Weak Valve Spring(s)....what to do?

[ebeltect]

I recently had my motor and transmission dropped to rebuild first gear. While the engine was out I decided to do some other minor maintenance, plugs, valve adjustment, clutch plate, replace hoses etc. During the valve adjustment it was brought to my attention that either 1 or some ( I need to confirm still) of the valve springs could be compressed by hand and that they should be replaced to alleviate the possibility of one breaking and having a bigger problem on hand. I'm ok with that but then there was talk about once the heads are pulled doing a top-end rebuild. I've had the car about a year have driven 4,000mi it has 112,000mi and it has no leaks (some minor seepage at some hoses), doesn't seem to burn anything, no smoke, and when it was smogged it passed with flying colors. I don't think I am being wrongly directed to do a top-end rebuild as I trust the mechanic (he is well known for building porsche racing engines) and his background is if it's worn fix it so he is giving me his opinion. What I am wondering is if I should just replace the springs (they aren't that expensive) and leave the engine alone or is there cause for concern that the mileage could warrant a top-end and if so what sort of things should I be looking at having done and what is the relative cost people have paid to do it? what other things can I check with the engine out to determine it's health without tearing things apart?

any advice is appreciated.

[911pcars]

I'm not one to fix things that aren't broken. However, once the valve springs are removed, your tech will inspect the valve guides for excessive wear. Unfortunately, this is an area that usually needs attention on 911 engines with mileage. If they're okay, you could just replace the springs and valve seals, then button it up. There may also be underlying reasons why the valve springs went soft.

If the valve guides are borderline, you can weigh the added cost to refurb the heads and regrind the valves/seats. At this point, you'll have saved in the long run to do it now unless you plan to sell the car. I suspect you like your car well enough to repair it and enjoy many more miles of ownership and driving.

Sherwood

[HawgRyder]

In the "old days"...LOL we used to listen to the race engines and for most laps during a race you could hear the crisp sound of RPMs going down the straights.
Towards the end of the race...some of the cars sounded "soft" or not as crisp...a sure sign of valve spring tension being lost.
Some of them "lost" as much as 1000 RPM off the top end because of it.
Changing springs is no big deal...you don't even have to disassemble the engine.
If you either pressure or pack (with sash cord) the chamber...and use a leverage device to compress the keepers...you can slip out the old and put in the new very quickly.
New springs have a lot better specs than when I raced...we used to figure the life expectancy in hours...now-a-days...it's much longer.
Bob

[911pcars]

Originally Posted by HawgRyder

In the "old days"...LOL we used to listen to the race engines and for most laps during a race you could hear the crisp sound of RPMs going down the straights.
Towards the end of the race...some of the cars sounded "soft" or not as crisp...a sure sign of valve spring tension being lost.
Some of them "lost" as much as 1000 RPM off the top end because of it.
Changing springs is no big deal...you don't even have to disassemble the engine.
If you either pressure or pack (with sash cord) the chamber...and use a leverage device to compress the keepers...you can slip out the old and put in the new very quickly.
New springs have a lot better specs than when I raced...we used to figure the life expectancy in hours...now-a-days...it's much longer.
Bob

Yes. With the appropriate special tool, one can R&R the valve springs with the engine installed (a little tricky, but doable). However, I was under the impression this wasn't a track car.

[Dodge Man]

In the old days we would replace stem seals & broken springs for a short term fix to stop the smoking. Most of the customers were trying to get grandma a few more low mileage years or flip the car. Valve guides & springs actually wear faster than rings in most engines. A valve job with new guides & stem seals generally tend to "wake a motor back up". "Pistons go up & down but heads make HP" is the old racers limerick. The 3.2 has a rep for wearing out the guides. Replacing the rings can also create some surprises. IMHO Do a lot of research. Best of luck.

[mreid]

Replace the springs and drive. Don't make it a bigger issue than it already is.

[ebeltect]

Thanks for the feedback thus far. This is not a track car but I do like to drive it and try to whenever. I'm typically a believer in if it isn't broke why fix it. Knowing that I only put about 4k on the car a year I feel as though if I got another 50K out of it that's a long time down the road without having to drop it again. My concern was if by making that decision to only replace the springs I'd regret in the short term but that doesn't seem to be the case.

[Nick Triesch]

If your car passes smog easy and does not leak, then just replace the springs. Your car is in great shape. My 85 just turned 145,000 and it has passed the last 8 California smogs. 112,000 is nothing on these cars!