worn valve guides on 3.2??

[Tachin]

Hoping to get some advice on this issue.

I have an '87 3.2 with 57,000 original miles on it.

Getting lots of white smoke on the deceleration .. for example, coming to a stop sign, taking my foot off the gas in a low gear.

My mechanic says that the decel is creating more vacuum and pulling oil in through the valve guides. I believe what he says. They are pros.

My question here is how could the valve guide on a low mileage car get so worn? Is this typical? Thought the 3.2's were bombproof. I have a valve job done about 2,000 miles ago (different mechanic) . Could a faulty valve job cause harmful wear of the guides?

Thank you

[SoCalSK8r]

If the valves were adjusted too tight it can cause premature wear.

The engines are bullet proof but the valve guides will wear over time resulting in a tip end rebuild which isn't cheap.

I'm interested to learn from more as the experienced folks chime in because I believe this work is inevitable and it's something I'm not saving for at the moment!



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[Jcslocum]

This is a very typical failure on the 3.2 and the guides need to be replaced. The guides are soft and will most definitely wear, but each engine will wear at it's own rate. Your engine seems to be doing it early at about 60K miles, How much oil are you using per 1000 miles??

You mention that you had a valve job, but I'm guessing you mean a valve adjustment.

If you can do the work yourself, I think you are looking at $2500 to $3500. If not then add labor to that and you are probably;y at $5K or so. Lots of DIY threads on here for you to study and see if you are up to it.

Do NOT overfill the oil or it will smoke also!!

[KTL]

Yep even low mileage engines suffer from guide wear. I had to do the valve guide replacement at ~70K on my '87 3.2

[chrisbruck]

The 3.2s are "bulletproof" EXCEPT for the valve guides. Mine were bad at 140k but I held out till 162k before I had the top end rebuilt. Many go much sooner.

Yours seem on the early side but not unheard of.

Monitor your oil usage carefully for a while. I was down to 300 miles per qt before I busted open the wallet.

[88911coupe]

Same here mine wore our "prematurely" at about 150,000 miles... I was using oil at a high rate but didn't really decide to replace them for quite a while. Worn teeth on the starter gear forced the issue at about 165,000 miles so decided to do a top end rebuild. Once I got started it just made sense to do a complete rebuild down to the crank. I had all the critical parts such as crank, pistons, cylinders, cams etc. inspected by a good local shop here in the DFW area and everything was well within spec. I sent the heads off to Competition Engineering to be rebuilt. Running great at 200,000, well except for an extremely annoying random "no start" issue I'm trying to nail down, but that's another story!

[john walker's workshop]

I've done top ends at 60K on 3.2s. Sometimes only one guide is sloppy, causing a plug to foul. the longer you wait, the more valve seat wear happens from the valve wobbling around and beating up the seat. Some seats were so bad that the second valve grind 125K down the road may need another set of heads or seat replacement, which I tend not to trust. I attribute the wear to the type of stem seals they went to after using teflon seals previously. not enough oil allowed to pass to lube the guide. Lead free fuel doesn't help either.

[Derek911]

Don't get me started on this "bulletproof" monicker. We all love these cars, I understand that, but bulletproof would mean valve guides don't wear at 57,000 miles or all the other problems that pop up. I can't understand how people can frequent these threads and not see how many problems pop up. These cars are not bulletproof, with a lot of maintenance, they can last for hundreds of thousands of miles, but that's with very careful Maintenance. "Bulletproof" is getting in the car and driving it all year without opening the hood, try that on a 911. Bulletproof is a Ford F 150 or Toyota Camry, or Honda Accord. You can literally drive for 20,000 miles or more and only put gas in it. Bulletproof is a car you can beat to death and it still runs. I have driven beat up pick up trucks and not even open the hood. My BMW, I have opened the hood just to put washer fluid in it. Try to drive a 911 20,000 miles and not open the engine bay. Broken head studs, top end rebuilds with less than 100,000 miles is a common occurrence. Let's be honest people.. Any other vehicle that needed to be rebuilt with less than 100,000 miles would be considered a lemon. Age is a factor, yes, but mileage is the key thing here. We drop our engines more often than other people rotate their tires. But, I still love it and wouldn't change a thing. Would I call it bulletproof?? Absolutely not because everyday we are waiting for the next thing to happen and we pray that the engine doesn't have some catastrophic failure. My truck with 200,000 miles on the other hand is bulletproof.

