Video - Help! Is this IMS? What's up with this engine?

[jnicholson30]

Here's a video of a 2000 Boxster S. I drove 300 miles to buy it and am now sleeping on it tonight while I try to figure out what this issue is before I fear I must reluctantly walk away. The car is absolutely beautiful with all the right features and options and then some. It was also JUST inspected for PPI but a Porsche dealer locally and passed except for the MAF which was fixed.

BUT, I get here and there's something up with the engine. Here's what's up:

1. When idling the engine RPMs bounce up and down between 500 RPM and 750 RPM. There is a also a bit of a rattle of sorts at this low RPM range. However, engine sounds runs great when 1000 RPM and up. Here's the kicker - the Porsche dealer JUST replaced the MAF this past week as we flagged this issue over the web and they claimed this would solve it. Clearly that was not the full issue.

> The video here shows me idling it at 1000-20000 without any issue and then letting go of the pedal to let the idle take over --> Boxster S idle issue - YouTube

> This video shows the engine sound close up. To be fair, it didn't sound as bad as the video when in person but here it is --> Boxster s idle sound - YouTube

2. Also up around 6000 RPM the engine seems to lose juice. The RPMs remain constant but there is a noticeable dip/ceiling in power.

I have no problem negotiating the price down if it is just a $1000-3000 fix. But if it could be a BIG (i.e. IMS style) issue then that would of course be a deal breaker.

This is now the 3rd Boxster that I've inspected and the 3rd straight with an issue. I'm dying to get into my new Porsche! Any thoughts so to what this might be would be greatly appreciated!!!!

Jeff

[Jager]

The idle bounce could be a number of things but I would get the throttle body cleaned first then test for vacuum leaks.

The rattle could just be chain tensioners.

I have no direct experience with IMS bearing failure but you will have a significant leak on the underside of the motor, then at some later point in time there will be nasty grinding sound just before the motor chews itself to pieces.

[Timco]

Originally Posted by Jager

The idle bounce could be a number of things but I would get the throttle body cleaned first then test for vacuum leaks.

The rattle could just be chain tensioners.

I have no direct experience with IMS bearing failure but you will have a significant leak on the underside of the motor, then at some later point in time there will be nasty grinding sound just before the motor chews itself to pieces.

I agree with vac leak / dirty throttle body.

[crumbum]

I had exactly the same issue. I had the wrong MAF sensor in my car. I replaced it with the correct one and it has been fine ever since. I was able to sell the "wrong" one along since there was nothing wrong with it other than the fact that it didnt match my car.

Do this. Check the part number on the MAF sensor in your car. Use the year model and VIN on your car to select the correct MAF sensor.

There are a LOT of articles on the web about this.

[jnicholson30]

Hi guys, thanks for the great feedback here. As a result I pulled the trigger and bought the car and got a great deal. Next up, I'll be checking the MAF is a match, cleaning throttle body and then checking for vac leaks. Wish me luck!

[desert_porsche]

I think you made the right choice. Probably not IMS although you should get that upgraded to the LN engineering retrofit as soon as you can.

I would have used the rough idle and engine sounds to bargain the price way down, and then taken it to an independent mechanic. A few hundred dollars in labor to determine the faulty part or sensor, and a few hundred dollars max in parts. Hopefully you were able to negotiate down several thousand. Almost anything causing rough idle is easily fixable

[jnicholson30]

Hi All,

An update: Bought the car and did the oil (Redline 5W 40). Also just finished the throttle body cleaning and it made a world of difference. Now we can really here that one noise on its own without the other issues complicating the matter.

2000 boxster s idle updated - YouTube

Any thoughts as to what this might be? One suggestion was chain tensioners... as long as it's not IMS! Any thoughts would be appreciated!

Thanks,
Jeff

2000 Boxster S; arctic silver/black

[Jager]

Check the spark plugs, see if they are tight. You might as well change them so you know the status. It's an easy job, you just need to remove the rear wheels and remove the fender liner. Think about replacing the spark plug tubes and the spark plug tube "O" ring seals too. There should be allot of info on this task on the forum, just do a search.

Also check the exhaust for leaks, check all the bolts and see if any are missing or loose, especially the headers.

[thom4782]

The are several failure modes where a timing chain can jump off a sprocket. When this happens, the engines self destructs. Replacing the chain tensioners is the probably the least labor intensive. I'm guessing replacing the IMS bearing is next followed by the variocam rails and lastly the chain tensioner paddles. IIRC, one must split the case to replace these latter items.

What is important at this point is to figure out which, if any, of the items mentioned above may be wearing out. My guess is you've read about inspecting the oil filter for metal and other debris. Others would describe better than me how to get a low cost look at the other items.

[jnicholson30]

I have cut apart the oil filter and there are no metal fragments in there. None in the drained oil and filter housing. Does this mean I'm "safe" for the IMS (at this moment anyway)? Or could this still be the issue?

I will look into the spark plugs and tensioners...

-Jeff

[thom4782]

A clean oil filter is a good sign. There are no guarantees, however, only probabilities.

There seem to be two factors that increase the odds of an IMS failure. If your engine has a singe row bearing, its about 5 times more likely to have its IMS fail that a dual row model engine. The dual row version fails about 1% of the time. There's a good chance your 00 model is dual row although the only way to know for certain is to inspect it. Some 00 cars have single row bearings and some 01 have dual row bearings.

The other factor seems to be related to oil contamination. Cars with more frequent changes have less failures Cars with more miles have less failures because they get more freqeusnt oil change. The the thinking hers is the less time the IMS seals are exposed to contaminated oil the better they will hold up. As IMS seals degrade, the IMS bearing grease gets contaminated and loses its lubricating properties. So many Boxster owners change oil every 3K to 5K miles or once a year which ever comes first to keep clean oil bathing the IMS seals.

If you're really concerned, you can install an IMS Guardian in your car. It's easy to do and will give you an early warning if your IMS is beginning to fail. Metal debris in the oil triggers the Guardian's warnings and lets you know to get the car checked out. It does this in real time as opposed to between oil changes.

[jnicholson30]

Thanks for the reply thom4782. I can confirm that this Boxster thankfully has the dual row. Thanks to all the great info on this forum, I checked for that during the purchase process by looking up the motor's serial number and identifying it is one of the early 2000's before they made the switch. So that's good news that at least reduces the probability. But as you say, doesn't eliminate it.... just not sure what that last remaining noise is.

[dmairspotter]

Hard to tell from your videos. and I am definitely no expert, but the random knocking sound seems like cam chain tension or a drive belt pulley bearing. From what I have read about IMSB, it would have grenaded by now if that was the problem.