What are tools required/procedure for adjusting tappets?
A good feeler gauge set and a basic set of sockets, wrenches, and a screw driver set will work for most engines. I hope this helps. Rod
Now first you check the clearance and record the clearances. If they are out you need to change the valve bucket (which comes in different sizes). This involves removing the camshaft to change the buckets and then reassemble and recheck the clearances. This is a big job and dealerships will often charge $1500 plus to do this job. I am going to post some info from a thread which will explain further. Many motorcycles are similar as well.
The general procedure for checking and adjusting the clearance based on having done this on bikes is;
Before removing old belt
Measure and record each intake and exhaust valve clearance using feelers gauges. Use the crank rotation sequence and measurement order listed in the manual, else you may get erroneous readings due to cam journal clearances and the valve springs pushing the cam around in the bearings. Some are not measured on the exact base of the cam (i.e suzuki)
Compare the readings to specification
If any are out of tol, calculate the difference between the reading and spec.
Remove the camshaft with the out of tolerance readings (usually both if one is out of tol).
Record the markings on the bottom of the buckets that are out of tolerance. (I usually like to measure these with a mike to verify markings and or determine if there is any measurable wear and adjust accordingly)
Refer to the list of available bucket sizes (from svc. manual or dealer parts counter)
Add or subtract the difference you calculated above to determine your new bucket size. (bikes typically tighten up so you end up going with a thinner shim, er bucket)
Order the buckets needed (sometimes you can swap them around between locations to minimize the qty needed to order).
Install new buckets in the proper locations.
Re-install cams, new belt, new tensioners, and new Idlers.
Repeat measurement process from above.
If measurements are in spec, you are done.
If not, repeat.
Last winter I checked the valve clearance on a 2001 Focus ZX3 with the 2.0L DOHC engine. It had about 85K on it. The clearances were all pretty close to nominal. I don't know the history on the car since new so they may have been adjusted at some time in its life. IIRC the interval for that car was 75K.
As I said above, bikes typically tighten up with this type of valve train. This is due to the valves seating deeper in the valve seats due to wear. This increases the installed height of the valve, decreasing the clearance to the cam. The rate of seat wear exceeds all other wear causing them to tighten.
Tight valves are worse than loose valves. Can eventually lead to low compression, and burnt valves.
If the wear of the cam, bucket, cam journal exceed that of the valve seat, the clearance will increase.
I don't know what the general trend on these engines are as far as tightening or loosening, but if they are like a bike, they will tighten.
I can tell you that on bikes if they are operated a significant amount of time near the red line, they will require more frequent adjustment compared to one operated more conservatively. A bike that is operated conservatively may not need any adjustment at the first inspection interval (not unusual for my Yamaha FZ1, 26,000 mile interval)
Sorry about being long winded, but I thought I would do a brain dump to help people understand the process.
I hope this helps. Rod
Aug 17, 2015 |
2008 Saturn Astra XE