I have a 1991 Volvo 740 with a 2.3 4cyl. I recently done a head gasket change and was advised to just get a new belt as well due to high mileage and no tune up history on car.

I have a new belt but it slides to the front face of the gear and tensioner puppy after a few cranks. The tensioner spring has plenty of spring in it and goes well past the bar it surrounds. I do not have the upper belt cover on but some people have suggested that the cover presses up against it hard enough to prevent that. I don't believe that but I thought I'd ask others with this engine about it. By the way the belt is tight and the tensioner is pressed out as far as it can be.

 

only thing I can think of that would do this would be if the tensioner is bent so its not parallel to the other axis.

always replace the tensioner with a new real volvo one when you replace the belt.

 

But right were the spring and rod with the pin hole meet the inlet hole should there had been a washer after the spring? I doubt it would help since the puppy seemed maxed out but it looks like things had been messed with all over the place on this vehicle by its previous owner. Also is the stud going thru the pulley on the tensioner supposed ti sit off centered or smack dab in the center of the pulley?

 

Could it be that you have the wrong timing belt for the sprocket? Apparently there was round tooth belts used in later models to improve the longevity of the timing belt. Search this forum for "round tooth" and you will come up with a few threads describing the belts and the type of behavior.

Actually one of the threads actually states that the inside of the timing belt cover was all chewed up from the belt walking off so the cover isn't what keeps it on.

 

I agree here and I replace the tensioner assembly at every belt change (50K miles). Something is either bent or off center or the lower sprocket bearing may be going.

 

The cover definitely has nothing to do with keeping the belt in place! I'd replace that tensioner--something is off, and the tensioner is the most logical culprit...

 

Maybe it's just the angle of the picture above but the top camshaft gear doesn't seem to line up with the idler or tensioner.
I'd take a good look at that and measure to ensure they're all squared up.

 

I'm not familiar with belt variations other than the v tooth looking set up and the flat than tooth than flat than tooth set up. The new belt looks identical to my old one and was the only one the computer at OReilly's brought up. Its a little shorter since the old belt stretched a small bit so it has even less slack.

 

that would be really challenging as the camshaft and crankshaft pretty much HAVE to be parallel unless the head isn't attached to the engine block properly. if the pulleys were bent on the shafts, then they'd wobble as they went around a circle.

which is why I suspect the tensioner pulley could be bent

 

I'm replacing the harmonic due to prominent wear but that spins without wobble, the can gear does too, the intermediate gear looked good too. I'm thinking the tensioner is lopsided even though I've eye balled it extensively. I've ordered a new tensioner but could not find a spring until the other day. Hopefully the old spring will work with the new tensioner. I've never heard any of the various warnings about replacing the tensioner speak on the spring.

 

per VADIS, tensioner pulley 463633, washer 463580, nut 971071, spring 463389, and spring guide 463386 comprise the whole thing.



http://www.volvopartswebstore.com/sh...=0&modelYear=0

 

When you replaced the harmonic balancer onto the crankshaft, did you remember to put back into place the large washer-type belt guide that goes between the balancer and the crankshaft gear? This guide keeps the belt in line from below and if forgotten/misplaced during reassembly the belt can do exactly this. Don't ask how I know.

 

The spring should be OK to reuse... The original may be better than a "new" one!

 

I know about that plate and its precisely why everything is good down stairs but I wish maybe that I could construct one for the can gear, intermediate gear and pulley as a worst case scenario fix.

Just to clear it up though guys there is no washer behind the can gear? I got the one up front and an extra one I can't find the purpose for but I know any washer behind it would need a key way cut in it too which my extra washer does not

 

The tensioner still hasn't come and I've noticed several wires exposed in a row in between two teeth on the belt so I'm replacing this belt I don't even have a mile on. I'm wondering if I should put the old belt back on for testing purposes? Also I see no scrape outline on the belt cover so I know the old belt wasn't slipping offer .

 

the parts diagram above sure doesn't show any such washer

 

The new tensioner did fix the issue. Its slightly smaller and had the same spring hang up leading me to have to hammer the ledge with the hole in it but its not slipped off at all.

Unfortunately now after getting that situated the car now revs up by itself in all gears and I'm looking into that right now and also trying to locate the idle control screw.

 

There is no idle screw, idle is controlled by the ECU. First check for air leaks around the intake manifold.

 

Well I know its got some screw on. It with its threads going vertically that keep the choke open but I've checked anyways and it was open.to the Max so scratch that

 

Check out post #2 on this thread:

https://volvoforums.com/forum/volvo-...cut-out-45047/

A nice description of how to set the idle on LH2.4 FI systems.