[kodioneill]

Originally Posted by Derek911

Don't get me started on this "bulletproof" monicker. We all love these cars, I understand that, but bulletproof would mean valve guides don't wear at 57,000 miles or all the other problems that pop up. I can't understand how people can frequent these threads and not see how many problems pop up. These cars are not bulletproof, with a lot of maintenance, they can last for hundreds of thousands of miles, but that's with very careful Maintenance. "Bulletproof" is getting in the car and driving it all year without opening the hood, try that on a 911. Bulletproof is a Ford F 150 or Toyota Camry, or Honda Accord. You can literally drive for 20,000 miles or more and only put gas in it. Bulletproof is a car you can beat to death and it still runs. I have driven beat up pick up trucks and not even open the hood. My BMW, I have opened the hood just to put washer fluid in it. Try to drive a 911 20,000 miles and not open the engine bay. Broken head studs, top end rebuilds with less than 100,000 miles is a common occurrence. Let's be honest people.. Any other vehicle that needed to be rebuilt with less than 100,000 miles would be considered a lemon. Age is a factor, yes, but mileage is the key thing here. We drop our engines more often than other people rotate their tires. But, I still love it and wouldn't change a thing. Would I call it bulletproof?? Absolutely not because everyday we are waiting for the next thing to happen and we pray that the engine doesn't have some catastrophic failure. My truck with 200,000 miles on the other hand is bulletproof.

I agree with your thoughts. I had a Camry with 260,000 miles would've gone many more if the wife didn't total it last month. Never opened the transmission or engine just put brakes, quick struts and tires on it of course.

[Jcslocum]

We all have different definitions of "bulletproof" and I for one know just how durable the 3.2 is. When I bought my first 911 in 1987 I began doing track days, this was the time before KIDS!! I did PCA days, BMW days and Corvette days. We punished these cars mercilessly at the track and then drove them home. I can tell you that when I did BMW or Corvette days the guys with the 911's would all drive (if there wasn't an unintended body modification) home after the day (or days) and many of the BMW's or Corvettes would be towed home with mechanical failures. To me, it was surprising the % of breakdowns. I was also using my 911 as a DD in those days. It was utterly bulletproof.

These cars are now getting old and some age failures are to be expected and the valve guide wear is a PIA but won't leave you for dead on the side of the road.

[gtc]

Eh.
This is a known weak point of the later 3.2s. Fix it and move on. Not all Honda Accords are perfect, either. Look at the V6s, which have both engine and transmission problems.
My '84 went ~375,000 miles before a rebuild... pretty bulletproof in my book.

[gliding_serpent]

I have learned the hard way that low miles can be bad for a car. Usually means short runs, improper warmup, possibly infrequent service, and possibly broken or rolled back odometer.

[86 911 Targa]

Originally Posted by john walker's workshop

I've done top ends at 60K on 3.2s. Sometimes only one guide is sloppy, causing a plug to foul. the longer you wait, the more valve seat wear happens from the valve wobbling around and beating up the seat. Some seats were so bad that the second valve grind 125K down the road may need another set of heads or seat replacement, which I tend not to trust. I attribute the wear to the type of stem seals they went to after using teflon seals previously. not enough oil allowed to pass to lube the guide. Lead free fuel doesn't help either.

At what point in time did Porsche transition the 3.2 stem seals?

And, I'm told that the synthetic oils are not correct for the 3.2 cars.

[KTL]

They may not be bulletproof but they still can be driven in a state of disrepair for many many years w/out giving any attention to the problem(s). I'm not endorsing this treatment. Just saying that it's not an absolute must to instantly address some of the common problems with the old air cooled engines. Is it risky to put off fixing the problems? Sure. But it's not certain death if they're not fixed instantly.

