Volvo Adventures, New Zealand - How to clean or replace a flametrap


lets see... Volvo Engines 101, the quick version:

the rest of the terms I used, lets see. an engine is an air pump. it sucks air in through the 'intake manifold' which is that silver cluster of cast pipes on the driver side of the engine. the air comes from the front of the car, goes through an 'air box' that has the air filter inside, then a duct to the 'throttle body' which is an air flap that the gas pedal controls, through the intake manifold, fuel is injected into it, and its all sucked into the engine. the burn exhaust gasses come out an exhaust manifold on the passenger side of the engine, and go down to the catalytic converter and the mufflers and the tail pipe.

the engine itself consists of the engine block that has the pistons and crankshaft inside, there's an oil pan on the bottom, and the head on top with the valves and cam which both of the manifolds are connected to, then a valve cover on top of the head (thats the long black thing that probably says VOLVO, with the oil filler cap on it).

There is a electric fuel pump inside the gas tank, and there's a electric main or pressure fuel pump underneath the car with the fuel filter next to it. These pump gasoline through the fuel rail along the top of the engine, through the fuel pressure regulator, and back to the gas tank. the 4 electric fuel injectors that stick into the intake manifold are connected to this fuel rail. The fuel injectors are controlled by a computer called the ECU, this computer is behind the dashboard.

The Distributor sticks out of the side of the engine block and sends the high voltage to each spark plug wire in order. This high voltage comes from the 'ignition coil' (coil, for short, its a sort of transformer that turns a 12V pulse into a very high voltage pulse that makes the spark), which in turn is controlled by the ignition ECU (computer).

There's a bunch of auxiliary stuff, including an oil pump inside the engine, and a water pump mounted on the front/left side of the engine. There's a series of important sensors that tell the fuel injection and ignition important things, like how much air is being sucked in (the MAS also called AMM), how hot the engine is, etc. There's a very important 'cam belt' that is behind the black cover on the front end of the engine, and connects the crankshaft to the cam shaft (this belt must be replaced every 50 or 60 thousand miles). there's a set of belts on the outside of the engine that turn the alternator which charges the battery, and the air conditioner compressor and the power steering pump.

There are a couple very important radiator hoses that go from the water pump to the radiator and back to the engine. There's some smaller heater hoses in the back of the engine, if they fail, you lose your coolant and overheat and the engine dies. There's a pile of thin vacuum hoses, some more important than others, but all need to be in good condition for the engine to run efficiently.

I probably forgot a few more minor subsystems. oh yeah, the wiring harness that interconnects all this stuff. some mid 80s Volvos have crappy wiring, where the insulation has started to crack and flake off and fail. My 87 has remained immune to this, but if it happens, it can be really expensive or hard to deal with.

(I bet this should be fleshed out into a FAQ, hah!)




sadly, half of new drivers crash and total their first car. happily, you'll probably walk away from a Volvo if you're wearing your seat belts.

Oh... hah. I bought this for my 20 yr old son who is in college, studying Geology.
https://lh5.googleusercontent.com/-d...2/IMG_8066.JPG


and my wife's old 240 sedan is the car my daughter is learning to drive in... my boy drove it too.
http://hogranch.com/files/Bitmaps/240.jpg

we're the original owners, it has about 400,000 miles, its been driven hard, put away wet, but serviced regularly. at this point in its life, its had a new radiator, 2 water pumps,. a new alternator, the AC hasn't worked for 20 years, the automatic transmission was rebuilt once, its gotten new rear suspension bushings and heavy duty springs (we were towing a sailboat with it for awhile), and the camshaft seal finally failed a little while ago and was replaced. I'm probably forgetting some stuff, but its never needed any major engine work. right now, it could use new shocks on all 4, and some front end bushings and/or suspension bearings, its getting a little clanky on parking lot backup turns.

That wagon looks clean, neat and straight. Check it out by following these guys recommendations (wish sites like this were around when I bought my first car), and hopefully all goes smooth. Pierce and Burn should right a book!

Oh yeah, I just assumed those were 14" rims, so those ratings on the door are not accurate. Just check the tire for the max pressure, shouldn't be above that of course. Ask the guy what he inflates them to and mention the recommended pressures on the door panel. This would be another test to see if her or she is car crazy, and if they really know this Volvo.
As for that flame trap, check this good picture out: http://cleanflametrap.com/tony/B230F_features_v1.pdf

As for the differential/rear axle, you may have a little difficulty checking that on the spot not knowing where it is and what size the bolt is. It is the big metal hunk connected to rear wheels in the middle, where the drive shaft goes into. There should be two bolts facing the rear of the car on earlier years (maybe just one but I'm not sure because they changed after '85.) If there are two bolts, you want to remove the top plug. Stick your pinky in, and it should be right below the hole. Also check the fluid for shiny metallic bits, that's bad. If that is all too complicated, at least check the differential for leaks. Is the differential oily?
In addition to that, wiggle the drive shaft. It should be snug, but if you can treat it like a jack in the box, that's bad. I don't know much about rear ends except that they are a pain.

Yeah, I think you really should, it would help clueless new guys know what to look for. I know a little about the basics, but not nearly enough to know what specific subsystems to czech. I appreciate all the info there. I did know some, but not much. What can I say, I'm a gunny, not a car nut... yet. :D


^One of the big reasons I'm trying to get a Volvo. I've heard that statistic, and I've seen some of the "first crashes" of people I know. Luckily, I've not even had a fender bender yet, but.. I'm sure it'll happen. And when it does, I'll be happy to know I'm driving a tank.



A pain in your rear end, eh? :D Okay, bad joke... but surprisingly, I did know what the rear diff is, but nothing else about how to czech the oil on it. I assume if there's metal shavings in it, that means the gears are somehow grinding wrong, but what would be the cause of this, and what's the worst that could happen from a problem like that?


Thanks again guys. I love learning about just about anything, and anything mechanical interests me(guns, cars, etc).

fwiw, my son has been driving for about 4 years now, no accidents, although he finally got his first ticket coming home from a memorial day weekend outing, I'd loaned him my 850 turbowagon, which gets better gas mileage then his 940 turbowagon but has about twice the 'go-faster'... so he was cruising a back road north of Merced and got popped for 55 in a 35 zone. ooops.

I would imagine you would just find a low mileage loaner and swap out the diff. I think trying to rebuild one would not be cost effective and time consuming, so says my mechanic. A two or three hour job at $75-95 an hour, plus a $100 or more at the junk yard.

the differential in a RWD volvo is a Dana unit, very heavy duty. in fact, tis the same size Dana as is used as the front axle in classic Jeeps. As long as they haven't been run dry, afaik, they last pretty much forever. its really low on the list of things I worry about.

Yeah, tell that to the guy who last owned mine...
One of the only reasons why I mention these things really.

lets see.... we've owned 6 RWD volvos and probably put 600000 or 700000 miles on them between us, with no differential problems. the 240 we bought new in 87 now has 400K miles alone.

in 40+ years of driving assorted vehicles, the only differential problem I can recall was our 2001 E150 van, it sprung a leak, but we caught it and had it serviced before it was too late. the transmission shop said the cover plate on those was too thin. this same van has blown two transmissions (under warranty).

Rub it in...

Well, the ad disappeared... :(:( Thanks for the help guys, I'll keep looking..

Oh man... well, at least you know what to look for now.