I have a '90 240 DL with the B230 engine and it cut off while doing about 75 on the freeway. After having it towed back and pulling the timing cover I saw several teeth stripped off of the belt. Belt let go. Still intact but missing several teeth. Manual says the B230 engine WILL experience damage because of closer tolerances between pistons and valves. Didn't hear any REAL loud noise when it cut it off but it did make a noise. I got the new belt..it's possible that the tensioner froze which caused the belt to lose some teeth. The question I have is how can I tell if serious damage has occured to the engine. Is this thing toast guaranteed? Or is there a chance that it may be ok if I change the belt and tensioner. Don't want to go through a bunch of work changing them then find out the motor is shot. Any help is greatly appreciated.

 

After a more extensive search on the subject I'm seeing conflicting opinions. Most say the B230 should be ok...but one said unless you were doing a hundred miles per hour. Well I was doing roughly 75 to 80. Anyone know the real truth?

 

The engine is non-interference, it will be OK. Be sure to replace the tensioner at the same time.

 

^^^Bubba speaks the truth...the B230 is a non-interference motor unless you have a high lift aftermarket cam. I broke a T belt at 120 running an IPD turbo cam and it didn't faze the motor...just saying.

 

Ok threw the new belt on and finally got it to fire up but I'm a tooth or two off. Also wouldn't you guess...can't get the number one plug out. I know I didn't cross thread it on last tune up but I'm not gonna force it. I need another way to find TDC on #1 cylinder if anyone can help me with that. Once it's running and gets warm I'll go at that plug again. My haynes (crap) manual shows another model with slightly different pics. There is a mark on the distributor sprocket which I have determined to be the proper mark as the rotor lines up with #1 plug wire. It's like a punch mark on the outer rim. Same kind of mark on the cam sprocket. These I'm assuming are the correct mark. There are also painted marks on both in different positions. That don't look factory. I'm going with the punch marks. The crank gear has a notch like a key way...but also a protruding nub which I'm thinking is the correct mark (the nub). This seems like it lines up with a casting ridge on the block. When it fired up it seemed like something was maybe one or two teeth off. If there is a specific way to line everything up that someone knows it will save me some time. I'll figure it out eventually but trying to juggle this along a full days work at the same time. At least the motor isn't fried.

 

attached

 

Thanks bubba. Got the number 1 plug out so got it at TDC. As far as I can tell from your diagram I have everything right. Still not starting...

 

Starting to look like this is not a non interference motor. Pulled the oil cap and there is one of the valve shims just laying there and a fairly large piece of broken aluminum just laying on top of the head. Not good. Mechanic is going to pull the valve cover in the morning then I'll know more. Looking like a new head minimum. :-(

 

Well, that's never good. Still, the motor isn't an interference motor. Now, it does seem like I remember reading the last year or two of the 940 motors may be interference but I wouldn't think so. Pretty much every n/a B230 got the M cam which is really tame. I've read that in Volvo manuals as well; the only thing I can think of is they were being cautious. So, rather than your timing belt breaking and causing valve train havoc, I'm thinking the valve train crapped out, froze the cam resulting in the belt stripping out. Suspects? A keeper flew off and/or the cam froze in one of the journals and/or the valve guides are worn and allowed a valve to bend. Regardless of the cause, I'd have to agree the cylinder head is most likely fubar'ed. Fortunately they are not scarce...yet. Let's hope you didn't drop a valve!

 

Thanks SJ...yeah not sure. Mechanic says doubtful there is any piston damage but guess we'll know for sure once the head is off. Luckily the mechanic is next door to my business so I'm getting the usual neighbor break where he lets me do alot of the wrenching and I get off pretty easy for parts and some labor. They're saying roughly $350 for a rebuilt head..plus whatever labor. Telling me they usually pull the heads with both manifolds still bolted on. Does this sound like normal procedure to you? If there's all kind of motor damage they just gonna have to shoot me and push me off a cliff in it after having to do a trani a month ago..and the other 2 grand I've put into it in the last year or so. Ah..the pleasures of having a car $500 dollar car with a quarter million miles on it.... :-I

 

A little update for anyone interested. One of the valve seals/keepers let go which caused all this. Number one piston smacked the valve (nice half moon imprint on the top of the piston) which caused the cam to seize momentarily...stripping several teeth off the belt. The head has some wear around some of the water ports meaning it needs some welding/resurfacing and a valve job. Might be cheaper to just do a remanufactured head. Looking into prices now. I'm in southern california so anyone know of any places that offer rebuilt heads for 240s at a reasonable price? Thanks in advance. Jim