996 very loud tapping

[nylewis]

A few weeks ago we had a blast of very cold weather in the northeast that lasted several weeks. My 99 C4 is a daily driver and after a couple of weeks, I started to notice the lifters tapping a little on startup. I thought no big deal, I'm running 10-40 and it seemed like it was going to be a very mild warm winter (70 in Jan). The tapping noise increased and now its very loud and doesn't stop when the car warms up. It increases with rpm and is very loud. I just pulled the belt and started the car to make sure it wasn't any accessory. It seems the tapping is coming from the pass side. The car seems to run fine, maybe a small loss in power but I get no CEL and I ran codes with my scanner (just a reg scanner) and nothing came up. My next step is to flush the oil system and change to 0-40 oil in hopes a lifter is clogged but I'm really thinking of a collapsed lifter. Would a collapsed lifter show a CEL? If the oil change doesn't work, I was going to do a compression test to see if I can locate the bad lifter. I know you have to remove the cam to get at the lifters. Can this be done with the engine in the car and is marking the cam enough to ensure it goes back in aligned? Thanks for any input you may have.

[viper501]

I hope the lifter is just clogged up. Miatas were notorious for lifter noise when the oil was dirty. The techs would send some ATF in (very small amount) to flush them along with a new oil change. After running the car for a while they would change the oil again. Normally cured mild cases.

[1999Porsche911]

I agree with running ATF through the system for a while. You can add a quart of the stuff to the crankcase and let it idle for 30 minutes or so. No worry about having too much fluid in the crankcase at idle and not enough ATF to effect sensors. Then drain the oil and throw in 15W50.

[nylewis]

I picked up a couple quarts of motor flush. I figured it was designed for a 5 quart system. This weekend I'm going to drain out 2 quarts and add them. Then run the car at idle for 15-20, then do an oil change. I went with 0-40 because we are still in winter and no telling if we get another artic blast. Avg temp right now is 40.

I saw lifters for $20 each and found a post of someone who replaced a valve spring with the engine still in the car. So if I have to go that route, at least there might be room. I looked at a cut away view of the engine. It looks like marking the cams and maybe taking 1 out at a time might be fine. I wont touch it unless I'm certain. I dont need a valve slamming into a piston. I might just purchased new lifters and have the dealer take care of it if they dont ask some insane price. I know, good luck.

Maybe I'll get lucky with the motor flush and thinner oil.

I am pretty discouraged in as this is my 4 Porsche and all of them had many problems. We put up with it and say things like "its only a RMS oil leak" cause we love the cars but it really seems Porsche can build performance and style, not reliability. To have lifters fail cause its 10 degrees out, give me a f****** break.

I had this car for 4K miles/1 year and I already had the alarm just set off all the time, airbag light come on, run very ruff and throw a cel when it rains hard (all my 911's did this, WTF) and now the lifters. Of course its out of warranty. My other 3 were the same. At least my Boxster was under warranty but still had to put up with really stupid things like "doing the chop" what an incredible poor design, and driving an engine that everyone told me was a time bomb. We pay a lot of money for these cars and then Porsche doenst even admit their bad designs like the RMS. My friends Mustang had a bad designed manifold that would crack. It took a class action suit but at least Ford paid for a new manifold or if you already replaced it, gave you the cash. Sorry for the rant but I'm really thinking of this being my last Porsche and going with a company that backs their work.

Edited February 22, 2007 by nylewis

[viper501]

The lifter realy is more of a function of the design of hydraulic lifters themselves. They are there to reduce the maintenance and inherent expense associated with adjusting solid lifter valves. Every time one of my Miatas got that tick, it was time to change the oil. Given the fact that you're only driving 4k miles per year, you might be seeing sludge issues from the short duty cycles. Frankly, and I *know* I'm jinxing myself by saying this, I've had a few problems, relatively minor so far, but with a daily driver with 118k miles, I can't complain, yet. :)

[gkrikori]

I had a similar situation as nylewis that started couple of weeks ago at the cold and coming from the passenger side as well!

Replaced the oil today and used the MOTUL engine cleaner before draining the old oil, but the noise is still there.

Also added SeaFoam product to see if it'll help with the lifter noise, it didn't help.

