So my 1992 240 B230f is acting funky. Cylinder 1 is not firing but its getting fuel and spark. My wife reported that it wasn't right so I did a basic tune up and replaced the cap and rotor, so on and so forth without even starting it up. The car is definitely not firing on cylinder 1 only (put back the old equipment to make sure it wasn't a bad cap or something, problem persists)

So its really looking like a valve spring has failed (or some other reason I am not getting compression on cylinder 1 only), but how do I tell. I have never done just a spring before, but I have rebuilt a couple heads in my lifetime, but always by removing it ad working on the bench. What should I do? a compression test is my next thing but that won't really tell if its a broken valve spring, or a blown head gasket or a burnt valve right?

 

If a cylinder is not "firing", it cannot possibly be getting fuel and spark! Fuel and spark make fire, no? A broken spring, or any mechanically based reason will not affect a cylinder not firing.
What are doing, chasing a misfire? What are your symptoms besides "acting funky"?
Not many failed springs in the b230...
Take that compression test, always a good start! But if you car was running well, and suddenly not, probably something less serious happened.

 

Perhaps my wording is incorrect

The car will start but its not firing on cylinder 1 and therefore shaking a lot, loss of power etc...

cylinders 2-4 fire fine, they are humming along as always

So I started with a simple test, pull one spark plug wire at a time and attempt to start the engine. Of course I placed the wire back on the corresponding plug after each test
pulled 1 - no change
pulled 2 - will not start
pulled 3 - will not start
pulled 4 - will not start

Check the plugs and #1 wet/smelled like fuel (2-4 are dry and warm)
checked to make sure that #1 is sparking and it is (swapped cabled just in case and there was no change)

so since #1 has spark, and is covered in fuel it seems like we have an issue with compression (still have not had a chance to test compression)


when this happened I went to start the car like normal and I hear a metallic pop. engine started running fine but I shut it off and checked it out, although there was nothing to see.

every time I have started the car since, it will attempt to start, and fail the first time, but it will start on the second attempt. at which point it is only firing on cylinders 2-4

 

As lev said, next step should be a compression test.

 

I agree. Also, it's possible to get a "bad" spark plug that won't fire. Wouldn't hurt to switch plugs 1 and 2. That's free.

 

did that, and nothing changed, plugged the spark plug into the boot and held it up to the block and it was working as one would expect.


sure enough something like 3-4 psi on cylinder 1 and all others are 155 psi +or-2

time to open up and do some surgery.

perhaps at 200k miles its time for new valves and seals anyway. Do the valves go bad on these commonly? Ive never had an issue with a Volvo but on Saturn cars the exhaust valves would burn up constantly.

 

kinda sounds like bad rings any oil getting in there and to the exhaust?

 

Take the head off, sse what's going on. Probably a burned valve...

 

no burning oil (no smoke and oil level really does not change within a 5k mile oil interval)

it was a sudden although not very dramatic thing, and I have had burned valves before and its never been quite like this. I will pull it apart this weekend and post what I find!

 

just asked a buddy of mine who works on lot volvo he says if take geads off to look at heads for a crack he seen more then one like that and sounds like it....
wish you luck on that and hope for just stuck valve

 

What were the results of the compression test

 

3-4 psi on cylinder 1 and all others are 155 psi +or-2

I didn't even consider a crack! This engine has never been taken apart, even so much as valve adjustment. I have every single record from the original landing page from when it got shipped to the US back in 92' so god knows what I will find in there!

 

Case closed , pull the head or sell the car.

 

worth while to fix it. Ive done this kind of thing on much more challenging cars, so I have all the tools and whatnot

besides, its been treated too well in its life to give it up

Thanks for the input gentlemen!


As always, the process goes:

1. develop a problem
2. realize its going to be a lot of work
3. check the forum in order to get someone to validate your desire to find an easy way out.
4. confirm undoubtably that it is a big problem
5. do the work that you were going to do anyway and deal with it lol

 

Usually a burned valve develops slowly--the engine starts to miss a little then more as the burned spot grows with time... A crack is possible, but what caused it? Definitely not something that "just happens" in these motors unless overheated but anything is possible. Keep us informed!

 

Fixed, leaking head gasket
simple enough

the "Bang" I heard was the starter disengaging while applying force to the flywheel. The thing still works but looks like a new starter/solenoid

its been fun!
glad its over