Valve Spring?

[drpaulmarsh]

1999 C2 Tip tronic with 73k miles. Purchased used in May of last year. PPI yields no real problems except MAF and compression test is good. Replaced MAF soon there after

I Brought in 1.5 weeks ago for a CEL on. Was told that a solenoid (helps control cam exhaust) on the back right was leaking oil. We put it up on the hoist, looked and saw the mild leak. Porsche fixed the solenoid. A few days later I noticed a low idle one time at a stop light. I thought nothing of it as the computer corrected it with in no time. I ran fine for a few days.

Then this sunday night about 1 mile from my house the enginge starts sputtering and dies. The CEL is now flashing. I restart it and the CEL is flashing for a few seconds, then steady on. I drive it half a mile towards home and when I come to a stop light it dies. I am scared to death so I go one more stop light and it dies again. Same thing. I call AAA and have it towed (flat bed). Porsche has had it now for 2-3 days. The first day they checked the oil for metal... It looks clean. They hook it up to the computer and describe to me that the catylytic converters are sending the computer errors. They checked the intermediate shaft and it looks good. Perplexed the tech said form the the outside everything looks great. No oil leaks, no broken hoses, belts are fine. So I ask the tech and he said something to the effect that the car is runing "rich" and to let him look at it for a few more days.

Today they call and the tell me there might be a valve spring bent/broken and that there is no compression in #4. They then proceed to tell me that it sounds like it is going to be in the 3-4 thousands to just diagnosis this! They are talking about pulling the motor and looking at he cylinders, head etc....

HELP!!!!!

:eek:

Paul

[Scouser]

That's a real bummer!

So if I read this right, the tech checked everything and said looks great. No oil leaks, busted hoses etc. You left the car with them for further diagnosis. Then they call you to say cyl #4 has no compression!

This sounds fishy to me. I would have thought that no compression in a cyl would be totally obvious the first time they looked at it. The issue is, have they done this damage?

Have they even checked the spark plug in #4?

Time to get it to an independent if it was me.

Best of luck mate.

[drpaulmarsh]

It definetly has had them stumped for a few days now. I asked if replacing hte solenoid had anything to do with this, but htey said no... The solenoid is used for the cam and the exghaust. This appears to be a problem with the engine....

Suggestions? Anyone? Loren? Tool pants??

[Loren]

I agree to get a second opinion if you can. A highly unusual failure on newer Porsches.

Was that the same side of the engine they previously did work on?

[drpaulmarsh]

Hmmm. Right rear side. But I don't know where the # 4 at????

I am so clueless to this stuff...

Paul

[Loren]

1 and 4 are closest to the rear bumper. Cylinder number 4 (5 and 6) would be on the passenger side.

[drpaulmarsh]

Yup, passenger side rear next to #4. Now the question is what afect does that solenoid have on my compression loss / damage.

[Loren]

...or did they let the camshaft slip when they took the valve cover off?

[drpaulmarsh]

That's a real bummer!

So if I read this right, the tech checked everything and said looks great. No oil leaks, busted hoses etc. You left the car with them for further diagnosis. Then they call you to say cyl #4 has no compression!

This sounds fishy to me. I would have thought that no compression in a cyl would be totally obvious the first time they looked at it. The issue is, have they done this damage?

Have they even checked the spark plug in #4?

Time to get it to an independent if it was me.

Best of luck mate.

<{POST_SNAPBACK}>

Sorry I might have been a little confusing at first...

When the tech looked at it from the underside it looked good, the oil was clean and nothing obvious stood out... But it still ran like crap.

So that is why he wanted me to leave it and get the compression checked. I know the guys at this Porshce dealership and they are great to me! Very thurough and more often than not OFTEN help me with costs on parts/ labor. I am generally in there on average 1x a month getting new mods (mostly asthetic enhancements) on it so they are very familiar with my car too.

I guess I need an education on cams, heads, solenoids and how they all work together...

[PTEC]

You need to know what DME faults you have. If you have misfires for cylinders 4, 5, and 6, then its likely your solenoid. If its only 4, and you have no compression then you have a mechanical problem.

For what its worth I have seen a 996 break a valve spring.

[umn]

...

Today they call and the tell me there might be  a valve spring bent/broken and that there is no compression in #4.  They then proceed to tell me that it sounds like it is going to be in the 3-4 thousands to just diagnosis this!  They are talking about pulling the motor and looking at he cylinders, head etc....

...

If you've got no compression on #4, there is likely to be a mechanical problem.

If you pressure test the cylinder with compressed air, you can get an idea where the pressure escapes (i.e. intake valves, outlet valves, crankcase, cylinder head gasket).

What I don't understand is why they want to pull the motor. If you suspect a defective valve, you can just take off the cam cover and have a look.

Cheers,

Uwe

[umn]

...

Have they even checked the spark plug in #4?

...

They must have done. Otherwise how would they have tested compression in cylinder #4?

Cheers,

Uwe

[drpaulmarsh]

Ok here is the update:

Cylinder leakage & compression tests were done... & #4 is dead. The tech pulled half of it apart and thinks it is the valve, but waited for my approval before pulling the engine. He is hoping that it is just a simple replacement the spring and praying that there was no damage done to the rest of it...

