ims bearing noise?

[boxster]

i know the ims bearing issue has been talked about till death, but id appreciate some feedback.
So ive got a 1999 2.5 with 72000 miles on the clock and its still has the original ims bearing. The other day i started it up and decided to try and get underneath the car as much as possible to see if i could hear any noises since some people report some kind of strange noises before bearing failure. After my mind managed to isolate the exhaust noise i was hearing a noise, which sounded like......TAC TAC TAC TAC coming from the engine. It variated according to revs. i could hear absolutely nothing when i wasnt underneath the car, except the injectors ticking. The noise i heard under the car as more like a low pitched clank. Is it normal for boxer engines to make this noise, or should i be concerned?

[Smallblock454]

Hi,

i think what you've heard where the valves, or to be more exact the hydraulic lifters. Especially when the engine is cold you can hear them.

I think you won't anything if an IMS bearing is faulty until a camshaft is out of timing, because a chain is broken or jumpes over. But then it's too late.

Regards
Markus

[boxster]

Thanks for your reply. I know unfortunately it will be too late by then�� some reports i read said that some people heard like a crunching noise shortly before the bearing let go. There is a video on youtube called: PORSCHE BOXSTER IMS BEARING NOISE? the noise i heard from under my car was quite similar although much much less noticeable and as i said only heard it from under the car.

[jb92563]

I would put a magnetic oil plug in and open up your oil filter and stretch out the paper to see if any magnetic particles are trapped there.

If you are getting magnetic debris then something bad is going on and the IMS could potentially be near its end.

[Smallblock454]

Hi,

did you mean this video: Porsche Boxster Noise IMS Bearing? - YouTube

Sounds like a hydraulic lifter problem to me. Also the fan is very loud. If it's a harder knocking it also could be a big end bearing problem (piston rod).

But as i said, a failed IMS will lead to bad engine timing because the chain is jumped over or to a total loss because the chain is torn. I don't think you can hear a bad bearing - and that won't be Tac Tac Tac, because it has to be a grinding, or abrazing noise when a ball bearing fails.

An oil check is a good idea. If you like to do an oil change you can also inspekt the filter. There are also laboratories that can examine oil samples.

Regards
Markus

[Jake Raby]

By the time an IMS Bearing will make any amount of noise its late at Stage 3 failure. It won't make noise long before it fails.

If you have an IMSB issue and you have noise, its already so late that foreign object debris has entered the oil system and has bypassed the filter at start up, creating engine- wide collateral damage thats silent.

Do a sump and filter inspection, but don't drive it again till you quantify that the IMSB is not failing.

Most IMSB failures never make any noise till the engine fails, you may have a bad water pump or something else wearing within the engine.

[boxster]

Thanks so much for the info guys,appreciate it. I already have a magnetic drain plug and everytime i change the oil i spend quite some time inspecting the plug and the filter,which i tear open to inspect for any debris.
Yes small block thats the video i was talking about. It is much less audible than that in my case and can only hear it when under the car. I wont even hear it when standing right beside it or from inside the car. So as you said its probably the hydraulic lifters I'm hearing. I will get the ims bearings replaced when i change my clutch, so hopefully the bearings will survive till then ��
I believe i have the dual row bearings, is it true that they are less prone to fail than the single row?