Been running 0W40 here in MA and replaced with the same grade Mobil1. :(

nylewis let us know what you found out to be your fix?

Thanks...

[nylewis]

Unfortunately no, I did the oil change (0-40 Mobil) and flushed the engine with 2 quarts of Gunk engine flush. We got a blast of warm weather (50) and I still have the same very loud tapping. Still no cel light and I ran codes and got nothing. I ordered a Manual to see the procedure for removing the cams. I'm hoping you can just mark the cams and reinstall. I found the lifters for $20 each so I would just replace all 12 on the pass side.

gkrikori - my tapping got much worse very quickly. At first it was only at startup but I think that artic blast we got for a few weeks caused a lifter not to get oil to pump it up and as Viper stated, due to the limited commute (which I love) the car never really gets warmed up. Now it's prob toast. I should have the manual in a week or so and I'll let you know how I make out.

[violaGT3]

I am interested in this one as my car has a loud noise on first start of the day. It sounds like one individual lifter or something that produces a noise like that. It was written off as some kind of air pump? Not sure as it has been some time. But I do know that if the car starts and the idle jumps then I get the noise but if the idle does not jump then I do not get the noise. There is no proof or sign of the noise after the first start of the day. I was thinking it had to do with the oil draining out of the banks, but it seems kinda odd that the sound would be so clean like one individual lifter? I have not had any dummy lights, or tell tale signs of power loss or oil loss and I am running 0w-40 Mobile 1 as per Porsche specs. I am pretty sure that it had 10w-40 Mobile 1 prior to last oil change. This is in my 99' C2 6spd. with 75kmls. The noise I would describe a a brrrrrrat, tat, tat, tat, tat, tat, uuuuummm it changes with the idle. Hadn't thought of it before but I will try and record it tommorow and post it.

Edited March 5, 2007 by ViolaGT3

[nylewis]

Well I just bought my car to a local garage that works on exotics. They have a couple of ex Porsche mechanics. They looked at the car and said it was the lifters and it's very common in my car. Because of the tiptronic, the bellhousing creates a shield that keeps the heat in. They said it's only a matter of time they fail but the new lifters have a better design that is supposed to not fail. They said the cams will have to be removed and the engine timed but everything can be done with the engine in the car. That was enough for me to hear to have them do the work. I don't want to mess around with timing the cams and they have done several cars. They said 1.5 days to do both sides. I ordered the lifters and got them for under $20 each. Labor is going to be around $1400!!! OUCH. So close to 2K in all. :cursing: Nice design Porsche. Just about as good as my 91 C2 that had a cover on the bottom of the engine causing the valve guides to go bad. Perhaps a Ford or Chevy mechanic could offer help in the engine design. <_< Just venting again.

[violaGT3]

Well I just bought my car to a local garage that works on exotics. They have a couple of ex Porsche mechanics. They looked at the car and said it was the lifters and it's very common in my car. Because of the tiptronic, the bellhousing creates a shield that keeps the heat in. They said it's only a matter of time they fail but the new lifters have a better design that is supposed to not fail. They said the cams will have to be removed and the engine timed but everything can be done with the engine in the car. That was enough for me to hear to have them do the work. I don't want to mess around with timing the cams and they have done several cars. They said 1.5 days to do both sides. I ordered the lifters and got them for under $20 each. Labor is going to be around $1400!!! OUCH. So close to 2K in all. :cursing: Nice design Porsche. Just about as good as my 91 C2 that had a cover on the bottom of the engine causing the valve guides to go bad. Perhaps a Ford or Chevy mechanic could offer help in the engine design. <_< Just venting again.

Hmmm, I do not know what to say to that other than wow that's original. Just off the top of my head I'm trying to think if the bellhousing is greatly different between the tip and the manual. Just not sure on specefics. I couldn't swallow this story, granted i'm not a guru but I know my way around a car and losing both banks of lifters due to excess heat in the front of the engine with no other breakdown effects sound kind of out there to me? There are a few reasons that valves could be out of whack. Change in ignition timing for some reason, carbon build uparound the valves could be causing them to drag, in my old dodges( Granted not a Porsche) we would run a pint or two of 2 cycle engine oil in the fuel system to help clean it out and to help lube it as auto makers haven't yet come up with a way to lube the valve train like the original leaded engine did, same design less the leaded lubricants. I feel for you man I would be PO'd to a horrible degree if I was given this story.

