ceramic innerliner exhaust ports came off... experts opinion

[dick911]

Last time I did a valve-clearance job, sparkplug change, oil change etc. etc.
I found 3 small pieces of ceramic origin in catalysator...

I did some research on all the well known forums about this and I found out that it often happens that the ceramic innerliner of the exhaust ports can come off. What I didn't find was a good answer about how bad this is...

So what is your opinion ? Can it harm the engine ? Will it run hotter ? What is your experience with this 'problem' ? Is it the start of more problems in the nearby future ? Will more ceramic particles come off ?

My car is a 1991 Carrera 2 Tiptronic with only 61.000 miles on it...

Hope some of the technicians can answer this

Thanks to all,

dick911

[afterburn 549]

your sig. dose not say anything about what model / year you have ...so leaves me only to guess that it was a "after market" coating done to your ports ?? If so it is a safe bet that the particles ( FOD) just shot out of there at what ever velocity the air was going thrue and no damage.

[dick911]

Hi Afterburn,

Indeed, no car in my signature...
But instead I mentioned my car in the topic (964 Carrera 2 Tip completly original and about 61.000 miles...).

Regards,

dick911

[afterburn 549]

ok, sorry my fault...same ans to problem...jmo

[garibaldi]

Ive seen it break off on the 964s before. It wont do much harm, sure, to some exent the heat transfer may change, but nothing that you should be so concerned about. I understand what Porsche was trying to do with the concept....get the heat away from the head, keep it in the exhaust etc, but that has got to be one of the dumbest ideas I think Ive seen them employ on a street motor, its like they packed the exhaust valve bowl with a two part epoxy and sent them on their way.....so that it can start eroding, or better yet break down after some time and useage. That and the cupholder.......and the water cooling....and the plastic trim.....and the motorized spoiler......and the boxter....jeez I could keep going with all their bright ideas....But to answer your question....short of getting new heads, no, theres nothing much you can do, leave it and it should be fine..

[dick911]

Ok, thanks for your reactions and advice.

Not much to worry about, good to hear.

Thanks,

Dick911

[garibaldi]

Its like the prize you get in the specially marked boxes of Kellog's cereal......collect all 6 port liner pieces.....get some crazy glue.....paste them all together....and youve got one helluva coffee mug!

[BReyes]

So if he did a top end he would have to replace the heads versus porting for example?

What year did they stop this process on the heads?

Regards

[ChrisBennet]

I seem to remember something about the ceramic exhaust port liners keeping the temps up for better emissions.
-Chirs

[garibaldi]

Dunno, I dont know if they carried over to the 993 heads. I never did a port job on a set of 964 heads, but Id imagine that there is just a deeper valve pocket behind the ceramic. But can tsay for sure.