Hello Everyone,

I have a '96 850 GLT wagon (non-turbo) with a 5 speed. Approximately two years ago at about a 105,000 miles, the lifters started "tapping" when I first started the car up. This first happened after the car had "sat" for several days. As soon as I started up the engine, in a minute or two, the "tapping" noise went away. If I drove the car each day, I never heard the noise when I started it the next day after the car spent the night in the garage. I was surprised, because the car has had the oil and oil filter changes every 5000 miles since new. The only reason why I think this problem developed, was there was a period of time, where is would sometimes (that preceded the developement of the tapping noise) take 6 months before I would rack up 5000 miles, before I would change the oil. At that time, I took mass transist Monday through Friday (I didn't drive the car at all, not even to the train station - I walked)and would only drive the car short distances on the weekends.

When this tapping noise developed, I immediately changed the oil and filter and added a quart of a product known as "Marvel Mystery Oil". I know the name sounds ridiculous, but this product has been around since 1923 and has been recommended to me by professional mechanics to fix stuck lifters. A few days after I installed the Marvel Mystery Oil, my local Volvo dealer inadvertently changed the oil on my car by mistake. When they saw the red colored oil, (cause by the Marvel Mystery Oil) they assumed I had synthetic oil in the car, and replaced with Mobil 1. Fortunately, I didn't have to pay for this expensive oil change, but the Service Manager said, that the Mobil 1 may fix the lifter problem by cleaning out the lifters. Apparently, he was right. For two yearrs, I never heard the "tapping noise" nolonger how long my car sat unused till yesterday. I plan to "follow" the same procedure as last time. Immediately change the oil and oil filter, and install a quart of Marvel Mystery Oil. Drive the car for about a 1000 miles, and then change the oil and oil filter again, and this time install Mobil 1. Then drive the car for 3000 miles, and then change the oil and oil filter with conventional motor oil. Assuming this protocol eliminates the "tapping noise" from the lifters, I'll go back to changing the oil at 5,000 mile intervales. As post note, I have another '96 850 GLT, non-turbo with a 5 speed, and a '99 XC both of which have their oil & filter changed at 5000 mile intervals with no problem. My experience with my personal 850 seems to be an abnormal.

Anyway, I would appreciate any thoughts or suggestions in how to eliminate the tapping of the lifters, short of have them physically replaced. Thanks to all who respond. I really appreciate your assistance.

Hugh Donnelly