I've been reading the Haynes manual for my new '85 740T. I mentions checking and adjusting the valve clearance every 24,000 miles. Is this for real? Just about every modern car has a non-adjustable hydraulic valve-train. Well, the manual also mentions using shims to set the clearance??? Older cars I've had allow you to turn a screw and locknut to adjust the valves (both with overhead cams and push-rods). Any tips on where to locate replacement shims? There is no Volvo dealer even remotely close to where I live. Do they come in an assorted package or do you special order them by size?

Any info is helpful.

Thanks to all who helped with my "engine bogging down" problem. Turned out to be a 25 cent piece of fuel hose in the gas tank that failed, thus starving the engine.

I assume the technique is the same as on my former diesel. Shims of different thickness set between the cam lobe and the top of a tappet on the top of the valve stem & spring assembly and adjust the clearance. Its important not to go too long as the valve seats usually wear faster and reduce the clearance which will lead to burnt valves! A shop assortment is very expensive at several $100!

Here is the technique I used. First buy the valve depressor tool and the shim pliers from your Volvo dealer. Then take off the valve cover and measure and record the clearance between the cam lobe and the shim, (assuming you know how to properly set the cam for this) Then using the tools, take out each shim in turn and read or measure its thickness and put it back, also record these values. Now put the valve cover back on using the old gasket for the few days you will need to get the new shims. Use the data recorded to determine the new shim value needed at each valve. (Always err on the loose side or more clearance if you must err!) Comapare the new determined shim numbers to those available from other valve positions and allocate your existing shims to as many locations as possible. The missing values are the ones you need to order from your volvo dealer along with a new cover gasket. Once the new shims arrive, go back to the car and move the existing shims to their new locations, install the new shims in the proper spots and save the left overs for some other time. The next time you can probably guess which shims are likely to be needed and order them before starting the project. Good luck. I got a lot of satisfaction in doing the job and saved the cost of the tools the first time.

iPd (http://www.ipdusa.com) rents out a shim kit for the B21/23/230 engines. You might also be able to get one from your local volvo dealer.

The first step is to find out if you need to adjust the valves. This requires a flat feeler gauge, the longer the better. Get a good shop manual, especially if you are far from a dealer or Volvo mechanic. Bentley and Haynes are good, the Volvo factory manuals are great but costly. Once you pull the cam cover off, you will see how the valves are adjusted. Basically you measure the clearance and if needed, pull out the shim and change it for another thickness. A special tool is needed to hold down the valve while you lift out the shim or you can measure all of them and remove the cam and change the shims all at once. That does require additional steps like removing the timing belt and cam seal. Since you should replace the belt every 50K or so, it makes sense to do it all at the same time.

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