[viper501]

I think I might try a second or third opinion before I dropped that kind of money on this. I also would be hesitant to let a non Porsche tech screw around with cam timing. And for that matter, if they're going to be doing all this, I'd have them drop the engine and give it a thorough once over. Just my two worthless cents.

[violaGT3]

I think I might try a second or third opinion before I dropped that kind of money on this. I also would be hesitant to let a non Porsche tech screw around with cam timing. And for that matter, if they're going to be doing all this, I'd have them drop the engine and give it a thorough once over. Just my two worthless cents.

Here, here, I second that.

[eastriver]

unless this is a well-knewn, well-trusted garage, i would seek 2nd opion.

my tip. also have loud tappging sound, not only startups, but aslo when idling. i asked my indy, he said it's OK.

i will switch my oil back to 15-50 to see if it helps.

[nylewis]

Thanks for everyone's input. I appreciate and respect it. The garage is well known and the mechanic I talked to, did work for the Porsche dealer down the road. They build and race Porsches. I did ask him several questions about parts and procedures to test his knowledge and he knew everything off the top of his head. He claims to have done several cars and after talking with him, I trust his skills.

I have degreed cams before but never dohc. If it wasn't for that, I would do that work myself. I normally do EVERYTHING myself (painting, engine/trans rebuild) but I really don't want to "learn" on an engine this expensive.

It's not just noisy lifters. You can hear it's only 1 or 2 and it's real loud. Changing to thicker oil won't help, it makes the noise when cold and fully warmed up and it's very cold here again so the oil is def in it's thickest state. I work for a living so I really don't want to shell out 2K in repairs but I don't see another option. I'm prob going to bring the car in the 15th, so I'll post on the 16th with how things went.

OTT - my friend was just over to listen to the car and he was talking about adding a supercharger to his Boxster. He asked me why don't I just add one to my C4. I "made" a kit for my hobby car. I looked up and found they get 10K for a Vortech kit! That's totally insane. I started looking at adding a Vortech and the price prob would be less than 30% of that, only prob is I wouldn't be able to tune it. I would need a tuner and run 5-6 psi (due to the high compression) with either a aftercooler or better still, alky injection. I've used alky on a few cars and it works amazing. I had a car with 10.5 compression running 13 psi @ 1800rpms running on 93, zero pinging. But then I thought an exchange engine is a lot of $$$ so I'll leave the blowers to my other toys...but then again, you never know. B)

[gkrikori]

I left my car at the dealership last Thursday and they couldn't figure it out with the ticking / oil burn / fuel.

After contacting the Porsche, they got directions on taking the engine out and starting probing it.

The Service manager told me that they say a scoring in the enginer block, based on Porsche's decision, they'll either get a rebuilt or new engine in there... He said it could be from a pison holding pin.

I wonder if I should get set of headers and mufflers while it's out or wait till everything gets fixed first.

Now my engine is sitting with trash bags taped all over it.. :(

He're the car.. it looks so empty...

[gas-man]

To gkrikori is your car still under warranty ?

[gkrikori]

To gkrikori is your car still under warranty ?

Yes, under the Certified Pre-owned warranty.

I'm guessing it'll cost around 20K, that would've been bad w/o warranty.

Definitely buying additional warranty once this one expires next year...

[marcesq]

FWIW, I just went through this with my wife's car. Ticking from left bank for a few months, then loss of power no idle, missing.

Shop found no compression in number 1 and then found bent valve with boroscope. Based on what I told them they said lifter failure, something that they had seen before.

The not so funny thing is that I found new lifters and they are similar in design (not dimension) to the type that failed in my 951 track car. Lifter failure is well known to 951 owners. To make matters worse, Porsche stopped making the lifters and ING (the bearing company) filled the demand void. ING lifters are failing much sooner than their Porsche counterparts. For 951 owners that have modified engines the only fix is a solid lifter set up.

Attached is a picture of the lifter that failed last year while I was on the track. The piston came out of the lifter and then seized pushing the valve into the piston.

The second picture is a 996 lifter from one of the online parts warehouses.

End of long winded story, if your 996 is ticking as described above, better do something about it sooner rather than later.