My buddy Mark (RIP) bought his '86 Carrera in 1999 and soon thereafter wanted to change the exhaust. We installed B&B headers and in doing so we could get a good look at the exhaust ports. #3 did not look good at all- VERY oily. Now nearly 15 yrs later his car hasn't been treated to a top end refresh. He drove it only a few thousand miles a year so the time bomb is ticking slow.

I think one of the reasons why the problems are addressed so religiously by a lot of people is because its largely a hobby/fun car. So there's a passion for it. Plus the cost if a major failure does happen is huge.

All cars have problems to some extent. None are bulletproof. Fords have coolant gasket suckage and seized spark plugs, Dodges have cylinder head issues (Pentastar crap), Hondas have head gasket issues if driven hard, the list goes on. You still gotta maintain them. BMWs eat water pumps & radiators. That said, blow up any of the other cars and a salvage engine won't bankrupt you. Blow a older BMW E36 engine and big deal, get a salvage yard engine for a few grand. Guys in our NASA GTS series do it all the time.

I agree that once the typical issues are addressed on these cars, they are pretty darn rock solid. Like Jslocum said, i've experienced the track day "carefree" attitude that a decent condition air cooled 911 can give you. We would drive our cars to the track, whoop on them for four or five 25-30 min. sessions, then drive home and they didn't feel any worse from the wear. Nobody ever broke down and needed a trailer ride home. Not even the friend who banged into someone and bent a wheel and a strut. We put his collapsible spare on and sent him home with a crooked wheel! Did it for years with just basic maintenance- change oils, brake service, occasional suspension part, occasional oil leak fix, new tires every so often and just kept on truckin' for years. My buddy Stefan did just that for ~10yrs straight on his '87 Carrera. 170K miles on the clock with virtually no major engine service and still runs like a scalded cat. Same can't be said for a lot of other cars.

[Tippy]

If you do the rebuild yourself, send your heads to "cgarr". Insanely cheap prices with unheard of customer service.

[whiz05403]

Originally Posted by tippy

if you do the rebuild yourself, send your heads to "cgarr". Insanely cheap prices with unheard of customer service.

+1

Pay the extra cash for him to replace ALL the exhaust studs!

[JeremyD]

My mechanic has a theory on the low mileage cars - by being driven so infrequently - the oil drains completely out of all the oil passages - after sitting so long between start ups - then when you do start up - this creates more wear - this is what creates valve guide issues.

My other car (1987 Cabriolet) had valve guide issues at 56,000 - it happens.

Conversely - one of my friends that used to instruct with had a 1989 with 400,000 miles that he drove daily and 15-20 track days a year (religiously around 15 years straight) just replacing the oil and tune up every 50,000 miles. He told me he went through about eight sets of wheel bearings and had his transmission rebuilt once.

[Tippy]

Quote de tippy

if you do the rebuild yourself, send your heads to "cgarr". Insanely cheap prices with unheard of customer service.

+1



Pay the extra cash for him to replace ALL the exhaust studs!

And twin plug. I'm totally kicking myself for not doing it.

If you never use it, at least you know you can.

[stlrj]

The air flow meter has been implicated as the cause of a cascade of events that lead to the early demise of the 3.2 valve guides.

The late Bruce Andersen, national technical chairman for PCA, mentioned in a recent tech response that there seems to be a correlation between 3.2's running rich at idle and excessive oil consumption due to early valve guide wear.

My conclusion is that the over rich mixtues is just the tip of the iceberg in a cascade of events leading to excessive heat in critical areas such as the cylinder heads/valve guides and the band aid solutions of ever larger oil coolers that bury the problem under what seems to be an elegant but low tech solution.

Rich mixtues are also implicated in the poor low end performance of our 3.2's and the Pelican archives have many testamonials of how leaning of overrich mixtures have been known to result in dramatic increase in low end performance.

Joe

[SoCalSK8r]

Joe - that is some useful info I don't think I've seen before, thanks for sharing.


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