I hate to sound stupid, but how do you tell if the motor mounts are shot and need replaced? My '87 740GLE has 129,000 mi. on it and seems like there is alot of movement to the engine with it idling. Just my imagination?
Thanks,
Tim '87 740 GLE "Olaf"
'94 850 "Olga"

You might check the intake manifold gasket. I thought that my motormounts were bad because of the same excessive movement. Turns out it was a bad gasket. It is common for them to fail, and it will cause your car to idle very roughly.

I knew I needed new motor mounts once mine failed - I noticed the oil filter was sitting directly on top of the rubber and that was a real bummer!

It is much better to replace them before they get to that point - if you are in doubt it is really not that hard to replace them, especially if you do one at a time and use a floor jack to support the engine while you place the new mounts in.

Your car will tell you. When the mounts are shot, you get a lot of vibration in the body. Usually sets things to rattling inside the doors. Check the pan to crossmember clearance.

The only way I know to tell is to climb under the car and make sure there is at least 1/4" clearance between the engine crossmember and the oil pan. New mounts will result in around 1/2" clearance. If the engine has excessive movement and shaking, it might be that there is some misfire problem, caused by any number of things.

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Matt L. Cary, NC three '89 740 sedans

if the fan is too low and rubs up against the fan shroud, your mounts need to be replaced. if there's less than about an inch of clearance between the blade at it's lowest position and the shroud, it needs to be replaced.
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Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'