » 20 Jul 2005, 10:06

okey , thanks for the answers ! . I

Guest · Post by **Guest** » 20 Jul 2005, 14:20

Immediately clean your Flame Trap. Google for where it is. Mine was doing that as the engine oil pressure was way too high due to a clogged FT. Also, when was the last time you changed your oil?

HyperOskar · Post by **HyperOskar** » 20 Jul 2005, 14:53

okej , thank for the advice , will do that

.
I have changed oil yesterday to a straight oil , no syntethic oil at all .
And before that it was just maybe 800 miles ago.

HyperOskar · Post by **HyperOskar** » 20 Jul 2005, 16:08

Tryed to search on "flame trap" to volvo 850 .. a picture came up , but i

yeagermeister · Post by **yeagermeister** » 20 Jul 2005, 19:57

here is the Flame Trap repair from www.volvospeed.com - it's under the throttle linkage cover, attached to the throttle body.

it's pretty cheap to replace the whole thing, so that's what i did, but it is something you could clean as well.

HyperOskar · Post by **HyperOskar** » 23 Jul 2005, 14:23

hello again.

I have just completed a cleaing of the flame trap and the other stuff around it. I did