J-McDonald

I've noticed that the valves on the driver's side of my 91 C2 are noisier (i.e., tapping) than those on the passenger side. The noise seemed to quiet down after an oil change and has gotten louder now that it's due for another oil change. The car just turned 103k and has been religiously maintained. I know that (like the pre-964 911's and unlike the 993's) the valves need to be periodically adjusted. I plan to do this when I take the car in for its 15,000 mile service (at 105k). How much should I expect to pay for a valve adjustment on my car? How much should I expect this to quiet down the valves?

Randall G.

Hello,

If it has been a long time since the valves were last adjusted, then a service can make a dramatic improvement. But, if it has only been 15k miles, well ... I normally wouldn't expect a big difference. But, who knows? Maybe the last adjustment wasn't done too well--or the mechanic forgot to do one side ?

A 15k service should run you anywhere from around $550 to $1000, depending on where you live and who you take the car to. This assumes only the stuff specified in the service manual--e.g., no new brakes. I think around $650 is a fair price at a reputable independent.

Of course, a major service also includes new spark plugs, oil/oil filter, and a few other odds and ends (e.g., fuel filter) depending on what's due for replacement. As I recall, the valve adjustment itself is about 6 hours labor, plus the cost of a service kit (i.e., gaskets).

Drew_K

A valve adjustment should be an included part of the 15K service (as is an oil change). One thing to keep in mind is that the engine needs to be completely cold when the valve adjustment is done, otherwise it won't be as accurate. It's just a guess, but perhaps the last adjustment was done without letting the engine cool down.

This is why my 15K services always take at least two days- I drop it off one day and my dealer does the valve adjustment the next morning.

Randall G.

Second Drew on the engine having to be cold before doing the valve adjustment. I used to drop mine off late in the afternoon, giving the engine a chance to sit overnight and cool before the valves were adjusted.

J-McDonald

Thanks very much for the advice!

BS911

I just gotta once again throw this out... I know that a lot of folks have no desire or time to even attempt to tackle a valve adjustment on their own, but for arguments sake - it is not a hard job at all. I usually spend about 250-300 on parts to include the valve cover gasket kit, spark plugs, distributor caps and rotors, oil, filters, etc., and then a weekend in the garage "playing" under my car. Other requirements are good jack stands and a jack (the jack in your trunk WON'T cut it), a set of sockets and wrenches in the metric flavors, a proper feeler gauge, and some good patience. Of course it will take longer for the home diy guy than a properly equipped shop, so if you add dollar values to your own time then you might only break even, but take out those 6+ hours a mechanic charges and you'll save a bundle. You might even give it a little more attention and actually do a better job than the mechanic - that is, if you happen to have a sloppy mechanic who rushes things. Besides, with the money I save on a single, would-be-yearly job, I get to tune mine up twice a year.

Anyway, just wanted to throw another argument out. And if you're interested, check out my web page (listed below) with full step-by-step instructions on the procedure.