He still sayes that he has to take the engine out because ther is no room to remove the parts necessary due to the fact my car is a tiptronic and takes up more space in the engine compartment. If he pulls the engine out though he will go through all of them (4,5,6 on the right side for me and check them out too)

Here is the list of fault codes:

75- Misfire damage to cat

66- Cylinder 4 misfire with damage to cat

68- Cylinder 6 misfire with damage to cat

53- Cylinder 4 misfire emmisions relevant

115 - Hot films MAF sensor

Estiamte for repair: $3800

Estimate for factory refurbished engine $9200 with 2 year warantee

Next I asked around if the removal and replacement of the solenoid & it's seal could have caused a timing problem and bent/broke the valve/spring and he said no way... In my car 99' C2 Tiptronic, it is located onthe same side but controls the upper portion and not the lower where the #4 valve is located.... They (3 techs) said that they has only seen this before 1 or 2 times and it was on a boxster - 6 speed and never a 996 tiptronic.

[umn]

...

He still sayes that he has to take the engine out because ther is no room to remove the parts necessary due to the fact my car is a tiptronic and takes up more space in the engine compartment.

...

Hi Paul,

I've just made some enquiries and contrary to what I've said before it is apparently standard practice to take out the engine for this kind of work.

Cheers,

Uwe

[drpaulmarsh]

I have spoke witha very knowledgable guy (from 6speedonline.com) who used to be a Porsche Dealer mechanic for 3 years and now has his own performance shop...

His recomendations were to have them pull it all apart and first see if it is a bent valve and if there are any marks on the pistons. (if it is bent, then there are some big decisions I will have to make... I will then have to weigh the costs vs. a re-furbished motor

If not, then replace all the springs #1-6 and thus paying a little more for preventative measures. He said that parts are only $100-200, and to see if Porsche will work with me on some of the labor to bring down the $3000 estimated price as a good will gesture.

Feedback? Thoughts? anyone???

[PTEC]

Make sure they know whats wrong before they pull the engine. Or at least elimate a broken valve spring before the engine is removed because I know for a fact that you can repace a valve spring with the motor in the car. If its not a broken spring, then yes, you have some choices to make.

Also I believe replacing all the springs is a bit excessive, as I've only ever seen or heard of one break

[umn]

I know for a fact that you can repace a valve spring with the motor in the car.

...

Also I believe replacing all the springs is a bit excessive, as I've only ever seen or heard of one break

...

Hi,

Ad 1): For Tiptronic engines, the factory recommended way is take the engine out. Otherwise, it gets very fiddly: You have to take the camshafts out, then you have to pressurise the cylinder so that the valve doesn't fall into the cylinder when working on it, later you have to re-set the timing, apparently that's all much easier if you take the engine out.

Ad 2): I agree, I wouldn't change the other springs.

Cheers,

Uwe

[PTEC]

Having a tiptronic doesn't in anyway effect the difficulty of replacing that valve. Because the book says one thing, it doesn't make it right every time. The book will also tell you that you need to pull the engine to remove a transmission on a 996 turbo. I can tell you firsthand, that is false.

After removing the camshaft you would have to re-time the engine, which is something I have never done on a 996, but the person I saw perform this job apparently didn't have any problem with it as it was done at a dealership.

Edited March 19, 2005 by PTEC

[slbates]

This just happened to me! My 99 quit 300 feet from my house traveling at about 25 mph. The CEL flashed 3 times and the engine quit. Diagnosis was zero compression on number 2. Borescope revealed the valves had come in intimate contact with the piston. Obvious valve spring failure since mine is also a TIP and cannot suffer an overrev. The DME reported failure at 2000 rpm. My 99 TIP had 96,000 miles so the decision was easy. I put a Porsche replacement engine in with the 2 year warranty. The engine looks absolutely new. The only obvious rebuilt item is the power steering pump, revealed by the part number. The casting marks on the heads show 2002 dates.

The original engine did not burn a drop of oil and I never had to add oil between changes. RMS was dry when I snapped a photo at the shop. The torque convertor input seal was weeping a bit, as well as the variocam cover. The engine ran really strong to the bitter end. It's a shame the valve spring let go...

I just got the car back yesterday. The new engine doesn't really feel any stronger the the 96k mile powerplant it has replaced but I will not really be able to tell until after the breakin period since I wil be keepo\ing it below 4200 roms.

Beware if you decide to replace coolant hoses. They are mighty hard to come by...one hose was not available according to the parts locater in either Atlanta warehouse or in Germany (996.106.250.55). Luckily I found one at a Florida dealer after spending mucho time on the phone chasing one down.

Alot of the expense of doing the work is the labor R&I on a TIP. You may want to factor this in your decision to fix or go with the replacement engine.

Good luck.

[drpaulmarsh]

Ok they pulled half of it apart and I could see the springs exposed. The bottom left one of # 4 was broken. Upon further investigation it appeared that the valve stem with it's washer looking retainer for the spring was either bent or loose, as it was angled ever so slightly downwards. When the tech put his hand in there and manipulated the stem in-n-out manually we could see that the valve wasn't seating / closing correctly upon shining a flash light up and into the motor.

His recomendations:

1. Replace all the springs and washer retainer looking pieces on right side for #'s 4-6.

2. Do a "valve job" and that's it...

Any thoughts? or suggestions?

[drpaulmarsh]

Well I spoke with Shaun at Pioneer and supposedly Moe my Tech there was able to save the day! Turns out it was only a valve spring, and he fixed it with out having to take the entire motor out or replace any valves/stems. They did a compression test & a leak down test and it is looking good! They just have to put the finishing touches and get it put back together tomorrow. It will be ready late tomorow night or first thing Monday. . .

Paul